The present invention discloses a preparation process of food-grade potassium dihydrogen phosphate, wherein phosphoric acid prepared from wet-process phosphoric acid is used for the preparation of high-purity potassium dihydrogen phosphate. The preparation process of food-grade potassium dihydrogen phosphate provided in the present invention effectively reduces the preparation cost of the high-purity potassium dihydrogen phosphate and has the advantage of high process controllability, and by such a process, high-purity potassium dihydrogen phosphate crystals that meet the food-grade requirements can be produced, which crystals have uniform particle size distribution and comprises few fine powder, having a very high market value.

Provided is a method of producing a composite active material that makes it possible to suppress aggregation of an active material in a process of coating with Li.sub.3PO.sub.4 to improve a discharge capacity. The method causes a neutralization reaction of a basic Li source and an acidic PO.sub.4 source on a surface of a particulate active material, to coat at least part of the surface of the active material with Li.sub.3PO.sub.4.

Process for the production of a compound comprising potassium phosphite comprising the steps of (a) reacting carboxylic acid of the formula R—(C(═O)OH).sub.n with phosphorous trichloride (PCl.sub.3) towards a mixture comprising phosphorous acid (H.sub.3PO.sub.3) and acid chloride of the formula R—(C(═O)Cl).sub.n; wherein R is a linear or branched alkyl or alkanediyl group with 1-20 carbon atoms and n is 1 or 2, (b) subjecting said mixture to a separation step, thereby obtaining (i) a fraction comprising crude phosphorous acid (H.sub.3PO.sub.3) and (ii) a fraction comprising acid chloride, (c) combining water, a potassium compound selected from KOH, KHCO.sub.3 and K.sub.2CO.sub.3, and the fraction comprising crude phosphorous acid, thereby forming an aqueous solution comprising potassium phosphite, and (d) removing organic compounds from said aqueous solution.

A method of making a proppant-gel matrix comprising: a) hydrating a gelling agent to form a hydrated gelling agent; b) adding a basic compound to the hydrated gelling agent to form a basic hydrated gelling agent having a pH in the range of 11.5 to 14.0; c) mixing the basic hydrated gelling agent and a proppant to form a basic hydrated gelling system; and d) adding a crosslinking agent to the basic hydrated gelling system to form the proppant-gel matrix, is disclosed. The proppant-gel matrix can then be used as a fracturing fluid in a hydraulic fracturing process.

The technology concerns methods for stabilizing slurries and/or electrophoretic deposition (EPD) bath suspensions for the preparation of electrodes and/or separation area or any other coating and specifically, to electrodes and separators for use in energy storage devices.

The technology concerns methods for stabilizing slurries and/or electrophoretic deposition (EPD) bath suspensions for the preparation of electrodes and/or separation area or any other coating and specifically, to electrodes and separators for use in energy storage devices.

An improved method of lithium recovery from borax dilute solution is provided. In this method, boron in the borax dilute solution is removed from the medium as borax decahydrate and while this removal process is carried out, liquid-liquid extraction with organic sedimentary chemicals or ion exchange resins are not used.

A method of treating mercury-contaminated material to obtain a treated product having reduced mercury leachability includes the steps of (a) admixing the mercury-contaminated material with a reagent system comprising calcium sulfide (CaS) and trisodium phosphate (TNaP), wherein the calcium sulfide and trisodium phosphate are preferably provided at a CaS:TNaP ratio of from 2:1 to 1:2, on a dry weight reagent basis, and the reagent system is preferably provided in an amount equal to 0.4% to 5% by weight of the contaminated material; and (b) adding water as needed to achieve a moisture content of at least 5% by weight of the contaminated material.

The present invention relates to compounds and their nonlinear optical (NLO) crystals of A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs), their producing method and uses thereof. A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) belong to triclinic crystal system, and have a space group of P1, crystal cell parameters of a=6.284(8)-8.784(3) , b=6.338(3)-8.838(3) , c=6.463(3)-8.963(3) , =70-105, =75-106, =76-107 and Z=1 and a unit cell volume of V=257.4(3)-696.0(6) .sup.3. A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) compounds were prepared by a high-temperature solid-state reaction method or a hydrothermal method, and A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) NLO crystals were prepared by a high-temperature solid-state reaction method, a hydrothermal method or a solution method. These materials can be used to manufacture second harmonic generator, up-down frequency converter, optical parametric oscillator, etc.

Provided is a cathode active material including a core including a compound represented by Formula 1; and a coating layer including a phosphorus-containing compound disposed on a surface of the core:

Li.sub.aZr.sub.W.sub.M.sub.1O.sub.2bS.sub.bFormula 1

In Formula 1, M, Zr, W, a, , , and b are the same as defined in relation to the present specification.