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.

A method for separating an amount of osmium from a mixture containing the osmium and at least one other additional metal is provided. In particular, method for forming and trapping OsO.sub.4 to separate the osmium from a mixture containing the osmium and at least one other additional metal is provided.

The subject invention provides safe, environmentally-friendly, compositions and methods for extracting minerals and/or metals from ore. More specifically, the subject invention provides for bioleaching using a composition comprising one or more biosurfactant-producing microorganisms and/or microbial growth by-products. In specific embodiments, the composition comprises biosurfactant-producing yeasts and/or their growth by-products.

The invention relates to a method for reductive extraction of elemental noble metal from an acidic aqueous solution containing noble metal, the method comprising the addition of non-noble metal including zinc and/or tin to the acidic aqueous solution containing noble metal to form a reaction mixture, wherein the dissolved noble metal includes iridium, rhodium and/or ruthenium, wherein the non-noble metal is added in a leaner-than-stoichiometric amount, and wherein the pH of the acidic aqueous solution containing noble metal prior to the addition of the non-noble metal is in the range of +0.8 to +3.0 and is also kept in this range in the reaction mixture.

A method of recovering gold from a metal combination includes contacting the metal combination with a first leaching liquid sufficient to oxidize one or more additional metals of the metal combination to produce an oxidized product liquid and a recovered gold product, wherein the first leaching liquid includes chloride ions.

The present request describes a process to obtain metallic gold nanoparticles from an effluent containing sulfide, resulting from a bioremediation process of acid mine drainage (AMD) based on the use of sulfate-reducing bacteria. The disclosed process consists of the effluent addition to a gold solution in concentrations between 20-250 mg/L, in batch or continuous systems, allowing to obtain nanoparticles of Au(0) with a yield of 70-100%.

The invention relates to a method for preparing a gold-containing solution by chloride leaching from gold-bearing raw materials. A further object of the invention is to provide a method for recovering gold and optionally silver from the prepared gold-containing solution. The invention relates also to a process arrangement for recovering gold and optionally silver.

The invention relates to a method for concentrating metals, in particular silver and/or tin and/or lead from scrap containing metal, by treating the material/scrap containing silver and/or tin and/or lead with a sulfonic acid of the formula RSO.sub.2OH in the presence of an oxidizing agent, wherein R can be an organic group or ammonia.

The present invention relates to separation and recovery of metals from ground alkaline batteries using anode mud (zinc electrolysis waste) and other manganese and zinc containing materials. The material commonly referred to as alkaline black (AKB) is solubilized into sulfate media and the manganese to zinc ratio is adjusted. The solution containing metals is processed using crystallization and ion exchange methods to produce manganese sulfate and zinc sulfate solutions for several possible applications.

A method is disclosed for recovering gold from a gold-containing organic solution containing soluble gold. The method comprises contacting the gold-containing organic solution with an aqueous stripping solution in order to extract gold from the gold-containing organic solution into the aqueous stripping solution. The aqueous stripping solution containing gold is separated from the organic solution. The separated aqueous stripping solution containing gold is contacted with a reducing agent containing sodium metabisulphite, in order to reduce gold from the aqueous stripping solution.