An arrangement for production of fully soluble, pure and well-defined mono- or di-potassium phosphates, comprises an extraction section, a stripping section and end treatment arrangements. The extraction section performs a liquid-liquid extraction of phosphate between a feed liquid comprising phosphoric acid. The stripping section performs a liquid-liquid extraction of phosphate between solvent loaded with phosphate and a strip solution. The solvent depleted in phosphate is recirculated to the extraction section for further extraction of phosphate. The strip solution is an aqueous potassium phosphate solution. The end treatment arrangements comprise a source of potassium base, an adding arrangement, a cooling arrangement, a precipitate remover and a recirculation system.

A method of producing lithium phosphate from a lithium source includes the step of (a) concentrating the lithium to produce a lithium concentrate, with an ion exchange sorbent, and (b) reacting the lithium concentrate with phosphate anions to produce lithium phosphate. The lithium phosphate may then be converted to lithium hydroxide or lithium 5 carbonate by reaction with calcium hydroxide or by electrolysis.

The present application relates to a positive electrode material for a sodium-ion battery and a preparation method thereof, and a sodium-ion battery, a battery module, a battery pack and an apparatus manufactured from the active material, the positive electrode material for the sodium-ion battery comprises a composite of sodium halophosphate with carbon having the following molecular formula: Na.sub.2M1.sub.hM2.sub.k(PO.sub.4)X/C, in which M1 and M2 are transition metal ions each independently selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Sr, Y, Nb, Mo, Sn, Ba and W; h is from 0 to 1, k is from 0 to 1, and h+k=1; X is halogen ion selected from F, Cl and Br, wherein the positive electrode material has a powder resistivity in the range of from 10 Ω.Math.cm to 5,000 Ω.Math.cm under a pressure of 12 MPa.

The present invention discloses a preparation method for water-soluble potassium polymetaphosphate, and relates to the technical field of potassium polymetaphosphate production and preparation. In the present invention, potassium dihydrogen phosphate is mixed with a divalent cationic metal oxide at a mixing mass ratio of 70-90:5-18 to obtained a mixture, wherein the divalent cationic metal oxide is one or more of calcia, magnesia and zinc oxide in the field of food processing; then the mixture is heated and melted, and the temperature is kept constant for 1-3 h at a temperature of 600-700° C.; and after temperature keeping, the melted mixture is cooled naturally to obtain a product. The water-soluble potassium polymetaphosphate prepared by the present invention has a high water solubility and effectively solves the application defect of a traditional potassium polymetaphosphate product which is insoluble in water.

A process of preparing a lithium metal phosphate includes contacting a water-soluble metal precursor, a water-insoluble metal precursor, and a phosphate precursor in an acidic aqueous medium; to form a reaction mixture; precipitating from the reaction mixture a metal phosphate; collecting the metal phosphate; combining the metal phosphate with a lithium precursor; and calcining the combined metal phosphate and lithium precursor at elevated temperature to form a lithium metal phosphate; wherein a mol ratio of water-soluble metal precursor to water-insoluble metal precursor is from 0.5:99.5 to 99.5:0.5.

An iron manganese phosphate precursor, a lithium iron manganese phosphate positive electrode material and a method for preparation thereof, an electrode material, an electrode, and a lithium-ion battery are disclosed. The lithium iron manganese phosphate precursor is represented by (NH.sub.4)Mn.sub.1-x-yFe.sub.xM.sub.yPO.sub.4H.sub.2O/C, wherein 0.1<x≤0.6 and 0≤y≤0.04, and M is selected from at least one of Mg, Co, Ni, Cu, Zn, and Ti. Lithium iron manganese phosphate positive electrode material prepared from the precursor is uniform in carbon coating, has a dense secondary spherical morphology, is high in compaction density, can improve the electrochemical performance of the lithium-ion battery when applied to the lithium-ion battery, is high in specific capacity and good in cycle performance.

The present invention discloses a preparation method for water-soluble potassium polymetaphosphate, and relates to the technical field of potassium polymetaphosphate production and preparation. In the present invention, potassium dihydrogen phosphate is mixed with a divalent cationic metal oxide at a mixing mass ratio of 70-90:5-18 to obtained a mixture, wherein the divalent cationic metal oxide is one or more of calcia, magnesia and zinc oxide in the field of food processing; then the mixture is heated and melted, and the temperature is kept constant for 1-3 h at a temperature of 600-700° C.; and after temperature keeping, the melted mixture is cooled naturally to obtain a product. The water-soluble potassium polymetaphosphate prepared by the present invention has a high water solubility and effectively solves the application defect of a traditional potassium polymetaphosphate product which is insoluble in water.

The invention relates to a method and system for phosphate recovery from a stream such as waste flow, sewage or another sludge stream. The method comprises the steps of: providing an incoming stream comprising an initial amount of phosphate; dosing/controlling iron salt to the stream such that precipitates are formed in the stream, wherein the precipitates comprise vivianite like structures comprising more than 60% of the initial amount of phosphate in the incoming stream, and preferably also the steps of: separating the vivianite like structures from the stream; and recovering the phosphates from the separated vivianite like structures.

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.

Metal (II) phosphate powders, lithium metal phosphate powders for a Li-ion battery and methods for manufacturing the same are provided. The lithium metal phosphate powders are represented by the following formula (II):
LiFe.sub.1-aM.sub.aPO.sub.4(II)
wherein M comprises at least one metal selected from the group consisting of Mn, Co, Ni, Cu, Cr, V, Mo, Ti, Zn, Zr, Tc, Ru, Rh, Pd, Ag, Cd, Pt, Au, Al, Ga, In, Be, Mg, Ca, Sr, B and Nb, 0.5<a1, the lithium metal phosphate powders are composed of plural flake powders, and a length of each of the flake powders is ranged from 50 nm to 10 m.