Methods of refining metals and methods of manufacturing positive electrode active materials are disclosed. The methods of refining metal comprise preparing an acid solution that includes an impurity and metal, adding a filtration aid to the acid solution to make a precipitation reaction solution, and filtering the precipitation reaction solution to separate a liquid including the metal and a solid including the impurity and the filtration aid. The filtration aid includes one or more of silicon dioxide (SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), calcium hydroxide (Ca(OH).sub.2).

Wasted gypsum boards are crushed and calcined to gypsum granular solid, and the gypsum granular solid is mixed with water to form gypsum slurry. Gypsum particles are deposited from the gypsum slurry in a crystallization tank. Heated steam is blown into the gypsum slurry at a height from surface of the gypsum slurry and down to upper of the gypsum slurry to heat the gypsum slurry and to eliminate foam on the gypsum slurry.

The present application provides a method for separating and purifying phosphoric acid and phosphogypsum from a wet-process phosphoric acid slurry, and phosphoric acid and phosphogypsum prepared thereby. The method is beneficial for the dissociation, precipitation and separation of colloidal silicon and carbon impurities, such that the aim of in-situ removal and rapid separation of colloidal impurities to obtain the ore slurry, from which impurities have been removed, during a reaction process for outputting phosphogypsum is realized, and a low-impurity phosphoric acid product and phosphogypsum product can be obtained after the ore slurry, from which impurities have been removed, has been further treated.

A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

The present disclosure relates to a method for producing sodium bicarbonate and gypsum using sodium sulfate.

A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

Aqueous slurry which includes solid foreign matter and paper dust is pressed by means of a screw press, provided with a mesh having openings not less than 1.5 mm and not greater than 3 mm, to separate the aqueous slurry into the solid foreign matter and the paper dust, and liquid component passing through the mesh. Then, the liquid component is sieved by means of a sieve having openings not greater than 1 mm to separate from the liquid component the solid foreign matter and the paper dust.

A method of preparing ferric phosphate from iron-containing waste, including: step a) providing a ferric chloride-containing mixture solution obtained from acidolysis of iron-containing waste; step b) adjusting pH of the ferric chloride-containing mixture solution to satisfy 0<pH2 and Fe.sup.3+ concentration to 10-80 g/L with an alkaline compound and water, to obtain an iron source solution; step c) mixing and reacting the iron source solution obtained from the step b) with a solution of calcium dihydrogen phosphate in a molar ratio of P to Fe of 1:1-1.8, to obtain a slurry with a pH of 0.2-2; and step d) performing aging and crystal transformation on the slurry, to obtain ferric phosphate. A battery-grade ferric phosphate with high purity and good product quality can be obtained without the need for deep purification of raw materials.

There is disclosed a process of developing a sustainable hybrid composite material, comprising the steps of developing the Extracted Powder Compound from Reject Brine (EPC-RB) and producing a Biodegradable Composite from a Biodegradable Polymer (PLA) reinforced with (EPC-RB). The Extracted Powder Compound from Reject Brine (EPC-RB), which is waste product from different industrial processes, serves as a filler or reinforcement within at least one polymer matrix in different ratios to produce a new hybrid composite material with at least one unique property. Further, reinforcing the Extracted Powder Compound from Reject Brine (EPC-RB) in Biodegradable Polymer (PLA) in different ratios enhances the mechanical, thermal, and other properties of the developed sustainable hybrid composite material.

A process may involve digesting raw phosphate with concentrated sulfuric acid and converting the raw phosphate to calcium sulfate in the form of dihydrate and/or hemihydrate, and phosphoric acid, separating off calcium sulfate as solid from a liquid phase of a suspension that is obtained, treating the calcium sulfate that is separated off or from a stockpile with an acid to give a suspension with purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, separating off the purified calcium sulfate as solid from a liquid phase of a suspension obtained, using the P.sub.2O.sub.5-containing liquid phase as a portion of the sulfuric acid required for digesting the raw phosphate or as feedstock for treating phosphogypsum from the stockpile to give a suspension of purified calcium sulfate and P.sub.2O.sub.5-containing acid solution, which is thereafter processed.