A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of: leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w; separating the first leach liquor and the undissolved first leach solids; leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second each solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof; separating the second leach liquor and the undissolved second leach solids; and thereafter separating the titanium dioxide and the iron content from the second leach liquor by precipitation, and regenerating the second lixiviant for recycle to the second leaching step.

A process for recovering titanium dioxide from a titanium-bearing material, the process including the steps of: leaching the titanium-bearing material in a first leaching step at atmospheric pressure and at a temperature of 70 to 97° C. with a first lixiviant to produce a first leach solution comprising undissolved first leach solids that include a titanium content and a first leach liquor, the first lixiviant comprising hydrochloric acid at a concentration of less than 23% w/w; separating the first leach liquor and the undissolved first leach solids; leaching the first leach solids in a second leaching step at atmospheric pressure and at a temperature of 60 to 80° C. with a second lixiviant in the presence of a Fe powder reductant to produce a second leach solution comprising undissolved second each solids and a second leach liquor that includes a leached titanium content and iron content, the second lixiviant comprising a mixed chloride solution comprising less than 23% w/w hydrochloric acid and an additional chloride selected from alkali metal chlorides, magnesium chloride and calcium chloride, or mixtures thereof; separating the second leach liquor and the undissolved second leach solids; and thereafter separating the titanium dioxide and the iron content from the second leach liquor by precipitation, and regenerating the second lixiviant for recycle to the second leaching step.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

A system for producing a magnesium chloride aqueous solution includes a crystallization unit configured to generate reaction slurry in which particles of magnesium hydroxide are dispersed by adding a sodium hydroxide aqueous solution to water to be treated, a precipitation unit configured to store reaction slurry, precipitate particles and separate the reaction slurry into recovered slurry and a separated liquid, a removal unit configured to remove divalent cations from the water to be treated or the separated liquid to generate a reaction liquid, an acid-alkali generation unit configured to generate a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid, and a reaction unit configured to generate a magnesium chloride aqueous solution by adding hydrochloric acid to the recovered slurry. The acid-alkali generation unit has a main body section configured to generate a sodium hydroxide aqueous solution and hydrochloric acid from the reaction liquid.

A process for the chemical conversion of contaminated magnesium hydroxide to high purity solutions of magnesium bicarbonate include steps of providing an impure reagent including at least 40% and less than 95% by total weight of total metals of magnesium in a form of solid magnesium hydroxide and at least 10% by weight of total metals of calcium carbonate, combining the impure reagent containing the solid magnesium hydroxide with carbonic acid in water, thereby generating magnesium bicarbonate and water and then filtering out solid calcium carbonate leaving a solution of magnesium bicarbonate in water having a by weight ratio of Mg/(Mg+Ca) in the solution of greater than 95%. Heating and/or drying the magnesium bicarbonate solution produces correspondingly high purity magnesium carbonate.

A process for the chemical conversion of contaminated magnesium hydroxide to high purity solutions of magnesium bicarbonate include steps of providing an impure reagent including at least 40% and less than 95% by total weight of total metals of magnesium in a form of solid magnesium hydroxide and at least 10% by weight of total metals of calcium carbonate, combining the impure reagent containing the solid magnesium hydroxide with carbonic acid in water, thereby generating magnesium bicarbonate and water and then filtering out solid calcium carbonate leaving a solution of magnesium bicarbonate in water having a by weight ratio of Mg/(Mg+Ca) in the solution of greater than 95%. Heating and/or drying the magnesium bicarbonate solution produces correspondingly high purity magnesium carbonate.

One object of the present disclosure is to provide a production method of magnesium hydride that is free of carbon dioxide and has high production efficiency, a power generation system that does not emit carbon dioxide or radiation using magnesium hydride, and an apparatus for producing magnesium hydride; therefore, the method for producing magnesium hydride of the present disclosure comprises a procedure for irradiating a magnesium compound different from magnesium hydride with hydrogen plasma, and a procedure for depositing a magnesium product containing magnesium hydride on a depositor for depositing magnesium hydride disposed within the range in which hydrogen plasma is present, wherein the surface temperature of the depositor is kept no more than a predetermined temperature at which magnesium hydride precipitates.

One object of the present disclosure is to provide a production method of magnesium hydride that is free of carbon dioxide and has high production efficiency, a power generation system that does not emit carbon dioxide or radiation using magnesium hydride, and an apparatus for producing magnesium hydride; therefore, the method for producing magnesium hydride of the present disclosure comprises a procedure for irradiating a magnesium compound different from magnesium hydride with hydrogen plasma, and a procedure for depositing a magnesium product containing magnesium hydride on a depositor for depositing magnesium hydride disposed within the range in which hydrogen plasma is present, wherein the surface temperature of the depositor is kept no more than a predetermined temperature at which magnesium hydride precipitates.

The present description relates to a process for producing magnesium metal from dihydrate magnesium chloride comprising the steps of dehydrating MgCI.sub.2.2H.sub.2O with anhydrous hydrochloric acid (HCI) to obtain anhydrous magnesium chloride in an inert environment, releasing the mixture of hydrous HCI and protection gas; and electrolyzing the anhydrous magnesium chloride in an electrolytic cell fed with hydrogen gas under free oxygen atmosphere content, wherein magnesium metal and anhydrous hydrogen chloride are produced, wherein a part of the hydrous HCI is passed through a scrubbing unit to obtain a hydrochloric acid solution, the other part of the hydrochloric chloride gas is dehydrated by contact with a desiccant agent in a drying unit to produce anhydrous HCI, and wherein the anhydrous HCI produced by at least one of the electrolytic cell and the drying unit is reused to dehydrate the of MgCI.sub.2.2H.sub.2O.