Patent GB-423451-A (GB)
Title: Process for the recovery of sulphur and/or sulphuretted hydrogen, or mixtures of sulphuretted hydrogen, sulphur dioxide and sulphur, from materials containing sulphur
IPC: C01B17/06
Filed: 1933-09-29
Abstract: <PICT:0423451/III/1> Sulphur and/or sulphuretted hydrogen or mixtures of sulphuretted hydrogen, sulphur dioxide and sulphur are obtained from sulphur-bearing materials in the presence of solid, liquid or gaseous carbonaceous materials, by treating such materials with steam and air in an internally heated rotary tube furnace, through which the gases and air and the material to be treated pass in counter current.  The rotary furnace has a preheating zone which <PICT:0423451/III/2> may also serve as a sulphur distillation zone if pyrites is the initial material, a main reaction zone in which a reducing atmosphere is maintained by regulating the introduction of air, steam and on occasion combustible gas through nozzles passing through the charge and evenly distributed over the length and periphery of the main reaction zone, and an outlet zone in which an oxidizing atmosphere is maintained by the introduction of oxygen containing gases with or without steam through nozzles. Sulphide ores or sulphates such as those of barium, calcium and magnesium may serve as initial materials.  The furnace is preferably provided with turning devices and/or baffle rings.  The heat may be generated by the combustion of gases rich in hydrogen such as coal gas, coke oven gas or water gas or of liquid fuels, steam for the process being thereby provided.  A portion of the heat may be supplied by internal electric heating or by indirect heating.  The hydrogen content of the exhaust gases may be returned to the process after the removal of their sulphur content and also preferably their carbon dioxide content.  The conversion of the mixture of sulphuretted hydrogen and sulphur dioxide into sulphur may take place either outside the furnace or within the furnace and for this purpose the gas outlet end of the furnace may be provided with a known contact chamber; in this case the original material is fed into the furnace through one or more openings in the shell of the furnace behind the contact chamber. Lignite coke or semi-coke may be employed as the carbonaceous addition to the sulphur-bearing material.  According to one example pyrites is fed into a rotary tube furnace.  Sulphur is distilled in the first zone, combustible gases and air are introduced through nozzles in the second zone and steam and air are introduced in the third zone.  The second zone has a temperature of 700--900 DEG  C. and a reducing atmosphere.  The resulting gas contains sulphur, sulphuretted hydrogen and sulphur dioxide.  According to a second example, a mixture of anhydrite and coal is fed into a rotary furnace, the second zone of the furnace being maintained at at least 900 DEG  C. by the admission of water gas through the nozzles.  The resulting gas contains sulphuretted hydrogen.  The Specification as open to inspection under Sect. 91 comprises also a rotary furnace A, Figs. 1 and 2 (Cancelled), provided with pipes R<2> and nozzles B for the introduction of liquid or gaseous fuel, pipes R<3> and nozzles L<1> for the introduction of combustion air, pipes R<1> and nozzles D for the introduction of steam, nozzles L<2> for the introduction of roasting air, a distributer head V for supplying the gases of combustion, air and steam, turning devices W and baffle rings S. This subject-matter does not appear in the Specification as accepted.