The present invention relates to a process A process for modifying a layered double hydroxide (LDH), the process comprising, a. providing a material comprising a layered double hydroxide of formula: [M.sup.z+.sub.1-xM.sup.y+.sub.x(OH).sub.2].sup.q+(X.sup.n).sub.q/n.bH.sub.2O wherein M and M are metal cations, z is 1 or 2, x is 0.1 to 1, b is 0 to 5, y is 3 or 4, X is an anion, n is 1 to 3 and q is determined by x, y and z, b. optionally washing the material at least once with a mixture of water and a mixing solvent miscible with water, and c. washing the material obtained in step a or b at least once with at least one first solvent, the first solvent being miscible with water and having a solvent polarity P

Systems and methods for separating Y and Sr are provided. The systems and methods provide combinations of solutions, vessels, and/or media that can provide Y solutions of industrially beneficial concentration.

A method for removing calcium in a lithium battery recycling process includes recovering acidic lithium liquid including calcium; adding an oxalate aqueous solution to the acidic lithium liquid as a first calcium removal process; raising the pH of the acidic lithium liquid to prepare an alkaline lithium liquid; and adding ammonium oxalate to the alkaline lithium liquid as a second calcium removal process.

The present disclosure provides a fluoride ion conductor having a perovskite structure with high ionic conductivity, a negative electrode mixture comprising the fluoride ion conductor, and a fluoride ion battery comprising the negative electrode mixture. The fluoride ion conductor of the disclosure has a perovskite structure, and is represented by the following formula (1): Ba.sub.1-x-ySr.sub.xA.sub.yLiF.sub.3-y: (1) wherein; A is an alkali metal element selected from among Na, K, Rb and Cs, 0.3<3 1xy<1.0, 0x<0.4, and 0<y<0.6. The negative electrode mixture of the disclosure comprises a fluoride ion conductor of the disclosure. The fluoride ion battery 1 of the disclosure has a negative electrode active material layer 20, the negative electrode active material layer comprising a negative electrode mixture of the disclosure.

The present disclosure provides a fluoride ion conductor having a perovskite structure with high ionic conductivity, a negative electrode mixture comprising the fluoride ion conductor, and a fluoride ion battery comprising the negative electrode mixture. The fluoride ion conductor of the disclosure has a perovskite structure, and is represented by the following formula (1): Ba.sub.1-x-ySr.sub.xA.sub.yLiF.sub.3-y: (1) wherein; A is an alkali metal element selected from among Na, K, Rb and Cs, 0.3<3 1xy<1.0, 0x<0.4, and 0<y<0.6. The negative electrode mixture of the disclosure comprises a fluoride ion conductor of the disclosure. The fluoride ion battery 1 of the disclosure has a negative electrode active material layer 20, the negative electrode active material layer comprising a negative electrode mixture of the disclosure.

An artificial tanzanite comprises aluminosilicate and vanadium, wherein the content of the aluminosilicate is in a range from 1 mass % to 30 mass % and the content of the vanadium is in a range from 1000 ppm to 40000 ppm. The artificial tanzanite is prepared by a method comprising: providing a synthetic raw material, wherein the synthetic raw material comprises the aluminosilicate, silicon-containing oxide, vanadium-containing oxide, and calcium-containing salt; and heating the synthetic raw material to a synthetic temperature, and keeping the synthetic raw material under a synthetic pressure to carry out synthetic reaction to form the artificial tanzanite after a period of synthetic time.

An artificial tanzanite comprises aluminosilicate and vanadium, wherein the content of the aluminosilicate is in a range from 1 mass % to 30 mass % and the content of the vanadium is in a range from 1000 ppm to 40000 ppm. The artificial tanzanite is prepared by a method comprising: providing a synthetic raw material, wherein the synthetic raw material comprises the aluminosilicate, silicon-containing oxide, vanadium-containing oxide, and calcium-containing salt; and heating the synthetic raw material to a synthetic temperature, and keeping the synthetic raw material under a synthetic pressure to carry out synthetic reaction to form the artificial tanzanite after a period of synthetic time.

Divalent ions are extracted from solids by leaching to form a divalent ion-containing solution. The divalent ion-containing solution is subjected to concentration to form a concentrated divalent ion-containing solution. Precipitation of a divalent ion hydroxide salt is induced from the concentrated divalent ion-containing solution. In other cases, the concentrated divalent ion-containing solution is exposed to carbon dioxide to induce precipitation of a divalent ion carbonate salt.

Provided are a method for removing aluminum which can effectively remove aluminum, and a method for recovering metals. A method for removing aluminum includes: a leaching step of bringing a raw material, the raw material having battery powder, the battery powder being obtained from lithium ion battery waste and comprising at least aluminum and nickel and/or cobalt, into contact with an acidic leaching solution to leach the battery powder to obtain a leached solution containing at least aluminum ions and nickel ions and/or cobalt ions; and a neutralization step of using the leached solution as a metal-containing solution, increasing a pH of the metal-containing solution and separating a neutralized residue to obtain a neutralized solution, wherein a molar ratio of fluorine to aluminum (F/Al molar ratio) of the raw material is 1.3 or more, and wherein, in the neutralization step, the metal-containing solution contains calcium and fluorine, a molar ratio of calcium to aluminum ions (Ca/Al molar ratio) in the metal-containing solution is 0.2 or more, the aluminum ions in the metal-containing solution are precipitated and contained in the neutralized residue together with calcium and fluorine.

Provided are a method for removing aluminum which can effectively remove aluminum, and a method for recovering metals. A method for removing aluminum includes: a leaching step of bringing a raw material, the raw material having battery powder, the battery powder being obtained from lithium ion battery waste and comprising at least aluminum and nickel and/or cobalt, into contact with an acidic leaching solution to leach the battery powder to obtain a leached solution containing at least aluminum ions and nickel ions and/or cobalt ions; and a neutralization step of using the leached solution as a metal-containing solution, increasing a pH of the metal-containing solution and separating a neutralized residue to obtain a neutralized solution, wherein a molar ratio of fluorine to aluminum (F/Al molar ratio) of the raw material is 1.3 or more, and wherein, in the neutralization step, the metal-containing solution contains calcium and fluorine, a molar ratio of calcium to aluminum ions (Ca/Al molar ratio) in the metal-containing solution is 0.2 or more, the aluminum ions in the metal-containing solution are precipitated and contained in the neutralized residue together with calcium and fluorine.