THIS invention relates to a process for the enhanced recovery of chromite and platinum group metals (PGMs) from a mixed chromite/PGM ore. Ore is ground 12, classified 14, to produce a coarse fraction and a fine fraction 36. The coarse fraction is subjected to gravity separation 16 and coarse particle flotation 20 to obtain a chrome concentrate and a PGM concentrate. The fine fraction 36 and PGM concentrate are ground 28, and subjected to conventional flotation 30 to obtain a PGM concentrate product 32. The benefits of this novel configuration of gravity concentration and coarse flotation technologies, as applied to both chromite and PGM recovery, are higher recoveries of chromite in a saleable concentrate, higher recoveries of PGMs and base metals, and lower chromite content in the PGM concentrate.

Conjugated organic polymers doped with anions and methods for the use of the anion-doped conjugated organic polymers in the selective electroless extraction and recovery of gold or silver from samples containing gold anions or silver anions are provided. The anion-doped polymers have a conjugated, positively charged backbone chain that is charge-balanced with associated dopant anions.

A method for recovering gold from electronic components includes a first macro-step of dissolving gold and copper from the electronic components using an aqueous solution comprising HNO.sub.3 concentrated in a percentage varying from 28% to 38% and concentrated HCl in a percentage varying from 15% to 25%. A second macro-step includes adding KOH to the obtained solution to bring it to a pH between 0.5 and 0.9. A third macro-step includes adding to the solution obtained in the second macro-step an amount of ascorbic acid dissolved in water equal to the amount of gold hypothetically present in a sample of the first macro-step, multiplied by a factor ranging between 1.5 and 3, causing precipitation of gold, which is separated from the solution and made available in powder form in a fourth macro-step.

A system for collecting mercury from feed material that can be tailings comprises: a water inlet for forming a slurry containing the tailings; at least one screen for separating tailings from the slurry to form a screened slurry; a rotatable collection chamber containing at least one plate, a drive for rotating the collection chamber for collecting mercury on the plate to provide a discharge material comprising water and treated tailings, the treated tailings containing less mercury than in the feed material.

Disclosed is a method for preparing a solid material including manganese, the method including the following steps: a. bringing into contact an aqueous effluent including manganese, for example at least 5 mg/L, typically at least 5 to 50 mg/L, and preferably 7 to 25 mg/L of manganese, with an oxidizing agent, manganese, preferably at a temperature between 10° C. and 50° C., and obtaining an oxidized aqueous solution; b. adding a base to the oxidized aqueous solution obtained at the end of step a) until a pH of between 8 and 12, preferably greater than 9, and preferably from 9 to 10.5, and obtaining a solution including a precipitate; c. filtration of the solution obtained at the end of step b); and d. obtaining a solid material including manganese, and especially manganese (IV) and/or Mn (III).

The invention provides an assay for identifying a bacterium capable of binding elemental heavy metal, comprising the following steps: cultivating a test bacterium in a suitable first culture medium; immersing at least a surface portion of a test tool into the first culture medium for a second predetermined period of time, said surface portion being coated by elemental heavy metal, respectively; removing said test tool from said first culture medium and optionally rinsing the test tool; contacting a second culture medium with the surface portion coated by elemental heavy metal of said test tool removed in the previous step; and identifying the test bacterium as being capable of binding elemental heavy metal from growth of the test bacterium in said second culture medium.

A method for breaking down a mixture, which is present in the form of solid particles, consisting of: (A) 0 to 99% by weight of metallic ruthenium, (B) 0 to 50% by weight of at least one element other than ruthenium, which is present in elementary form, selected from the group of elements of the atomic numbers 13, 21-30, 39-42, 45-52, and 72-83, (C) 0 to 99% by weight of ruthenium oxide, (D) 0 to 70% by weight of at least one solid element oxide other than ruthenium, (E) 0 to 30% by weight of at least one inorganic substance other than (A) to (D), and (F) 0 to 3% by weight of at least one organic substance, wherein the sum of the % by weight of the compounds (A) to (F) is 100% by weight and the ruthenium content of the mixture is 2 to 99% by weight, and wherein the method comprises the steps of: (1) optionally mixing said mixture with alkali carbonate by forming a blend, (2) alkaline oxidizing breakdown of the mixture or of the blend, respectively, formed in optional step (1) into molten potassium hydroxide using a gaseous oxidizing agent selected from the group consisting of air, oxygen, and air/oxygen mixtures, and without use of nitrate, and (3) cooling down the breakdown material formed in step (2) to a temperature below its solidification temperature, wherein the gaseous oxidizing agent is introduced into the melt in step (2).

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 for extracting noble metals from mining tailings and other solids is provided. The method uses a Lewis acid, Brønsted acid, complexing agent and oxygen to provide excellent extraction without the need for chorine gas or cyanide.

A method for clean recovery of palladium is provided, including the following steps: mixing a palladium-containing material, a Ce.sup.4+-containing acidic solution, and an additive, subjecting a resulting mixture to leaching to obtain a Pd.sup.2+-containing solution, and subjecting the Pd.sup.2+-containing solution to electrolysis to obtain palladium. In the method, the palladium-containing material is subjected to solution leaching with Ce.sup.4+ as an oxidative leaching agent and a chlorine-containing additive. After leaching is complete, a Ce.sup.4+ and Pd.sup.2+-containing leaching liquor is subjected to electrolysis to realize the green regeneration of Ce.sup.4+ and palladium. The method of the present disclosure does not lead to the generation of NOx and waste liquid. The present disclosure can significantly reduce the environmental impact and production cost and has excellent economic benefits and application prospects.