Abstract: This invention relates to the development of a viable metallurgical process capable of treating low grade concentrates, bulk concentrates, dirty concentrates, or ore directly for the recovery of non-ferrous metals such as zinc, lead, copper, and precious metals and accordingly is significant to the development of massive fine grained sulphide ore bodies found throughout the world. The process involves the consecutive steps of sulphatizing roasting in a fluidized bed reactor, a two stage leach, metal recovery from solution by conventional processes such as electrowinning and precipitation, and recycling of residue wash waters and leach liquors containing high concentrations of iron and minor impurity elements to the roaster or a spray dryer for thermal decomposition. Simple and efficient rejection of iron from the circuit to residue as stable hematite is the net result of the recirculation and thermal decomposition.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper iron from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.

Abstract: Residues containing lead as lead sulphate and silver in the form of native silver or silver chloride, sulfide or sulphate, as well as silver complexes with other metals, and resulting from the roasting and leaching of sulfide concentrates containing lead, zinc, copper, and silver are treated to produce a high grade lead and silver product containing lead predominantly as calcium plumbate in a process wherein the residue is leached with brine, the resultant leach solution treated with lime to precipitate lead as oxychlorides, and the resultant lime-oxychloride precipitate is calcined to produce a mixture of calcium orthoplumbate and lead oxide. Residual chloride can be washed easily from this product which may then be treated in a lead blast furnace to recover lead and associated silver in their elemental state.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.

Abstract: The specification discloses a method for recovering non-ferrous metals such as zinc or copper from their concentrates, ores or any other metal containing materials into a solution containing these non-ferrous metals as sulphates and a minimal amount of dissolved iron. The resultant solution is suited without or with minimum pre-purification treatment for conventional electrowinning processes to recover such non-ferrous metals with less difficulties than the previous methods involving complex iron-removal processing. There is disclosed a method for recovering at least one non-ferrous metal soluble in sulphuric acid from a strong sulphuric acid solution containing said metal and iron as sulphates, said method comprising the following consecutive steps:subjecting said solution in a sub-divided form to thermal decomposition in a fluidized bed reactor at a temperature of from 600.degree. to 750.degree. C.