Patent Publication Number: US-7722759-B2

Title: Apparatus, system, and method for separating minerals from mineral feedstock

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/732,542 entitled “Apparatus, system, and method for separating minerals from mineral feedstock” and filed on Nov. 2, 2005 for Jay and Shane Duke, which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to solvent-based separation of minerals from mineral feedstock, and more particularly relates to extracting bitumen from tar sands. 
     2. Description of the Related Art 
     Separation of bitumen from tar sands is known in the current art. The currently available technologies suffer from a number of drawbacks—low yield of bitumen recovery, environmental issues with waste water disposal, environmental issues with sand disposal, release of solvent vapors to the atmosphere, release of hydrocarbons to the atmosphere, sensitivity to clays, sensitivity to oil-wet tar sands, generation of emulsions during separation, high energy input, clogging of sand draining screens, and clogging of the valves that manage counter-current flow. 
     Most of the processes used in the current art are some variation of the Clark hot water process. One common variation of this process is to run mineral feedstock up a a partially vertical screw feeder. The mineral feedstock is run through a solvent layer, then a water layer. 
     The solvent-hydrocarbon miscella formed is denser than water and must be extracted below the water layer. The fluid levels and extraction rates must be carefully controlled, or water will be drawn into the miscella extraction apparatus. The fluid layers are not stable in such systems. Any hydrocarbons that are in a miscella without enough solvent portion will float to the top of the contact chamber. This means that some hydrocarbon will be floating to the top of the system regardless of the design, and that the extracted miscella must be solvent-rich rather than hydrocarbon-rich so that the miscella doesn&#39;t float. The separation of solvent-rich miscella is more energy intensive than the separation of hydrocarbon-rich miscella. 
     An additional water layer serves as a cap to contain the organic solvent in the solvent-sand mixing chamber of such systems. That exposes the sand-solvent mixture to water. Water exposure of the sand-solvent mixture can swell clays, flocculate the mineral feedstock, and create emulsions within the sand-solvent mixture. All of these effects complicate the separation process. 
     The process allows only a single solvent-feedstock contact, the solvent-hydrocarbon miscella composition must be kept within a narrow range of compositions, and the waste water from these systems cause environmental complications. Overall, this process provides an inflexible solvent contact method and produces low bitumen recovery from the mineral feedstock—typically on the order of 50%. 
     Another process in the current art is to run mineral feedstock up a partially vertical screw feeder and run solvent without water in counter flow with the sand. Solvent flow is usually controlled in these systems with reed valves that get plugged, and stuck partially open with sand and are therefore high maintenance. Another solvent flow control employs tortuous slots in the flights of the screw feeder which allow liquid but not solids to pass. This mechanism complicates control of the contact time of the solvent with the mineral feedstock, and the contact times between the solvent and the mineral feedstock tend to be short as the solvent gravity feeds through the system. In addition, the slots become clogged with fines from the mineral feedstock. The clogging causes poor solvent-feedstock contact, and is a complicated maintenance problem to both diagnose the occurrence of the clogging, and to shut the system down to fix the clogging. 
     Overall, this process is a high maintenance process which produces low bitumen yields because the solvent-feedstock contact times are difficult to control. The counter flow nature of these processes is better than the single pass contact of the typical Clark hot water implementation, but is still not as controllable. Much of the solvent-feedstock contact occurs at the end of the system where the miscella is hydrocarbon-rich. Consequently, this solvent-feedstock contact is low quality, and these systems must be large or they must be designed for a low hydrocarbon yield. 
     Another process in the current art is to run mineral feedstock along a continuous belt, while spraying solvent onto the sand at various points along the belt. The solvent picks up some fraction of the hydrocarbon material and drains through perforations in the belt. This process allows multiple contacts between fresh solvent and feedstock, but the contact occurs in a static feedstock environment, the contact time is minimal, and the contact time cannot be controlled because it relies on gravity. Because only limited amounts of hydrocarbon are stripped by the solvent, the process requires some combination of: significant amounts of fresh solvent, pumping significant amounts of recycled solvent, a large conveyor system, or a design for a low hydrocarbon yield. Further, the perforations in the belt tend to plug with fines from the mineral feedstock. The plugging of the perforations is a complicated maintenance problem to both diagnose the occurrence of the plugging, and to shut the system down to fix the plugging. 
     Finally, the current art depends upon passive containment to prevent escape of solvent vapors to the atmosphere. Typically, a water layer is kept on top of all otherwise exposed solvent layers. Where water is not used, solvent is exposed to the atmosphere through the sand feeder. 
     The state of the current art is perhaps best highlighted by the fiscal year 2005 United States Department of Energy solicitations for new technologies. Technical topic 12(d) is a request for Tar Sands and Oil Shale Development, wherein the Department requests a technology that leaves clean sands, leaves low organic content in the waste water, does not release excessive volatiles to the atmosphere, leaves minimal fines in the bitumen product, and that will not flocculate clays. 
     From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that separates minerals from mineral feedstock. Beneficially, such an apparatus, system, and method would produce clean sand, generate no waste water, have low atmospheric emissions, be adaptable to the clay content and wetting of the mineral feedstock, minimize mechanical complications, and have low energy input requirements. 
     SUMMARY OF THE INVENTION 
     The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available technologies. Accordingly, the present invention has been developed to provide an apparatus, system, and method for separating minerals from mineral feedstock that overcome many or all of the above-discussed shortcomings in the art. 
     An apparatus to separate minerals from mineral feedstock is disclosed. In one embodiment, the apparatus comprises a staged mineral separator comprising a plurality of walls that define at least two fluid isolation residence chambers. The separator is configured to receive a mineral feedstock. A first stage within the separator adds solvent to the residence chambers to create a first solvent-mineral feedstock slurry, maintains the solvent contact for a first specified time period, and drains the liquid portion of the slurry from the residence chambers to create a first drained mineral feedstock stream and a first stage miscella stream. A final stage within the separator adds solvent to the residence chambers to create a final solvent-mineral feedstock slurry, maintains the solvent contact for a final specified time period, rinses the slurry by adding solvent while draining the liquid portion of the slurry from the residence chambers, then continues to drain the liquid portion of the slurry from the residence chambers to create a final drained mineral feedstock stream and a final stage miscella stream. 
     A transition module is configured to control the rate each residence chamber travels through the stages of the staged mineral separator. The apparatus may further comprise a timing module configured to signal the transition module to adjust each of the specified time periods. A solvent stripper is configured to strip solvent from the final drained mineral feedstock stream to create a cleaned mineral feedstock stream. A miscella storage unit is configured to receive a miscella product stream and to provide a liquid flash stream, where the miscella product stream comprises the first stage miscella stream. A flashing module is configured to receive the liquid flash stream, and to provide a solvent recovery stream, a volatile byproducts stream and a final mineral product stream. The flashing module may include a first flash tank, a second flash tank, a compressor, an evaporator, and a first refrigerated condenser. 
     The separator may be sealed from vapor exchange with the atmosphere. The apparatus may also comprise a staging size module configured to control a travel distance of the residence chambers within each of the stages. The staging size module may comprise replaceable segments of an outer wall of the separator, each replaceable segment comprising one of a drain screen and a blank screen, and each stage comprising at least one blank screen and at least one drain screen, such that the residence chambers travel across the at least one blank screen followed by the at least one drain screen. 
     The staged separator may comprise a cylinder, and the plurality of walls may comprise turns of helicoid flighting disposed within the separator, wherein the flighting is coupled to an interior wall of the separator, and wherein the transition module comprises a motor configured to turn the separator about a longitudinal axis of the separator and thereby control the rate each residence chamber travels through each of the stages. The separator may be oriented horizontally. 
     The apparatus may further comprise at least one intermediate stage within the separator, where each intermediate stage adds a solvent to the residence chambers to create a solvent-mineral feedstock slurry, maintains a solvent contact for a specified time period associated with each intermediate stage, and drains the liquid portion of the slurry from the residence chambers to create an intermediate drained mineral feedstock stream and an intermediate stage miscella stream associated with each intermediate stage. 
     The solvent stripper may comprise a low temperature dryer and a high temperature dryer, where the low temperature dryer heats the final drained mineral feedstock stream to a first temperature, and where the high temperature dryer heats the final mineral feedstock stream to a second temperature. The low temperature dryer may deliver a first solvent vapor stream to the first stage, and the high temperature dryer may deliver a second solvent vapor stream to the final stage. The apparatus may further include a pressure relief valve configured to vent solvent vapor pressure above a threshold from the separator to the miscella storage unit; the miscella storage unit may further provide a solvent vapor stream and a solvent liquid stream. 
     The apparatus may further include an oil heater configured to provide heated oil first to a first heating jacket on the high temperature dryer, and subsequently to a second heating jacket on the low temperature dryer, and finally to a first heat exchanger to exchange heat from the oil exiting the second heating jacket to the final mineral product stream. The apparatus may further include a second heat exchanger configured to transfer heat from the cleaned mineral feedstock stream to the liquid flash stream. 
     The apparatus may further include a crusher, a plurality of mixers, a feed pump, and a cyclone. The crusher may be configured to crush tar sand to a nominal size and supply the crushed tar sand to the plurality of mixers. Each mixer may comprise a screw feeder and a rejection screen to intermittently provide mineral feedstock to a feed pump. The rejection screens may be configured to prevent the mixers from providing large feedstock clumps to the feed pump. The feed pump may deliver the mineral feedstock to the cyclone. The cyclone may separate a mineral feedstock fines stream from the mineral feedstock and deliver the remaining mineral feedstock to the separator. 
     The apparatus may further comprise a manifold that combines the final stage miscella stream and an intermediate stage miscella stream creating a solvent-rich miscella stream. The apparatus may further comprise a control valve that divides the solvent-rich miscella stream into a solvent reuse stream that recycles to the first stage and a secondary recovery stream. The apparatus may further comprise a solvent controller configured to manipulate the control valve to achieve a specified amount of solvent entering the first stage. The miscella product stream may further comprise a secondary recovery stream. 
     The apparatus may further comprise a densitometer configured to detect a density of the first stage miscella stream. The solvent controller may be further configured to manipulate a flow rate of solvent to the first stage to achieve a target density of the first stage miscella stream. The apparatus may further comprise a secondary recovery pump configured to add the mineral feedstock fines stream to the secondary recovery stream. The miscella product stream may further comprise the secondary recovery stream 
     The apparatus may further comprise a second refrigerated condenser configured to receive a solvent vapor stream and to provide a volatile vapor stream and a condensed solvent stream. The volatile vapor stream may be added to a volatile byproducts stream. The condensed solvent stream may be added to the solvent recovery stream. The apparatus may further comprise an energy recovery module that receives the volatile byproducts stream and may recover energy from the volatile byproducts stream through the burning of the volatile byproducts stream in a burner to add heat to a heated oil. 
     A method is disclosed to separate minerals from a mineral feedstock. The method may comprise configuring a plurality of residence times corresponding to a plurality of stages in a separator. The plurality of residence times may be configured by changing an axial length of the stages in the separator, and/or by changing a rotational speed of the separator. The method further includes creating a first slurry by contacting mineral feedstock and a solvent in a residence chamber at a first stage for a first residence time, draining a liquid portion of the slurry as a first stage miscella stream. The method further includes creating a final slurry by contacting mineral feedstock and a solvent in the residence chambers at a final stage for a final residence time, and draining a liquid portion of the final slurry while adding solvent at a rinse portion of the final stage. The method may further include continuing to drain the liquid portion of the final slurry at a drain portion of the final stage to create a final stage miscella stream. 
     The method may further include combining the first stage miscella stream and a portion of the final stage miscella stream into a miscella product stream. The method may include delivering the miscella product stream to a miscella storage unit, and delivering a liquid flash stream from the miscella storage unit to a flashing module. The method may include separating the liquid flash stream into a final mineral product stream, a solvent recovery stream, and a volatile byproducts stream. The method may further comprise dividing the final stage miscella stream into a solvent reuse stream and a secondary recovery stream, and adding the solvent reuse stream to the first stage. 
     The method may further comprise a removing a mineral feedstock fines stream from the mineral feedstock and adding the mineral feedstock fines stream to the secondary recovery stream. The method may comprise heating a final drained mineral feedstock stream to a first temperature, and further heating the final mineral feedstock stream to a second temperature. The second temperature may be higher than the first temperature and higher than a boiling point of the solvent, thereby creating a cleaned mineral feedstock stream. The method further include transferring heat from a heated oil to a high temperature dryer, then transferring heat from the heated oil to a low temperature dryer, and finally transferring heat from the heated oil to the final products stream. The method may further include transferring heat from the cleaned mineral feedstock stream to the liquid flash stream. 
     Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
     Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
     These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG. 1  is a schematic block diagram illustrating one embodiment of an apparatus to separate minerals from mineral feedstock in accordance with the present invention; 
         FIG. 2  is an illustration of one embodiment of a staged separator in accordance with to the present invention; 
         FIG. 3  is an illustration of one embodiment of a residence chamber in accordance with to the present invention; 
         FIG. 4  is an illustration of one embodiment of a staging size module in accordance with to the present invention; 
         FIG. 5  is a schematic block diagram illustrating one embodiment of a flashing module in accordance with the present invention; 
         FIG. 6  is an illustration of one embodiment of a miscella storage unit in accordance with to the present invention; 
         FIG. 7A  is a schematic flow chart diagram illustrating an embodiment of a method for separating minerals from mineral feedstock in accordance with to the present invention; and 
         FIG. 7B  is a continuation of the schematic flow chart diagram of  FIG. 7A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, system, and method of the present invention, as presented in  FIGS. 1 through 7B , is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. 
     Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of materials, fasteners, sizes, lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. 
     Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. 
     Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. 
     Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of materials, fasteners, sizes, lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     Throughout the figures, except as noted, dashed lines are used to represent energy transfers or energy recovery streams for the given embodiment of the invention. An energy transfer is the transferring of energy from one part of the system to another by any method, and can include at least exchanging heat through a heat exchanger, or physically mixing two streams to transfer energy. An energy recovery typically occurs in the form of thermal energy, but may be any other form of recovery including stored potential energy. 
       FIG. 1  is a schematic block diagram illustrating one embodiment of an apparatus  100  to separate minerals from a mineral feedstock  102  in accordance with the present invention. In one embodiment, the minerals comprise bitumen and the mineral feedstock  102  comprises a tar sand. Other mineral-feedstocks are known and contemplated within the scope of the invention, for example an oil-bearing shale. The apparatus  100  comprises a staged mineral separator  102  configured to receive a mineral feedstock  104 . The separator comprises fluid isolation chambers defined by a plurality of walls separating the chambers. The chambers may be configured to travel through the separator  102 . The separator  102  may be oriented horizontally, or at an incline. 
     The separator  102  comprises a first stage  106  within the separator  102  that adds solvent  109  to the residence chambers to create a first solvent-mineral feedstock slurry. The solvent  109  may be stored in one or more solvent tanks  108  and supplied to the separator through a pump (not shown), by gravity feed, or the like. The solvent  109  may comprise any solvent known in the art capable of dissolving the target mineral from the mineral feedstock. For example, the solvent  109  for a tar sand may comprise kerosene, naphtha, or an organic halide (an R-X n compound, where R is an organic component and X n  is at least one halogen molecule). In one embodiment, the solvent  109  comprises n-propyl bromide. 
     The first stage  106  further maintains the solvent  109  contact for a first specified time period, and drains the liquid portion of the slurry from the residence chambers to create a first drained mineral feedstock stream  110  and a first stage miscella stream  112 . Miscella, as used within the present description, comprises a liquid stream with mixed components of solvent  109  and mineral product—for example bitumen. 
     The separator  102  further comprises a final stage  114  that adds solvent  109  to the residence chambers to create a final solvent-mineral feedstock slurry. The final stage  114  further maintains the solvent  109  contact for a final specified time period, rinses the slurry by adding solvent while draining the liquid portion of the slurry from the residence chambers. The final stage  114  continues to drain the liquid portion of the slurry to create a final drained mineral feedstock stream  116  and a final stage miscella stream  118 . 
     The apparatus  100  further comprises a transition module  102  configured to control the rate each residence chamber travels through the stages  106 ,  114  of the separator  102 . In an example embodiment, the separator  102  comprises a cylinder with a helicoid flighting disposed within the separator  102  and coupled to the interior walls of the separator  102 . In the example, the plurality of walls defining the residence chambers comprise turns of the helicoid flighting within the separator  102 . When the separator  102  turns, the residence chambers advance with the turns of the flighting. In the example, the transition module  102  may be a motor configured to turn the separator  102  about a longitudinal axis of the separator  102  and thereby control the rate each residence chamber travels through each of the stages  106 ,  114 . 
     The apparatus  100  further comprises a solvent stripper  122  configured to strip solvent from the final drained mineral feedstock stream  116  to create a cleaned mineral feedstock stream  124 . The apparatus  100  further comprises a miscella storage unit  126  configured to receive a miscella product stream  128 , which comprises the first stage miscella stream  112 . The miscella storage unit  126  provides a liquid flash stream  136 . 
     The apparatus  100  further comprises a flashing module  138  configure to receive the liquid flash stream  136 . The flashing module  138  provides a solvent recovery stream  140 , a volatile byproducts stream  142 , and a final mineral product stream  144 . The final mineral product stream  144  may comprise bitumen from a tar sand, oil from oil shale, gold-rich effluent from a gold leaching process, and the like. 
     The separator  102 , in one embodiment, is sealed from vapor exchange with the atmosphere. For example, on the outlet of the clean mineral feedstock stream  124 , the apparatus  100  may comprise an airlock  146  configured to prevent vapor escape to the atmosphere. On the inlet side of the separator  102 , a second airlock (not shown) may be used, or a feed pump  177  may comprise a positive displacement pump that prevents vapor escape to the atmosphere. The apparatus  100  may be configured to vent vapor buildup  145  in the separator  102  to a pressure relief valve  156 . The pressure relief valve  156  may be configured to vent  145  vapor pressure at a threshold value from the separator  102  to the miscella storage unit  126 . The overall vapor pressure within the separator  102  should be limited by the mechanical constraints of the separator  102 , and potentially by leakage rates and environmental considerations for solvent vapor release—a typical venting pressure may comprise about 5 psig. 
     The apparatus  100  may further comprise a timing module  147  configured to signal the transition module  120  to adjust each of the specified time periods. For example, the timing module may determine that the first specified time period should change from 90 seconds to 120 seconds, and the timing module  147  may signal the transition module  120  to change a rotational rate of the separator from four RPM to three RPM. 
     The form of the signal to the transition module  120  is a mechanical step dependent upon the form of the apparatus  100  and a controller  148  which may comprise the timing module  147 . For example, the signal could be electronic, a datalink command, or a pneumatic command. The hardware comprising the separator  102 , the hardware comprising the stages  106 ,  149 ,  114  and the residence chambers, and the hardware comprising the transition module  120  will determine the type of command (e.g. RPM change, speed of a conveyor belt, etc.) and the values of the command. In one example, the separator  102  comprises a cylinder with helicoid flighting at one turn per foot, and one RPM advances the residence chambers one foot per minute. In the example, if the first stage  106  is six feet long, a turning speed of four RPM for the separator yields a first residence time of 90 seconds. 
     The separator  102  may comprise one or more intermediate stages  149 . Each intermediate stage  149  adds solvent  109  to the residence chambers to create a solvent-mineral feedstock slurry, maintains a solvent contact for a specified period of time associated with each intermediate stage  149 , and drains the liquid portion of the slurry from the residence chambers to create an intermediate drained mineral feedstock stream  150  and an intermediate stage miscella stream  151  associated with each intermediate stage  149 . For example, the separator  102  may comprise two intermediate stages  149 , wherein a first intermediate stage  149  is associated with a 30-second residence time and a first intermediate stage miscella stream  151 , and wherein the second intermediate stage  149  is associated with a 40-second residence time and a first intermediate stage miscella stream  151 . 
     The intermediate stages  149  allow the total residence time of all stages  106 ,  149 ,  114  to achieve enough time to remove the minerals from the mineral feedstock  104 , while allowing the first stage miscella stream  112  to have a higher mineral product cut, and while allowing the solvent-consuming rinsing portion of the final stage  114  to be smaller than without the intermediate stage(s)  149 . The mineral product cut refers to the fraction of the stream that is final mineral product versus solvent. For example, if the first stage miscella stream  112  is 12% bitumen, while the final stage miscella stream  118  is 3% bitumen, the first stage miscella stream has a higher mineral product cut. 
     In one embodiment, the sum of the residence times of all stages  106 ,  149 ,  114  is at least 180 seconds. The required residence time depends upon the specific characteristics of the solvent  104 , the mineral feedstock  104 , and the temperature of the slurries within the separator  102 . Weaker solvents, for example kerosene, may require longer total residence times. It is a mechanical step for one of skill in the art to determine the required residence time for a given apparatus  100 , and to design intermediate stages  149  to achieve the total required residence time while achieving the desired product cut in the first stage miscella stream  112  and the desired rinsing portion of the final stage  114 . 
     The solvent stripper  122  may comprise a low temperature dryer  152  and a high temperature dryer  153  to strip solvent  109  from the final drained mineral feedstock stream  116 . The low temperature dryer  152  may heat the final drained mineral feedstock stream  116  to a first temperature that drives off the bulk of the liquid solvent  109  from the final drained mineral feedstock stream  116  and pre-heats the final drained mineral feedstock stream  116 . The first temperature may be a temperature near the boiling point for the solvent  109 . For example, the solvent n-propyl bromide has a boiling point at atmospheric pressure of about 68 degrees C. The first temperature with n-propyl bromide may be in the range 65-100 degrees C. 
     The low temperature dryer  152  may be configured to deliver a first solvent vapor stream  154  to the first stage  106 . In one embodiment, the first solvent vapor stream  154  may be delivered to the first stage  106  by mixing the vapor stream  154  with the mineral feedstock  104  coming into the separator. In an embodiment where the separator  102  is sealed from vapor exchange with the atmosphere, the vapor stream  154  should be added to the apparatus  100  at any position upstream of the sealing mechanism—for example, a positive displacement feed pump  177 . 
     The solvent vapor stream  154  transfers energy from the low temperature dryer  152  to the first stage  106  resulting in a warmer slurry within the residence chambers. The warmer slurry makes the solvent stripping process more efficient as measured by time and solvent usage. The selected value for the first temperature utilized in the low temperature dryer  152  is determined from apparatus  100  specific considerations. For example, the amount of vapor  154  recycled to the first stage  106 , the amount of heat energy that should be transferred from the dryer  152  to the first stage  106 , the allowable vapor pressure within the separator  102  by a pressure relief valve  156 , the most efficient energy burden between the low temperature dryer  152 , the high temperature dryer  153  to achieve the required solvent concentrations in the cleaned mineral feedstock stream  124 , and the like. These determinations are a mechanical step for one of skill in the art based on a known solvent  109 , mineral feedstock  104 , and apparatus  100  hardware configuration. 
     The high temperature dryer  153  may heat the final drained mineral feedstock stream  116  to a second temperature that drives off solvent  109  residue from the final drained mineral feedstock stream  116  to create the cleaned mineral feedstock stream  124 . The second temperature may be significantly higher than the solvent  109  boiling point at atmospheric pressure. For example, in one embodiment a second temperature for the solvent n-propyl bromide may comprise 80-135 degrees C. The second temperature has no theoretical upper limit, but the constraints and costs of the apparatus  100  may limit the second temperature because other stripping methods (for example, steam stripping) to create the cleaned mineral feedstock  124  may compete economically with drying  152 ,  153  at high second temperatures. The given range is for one embodiment of the apparatus  100  and an n-propyl bromide solvent  109 . The high temperature dryer  153  may be configured to deliver a second solvent vapor stream  155  to the final stage  114 . 
     The apparatus  100  may further comprise an oil heater  157  configured to provide heated oil  158  to a first heating jacket on the high temperature dryer  153 , and subsequently provide the heated oil  159  to a second heating jacket on the low temperature dryer  152 , and finally provide the heated oil  160  to a first heat exchanger  161  to exchange heat from the oil exiting the second heating jacket to the final mineral product stream  144 . The oil heater  157  may thereby heat the high temperature dryer  153  to the second temperature, heat the low temperature dryer  152  to the first temperature, which is lower than the second temperature, and heat the final mineral product stream  144  to reduce the viscosity and required pumping work for the final mineral product stream  144 . It is a mechanical step for one of skill in the art to determine initial temperatures and pumping rates for the heated oil  158 ,  159 ,  160  to achieve the various desired temperatures based on the characteristics of a given embodiment of the apparatus  100 . 
     The apparatus  100  may further comprise a second heat exchanger  162  configured to transfer heat  163  from the cleaned mineral feedstock stream  158  to the liquid flash stream  136 . The heat exchanger  162  may comprise a tube that the liquid flash stream  136  flows through, where the tube is disposed within the flow of the cleaned mineral feedstock stream  158 . The cleaned mineral feedstock stream  158 , in one embodiment, is heated by the high temperature dryer  153  and comprises excess heat which can be recovered through the second heat exchanger  162  to improve the effectiveness of the separation in the flashing module  138 . 
     The apparatus  100  may further comprise an energy recovery module  164  that receives the volatile byproducts stream  142  and recovers energy from the volatile byproducts stream  142 . Recovering the energy from the volatile byproducts stream  142  may comprise recovering the volatile byproducts stream  142  as stored chemical potential energy, and/or converting the volatile byproducts stream  142  to electricity—for example in a fuel cell (not shown). In one embodiment, recovering the energy from the volatile byproducts stream  142  comprises burning the volatile byproducts stream  142  and providing the subsequent heat  165  to the oil heater  157 . 
     In one embodiment, the volatile byproducts stream  142  comprises the high end hydrocarbons from the mineral feedstock  104 . The volatile byproducts stream  142  may have impurities, such as sulfur compounds or the like, that may be removed before the energy recovery module  164  recovers the energy from the stream  142 . Removing the impurities from a hydrocarbon stream is a mechanical step for one of skill in the art, and the details of this (for example, using a carbon adsorption unit) are not shown to avoid obscuring aspects of the present invention. 
     The apparatus  100  may further comprise a manifold  166  that combines the final stage miscella stream  118  with the intermediate stage miscella stream(s)  151  into a solvent-rich miscella stream  167 . The apparatus  100  may further include a control valve or valves  168 ,  169  that divides the solvent-rich miscella stream  167  into a solvent reuse stream  170  that recycles to the first stage  106 , and a secondary recovery stream  171 . The secondary recovery stream  171  may be mixed with the first stage miscella stream  112  to make the miscella product stream  128 . 
     The apparatus  100  may further comprise a solvent controller  172  configured to manipulate the control valve(s)  168 ,  169  to achieve a specified amount of solvent  109 ,  170  entering the first stage  106 . The apparatus  100  may further comprise a densitometer  173  configured to detect a density of the first stage miscella stream  112  and manipulate a flow rate of solvent  109 ,  170  to the first stage  106  to achieve a target density  173  for the first stage miscella stream  112 . 
     In one embodiment, the target density of the first stage miscella stream  112  comprises a value between about 1,020 kg/m 3  and 1,260 kg/m 3 . For an apparatus  100  using tar sand as the mineral feedstock  104 , many solvents  109  of the organic halide have a density around 1,350 kg/m 3 , and the bitumen in the tar sand comprises a density around 700 kg/m 3 . In one design, the solvent controller  172  may target a bitumen cut of 5-15% in the first miscella stream  112 . In another design, the solvent controller  172  may target 70-90% removal of bitumen from the tar sand in the first stage  106 , with a tar sand composition of 10-20% bitument, and with a nominal solvent inlet rate  109 ,  170  of about 9 parts solvent to about 13 parts tar sand, by weight. The solvent controller  172  may account for the composition of the solvent reuse stream  170  by detecting the composition with a second densitometer (not shown), although only a small error is typically introduced by assuming the solvent reuse stream  170  comprises only solvent. 
     The target densities, tar sand compositions, stream compositions, and removal of bitumen from the tar sand in the first stage  106  are shown for illustration in one embodiment only. One of skill in the art can calculate these interrelated parameters based on the disclosures herein for a given apparatus  100  and mineral feedstock  104  by fixing the parameters that are important for a given embodiment (e.g. the mineral cut of the first stage miscella stream  112 ), and determining the required values for the other parameters (e.g. the required target density  173 ). Of course, one of skill in the art will recognize that certain parameters—such as the mineral fraction of the mineral feedstock  104 —typically cannot be changed as independent variables, the calculation of required stream densities  173  and solvent flow rates  109 ,  170  can help a practitioner determine a range of mineral feedstocks  104  for which a given embodiment of the apparatus  100  will commercially remove the minerals. 
     Determining a control scheme to control the flow rate of solvent  109 ,  170  based on the target density  173  is within the skill of one in the art. However, the following example solvent controller description  172  is intended to clarify and expedite the determination of an appropriate solvent controller  172  scheme. For the example, the solvent  109  comprises a density higher than the density of the mineral in the mineral feedstock  104 . It is a mechanical step for one of skill in the art to adjust the example where the mineral density is higher than the solvent  109  density, or where a different composition detection method is used than the density  173 . 
     The example solvent controller  172  compares the density  173  of the first stage miscella stream  112  to the target density. If the density  173  is low, the first stage miscella stream  112  is deemed “solvent-poor” and the solvent controller  172  increases the rate of the solvent reuse stream  170  with the control valve  168 . If the rate of the solvent reuse stream  170  is saturated—for example if the secondary recovery stream  171  is already zero or at a minimum imposed flow rate (e.g. the minimum to manage the mineral feedstock fines stream  179 ), then the rate of fresh solvent flow  109  is increased. The change rates on the solvent reuse stream  170  may be controlled by a standard feedback proportional-integral-derivative (PID) controller with appropriate tuning for response and stability. 
     If the density  173  is high, the first stage miscella stream  112  is deemed “solvent-rich” and the solvent controller  172  decreases the rate of fresh solvent flow  109 . If the rate of fresh solvent flow  109  is saturated—i.e. zero—the solvent controller  172  may reduce the solvent reuse stream  170  by increasing the rate of the secondary recovery stream  171 , if possible. If the fresh solvent flow  109  is zero and the secondary recovery stream  171  is maximized, the density  173  should return to the design level unless an error—for example a mineral-poor mineral feedstock  104 —has occurred. One of skill in the art will recognize that the example solvent controller  172  is based on the solvent management principle of conserving fresh solvent  109 , and can be adjusted for an apparatus  100  with a different solvent management principle—for example to maintain a minimum fresh solvent  109  flow rate. 
     The apparatus  100  may further comprise a crusher  174  configured to crush the mineral feedstock  104 , which may be tar sand, to a ¼ inch nominal size. The crusher  174  may supply the crushed tar sand  104  to a plurality of mixers  175 ,  176 . Each mixer  175 ,  176  may comprise a screw feeder and a rejection screen, and may be configured to intermittently provide mineral feedstock  104  to a feed pump  177 . The use of multiple mixers  175 ,  176  provides a continuous delivery of mineral feedstock  104  to the feed pump  177 . Each rejection screen may be configured to prevent feedstock clumps larger than about 3/16 inch from being provided to the feed pump  177  by the mixers  175 ,  176 . Each rejection screen may require periodic cleaning. 
     The feed pump  177  may be a positive displacement pump that provides a vapor seal for the separator  102 . The vapor seal for the separator  102  may also be an airlock (not shown) or some other feature of the apparatus  100 . The feed pump  177  may be configured to deliver mineral feedstock  104  to a cyclone  178 . The cyclone  178  may separate a mineral feedstock fines stream  179  from the mineral feedstock  104 , and deliver the mineral feedstock  104  to the separator  102 . 
     The apparatus  100  may comprise a secondary recovery pump  180 , which may be a disc flow pump, configured to add the mineral feedstock fines stream  179  to the secondary recovery stream  171 . The miscella product stream  128  may include the secondary recovery stream  171  and the first stage miscella stream  112 . In one embodiment, a first hydrocyclone  181  may remove fines from the secondary recovery stream  179 , and a second hydrocyclone  182  may remove fines from the first stage miscella stream  112 . The addition of the mineral feedstock fines stream  179  to the relatively solvent-rich secondary recovery stream  179  may allow extra removal of minerals from the mineral feedstock fines  179 . The fines  179  maybe difficult to manage in other parts of the apparatus  100 , depending upon the screens, pumps, and other equipment utilized throughout the apparatus  100 . 
     The miscella storage unit  126  may be further configured to provide a solvent vapor stream  132  and a solvent liquid stream  134 . The apparatus  100  may further comprise a second refrigerated condenser  183  (refer to the description referencing  FIG. 5  for one embodiment of a first refrigerated condenser) configured to receive the solvent vapor stream  132 , to condense the solvent vapor stream  132 , and to provide volatile vapor stream  184  and a condensed solvent stream  185 . The condense solvent stream  185  may be added to the solvent recovery stream  134 , and the volatile vapor stream  184  may be added to the volatile byproducts stream  142 . 
       FIG. 2  is an illustration of one embodiment of a staged separator  102  in accordance with the present invention. The separator  102  comprises a plurality of walls  202  that define at least two fluid isolation residence chambers  204 . The separator  102  is configured to receive a mineral feedstock  104 . In one embodiment, fluid isolation indicates that liquid portions within the fluid isolation residence chambers  204  do not communicate with other residence chambers  204 . 
     The illustrated stages  106 ,  149 ,  114  in  FIG. 2  are not shown to scale but are shown only to give an example order of the stages for one embodiment of the present invention. In one embodiment, the sizing of each stage is controlled by the staging module (refer to the description referencing  FIG. 4 ). The separator  102  may comprise a first stage  106  within the separator  102  that adds solvent  206  to a first solvent-mineral feedstock slurry, maintains the solvent contact for a first specified time period, and drains  208  the liquid portion of the slurry to create a first drained mineral feedstock stream and a first stage miscella stream  112 . The separator  102  may comprise a final stage  114  within the separator  102  that adds solvent  210  to a final solvent-mineral feedstock slurry, rinses the slurry by adding solvent  214  while draining  218  the liquid portion of the slurry from the residence chambers  204 , then continues to drain  218  the liquid portion of the slurry from the residence chambers  204  to create a final drained mineral feedstock stream  116  and a final stage miscella stream  118 . 
     The separator  102  may further comprise one or more intermediate stages  149  that add solvent  224  to a first solvent-mineral feedstock slurry, maintain the solvent contact for a specified time period, and drain  226  the liquid portion of the slurry to create an intermediate drained mineral feedstock stream and an intermediate stage miscella stream  151 . The solvent flow rates  206 ,  224 ,  210 ,  214  may be varied individually by stage via a signal from a controller  148  to one or more control valves  212 . The solvent added to the first stage  106  may further comprise the solvent reuse stream  170 . 
     In one embodiment, the staged separator comprises a cylinder, wherein the plurality of walls  202  comprise turns of helicoid flighting  202  disposed within the separator  102 . The flighting  202  may be coupled to an interior wall  222  of the separator. The separator  102  may further comprise a transition module  102  that may be a motor configured to turn the separator  102  about the longitudinal axis of the separator  102  and thereby control the rate each residence chamber  202  travels through each of the stages  106 ,  149 ,  114 . The apparatus  100  may comprise a controller  148  that signals  228  the transition module  120  to adjust each of the specified time periods (for the first, intermediate, and final stages). 
       FIG. 3  is an illustration of one embodiment of a residence chamber  204  in accordance with the present invention. The residence chamber  204  may be defined by a plurality of walls  202 . A solvent-mineral feedstock slurry may be disposed within the residence chamber  204 . In one embodiment, the walls  202  comprise turns of a helicoid flighting, and the slurry level  304  is limited to the vertical thickness  304  of the flighting from the separator interior wall  222  to maintain fluid isolation between residence chambers  204 . The residence chambers  204  may contain agitating members  302  to prevent a liquid-solid slurry from settling. 
       FIG. 4  is an illustration of one embodiment of a staging size module  400  in accordance with the present invention. The apparatus  100  may comprise a staging size module  400  configured to control a travel distance of the residence chambers  204  within each of the stages  106 ,  149 ,  114 . In one embodiment, the staging size module  400  comprises replaceable segments  402  of an outer wall of the separator  102 . Each replaceable segment  402  may comprise one of a drain screen  402 A,  402 B and a blank screen  402 C. 
     Each stage  106 ,  149 ,  114  may comprise at least one blank screen  402 C and at least one drain screen  402 A,  402 B such that the residence chambers  204  travel across the at least one blank screen  402 C followed by the at least one drain screen  402 A,  402 B. A residence time section of a stage  106 ,  149 ,  114  may comprise blank screens  402 C, while a drain section  404  of a stage  106 ,  149 ,  114  may comprise one or more drain screens  402 A,  402 B. The drain screens may have drain slots aligned radially  402 A, axially  402 B, or the drain screens may comprise holes (not shown). 
     The screen slot or hole sizing determines the fines content of the liquid draining  112 ,  151 ,  118  from a stage  106 ,  149 ,  114 . In one embodiment, the level of fines required in the final product is about 5 micron particles or lower. An engineering economic analysis demonstrates, in one embodiment, that a hydrocyclone  181 ,  182  is the most economical device to reduce liquid fines from about 37-50 microns to about 5 microns, and that drain screens are the most economical device to reduce liquid fines from the bulk slurry to about 37-50 microns. The final target particulate level, and the availability and cost of fines-reducing equipment, will define the most economic equipment configurations for a particular system, and these calculations are within the skill of one in the art. 
     In one embodiment, the replaceable segments  402  are easily removable and comprise wing nut attachments (not shown). One of skill in the art will recognize that the separator  102  requires an outer shell as a vapor barrier (not shown) for embodiments where the separator  102  is sealed from releasing vapor to the atmosphere. The drain sections  404  should align with the associated drain  208 ,  226 ,  218  configured to accept the appropriate stage miscella stream  112 ,  151 ,  118 . 
       FIG. 5  is a schematic block diagram illustrating one embodiment of a flashing module  138  in accordance with the present invention. The flashing module  138  may comprise a first flash tank  502 , a second flash tank  504 , a compressor  506 , an evaporator  508 , and a first refrigerated condenser  510 . The first flash tank  502  may receive the liquid flash stream  136  and provide a vapor stream A  514  and a liquid stream B  516 . The vapor stream A  514  may comprise mostly solvent and volatile hydrocarbon byproducts. The liquid stream B  516  may comprise mostly the primary mineral product. 
     The evaporator  508  may receive the liquid stream B  516  and provide a vapor stream C  520  and the final mineral product stream  144 . The evaporator  508  may comprise a wiped film evaporator, a falling film evaporator, or any other separation equipment known in the art to separate residual solvent  109  from the liquid stream B  516  comprising mostly primary mineral product. 
     The compressor  506  may receive the vapor stream A  514  and the vapor stream C  520 , and provide the compressed stream  524 . The second flash tank  504  may receive the compressed stream  524  and provide a vapor stream D  528  and the solvent recovery stream  140 . The first refrigerated condenser  510  may receive the vapor stream D  528 , and provide the volatile byproducts stream  142 . The first refrigerated condenser  510  may further provide the condensed stream  526  which the second flash tank  504  receives. 
       FIG. 6  is an illustration of one embodiment of a miscella storage unit  126  in accordance with the present invention. The miscella storage unit  126  may comprise a shell-side  604  and a tube-side  602 . The miscella storage unit  126  may receive the vented vapor  145  from the separator  102 , and pass the vented vapor  145  through the miscella storage unit  126  on the tube-side  602 . A fraction of the vapor  145  may condense and comprise the solvent liquid stream  134 , while the remaining vapor  145  may comprise the solvent vapor stream  132 . The solvent vapor stream  132  may contain volatile byproducts from the mineral feedstock, and the solvent vapor stream  132  may be passed to the second refrigerated condenser  183  to separate remaining solvent from volatile byproducts. The miscella product stream  128  may be received on the shell-side of the miscella storage unit  126 , and be later provided as the liquid flash stream  136 . In addition to providing the heat transfer between the solvent vapors  145  and the miscella product stream  128 , the miscella storage unit  126  provides a physical buffer between the section of the apparatus  100  that separates minerals from the mineral feedstock  104  (primarily the separator  102 ), and the section of the apparatus  100  that separates product minerals from the solvent  109  (primarily the flashing module  400 ). 
     The schematic flow chart diagrams that follow are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. 
       FIG. 7A  is a schematic flow chart diagram illustrating an embodiment of a method  700  for separating minerals from mineral feedstock in accordance with to the present invention. The method  700  may begin with the timing module  147  and/or staging size module  400  configuring  702  a plurality of residence times corresponding to a plurality of stages  106 ,  149 ,  114  in a separator  102 . The method  700  may continue with the separator  102  creating  704  a first slurry by contacting mineral feedstock  104  and a solvent  109  in a plurality of residence chambers  204  at a first stage  106  for a first residence time. The method  700  may continue with the separator  102  draining  706  a liquid portion of the slurry as a first stage miscella stream  112 , and creating  708  a final slurry by contacting mineral feedstock and a solvent in the residence chambers  204  at a final stage  114  for a final residence time. The method  700  may continue with the separator  102  draining  710  a liquid portion of the final slurry at a rinse portion of the final stage while adding more solvent, and continuing to drain the liquid portion of the final slurry at a drain portion of the final stage as a final stage miscella stream  118 . 
     The method  700  may include a solvent stripper  122  heating  712  the final mineral feedstock stream  116  to a first temperature, and further heating the final mineral feedstock stream  116  to a second temperature, wherein the second temperature is higher than the first temperature and higher than a boiling point of the solvent  109 , thereby creating a cleaned mineral feedstock stream  124 . The method  700  may include the solvent controller  172  dividing the final stage miscella stream  118  into a solvent reuse stream  170  and a secondary recovery stream  171 . 
     The method  700  may continue (Referring to  FIG. 7B ) with a cyclone  178  removing  716  a mineral feedstock fines stream  179  from the mineral feedstock  104 , and a secondary recovery pump  180  adding the mineral feedstock fines stream  179  to the secondary recovery stream  171 . The secondary recovery pump  180  may combine  718  the first stage miscella stream  112  and at least a portion of the final stage miscella stream  118  into a miscella product stream  128 , and the separator  102  and/or secondary recovery pump  180  may deliver  720  the miscella product stream to a miscella storage unit  126 . 
     The method  700  may further include transferring  722  heat from the cleaned mineral feedstock stream  124  to the liquid flash stream  136 . The flashing module  138  may separate  726  the liquid flash stream  136  into a final mineral product stream  144 , a solvent recovery stream  140 , and a volatile byproducts stream  142 . The method  700  may further include an oil heater  157  transferring  728  heat from a heated oil to the high temperature dryer  153 , then transferring heat from the heated oil to the low temperature dryer  152 , and a heat exchanger  161  then transferring  728  heat from the heated oil to the final products stream  144 . 
     The present invention provides an apparatus, system, and method for removing minerals from mineral feedstock. The present invention introduces fewer environmental complications, and is a water-free process (when water is not the solvent) that will not complicate processing of mineral feedstock containing clays. The sizing and residence times within the present invention are reconfigurable and easily scalable, and heat and energy stream managements within the process allow for an efficient separation of minerals from mineral feedstock. 
     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.