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Extraction of metal values from lateritic ores.
Leavenworth HW Jr.; Amey EB III
U S Pat 3 892 639 1975 Jul; :
A process is disclosed for recovering fe as oxide and other valuable metals from laterite ores, which starts with treating the dried ore with h2 and recycled cl2 in a fluidized bed at 1,000 deg c for 3 h to chlorinate fe, ni, CO, and mn, these chloride vapors being condensed at different temperatures on cooling, so that the liquids are thus separated. The bed residue containing chromite is continuously drawn off and smelted in an arc furnace with coal and lime to produce a high-carbon fe alloy containing about 10 pct cr, which is cooled and leached with an acid (nh4)2so4 solution to separate soluble sulfates from gangue and slag. The mixed sulfate solution is cooled to crystallize fe(nh4)2(so4)2, which is then removed from a solution of cr(nh4)2(so4)2 that is electrolyzed in a cell to deposit cathode cr, the nh4hso4 byproduct being recycled for leaching. The fecl3, which is the first chloride condensed from the mixed vapors collected from the fluidized-bed reactor, is fed into a separate similar reactor which is fluidized with n2 at 800 deg c, where o2 is also added to decompose the chloride to fe2o3 as a product while the cl2 is recycled to the original chlorinating bed. Each of the chlorides of ni, CO, and mn, removed at its progressively lower liquefying temperature as the mixed vapor cools, is reduced to metal in a separate electrolysis cell for cathode deposition of the metal, with cl2 recycled to the original chlorinating bed.
U.S. Pat. 3,892,639; July 1, 1975; Chem. Abstr. 83:135,486X
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