A method for controlling the concentration of impurities in Bayer liquors, the method comprising the steps of adding an oxide and/or a hydroxide of a metal other than aluminium to a Bayer liquor with a desired TA; forming a layered double hydroxide; and incorporating at least one impurity in said layered double hydroxide, wherein the impurities are selected from the group comprising phosphorus, vanadium and silicon.

A method for controlling the concentration of impurities in Bayer liquors, the method comprising the steps of adding an oxide and/or a hydroxide of a metal other than aluminium to a Bayer liquor with a desired TA forming a layered double hydroxide; and incorporating at least one impurity in the layered double hydroxide, wherein the impurities are selected from the group comprising chloride, fluoride, sulfate and TOC.

The invention relates to a method for exchanging interlayer anions of a layered double hydroxide (LDH) with other anions whose affinity for the LDH is lower than the one of the starting interlayer anions, which comprises the successive steps of: (1) exchanging the starting interlayer anions of a layered double hydroxide with polyoxometalate anions in order to obtain a layered double hydroxide with polyoxometalate anions as interlayer anions, and (2) exchanging the polyoxometalate anions of the layered double hydroxide obtained in step (1) with other anions whose affinity for the LDH is lower than the one of the starting interlayer anions in order to obtain a layered double hydroxide with other anions as interlayer anions.

The present invention relates to a method for preparing a CaMgAl mixed oxide comprising the steps: a) providing a modified layered double hydroxide of the formula (I) wherein in formula (I) 0<x<0.9; b is from 0 to 10, preferably 1 to 10; c is from 0 to 10, preferably 1 to 10 and the AMO-solvent is an organic solvent miscible with water; b) calcining the modified layered double hydroxide; c) reacting the calcined modified layered double hydroxide with a calcium salt in the presence of an (a) organic acid; and d) calcining the product obtained in step c) to obtain the CaMgAl mixed oxide; a CaMgAl mixed oxide obtainable this way; and the use thereof.

A method for producing hydrotalcite particles includes dissolving aluminum hydroxide in an alkaline solution to prepare an aluminate solution, causing a reaction of the aluminate solution prepared in the first step with carbon dioxide to precipitate a low-crystallinity aluminum compound, causing a first-order reaction by mixing the low-crystallinity aluminum compound with a magnesium compound to prepare a reactant containing hydrotalcite nuclear particles, and causing a hydrothermal reaction of the reactant to synthesize hydrotalcite particles. The hydrotalcite particles can impart excellent heat resistance, transparency, flowability, and are useful as a resin stabilizer.

Porous particles comprising an active ingredient and a coating exhibiting greater dissolution rate in aqueous media than in alcoholic media are disclosed. A process for the manufacture of the particles is also disclosed, as well as tamper-proof particles and solid dosage forms comprising the coated particles. The differential solubility characteristics of the particle coating allow the particles to be incorporated into abuse-deterrent medicaments.

The present disclosure relates to a method for producing lanthanide doped layered double hydroxides (Ln-doped LDHs). The method includes the steps of preparing a carbonate free alkaline solution; preparing a solution of metal salts comprising a salt of a lanthanide; co-precipitating the alkaline solution and the solution of metal salts to form a mixture and Ln-doped LDH precipitate wherein the pH of the mixture is maintained at a constant value; aging the precipitate; and separating the precipitate from the solution. The alkaline solution is an aqueous ammonia solution. The present disclosure is also related to lanthanide-doped layered double hydroxides (La-doped LDHs) obtainable by such a method, as well as to the use of the lanthanide-doped layered double hydroxides obtainable by such a method.

A method of making silica-layered double hydroxide microspheres having the formula I: (i) wherein, M.sup.z+ and M.sup.y+ are two different charged metal cations; z=1 or 2; y=3 or 4; 0<x<0.9; b is 0 to 10; c is 0 to 10; P>0, q>0, X.sup.n is an anion; with n>0 a=z(1x)+xy2; and the AMO-solvent is an 100% aqueous miscible organic solvent; comprises the steps: (a) contacting silica microspheres and a metal ion containing solution containing metal ions M.sup.z+ and M.sup.y+ in the presence of a base and an anion solution; (b) collecting the product; and (c) optionally treating the product with AMO-solvent and recovering the solvent treated material to obtain the silica-layered double hydroxide microspheres. Preferably, M in the formula I is Li, Mg, Ni or Ca. Preferably, M in formula I is Al. The invention further provides silica-layered double hydroxide microspheres having the formula I. The silica-layered double hydroxide microspheres may be used as catalysts and/or catalyst supports.
(SiO.sub.2).sub.p@{[M.sup.z+.sub.(1-x)M.sup.y+.sub.x(OH).sub.2].sup.a+(X.sup.n).sub.a/n.bH.sub.2O.c(AMO-solvent)}.sub.q(I)

This invention is directed to regeneration of solutions comprising metal ions, and production of valuable hydroxide compounds. Specifically, the invention is related to regeneration of spent electrolyte solutions comprising metal ions (e.g. Al ions), such as electrolyte solutions used in metal/air batteries. The invention is further related to production of layered double hydroxides, and, optionally aluminum tri-hydroxide from aluminate.

A scale inhibition fluid for use in a wellbore comprises a layered double hydroxide (LDH) having a scale inhibitor (SI) intercalated between positively-charged layers thereof. Also disclosed is a scale treatment fluid comprising such an LDH and SI and methods of making and using same. The material can be formed prior to use in a wellbore, formed during a treatment, formed within the wellbore, or the LDH can be recharged within a wellbore by injecting a SI after the material has been in place within the wellbore, or any combination thereof.