C22B11/023

METHOD FOR EXTRACTING METALS FROM CONCENTRATED SULPHURATED MINERALS CONTAINING METALS BY DIRECT REDUCTION WITH REGENERATION AND RECYCLING OF THE REDUCING AGENT, IRON, AND OF THE FLUX, SODIUM CARBONATE
20180282837 · 2018-10-04 ·

A method is disclosed for extracting metals from concentrated sulphurated minerals containing metals by direct reduction with regeneration and recycling of the reducing agent, iron, and of the flux, sodium carbonate. It is a combination of pyrometallurgical and hydrometallurgical processes which differ from the conventional processes. They do not require previous toasting of the concentrated sulphurated minerals and are technically and economically more advantageous than the presently used processes, since they directly reduce to zero the positive oxidation state of the metal, using a single reactor for extracting the metal, regenerating and recycling the metallurgical feed materials in complementary processes, the kinetics of the chemical reactions being characterised by high speed, without generating any slags or pollutant gases. The metals can be extracted at a reduced cost and in an environmentally sustainable manner

PROCESS FOR EXTRACTING NOBLE METALS FROM ANODE SLIME
20170145541 · 2017-05-25 ·

The present invention provides a process for extracting noble metals from anode slime, comprising: mixing sodium carbonate, quartz and coke powder and impurity-removed anode slime, and subjecting the mixture to smelting and converting to obtain alloys of noble metals. The present invention avoids problem of lead pollution by using metallic bismuth to collect noble metals; meanwhile, metallic bismuth has low melting point, high specific gravity, and formation heat of bismuth oxide of 45.6 kcal/g atomic oxygen, thus it is easy to be reduced and the reduction temperature is low, which are beneficial for saving energy consumption and reduction time; the much smaller amounts of copper, nickel, antimony and arsenic entering noble bismuth in a slightly reductive smelting atmosphere than those entering noble lead make the converting of noble bismuth become simple, thereby decreasing smelting time and increasing the direct recovery rate of noble metals in anode slime.

TREATMENT OF ZINC LEACH RESIDUE

According to the present invention there is provided a method for treating a zinc leach residue comprising the steps of: adding the zinc leach residue and a sulfide material comprising copper and flux to a furnace having a molten bath therein; operating the furnace to produce a matte comprising copper and a slag comprising zinc; separating the matte from the slag; and recovering zinc from the slag. The method preferably comprises the additional step of recovering the copper and/or other precious metals such as silver and gold, from the matte.

Method for the production of a collector alloy comprising precious metal or of pure silver

A method for producing a collector alloy comprising 25 to 100 wt % precious metal in total, comprising 0 to <97 wt % of the precious metal silver, 0 to 75 wt % of at least one precious metal selected from gold, platinum, rhodium and palladium, and 0 to 75 wt % of at least one non-precious metal selected from copper, iron, tin and nickel, or for producing pure silver, comprising the steps of: (1) providing precious metal sweeps; (2) providing a flux which, during collective melting with the refractory inorganic material from the precious metal sweeps provided in step (1); (3) collective melting of the materials provided in steps (1) and (2) at a temperature in the range of from 1300 to 1600 C., forming a melt comprising at least two phases of different densities arranged one above the other; and, (4) separating the upper phase and the lower phase.