The invention discloses a method and crystallization device for preparing electronic-grade nickel sulfate from nickel powder, and a control method of the crystallization device, and relates to the technical field of non-ferrous metal hydrometallurgy. The method comprises: oxidation, cooling, acid leaching, copper removal, acid adjustment, concentration, cooling crystallization, drying and screening, and secondary leaching: the oxidation comprises: controlling a temperature of nickel powder in a calcining furnace to be 400 C. to 700 C., allowing a use amount of compressed air for each kilogram of nickel powder to be 1 m.sup.3 to 5 m.sup.3, and making the reaction last for 1.0 hour to 2.5 hours; and the acid leaching comprises: placing cooled nickel oxide in a reactor, controlling a temperature to be 45 C. to 70 C., adding dilute sulfuric acid to control a pH value to be 0.5 to 1.5, and making the reaction last for 1 hour to 3 hours.

The invention discloses a method and crystallization device for preparing electronic-grade nickel sulfate from nickel powder, and a control method of the crystallization device, and relates to the technical field of non-ferrous metal hydrometallurgy. The method comprises: oxidation, cooling, acid leaching, copper removal, acid adjustment, concentration, cooling crystallization, drying and screening, and secondary leaching: the oxidation comprises: controlling a temperature of nickel powder in a calcining furnace to be 400 C. to 700 C., allowing a use amount of compressed air for each kilogram of nickel powder to be 1 m.sup.3 to 5 m.sup.3, and making the reaction last for 1.0 hour to 2.5 hours; and the acid leaching comprises: placing cooled nickel oxide in a reactor, controlling a temperature to be 45 C. to 70 C., adding dilute sulfuric acid to control a pH value to be 0.5 to 1.5, and making the reaction last for 1 hour to 3 hours.

The present invention provides a method for directly preparing nickel sulfate from low nickel matte, a nickel sulfate and an application thereof, the method comprising the following steps: a) pre-treating a low nickel matte to obtain ferronickel powder; b) mixing the ferronickel powder with a sulfuric acid solution, stirring, dissolving, and then evaporating, to obtain a supersaturated sulfate solution; c) cooling the supersaturated sulfate solution to 5 C.-0 C., and performing suction filtration to obtain an insoluble solid; d) washing the insoluble solid with water, and removing impurities from the filtrate to obtain a nickel hydroxide precipitate; impurity removal comprising successively removing iron, and removing calcium and magnesium; e) washing the nickel hydroxide precipitate with water, acid-dissolving and evaporating to obtain nickel sulfate. The present invention increases the amount of nickel recovered, the purity of nickel sulfate being 18.10%-19.24% nickel, and the recovery rate being 94.8%-97.1%.

The present invention provides a method for directly preparing nickel sulfate from low nickel matte, a nickel sulfate and an application thereof, the method comprising the following steps: a) pre-treating a low nickel matte to obtain ferronickel powder; b) mixing the ferronickel powder with a sulfuric acid solution, stirring, dissolving, and then evaporating, to obtain a supersaturated sulfate solution; c) cooling the supersaturated sulfate solution to 5 C.-0 C., and performing suction filtration to obtain an insoluble solid; d) washing the insoluble solid with water, and removing impurities from the filtrate to obtain a nickel hydroxide precipitate; impurity removal comprising successively removing iron, and removing calcium and magnesium; e) washing the nickel hydroxide precipitate with water, acid-dissolving and evaporating to obtain nickel sulfate. The present invention increases the amount of nickel recovered, the purity of nickel sulfate being 18.10%-19.24% nickel, and the recovery rate being 94.8%-97.1%.

Provided is a method for enabling recovery of metal element leaching capacity of a deep eutectic solvent used for leaching a metal element from an ore containing the metal element. A method for recycling a hydrophobic deep eutectic solvent disclosed here includes: preparing a hydrophobic deep eutectic solvent used for leaching a metal element from an ore containing the metal element; and bringing the hydrophobic deep eutectic solvent and hydrochloric acid into contact with each other. In the hydrophobic deep eutectic solvent, a hydrogen bond donor is a carboxy group-containing compound, and a hydrogen bond acceptor is chloride salt. The amount of use of the hydrochloric acid is such that hydrogen chloride is 1 mole or more with respect to 1 mole of the hydrogen bond acceptor.

Provided is a method for enabling recovery of metal element leaching capacity of a deep eutectic solvent used for leaching a metal element from an ore containing the metal element. A method for recycling a hydrophobic deep eutectic solvent disclosed here includes: preparing a hydrophobic deep eutectic solvent used for leaching a metal element from an ore containing the metal element; and bringing the hydrophobic deep eutectic solvent and hydrochloric acid into contact with each other. In the hydrophobic deep eutectic solvent, a hydrogen bond donor is a carboxy group-containing compound, and a hydrogen bond acceptor is chloride salt. The amount of use of the hydrochloric acid is such that hydrogen chloride is 1 mole or more with respect to 1 mole of the hydrogen bond acceptor.

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.

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.

The present disclosure relates to a hydrometallurgical recovery method for nickel sulfate. More specifically, the present disclosure relates to a hydrometallurgical nickel sulfate recovery method in which a wet smelting process is used to extract a high-purity nickel sulfate aqueous solution from a raw material containing nickel (Ni), cobalt (Co), and manganese (Mn). In the method, sodium hydroxide or sodium carbonate is not used as a neutralizer but nickel hydroxide is used, which prevents salts of impurities from being generated as a precipitate in a solvent extraction process, thereby increasing process efficiency of the solvent extraction process.

Disclosed is a method for producing battery-grade nickel sulfate by using laterite nickel ore comprising the following steps: sorting the laterite nickel ore to obtain lump ore and sediment ore; crushing the lump ore, and then performing heap leaching, to obtain a crude nickel sulfate solution A; separating the sediment ore to obtain high chromium ore, low iron, high magnesium ore, and high iron, low magnesium ore, and drying, roasting, reducing, and sulfurating the low iron, high magnesium ore to obtain low nickel matte; blowing and performing water extraction on the low nickel matte, and then performing oxygen pressure leaching, to obtain a crude nickel sulfate solution B; performing pressure leaching on the high iron, low magnesium ore to obtain a crude nickel sulfate solution C; and performing extraction on the crude nickel sulfate solutions A, B, and C, and then evaporating and crystallizing, to obtain battery-grade nickel sulfate.