The present invention discloses a method for preparing iron ore concentrates by recycling copper smelting slag tailings, and belongs to the technical field of metallurgy and tailings recycling. In the present invention, copper slag tailings obtained after copper pyrometallurgy and flotation and water are used as raw materials, and low-concentration sulfur dioxide flue gas is used as a leaching agent for leaching of metals such as iron, zinc, copper, arsenic, and silicon in the slag tailings; the leachate is purified step by step through processes such as replacement by metal iron powder and sulfide precipitation control, to separate zinc, copper, arsenic, etc.; a purified solution is mainly composed of FeSO.sub.4 or can be used for producing a ferric salt flocculant; obtained tailings are used to obtain iron ore concentrates through magnetic separation, and the obtained iron ore concentrates can be used for further producing ultra-pure iron ore concentrates.

The present invention discloses a method for preparing iron ore concentrates by recycling copper smelting slag tailings, and belongs to the technical field of metallurgy and tailings recycling. In the present invention, copper slag tailings obtained after copper pyrometallurgy and flotation and water are used as raw materials, and low-concentration sulfur dioxide flue gas is used as a leaching agent for leaching of metals such as iron, zinc, copper, arsenic, and silicon in the slag tailings; the leachate is purified step by step through processes such as replacement by metal iron powder and sulfide precipitation control, to separate zinc, copper, arsenic, etc.; a purified solution is mainly composed of FeSO.sub.4 or can be used for producing a ferric salt flocculant; obtained tailings are used to obtain iron ore concentrates through magnetic separation, and the obtained iron ore concentrates can be used for further producing ultra-pure iron ore concentrates.

Pyrometallurgic process for obtaining lithium compounds and intermediates, the process being characterized by comprising the steps of a) contacting lithium aluminosilicate particles with at least a fluorine solid compound, b) heating until a temperature of 25 to 900 C. obtaining a solid mixture and c) carrying out at least a leaching process of the mixture in step b).

Recovery of rare earth elements (REEs) from electronic wastes is a promising approach. The existing methods for separation of REE from the secondary sources are not economically viable and scalable. A method and system for separation of rare earth metals from a plurality of secondary sources has been provided. The magnet is obtained from the secondary sources which is then crushed to a coarser size. The powder is then demagnetized by heating and roasted at high temperature to obtain the metal oxides. The metals oxides are then dissolved by acid leaching to obtain leach liquor. Iron is removed from leach liquor by precipitation and separated by filtration. The individual REE is then separated by liquid-liquid extraction. The conditions in liquid-liquid extraction are adjusted such that only desired REE is separated. The extracted REE is then stripped out by acid. The individual rare earth element is then precipitated and dried.

Recovery of rare earth elements (REEs) from electronic wastes is a promising approach. The existing methods for separation of REE from the secondary sources are not economically viable and scalable. A method and system for separation of rare earth metals from a plurality of secondary sources has been provided. The magnet is obtained from the secondary sources which is then crushed to a coarser size. The powder is then demagnetized by heating and roasted at high temperature to obtain the metal oxides. The metals oxides are then dissolved by acid leaching to obtain leach liquor. Iron is removed from leach liquor by precipitation and separated by filtration. The individual REE is then separated by liquid-liquid extraction. The conditions in liquid-liquid extraction are adjusted such that only desired REE is separated. The extracted REE is then stripped out by acid. The individual rare earth element is then precipitated and dried.

A method for recovering valuable elements from pre-combustion coal-based materials includes the steps of grinding the materials to a predetermined size, roasting the ground materials at a temperature of 600 C.-700 C. for a predetermined residence time needed for mineral decomposition, submerging the roasted, ground materials in a solution of lixiviant, filtering the lixiviant solution to separate residual solids from a pregnant leach solution including the valuable elements and recovering and concentrating the valuable elements from the pregnant leach solution.

A method for recovering valuable elements from pre-combustion coal-based materials includes the steps of grinding the materials to a predetermined size, roasting the ground materials at a temperature of 600 C.-700 C. for a predetermined residence time needed for mineral decomposition, submerging the roasted, ground materials in a solution of lixiviant, filtering the lixiviant solution to separate residual solids from a pregnant leach solution including the valuable elements and recovering and concentrating the valuable elements from the pregnant leach solution.

The embodiments disclosed herein relates to a method for producing a secondary battery material from black mass. The method for producing a secondary battery material from black mass according to one embodiment includes a roasting step of roasting black mass, a pre-extraction step of leaching a roasted black mass roasted in the roasting step with water to separate a lithium solution and a cake, a first evaporation concentration step of producing lithium carbonate crystals by evaporating and concentrating the lithium solution produced in the pre-extraction step, a leaching step of leaching the cake separated in the pre-extraction step, a first purification step of removing copper and aluminum from the leaching solution produced in the leaching step, a post-extraction step of neutralizing the solution prepared in the first purification step and separating the solution into a lithium solution and a cake containing Ni, Co, and Mn (NCM cake), a feeding step of feeding the lithium carbonate crystals produced in the first evaporation concentration step and the lithium solution prepared in the post-extraction step to a lithium hydroxide production step.

The embodiments disclosed herein relates to a method for producing a secondary battery material from black mass. The method for producing a secondary battery material from black mass according to one embodiment includes a roasting step of roasting black mass, a pre-extraction step of leaching a roasted black mass roasted in the roasting step with water to separate a lithium solution and a cake, a first evaporation concentration step of producing lithium carbonate crystals by evaporating and concentrating the lithium solution produced in the pre-extraction step, a leaching step of leaching the cake separated in the pre-extraction step, a first purification step of removing copper and aluminum from the leaching solution produced in the leaching step, a post-extraction step of neutralizing the solution prepared in the first purification step and separating the solution into a lithium solution and a cake containing Ni, Co, and Mn (NCM cake), a feeding step of feeding the lithium carbonate crystals produced in the first evaporation concentration step and the lithium solution prepared in the post-extraction step to a lithium hydroxide production step.

A method for dissolving a lithium compound according to the present invention includes bringing a lithium compound into contact with water or an acidic solution, and feeding, separately from the lithium compound, a carbonate ion to the water or the acidic solution to produce carbonic acid, and allowing the carbonic acid to react with the lithium compound to produce lithium hydrogen carbonate.