Abstract:
The present invention provides a mixer-settler extraction circuit for separating liquids from each other. The mixer-settler extraction circuit includes a flow distributor. The flow distributor comprises a slat assembly which directs the incoming liquid into the settling portion of the mixer-settler extraction circuit. The slats of the slat assembly may be spaced apart from each other at varying distances.

Description:
FIELD OF INVENTION 
       [0001]    The invention relates to systems and methods for separating components of a mixture of liquids. In particular, this invention relates to systems and methods for controlling fluid flow in a liquid-liquid separation context. The systems include a mixer-settler, as well as a flow distributor. 
       BACKGROUND OF THE INVENTION 
       [0002]    Liquid-liquid separation systems are frequently utilized to separate mixtures of liquids. Extraction circuits, such as, for example, mixer-settlers, allow the liquid components of a mixture to separate by density. Typically, mixer-settlers include a mixing section, which mixes the incoming feed liquids to form a dispersion. The dispersion then progresses to a settling section, where the two liquid components settle and are selectively removed from the extraction circuit. 
         [0003]    Mixer-settlers are commonly used in hydrometallurgical processes. For example, hydrometallurgical processes often utilize solvent extraction to remove metal values from pregnant leach solutions created by leaching processes. During solvent extraction, metal values from the pregnant leach solution are extracted into an organic extraction chemical. This extraction may be performed in a mixer-settler. In such configurations, the leach solution is forwarded to a mixer-settler, where the metal contained in the aqueous leach solution is extracted into the organic extraction chemical to create a loaded organic stream. The resulting loaded organic stream is forwarded to the mixer-settler. In the mixing section, a scrubbing solution is mixed with the organic phase. This dispersion is forwarded to the settling phase, which separates the organic solution from the metal value-containing aqueous solution. 
         [0004]    In an exemplary hydrometallurgical process for extracting metal, such as, for example, copper, sulfide or oxide bearing minerals are leached to create a pregnant leach solution containing copper. The pregnant leach solution is forwarded to a solvent extraction system. A suitable organic extractant, such as, for example Alamine 336, aldoxime, an aldoxime/ketoxime blend, or a modified aldoxime/ketoxime blend, is used to extract the copper present in the pregnant leach solution, creating a loaded organic stream. The loaded organic is forwarded to a mixer-settler. In the mixing section, a stripping solution, such as an alkali metal base solution, is added to the loaded organic stream. The two liquids are mixed to create a dispersion. The dispersion is forwarded to the settling section of the circuit. The dispersion is separated into two liquid components in the settling section, and the stripped organic extractant and metal-containing stripping solution may be selectively removed from the circuit. 
         [0005]    Conventional mixer-settlers utilize a flow distributor to control the fluid flow of the dispersion as it enters the settling section of the extraction circuit. For example, as the fluid enters the settling section of the circuit, it is beneficial to decrease the flow rate of the dispersion. It is also beneficial to create a linear flow front, so that the dispersion progresses through the settling at an even rate. A more linear flow front may reduce the entrainment of species present in the dispersion. Therefore, damming members, which may include traditional picket fences, may be used to beneficially modify the flow rate and profile of the dispersion. 
       SUMMARY OF THE INVENTION 
       [0006]    The present disclosure provides systems and methods for the separation of multiple liquid phases from a dispersion. Using the systems and methods of the present disclosure, a dispersion of two separable liquid components may be effectively separated. The present disclosure provides for improved forward progression of the dispersion through the mixer-settler circuit. As the dispersion moves across the flow distributor of the mixer-settler circuit, its velocity profile is improved to approach an even rate of forward progression, such as a plug flow model. Plug flow approximation helps to decrease entrainment, reduce separation times, and improve the separation efficiency of the mixer-settler circuit. 
         [0007]    An exemplary flow distributor in accordance with the present disclosure comprises a support structure having a picket-fence configuration, a first slat assembly coupled to the support structure comprising a couplet of slats, a second slat assembly coupled to the support structure comprising a couplet of slats, a third slat assembly coupled to the support structure comprising a couplet of slats, wherein the slats of the second and third slat assemblies comprise beveled edge surfaces and may be variably spaced from one another. In various embodiments, the flow distributor has a substantially chevron-shaped configuration. 
         [0008]    A mixer-settler assembly in accordance with the present disclosure comprises a vessel configured to conduct the flow of a liquid mixture and/or dispersion comprising an inbound portion, an outbound portion, a flow distributor having a chevron configuration, wherein the flow distributor has an apex configured to point in the direction of the inbound liquid mixture and/or dispersion. 
         [0009]    A method in accordance with the present disclosure comprises introducing a liquid mixture and/or dispersion into an inbound portion of a vessel comprising the inbound portion and an outbound portion, and regulating the flow of the liquid mixture and/or dispersion by passing the it through a flow distributor having a chevron configuration, wherein the flow distributor has an apex configured to point in the direction of the inbound liquid mixture and/or dispersion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. The present disclosure will become more fully understood from the detailed description and the accompanying drawings herein: 
           [0011]      FIG. 1  illustrates an exemplary hydrometallurgical metal recovery process; 
           [0012]      FIG. 2  illustrates a top view of an exemplary mixer-settler apparatus; 
           [0013]      FIG. 3  illustrates a top view of an exemplary flow distributor; 
           [0014]      FIG. 4  illustrates a front view of an exemplary flow distributor; 
           [0015]      FIG. 5  illustrates a top view of components of an exemplary flow distributor; and 
           [0016]      FIG. 6  illustrates a front view of an exemplary flow distributor. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    The detailed description of various embodiments herein makes reference to the accompanying drawing figures, which show various embodiments and implementations thereof by way of illustration and best mode, and not of limitation. While these embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, it should be understood that other embodiments may be realized and that mechanical and other changes may be made without departing from the spirit and scope of the present disclosure. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component may include a singular embodiment. 
         [0018]    Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, though the various embodiments discussed herein may be carried out in the context of metal recovery, it should be understood that systems and methods disclosed herein may be incorporated into anything needing to separate components of a dispersion in accordance with the present disclosure. 
         [0019]    The various embodiments of a flow distributor comprise the features hereinafter described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail and demonstrate certain illustrative embodiments of the disclosure. However, these embodiments are indicative of but a few of the various ways in which the principles disclosed herein may be employed. Other objects, advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings. 
         [0020]    To assist in understanding the context of the present disclosure, an exemplary hydrometallurgical metal recovery process configured to utilize systems and methods to separate dispersions in accordance with the present disclosure is illustrated in  FIG. 1 . In the exemplary process, metal bearing material  22  is subjected to hydrometallurgical metal recovery process  10  to recover metal value contained in the sulfide ore. Metal bearing mineral  22  may include chalcopyrite (CuFeS 2 ), chalcocite (Cu 2 S), bornite (Cu 5 FeS 4 ), and covellite (CuS), malachite (Cu 2 CO 3 (OH) 2 ), pseudomalachite (Cu 5 [(OH) 2 PO 4 ] 2 ), azurite (Cu 3 (CO 3 ) 2 (OH) 2 ), chrysocolla ((Cu,Al) 2 H 2 Si 2 O 5 (OH) 4 .nH 2 O), cuprite (Cu 2 O), brochanite (CuSO 4 .3Cu(OH) 2 ), atacamite (Cu 2 [OH 3 Cl]) and other copper-bearing minerals. Metal bearing material  22  may comprise any metal suitable for extraction via solvent extraction. 
         [0021]    Metal bearing material  22  is processed in a preparation step  12 , creating prepared metal bearing material  24 . Prepared metal bearing material  24  is forwarded to a leach step  14 . Leach step  14  produces a metal bearing slurry  28 , which is forwarded to a solid-liquid separation step  16 . Leach step  14  may comprise a pressure leach, heap leach, and/or agitation process. Solid-liquid step  16  produces a solid residue  30  and a metal bearing solution  32 . Metal bearing solution  32  is then subjected to a solvent extraction step  18 . Solvent extraction step  18  produces a loaded organic stream  34  and an extracted solution  36 . Loaded organic stream  34  is processed by a liquid-liquid separation step  20 , which produces a barren organic stream  40  and a separated metal bearing solution  38 . In various embodiments, separated metal bearing solution  38  comprises a rich electrolyte. Separated metal bearing solution  38  may then be subjected to a further processing step  42 , such as, for example, electrowinning. 
         [0022]    In accordance with various embodiments, liquid-liquid separation step  20  comprises a mixer-settler extraction circuit. With initial reference to  FIG. 2 , an exemplary settling section  100  is illustrated. A feed  102  enters settling section  100  at a feed section  104 . In an exemplary embodiment, feed  102  comprises loaded organic stream  34  from hydrometallurgical metal recovery process  10 . However, feed  102  may be any mixture containing at least two immiscible and separable liquids, including a dispersion and/or emulsion. 
         [0023]    In various exemplary embodiments, settling section  100  further comprises a perimeter wall  103  and a perimeter wall  105 . Further, settling section  100  may comprise a discharge section  160 . In various exemplary embodiments, separated liquid phases exit the settling section  100  from discharge section  160 . 
         [0024]    In accordance with an exemplary embodiment, and with continued reference to  FIG. 2 , settling section  100  further comprises a primary flow distributor  106 . Settling section  100  may further comprise a secondary flow distributor  130  and a tertiary flow distributor  131 . Although  FIG. 2  illustrates two additional flow distributors, the use of any number of additional flow distributors is in accordance with the present disclosure. 
         [0025]    With reference to  FIG. 4 , primary flow distributor  106  may comprise a support structure  109 . In various exemplary embodiments, support structure  109  comprises at least one horizontal support member  110 . In a preferred embodiment, support structure  109  comprises two horizontal support members  110 . In various exemplary embodiments, support structure  109  may further comprise at least one vertical support member  112 . In a preferred embodiment, the support structure comprises a plurality of vertical support members  112  connected to horizontal support members  110 . Other exemplary support structure  109  configurations may include a series of cross braces, floor mounted brackets, and/or top caps. However, any configuration of support structure  109  that provides adequate support for primary flow distributor  106  is in accordance with the present disclosure. 
         [0026]    In various exemplary embodiments, support structure  109  comprises a corrosion resistant material. The material selected for support structure  109  may be dependent on the compositions of feed  102 . For example, support structure  109  may comprise ABS, nylon, PTFE, polyvinyl chloride, fiberglass reinforced plastic, or any suitable corrosion resistant plastic material. Support structure  109  may also comprise stainless steel, aluminum, titanium, or any suitable corrosion resistant metal. Any material which provides sufficient structural rigidity and durability to support structure  109  and is suitable for use with the components of feed  102  is in accordance with the present invention. 
         [0027]    In various exemplary embodiments, primary flow distributor  106  comprises a plurality of slats  108 . In various exemplary embodiments, slats  108  are connected to the components of support structure  109 . In a preferred embodiment, slats  108  are connected to at least one horizontal support member  110 . Slats  108  may be connected to at least one horizontal support member  110  by bolts, clips, or any other suitable fastener. In addition, slats  108  may be connected to horizontal support member  110  by permanent means, such as welding. However, any method of attachment which joins slats  108  to support structure  109  and/or horizontal members  110  is in accordance with the present disclosure. 
         [0028]    In various exemplary embodiments, support structure  109  is configured to orient slats  108  in a substantially linear configuration. In other exemplary embodiments, support structure  109  is configured to hold slats  108  in a substantially chevron-shaped configuration. In yet other embodiments, support structure  109  is configured to hold slats  108  in a substantially configuration. In a preferred embodiment, support structure  109  orients slats  108  in a chevron-shaped configuration, the apex of which faces in the direction of the flow of feed  102 . 
         [0029]    In various exemplary embodiments, slats  108  comprise a corrosion resistant material. The material selected for slats  108  may be dependent on the composition of feed  102 . For example, slats  108  may comprise ABS, nylon, PTFE, or any suitable corrosion resistant plastic material. Slats  108  may also comprise stainless steel, aluminum, titanium, or any suitable corrosion resistant metal. Any material which is suitable for use with the components of feed  102  is in accordance with the present invention. 
         [0030]    In various exemplary embodiments, primary flow distributor  106  may comprise a number of different types of slats  108 . For example, primary flow distributor  106  may comprise slats  108  of three different configurations. With reference to  FIG. 3 , in an exemplary embodiment, flow distributor  106  comprises a first section  114 , a second section  116 , and a third section  118 . Each section ( 114 ,  116 , and  118 ) may be comprised of slats  108  that differ from each other in size and shape. For example, primary flow distributor  106  may comprise slats  108  of varying widths and/or heights. 
         [0031]    With reference to  FIGS. 3 and 6 , in various exemplary embodiments, first section  114  comprises at least a pair of first section slats  119 . In an exemplary embodiment, first section  114  is situated in the center of flow distributor  106 . In another exemplary embodiment, first section  114  is situated at the apex of the flow distributor  106 , so that first section  114  comprises the peak of the chevron-shaped configuration. In a preferred embodiment, first section  114  is symmetrical about a plane bisecting the apex of flow distributor  106 . 
         [0032]    In a preferred embodiment, first section slats  119  comprise a substantially rectangular configuration, including a parallel front face and rear face of substantially the same height and width. First section slats  119  further comprise a left side face and right side face of substantially the same height and width. In various exemplary embodiments, first section slats  119  are separated by gaps  113 . In a preferred embodiment, each first section slat  119  is spaced equidistantly from each other, so that each gap  113  is the same dimension. However, any spacing of first section slats  119  that provides sufficient flow distribution, including variable dimensions of gaps  113 , is in accordance with the present disclosure. 
         [0033]    With reference to  FIGS. 3 and 6 , in an exemplary embodiment, second section  116  comprises at least a pair of second section slats  120 . In an exemplary embodiment, second section  116  is adjacent to first section  114 . Preferably, second section  116  is positioned between first section  114  and perimeter wall  103  of settling section  100 . 
         [0034]    With reference to various figures, including  FIGS. 3 and 6 , in various exemplary embodiments, second section slats  120  are separated by gaps  115 . Gaps  115  may comprise various differing dimensions. In a preferred embodiment, gaps  115  may increase in dimension from the second section slat  120  closest to first section  114  to the second section slat  120  closest to the wall of mixer-settler  100 . However, any spacing of second section slats  120  that provides sufficient flow distribution is in accordance with the present disclosure. 
         [0035]    With reference to  FIG. 6 , in a preferred embodiment, second section slats  120  comprise a substantially parallelogram configuration. Second section slats  120  comprise a front face  122  and a substantially parallel rear face  124 . Front face  122  and rear face  124  are substantially the same height and width as each other. Second section slats  120  further comprise a beveled left side face  128  and a substantially parallel right side face  126 . Left side face  128  and right side face  126  are substantially the same height and width as each other. In a preferred embodiment, left side face  128  and right side face  126  are beveled to an angle 45 degrees below the plane of front face  122 . Left side face  128  and right side face  126  are configured to reduce the sideways velocity of feed  102  and direct the flow towards discharge section  160 . However, any dimensions of the various components of second section slats  120  ( 122 ,  124 ,  126  and  128 ), as well as any degree of bevel, which facilitates reducing the sideways velocity of feed  102  is in accordance with the present disclosure. 
         [0036]    With reference to  FIGS. 3 and 6 , in an exemplary embodiment, third section  118  comprises at least a pair of third section slats  220 . In an exemplary embodiment, third section  118  is adjacent to first section  114 . Preferably, third section  118  is positioned between first section  114  and perimeter wall  105  of settling section  100 . In a preferred embodiment, second section  116  and third section  118  are symmetrical about a plane which bisects the apex of flow distributor  106 . 
         [0037]    With reference to various figures, including  FIGS. 3 and 6 , in various exemplary embodiments, third section slats  220  are separated by gaps  117 . Gaps  117  may comprise various differing dimensions. In a preferred embodiment, gaps  117  may increase in dimension from the third section slat  220  closest to first section  114  to the third section slat  220  closest to perimeter wall  105  of settling section  100 . However, any spacing of third section slats  220  that provides sufficient flow distribution is in accordance with the present disclosure. 
         [0038]    With reference to  FIG. 6 , in a preferred embodiment, third section slats  220  comprise a substantially parallelogram configuration. Third section slats  220  comprise a front face  222  and a substantially parallel rear face  224 . Front face  222  and rear face  224  are substantially the same height and width as each other. Third section slats  220  further comprise a beveled left side face  228  and a substantially parallel right side face  226 . Left side face  228  and right side face  226  are substantially the same height and width as each other. In a preferred embodiment, left side face  228  and right side face  226  are beveled to an angle 45 degrees above the plane of front face  222 . Left side face  228  and right side face  226  are configured to reduce the sideways velocity of feed  102  and direct the flow towards discharge section  160 . However, any dimensions of the various components of second section slats  220  ( 222 ,  224 ,  226  and  228 ), as well as any degree of bevel, which facilitates reducing the sideways velocity of feed  102  is in accordance with the present disclosure. 
         [0039]    In accordance with various exemplary embodiments, first section slats  119 , second section slats  120 , and third section slats  220  comprise varying widths. For example, first section slats  119  may vary in width across first section  114 . Second section slats  120  may vary in width across second section  116 , and third section slats  220  may vary in width across third section  118 . Any configuration of first section slats  119 , second section slats  120  and third section slats  220  which facilitates reducing the sideways velocity of feed  102 , including the use of slats of varying width, is in accordance with the present disclosure. 
         [0040]    In accordance with various exemplary embodiments, settling section  100  further comprises a primary phase weir  112  and a secondary phase weir  114 . In various embodiments, primary phase weir  112  and secondary phase weir  114  are located in a discharge section  160 . 
         [0041]    In various exemplary embodiments, as feed  102  progresses through settling section  100 , feed  102  is separated into two phases; a primary phase  121  and a secondary phase  123 . Each of the two phases is isolated in a corresponding weir. In various exemplary embodiments, primary phase  121  is an organic phase. In various exemplary embodiments, secondary phase  123  is an aqueous phase which contains the metal values to be recovered in hydrometallurgical metal recovery process  10 . However, primary phase  121  (not shown) and secondary phase  123  (not shown) may be any liquids which are inclined to separate from each other in settling section  100  in accordance with the present disclosure. 
         [0042]    In an exemplary embodiment, primary phase weir  112  isolates primary phase  121  of feed  102 . Primary weir  112  may comprise a well, adjustable weir, outlet pipe or pipes, extraction chute and/or collection channel. However, any physical structure which allows for the selective separation and removal of primary phase  121  from feed  102  is in accordance with the present disclosure. 
         [0043]    In an exemplary embodiment, secondary phase weir  114  isolates secondary phase  123  of feed  102 . Secondary weir  114  may comprise a well, adjustable weir, outlet pipe or pipes, extraction chute and/or collection channel. However, any physical structure which allows for the selective separation and removal of secondary phase  123  from feed  102  is in accordance with the present disclosure. 
         [0044]    Thus, the flow distributor of the present disclosure provides means to control the fluid flow of a dispersion as it progresses through an extraction circuit. The flow distributor beneficially decreases the flow rate of the dispersion and creates an approximately linear flow front, which allows the dispersion to progress through the circuit at a more even rate. 
         [0045]    Finally, the present disclosure has been described above with reference to a number of exemplary embodiments. It should be appreciated that the particular embodiments shown and described herein are illustrative of the invention and its best mode and are not intended to limit in any way the scope of the invention. Those skilled in the art having read this disclosure will recognize that changes and modifications may be made to the exemplary embodiments without departing from the scope of the present invention. Various aspects and embodiments of this invention may be applied to fields of use other than copper mining. Although certain preferred aspects of the invention are described herein in terms of exemplary embodiments, such aspects of the invention may be achieved through any number of suitable means now known or hereafter devised. Accordingly, these and other changes or modifications are intended to be included within the scope of the present invention.