The present invention relates to the desulfurisation of lead-containing waste. In particular, the present invention relates to a method in which lead-containing waste is desulfurised to form a desulfurised lead-containing waste material which is suitable for recycling into lead or leady oxide. The method is particularly suitable for desulfurising lead-acid battery paste.

The present invention relates to the desulfurisation of lead-containing waste. In particular, the present invention relates to a method in which lead-containing waste is desulfurised to form a desulfurised lead-containing waste material which is suitable for recycling into lead or leady oxide. The method is particularly suitable for desulfurising lead-acid battery paste.

The present invention provides a method for the treatment of sludge containing iron and between 4.5% to 12% by weight of zinc. This method includes a leaching step wherein leaching agents include hydrochloric acid and chlorate, and wherein the pH of the leachate directly resulting from this leaching step is set at a value below 1.5. A recycling method and treatment installation are also provided.

A method of midstream production of Ge and Ga from an REE extraction process is compatible with downstream industrial processes, and may produce Ge and Ga that is 90% pure as oxides, salts, or metals. A method for producing critical minerals includes vaporizing a feedstock comprising the critical minerals; cooling the vaporized feedstock to a condensation temperature of a critical mineral; and capturing the condensed critical mineral. Systems and methods disclosed herein for producing critical minerals are integrated into a rare earth extraction process to co-produce germanium and gallium concentrates.

The invention discloses a method for cracking slag and smelting soot of the waste circuit board, belongs to the field of comprehensive recycling of valuable elements from typical soot of waste circuit boards, and particularly relates to a method for cracking slag and smelting soot of the waste circuit board for debromination and comprehensive recovery of copper and zinc. The method includes the following steps of: crushing and sorting, mixture roasting, reinforced leaching, replacement and silver precipitation, sulfuration and copper precipitation, and evaporation crystallization. Compared to traditional recycling technology, the purpose of treating two kinds of solid waste in a coupling mode through one recycling technology is achieved. Through mixed sulfuric acid roasting, the requirement of bromide synergistic removal of the waste circuit board cracking slag and smelting soot is met, and the purpose of selective conversion of copper and zinc is achieved.

The invention relates to a method for extracting metal from metal-containing raw material in a batch process by using a direct current electric arc furnace (100) having one or more than one top electrode (125) and at least one bottom electrode (115), wherein the method comprises the following steps: adding the metal-containing raw material to the furnace (100), thereby obtaining a loaded bath, moving the top electrode(s) (125) onto the raw material, heating the loaded bath in a heating step by applying direct current through the top electrode(s) to provide an arc to melt the raw material, thereby obtaining molten metal (202), wherein an average voltage during the heating step is from 20 V to 110 V, and forming solid metal from the molten metal (202). The invention further relates to a direct current electric arc furnace, a system comprising a direct current electric arc furnace, and a solid metal obtainable by the method.

A production method includes: an alkali extraction step of adding an alkali and water, or an alkali solution, to raw material ash containing an ammonium sulfate component, sulfuric acid, vanadium, and at least one other metal selected from nickel, iron, and magnesium, wherein a pH of 13 or higher is achieved, to obtain an alkali leachate; a solid-liquid separation step on the alkali leachate to obtain a leach filtrate containing vanadium; an evaporation concentration step of evaporating and concentrating the leach filtrate to obtain a concentrated liquid; and a crystallization/solid-liquid separation step of cooling and crystalizing the concentrated liquid and recovering a precipitate containing a vanadium compound. Another production method includes an alkali extraction step, a solid-liquid separation step, an evaporation concentration step, an alkali concentration adjustment step of further adding an alkali or alkali solution to a concentrated liquid to obtain a concentration-adjusted liquid, and a crystallization/solid-liquid separation step.

A high-purity artificial zeolite is industrially mass produced by carrying out osmosis treatment of fly ash in an alkaline aqueous solution, subsequently carrying out the osmosis treatment again with an acidic aqueous solution of pH 1.0 or less obtained by adding acid to the osmotic aqueous solution of fly ash, then performing solid-liquid separation while water wash and dewatering in a centrifuge, thereby synthesizing a starting composition, and performing hydrothermal reaction treatment to this starting composition.

The invention discloses a method for co-processing cracking slag and smelting soot of the waste circuit board, belongs to the field of comprehensive recycling of valuable elements from typical soot of waste circuit boards, and particularly relates to a method for co-processing cracking slag and smelting soot of the waste circuit board for debromination and comprehensive recovery of copper and zinc. The method mainly comprises the following steps of: crushing and sorting, mixture roasting, reinforced leaching, replacement and silver precipitation, sulfuration and copper precipitation, and evaporation crystallization. Compared with a traditional recycling technology, the purpose that two kinds of solid waste are treated in a coupling mode through one recycling technology is achieved. Through mixed sulfuric acid roasting, the requirement of bromide synergistic removal of the waste circuit board cracking slag and smelting soot is met, and the purpose of selective conversion of copper and zinc is achieved.

A method for recovering metal zinc from a solid metallurgical waste containing zinc and manganese, may include: (a) bringing the solid metallurgical waste into contact with an aqueous leaching solution comprising chloride ions and ammonium ions to produce at least one leachate including zinc ions and manganese ions and at least one insoluble solid residue; (b) cementing the leachate, by adding metal zinc as a precipitating agent, to eliminate at least one metal other than zinc and manganese possibly present in the leachate as ions and producing a purified leachate; (c) subjecting the purified leachate to electrolysis in an electrolytic cell including at least one cathode and at least one anode immersed in the purified leachate to deposit metal zinc on the cathode and producing at least one exhausted leachate, and, before the electrolysis, precipitating manganese ions by oxidation with permanganate ions and subsequently separating a precipitate including MnO.sub.2.