Improvements in or relating to the extraction of tin from ores and the like

摘要

In the extraction of tin from ores or concentrates by chloridization by calcium chloride in the presence of carbon, the ore particles are bonded with a solution of calcium chloride into a pasty granular form, whereby dusting is prevented during chloridizing. The ore, carbonaceous material, and chloride solution may be ground together to the consistency of wet sand, and the mixture dried to remove free water in a rotary furnace, whereby non-dusting agglomerates are formed. Chloridization with distillation of tin as chloride is then effected in a muffle furnace with or without rabbling of the charge. The distillate is condensed to form a solution from which tin may be recovered by electrolysis, the recovered chlorine being converted to calcum chloride with or without calcium hypochlorite for re-use, or to hydrochloric acid by passage together with a hydrogenous reducing gas over a contact agent such as firebrick heated to redness. The residues from the chloridizing furnace are leached to recover calcium chloride, which is used in excess. Enough carbon is used to reduce all metallic bases present to metal. A flow sheet for the process is included in the Specification. Specification 56/12, [Class 1 (iii), Oxides &c. Metallic], is referred to. The Provisional Specification refers to Specifications 276,743 [Class 1 (iii), Oxides &c. Metallic], and 403,122.