Processes for making magnesium-containing layered double hydroxides from a magnesium phosphate-containing mineral are disclosed, as well as a magnesium-containing layered double hydroxides and their uses.

Described is a method for extracting lithium from salt lake brine and simultaneously preparing aluminum hydroxide. This method includes a. adding an aluminum salt to the brine, adding an alkali solution, then subjecting to crystallization reaction and solid-liquid separation to obtain lithium-containing brine; b. evaporating and concentrating the lithium-containing brine, adding an aluminum salt, adding an alkali solution dropwise to perform a co-precipitation reaction and solid-liquid separation to obtain a lithium-containing layered material filter cake, wherein in steps a and b, the alkali solution is an alkali solution free of carbonate ion; c. dispersing the lithium-containing layered material filter cake in deionized water to form a suspension slurry, then adjusting the pH value of the suspension slurry so as to carry out a lithium deintercalation reaction; d. filtering to obtain aluminum hydroxide filter cake; e. washing the aluminum hydroxide filter cake with deionized water and drying.

A preparation method of lithium hydroxide includes the following steps: A. coprecipitating a lithium extraction mother solution of salt lake brine with an aluminum salt solution and a sodium hydroxide solution, aging and then performing solid-liquid separation, washing and drying to obtain lithium aluminum hydrotalcite; B. acidifying the lithium aluminum hydrotalcite to obtain a lithium aluminate solution; C. performing nanofiltration on the lithium aluminate solution for lithium-aluminum separation, and sequentially performing primary concentration by reverse osmosis to obtain a primary concentrated lithium-rich solution; D. deeply removing aluminum from the lithium-rich solution to obtain an aluminum-removed lithium-rich solution; E. performing bipolar membrane electrodialysis on the aluminum-removed lithium-rich solution to obtain a secondary concentrated lithium-rich solution; F. evaporating the secondary concentrated lithium-rich solution for concentration to obtain lithium hydroxide.

A method for preparing an anion adsorbent may be provided, which comprises the steps of: mixing at least two metal salts with each other, thereby forming a stack structure in which cationic compound layers and anionic compound layers containing anions and water of crystallization are alternately stacked on one another; performing a first heat treatment on the stack structure to expand between the cationic compound layers, thereby preparing a preliminary anion adsorbent; and performing a second heat treatment on the preliminary anion adsorbent to remove the anions and the water of crystallization from the anionic compound layers while allowing at least one of the anions to remain, thereby preparing the anion adsorbent.

The present invention relates to a process for modifying a layered double hydroxide (LDH), the process comprising, a. providing a water-wet layered double hydroxide of formula:
[M.sup.z+.sub.1-xM′.sup.y+.sub.x].sup.a+(X.sup.n−).sub.a/r.bH.sub.2O   (1) wherein M and M′ are metal cations, z=1 or 2; y=3 or 4, x is 0.1 to 1, preferably x<1, more preferably x=0.1-0.9, b is greater than 0 to 10, X is an anion, r is 1 to 3, n is the charge on the anion X and a is determined by x, y and z, preferably a=z(1-x)+xy-2; b. maintaining the layered double hydroxide water-wet, and c. contacting the water-wet layered double hydroxide with at least one solvent, the solvent being miscible with water and preferably having a solvent polarity (P′) in the range 3.8 to 9,
as well as to a layered double hydroxide prepared according to that process.

The present invention aims to provide techniques for preparing complexes of a hydrotalcite and a fiber. The complexes of a hydrotalcite and a fiber can be synthesized efficiently by synthesizing the hydrotalcite in an aqueous system in the presence of the fiber.

The present disclosure relates to a method for extracting lithium from salt lake brine and simultaneously preparing aluminum hydroxide. This method includes: a. adding an aluminum salt to the brine to obtain a mixed salt solution A, adding an alkali solution to the mixed salt solution A for co-precipitation reaction, then subjecting to crystallization reaction and solid-liquid separation at the end of the reaction to obtain magnesium-aluminum hydrotalcite solid product and lithium-containing brine, wherein in step a, the alkali solution is an alkali solution free of carbonate ion; b. evaporating and concentrating the lithium-containing brine to obtain a lithium-rich brine, adding an aluminum salt to the lithium-rich brine to obtain a mixed salt solution B, adding an alkali solution dropwise to the mixed salt solution B to perform a co-precipitation reaction and solid-liquid separation after the end of the reaction to obtain a lithium-containing liquid and a lithium-containing layered material filter cake, wherein in step b, the alkali solution is an alkali solution free of carbonate ion; c. dispersing the lithium-containing layered material filter cake in deionized water to form a suspension slurry, then adjusting the pH value of the suspension slurry so as to carry out a lithium deintercalation reaction; d. filtering the slurry obtained after the lithium deintercalation reaction to obtain a lithium-containing solution and aluminum hydroxide filter cake; e. washing the aluminum hydroxide filter cake with deionized water and drying to obtain aluminum hydroxide solid.

With respect to a plate-shaped hydrotalcite in which the average width of primary particles is increased, (1) the aspect ratio of secondary particles is increased by suppressing aggregation of primary particles by relatively reducing the average thickness thereof, and 2) the formation of a by-product that impairs the transparency of a resin is suppressed. Provided is a plate-shaped hydrotalcite represented by a formula (1) below:
(M.sup.2+).sub.1−x(M.sup.3+).sub.x(OH).sub.2(A.sup.n−).sub.x/n.Math.mH.sub.2O  (1) where M.sup.2+ indicates at least one divalent metal, M.sup.3+ indicates at least one trivalent metal, A.sup.n− indicates an n-valent anion, n indicates an integer of 1 to 6, and x and m are within respective ranges of 0.1≤x≤0.33 and 0≤m≤10, the formula (1) satisfying (A) to (D) below: (A) the average width of primary particles as measured using an SEM method is 1 μm or greater; (B) the average thickness of primary particles as measured using an SEM method is 80 nm or less; (C) the degree of monodispersity of width is 50% or greater; and (D) the degree of monodispersity of thickness is 50% or greater.

Disclosed herein is a constant shear continuous reactor device, comprising: an annular gas delivery tube comprising a gas inlet and a gas outlet; a first annular liquid delivery tube comprising a first liquid inlet and a first liquid outlet arranged concentrically around the annular gas delivery tube along a common axis, where the first liquid outlet is located at a downstream position relative to the gas outlet or is coterminous with the gas outlet; and an annular reactor wall tube comprising a final liquid inlet, a mixing zone section and a reactor outlet, where the annular reactor wall tube is arranged concentrically around the first annular liquid delivery tube along the common axis.

To improve the thermal stability of a brominated polymer type flame retardant in a flame-retardant resin composition containing a styrene-based resin and the brominated polymer type flame retardant to provide a flame-retardant resin molded article in which occurrences of black foreign substances and discoloration decrease The flame-retardant resin composition contains a styrene-based resin, a brominated polymer type flame retardant, an epoxy compound, and a halogen capture agent, wherein a content of bromine is 18 to 42% by mass.