A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

Methods of recovering rare earth elements, vanadium, cobalt, or lithium from coal are described. The coal is dissolved in a first solvent to dissolve organic material in the coal and create a slurry containing coal ash enriched with rare earth elements, vanadium, cobalt, or lithium. The enriched coal ash is separated from the first solvent. Residual organic material is removed from the coal ash. The rare earth elements, vanadium, cobalt, or lithium can then be recovered from the coal ash. The coal ash is mixed with an acid stream that dissolves the rare earth elements, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

A method of recovering cobalt and nickel includes the steps of: adding alkaline to an acidic solution containing aluminum together with cobalt and nickel, adjusting pH of the acidic solution to 5 to 7, and converting the cobalt, the nickel and the aluminum into hydroxides thereof; recovering the hydroxides by solid-liquid separation, mixing the recovered hydroxides with an alkaline solution, and leaching aluminum contained in the hydroxides under a liquid condition of pH 8 or more; and recovering a cobalt hydroxide and a nickel hydroxide that aluminum is separated therefrom by solid-separation on a leachate.

A method of making a zeolite comprises: adding a zeolite seed to a leach solution containing silicon and aluminum; and heating the leach solution to obtain the zeolite. The leach solution can be made by mixing coal ash with a basic stream, thereby creating (i) a leach solution containing silicon and aluminum, and (ii) leached ash; and separating the leach solution from the leached ash.

The presently disclosed subject matter is directed to a method of hydrothermally treating metallic packaging, metallic labeling material, and scrap metal items. Particularly, the disclosed method initially comprises providing a metallic starting material. The metallic starting material is introduced to a reactor and processed at elevated temperature and/or pressure for a desired amount of time. As a result, the metallic portion of the starting material separates into a distinct layer that can be removed from the remainder of the starting material.

Disclosed in the present invention is a method for recovering nickel from iron-aluminum slag obtained by battery powder leaching. The method comprises the following steps: adding a sulfuric acid solution into an iron-aluminum slag to dissolve, so as to obtain a sulfate solution; then adding an oxidizing agent; adding ammonia water and carbonate into the oxidized sulfate solution; adjusting the pH to 1.0-3.2 for reaction; separating ferric hydroxide to precipitate to obtain an iron-removed solution; adding carbonate into the iron-removed solution, adjusting the pH to 3.2-5.5 for reaction; separating aluminum hydroxide to precipitate to obtain an aluminum-removed solution; adding ammonia water to the aluminum-removed solution, adjusting the pH to 7.0-8.8 for reaction; washing and removing impurities to obtain a nickel complex; adding an oxidizing agent to the nickel complex to break the complex, so as to obtain a nickel-containing solution. By means of the present method, efficient separation of iron, aluminum and nickel in the iron-aluminum slag is efficiently achieved, the separation effect of iron, aluminum and nickel is improved, the loss of nickel is reduced, and the recovery rate of nickel is improved.

A valuable metal recovery method includes: recovering a battery slag from lithium ion battery waste; adding an acid to the battery slag; adding a sulfur compound the leachate; filtering the first processed product to obtain a first processed filtrate; adding a sulfur compound to the first processed filtrate; filtering the second processed product to obtain a second processed filtrate; adding calcium hydroxide to the second processed filtrate; filtering the third processed product to obtain a third processed filtrate; adding sodium carbonate to the third processed filtrate; filtering the processed product; heating the fourth processed filtrate; blowing carbon dioxide or adding a carbonate; and filtering the processed product, wherein a pH of the second processed product is higher than a pH of the first processed product, and a pH of the third processed product is higher than the pH of the second processed product.

Proposed is a method of selectively leaching lithium (Li) and aluminum (Al) from a mixed carbonate precipitate (MCP) and, more specifically, a method of selectively leaching Li and Al from an MCP, by which a high-purity MCP can be prepared through selective leaching of Li and Al contained in an MCP used as a raw material for recovering valuable metals including nickel (Ni), cobalt (Co), and manganese (Mn).

A method includes one or more of the following five steps: (1) rough processing, (2) comminuting the material, (4) washing the material with acid, and (5) collecting/sorting the material to recover an aluminum product or a very pure aluminum product. A system may execute one or more of these steps to recover an aluminum product or a very pure aluminum product

Disclosed is a method for efficiently removing fluorine from a spent lithium battery. The method comprises: mixing aluminum and a sodium hydroxide solution for reaction to obtain a sodium metaaluminate solution; introducing sulfuric acid into the sodium metaaluminate solution, and stirring to react at a certain temperature to obtain a fluorine removal agent; adding a sodium fluoroaluminate seed crystal and the fluorine removal agent into an impurity-removed battery powder leaching solution, introducing a sodium carbonate solution at the same time, performing reaction at a certain temperature, controlling the pH value of a reaction endpoint, and performing solid-liquid separation after the reaction is finished to obtain a fluorine-removed liquid and filter residues; and adding the sodium hydroxide solution into the filter residues for reaction, and performing solid-liquid separation to obtain a filtrate containing fluorine and aluminum, and insoluble residues. According to the present invention, fluorine removal is induced by adding the sodium fluoroaluminate seed crystal; and during fluorine removal, the seed crystal sodium fluoroaluminate is firstly added into the battery leaching solution, and by means of induction of the seed crystal, combination of fluorine and aluminum in the solution can be accelerated to generate sodium hexafluoroaluminate, the reaction time is shortened, the fluorine removal efficiency is improved, and fluorine in the solution can be removed to be lower than 20 mg/L, thereby achieving the purpose of deep fluorine removal.