A process for bio-oxidation of sulfides in mineral ore having a metal such as gold occluded or dispersed within the ore as a sulfide is disclosed. The first step comminutes the ore into particles with a size distribution having a P80 of less than 0.25 inch with minus 106 micron particles in the range of 15% to 40% by weight. Agglomerates are formed by adding to the comminuted ore particles an acidic inoculate solution including water, with the solution further including microorganisms capable of bio-oxidizing the sulfides. The agglomerates are then placed in at least one bio-reactor containment vessel to form an ore bed. The process continues by bio-oxidizing the sulfides in the ore bed; then re-circulating the solution through the ore bed, and continuing the bio-oxidation until a desired bio-oxidation level is achieved. Thereafter, the metal is recovered from the ore.

A process for bio-oxidation of sulfides in mineral ore having a metal such as gold occluded or dispersed within the ore as a sulfide is disclosed. The first step comminutes the ore into particles with a size distribution having a P80 of less than 0.25 inch with minus 106 micron particles in the range of 15% to 40% by weight. Agglomerates are formed by adding to the comminuted ore particles an acidic inoculate solution including water, with the solution further including microorganisms capable of bio-oxidizing the sulfides. The agglomerates are then placed in at least one bio-reactor containment vessel to form an ore bed. The process continues by bio-oxidizing the sulfides in the ore bed; then re-circulating the solution through the ore bed, and continuing the bio-oxidation until a desired bio-oxidation level is achieved. Thereafter, the metal is recovered from the ore.

A process to significantly improve the copper chemical leaching process for primary and secondary minerals, using calcium chloride including the agglomeration, curing, and leaching with a high content of chloride, iron and copper stages. The mineral is then washed with a low concentration of copper and a high concentration of acid, where the impregnated copper is extracted from the pit and wherein a recirculated solution is used in the agglomeration stage.

A process to significantly improve the copper chemical leaching process for primary and secondary minerals, using calcium chloride including the agglomeration, curing, and leaching with a high content of chloride, iron and copper stages. The mineral is then washed with a low concentration of copper and a high concentration of acid, where the impregnated copper is extracted from the pit and wherein a recirculated solution is used in the agglomeration stage.

A method for producing granular metallic iron of the present invention includes: an agglomeration step of obtaining agglomerates through agglomeration of a mixture that contains an iron oxide-containing material and a carbonaceous reducing agent; and a granulation step of obtaining granular metallic iron by heating the agglomerates, reducing iron oxides in the agglomerates, aggregating generated metallic iron to be granular while separating the metallic iron from slag generated as a by-product, and thereafter cooling and solidifying the metallic iron, wherein agglomerates satisfying all the conditions given by formulas (1) to (3) below are used as the agglomerates: (1) [(total CaO amount+total SiO.sub.2 amount+total Al.sub.2O.sub.3 amount)/total Fe amount]≧0.250; (2) (total CaO amount/total SiO.sub.2 amount)≧0.9; (3) [total Al.sub.2O.sub.3 amount/(total CaO amount+total SiO.sub.2 amount+total Al.sub.2O.sub.3 amount)]×100≧9.7. In the formulas, the total CaO amount, the total SiO.sub.2 amount, the total Al.sub.2O.sub.3 amount and the total Fe amount respectively represent the mass percentage of CaO, the mass percentage of SiO.sub.2, the mass percentage of Al.sub.2O.sub.3 and the mass percentage of Fe contained in the agglomerates.

A method for producing granular metallic iron of the present invention includes: an agglomeration step of obtaining agglomerates through agglomeration of a mixture that contains an iron oxide-containing material and a carbonaceous reducing agent; and a granulation step of obtaining granular metallic iron by heating the agglomerates, reducing iron oxides in the agglomerates, aggregating generated metallic iron to be granular while separating the metallic iron from slag generated as a by-product, and thereafter cooling and solidifying the metallic iron, wherein agglomerates satisfying all the conditions given by formulas (1) to (3) below are used as the agglomerates: (1) [(total CaO amount+total SiO.sub.2 amount+total Al.sub.2O.sub.3 amount)/total Fe amount]≧0.250; (2) (total CaO amount/total SiO.sub.2 amount)≧0.9; (3) [total Al.sub.2O.sub.3 amount/(total CaO amount+total SiO.sub.2 amount+total Al.sub.2O.sub.3 amount)]×100≧9.7. In the formulas, the total CaO amount, the total SiO.sub.2 amount, the total Al.sub.2O.sub.3 amount and the total Fe amount respectively represent the mass percentage of CaO, the mass percentage of SiO.sub.2, the mass percentage of Al.sub.2O.sub.3 and the mass percentage of Fe contained in the agglomerates.

A method of forming a metal alloy. The method comprises forming a metal oxide precursor and conducting cathodic polarization of the metal oxide precursor in a molten salt electrolyte to form a metal alloy. In an additional method, a metal oxide precursor is formed. The metal oxide precursor is reduced to a metal in an electrochemical cell that comprises a working electrode, a counter electrode, and an electrolyte. The metal is reacted with a metal of the working electrode to form a metal alloy. In another method, a metal oxide precursor is formed on a base material. The base material is introduced into a molten salt electrolyte of an electrochemical cell and the metal oxide precursor is reduced to a metal in the electrochemical cell. The metal is reacted with the base material to form a metal alloy on the base material.

A method of forming a metal alloy. The method comprises forming a metal oxide precursor and conducting cathodic polarization of the metal oxide precursor in a molten salt electrolyte to form a metal alloy. In an additional method, a metal oxide precursor is formed. The metal oxide precursor is reduced to a metal in an electrochemical cell that comprises a working electrode, a counter electrode, and an electrolyte. The metal is reacted with a metal of the working electrode to form a metal alloy. In another method, a metal oxide precursor is formed on a base material. The base material is introduced into a molten salt electrolyte of an electrochemical cell and the metal oxide precursor is reduced to a metal in the electrochemical cell. The metal is reacted with the base material to form a metal alloy on the base material.

A process of extracting copper from copper sulphide minerals which is enhanced at solution potentials exceeding 700 mV SHE, in the absence of any microorganism, by contacting the minerals in a pre-treatment phase using an acid solution at a high chloride content containing dissolved copper.

A process of extracting copper from copper sulphide minerals which is enhanced at solution potentials exceeding 700 mV SHE, in the absence of any microorganism, by contacting the minerals in a pre-treatment phase using an acid solution at a high chloride content containing dissolved copper.