This invention relates to the regeneration of spent alkaline solutions, for example, alkaline electrolyte solutions used in metal/air batteries, specifically in aluminum/air batteries. The invention provides methods and systems to regenerate alkaline electrolyte solutions by adding water and optionally other solvents to spent electrolyte solutions, thus precipitating metal hydroxides from the spent electrolyte solution.

This invention relates to the regeneration of spent alkaline solutions, for example, alkaline electrolyte solutions used in metal/air batteries, specifically in aluminum/air batteries. The invention provides methods and systems to regenerate alkaline electrolyte solutions by adding water and optionally other solvents to spent electrolyte solutions, thus precipitating metal hydroxides from the spent electrolyte solution.

Disclosed is a method for manufacturing lithium hydroxide from a lithium-ion battery waste. The method includes heat-treating the cathode scraps as the lithium-ion battery waste under an NH.sub.3 gas atmosphere to convert lithium incorporated in the cathode scraps into lithium oxide (Li.sub.2O) or lithium hydroxide (LiOH). The lithium is then leached using water, followed by solid/liquid separation to remove solid residues. CaO is added to the filtered leached solution to precipitate impurities, which are removed before passing the solution through ion exchange resin. After evaporation, crystallization is achieved either by adding isopropyl alcohol or using an evaporative crystallizer, yielding high-purity LiOH.Math.H.sub.2O crystals. This process offers an efficient recycling method for lithium-ion batteries with high lithium recovery and purity.

Disclosed is a method for manufacturing lithium hydroxide from a lithium-ion battery waste. The method includes heat-treating the cathode scraps as the lithium-ion battery waste under an NH.sub.3 gas atmosphere to convert lithium incorporated in the cathode scraps into lithium oxide (Li.sub.2O) or lithium hydroxide (LiOH). The lithium is then leached using water, followed by solid/liquid separation to remove solid residues. CaO is added to the filtered leached solution to precipitate impurities, which are removed before passing the solution through ion exchange resin. After evaporation, crystallization is achieved either by adding isopropyl alcohol or using an evaporative crystallizer, yielding high-purity LiOH.Math.H.sub.2O crystals. This process offers an efficient recycling method for lithium-ion batteries with high lithium recovery and purity.

A movable device, e.g., a laboratory, for obtaining lithium salt from brine has a movable box, and a device for removing impurities from brine and a lithium precipitation device that are disposed in the movable box. The device for removing impurities from brine is connected to the lithium precipitation device. The device for removing impurities from brine comprises one or more of an adsorption-separation device, a membrane device, an electrodialysis device, a device for deeply removing impurities with resin, and an evaporation device. The laboratory is in a form of box modular assembly and may be placed on a truck and flexibly transported to a brine lake. In a case of a large-scale pilot test, an adsorption-membrane coupling technology to evaporation and lithium precipitation may be completely implemented, so that a simulation test of a whole lithium carbonate process may be carried out on site.

A movable device, e.g., a laboratory, for obtaining lithium salt from brine has a movable box, and a device for removing impurities from brine and a lithium precipitation device that are disposed in the movable box. The device for removing impurities from brine is connected to the lithium precipitation device. The device for removing impurities from brine comprises one or more of an adsorption-separation device, a membrane device, an electrodialysis device, a device for deeply removing impurities with resin, and an evaporation device. The laboratory is in a form of box modular assembly and may be placed on a truck and flexibly transported to a brine lake. In a case of a large-scale pilot test, an adsorption-membrane coupling technology to evaporation and lithium precipitation may be completely implemented, so that a simulation test of a whole lithium carbonate process may be carried out on site.

A process for recovering alkali from power boiler ash is provided. The power boiler ash is first contacted with Na.sub.2CO.sub.3 to produce a mixture containing settling and non-settling solid particles. A fraction of the settling particles is then separated from the mixture to produce a first clarified alkaline solution. The first clarified alkaline solution contains species such as NaOH and KOH depending upon the power boiler ash characteristics. The non-settling solid particles may optionally be further separated from the first clarified alkaline solution to obtain a second clarified alkaline solution. This process is also applicable for the extraction of alkali from other oxide/hydroxide containing materials.

A method for preparing battery grade and high purity grade lithium hydroxide and lithium carbonate from high-impurity lithium sources includes steps for preparation of a refined lithium salt solution, preparation of battery grade lithium hydroxide, preparation of high purity grade lithium hydroxide, preparation of high purity grade lithium carbonate and preparation of battery grade lithium carbonate. The system to carry out the preparation includes a refined lithium salt solution preparation subsystem, a battery grade lithium hydroxide preparation subsystem, a high purity grade lithium hydroxide preparation subsystem, a high purity grade lithium carbonate preparation subsystem and a battery grade lithium carbonate preparation subsystem arranged in turn according to production sequence. A combination of physical and chemical treatment methods are used to treat the high-impurity lithium sources having variations in lithium contents, impurity categories, and impurity contents.