GB347680A - Process for separating gold and antimony contained in sulphide of antimony ores - Google Patents

Abstract

Gold and antimony are separated from sulphide or other ores of antimony by mixing the ore or matte in the form of a finely-crushed concentrate with any one of the fluxes nitre cake, salt cake, a bisulphate of the alkali metals, magnesium sulphate, aluminium sulphate, soda or potash alum, sodium sulphate and sulphuric acid, or common salt and sulphuric acid, and roasting the mixture in a furnace with a regulated supply of air. The resulting mass is leached with water and the residue treated by any method for the recovery of the gold. The concentrate containing the gold native or as sulphide, arsenide, telluride, selenide or in any other form mixed with the flux in the proportion of 2 parts or less of flux to one of concentrate is charged into a furnace at a temperature of 100-150 DEG C. and roasted until all the sulphides arsenides and the antimony are oxidized and the sulphide content is nil, the final and maximum temperature of the mass not exceeding 450-500 DEG C. The arsenic given off during roasting may be condensed and purified and the sulphur and sulphur dioxide used for the production of sulphuric acid. Agitation of the cooled mass in cold water converts the antimony into oxide and the insoluble residue is collected in a filter. To obtain a high recovery of gold should mercury be used, the residue should be slimed before or during amalgamation. Leaching before amalgamation is not always necessary and the mass from the furnace may be made into a thick pulp with water, slimed and amalgamated directly, the water insoluble portion after the removal of the amalgam being treated for the extraction of the antimony. To separate the antimony the residue after leaching is collected, dried, and reduced with fluxes to give a regulus. Small quantities of arsenic, iron, and antimony pass into the solution after leaching and the antimony is recovered by agitating it with milk of lime or preferably of magnesia and heating for rapid precipitation. Sodium sulphate is recovered by evaporation and crystallization and may be converted into bisulphate to be used again in the process.ALSO:Gold and antimony are separated from sulphide or other ores of antimony by mixing the ore or matte in the form of a finely-crushed concentrate with any one of the fluxes nitre cake, salt cake, a bisulphate of the alkali metals, magnesium sulphate, aluminium sulphate, soda or potash alum, sodium sulphate and sulphuric acid, or common salt and sulphuric acid, and roasting the mixture in a furnace with a regulated supply of air. The resulting mass is leached with water and the residue treated by any method for the recovery of the gold. The concentrate containing the gold native or as sulphide, arsenide, telluride, selenide or in any other form mixed with the flux in the proportion of 2 parts or less of flux to one of concentrate is charged into a furnace at a temperature of 100-150 DEG C. and roasted until all the sulphides arsenides and the antimony are oxidized and the sulphide content is nil, the final and maximum temperature of the mass not exceeding 450-500 DEG C. The arsenic given off during roasting may be condensed and purified and the sulphur and sulphur dioxide used for the production of sulphuric acid. Agitation of the cooled mass in cold water converts the antimony into oxide and the insoluble residue is collected in a filter. To obtain a high recovery of gold should mercury be used, the residue should be slimed before or during amalgamation. Leaching before amalgamation is not always necessary and the mass from the furnace may be made into a thick pulp with water, slimed and amalgamated directly, the water insoluble portion after the removal of the amalgam being treated for the extraction of the antimony. To separate the antimony the residue after leaching is collected, dried, and reduced with fluxes to give a regulus. Small quantities of arsenic, iron, and antimony pass into the solution after leaching and the antimony is recovered by agitating it with milk of lime or preferably of magnesia and heating for rapid precipitation. Sodium sulphate is recovered by evaporation and crystallization and may be converted into bisulphate to be used again in the process.