Patent GB-377705-A (GB)
Title: Improvements in or relating to processes for recovering metal values from ores and other metalliferous materials
IPC: C22B1/08
Filed: 1931-04-23
Abstract: In a process for recovering metal values from metalliferous materials a finely divided mixture of the ore &c. and a reagent p  metal in the form of -ous oxide is treated in a "quasi-wet" condition and under agitation with an acid reagent gas, the quasi-wet condition being maintained at least until the reagent metal has reacted with the reagent gas.  After further heat treatment to solubilize metal values, the latter are recovered by leaching.  Copper, manganese, and iron are specified as reagent metals, but in practising the process ferrous oxide or ferroso-ferric oxide is preferably used. Chloridizing of oxides, sulphates, silicates, or carbonates may be effected by a countercurrent or co-current stream of chlorine with added air in a rotary or multiple hearth furnace, the temperature being raised gradually say to 400 DEG  C., and chlorination being completed if necessary at temperatures up to 550 DEG  C. by effecting decomposition of an added halide such as sodium chloride as by introduction of sulphur dioxide.  Ferrous oxide may be added to the ore to be treated, or be provided therein by subjecting an iron-bearing ore to a preliminary reduction treatment of to a sulphating roast below 475 DEG  C. with a limited supply of air. When the reagent gas is sulphur dioxide, sulphates are produced.  In some cases reaction may advantageously be effected under pressure. In examples the extraction by preliminary roasting followed by chlorination of copper, silver, and antimony from a sulphide ore, of copper, nickel, and cobalt from a complex ore, and of copper and cobalt with or without nickel from iron sulphide ores leaving a purified iron ore, is described.  In some cases a leaching step to remove sulphates formed follows the preliminary roast, and in some cases chlorination is effected under pressure.  Further examples relate to a chloridizing treatment for the tailings from a roasted and leached zinc ore with recovery of copper, lead, zinc, and silver, and to a purely sulphating treatment of iron ores, after preliminary reduction, with recovery of nickel, cobalt, and copper as sulphates. Reference is made also to chloridization of copper gold ores, to preliminary sulphatizing of zinc and manganese ores or ores containing titanium or nickel sulphides, and to the volatilization of silver and arsenic from ores during their treatment.  Specification 336,770, [Class 1 (iii), Oxides &c., Metallic], is referred to.ALSO:In a process for removing copper, cobalt, and nickel from iron ores, the finely divided oxidized or roasted ore containing ferrous oxide or ferroso-ferric oxide is treated in a "quasi-wet" condition and under agitation with chlorine or sulphur dioxide, the quasi-wet condition being maintained at least until the ferrous oxide has reacted with the gas employed. Thereafter the temperature is raised to decompose the ferrous salt formed and in the presence of air to form chlorides or sulphates of the metals to be removed, which are recovered by leaching.  The ore may be subjected to preliminary reduction treatment to provide ferrous oxide therein.  Specification 336,770, [Class 1 (iii), Oxides &c., Metallic], is referred to.