18results about "Phosphates" patented technology

The present invention relates to a method for producing liquid NPK fertilizer, characterized in that the reactants K2CO3 or KHCO3, NH4HCO3, and H3PO4 are reacted in an aqueous solution to produce potassium and ammonium phosphate salts, particularly K3PO4 and (NH4)3PO4; the reaction is carried out in multiple steps and includes at least one exothermic reaction and at least one endothermic reaction; and the temperature of the reaction is controlled by adjusting the amount and rate of addition of each reactant in the various steps so as to maintain the reaction mixture within a desired temperature range, preferably between 5°C and 50°C, throughout the reaction, without the need for external cooling or heating devices to control the temperature of the reaction. In a more specific embodiment, the method according to the invention is characterized in that at least one exothermic reaction comprises the reaction of K2CO3 with HO to produce KHCO3 and KOH and / or the reaction of KHCO3 with H3PO4 to produce K3PO4, CO2, and HO, and at least one endothermic reaction comprises the reaction of NH4HCO3 with H3PO4 to produce (NH4)3PO4, CO2, and HO.

This application discloses a method for producing industrial-grade ammonium dihydrogen phosphate, comprising: a desulfurization reaction tank, a heavy metal removal reaction tank, a multi-stage aeration tank, a settling tank, a primary membrane filter, an acid mixer, a neutralization reaction tank, and a multi-stage plate and frame membrane filter assembly; the desulfurization reaction tank and the heavy metal removal reaction tank are connected by pipelines; the outlet of the heavy metal removal reaction tank is connected by pipeline to the inlet of the first-stage aeration tank of the multi-stage aeration tank; the outlet of the last-stage aeration tank of the multi-stage aeration tank is connected by pipeline to the inlet of the settling tank. This method, by adding a primary membrane filter assembly before acid conditioning, reduces the impurity and solid content of the pretreated acid, increases phosphorus yield, reduces the amount of ammonium slag in the pretreated acid, and reduces filtration intensity, which is beneficial for improving product quality and the system's capacity after maintenance. The equipment used is reliable, requires low investment, has low labor intensity, and can achieve continuous and stable operation.

A method for recovery of rare earth elements from apatite mineral comprises dissolving (S10) of apatite mineral of magmatic origin in an acid comprising hydrochloric acid. The dissolving results in a first liquid solution comprising phosphate, calcium and chloride ions, rare earth elements, arsenic and iron. The arsenic and any ferric iron are removed. The first liquid solution is treated (S20) into a second liquid solution by extracting (S22) of a major part of the phosphate ions with an organic solvent. The treating of the first liquid solution into the second liquid solution further comprises partially neutralizing (S75) a raffinate resulting from the extracting of a major part of the phosphate to a pH > 1.5, causing precipitation of phosphates of rare earth elements, and filtering (S76) the precipitated phosphates of rare earth elements from the raffinate.

The method for producing powdery high-concentration monoammonium phosphate by two-stage neutralization of high-impurity raffinate acid is as follows: the by-product raffinate acid generated in the production process of wet purified phosphoric acid is preheated to 65-75 DEG C, ammonia gas is first introduced to perform a first-stage neutralization reaction, the pre-stable impurity neutralization slurry is obtained after constant temperature ripening, ammonia gas is introduced to perform a second-stage neutralization reaction on the pre-stable impurity neutralization slurry, the qualified monoammonium phosphate slurry is obtained after constant temperature ripening, the qualified monoammonium phosphate slurry is continuously subjected to grading concentration, drying is performed after the slurry solid content is concentrated to 70-75%, and the powdery high-concentration monoammonium phosphate product is prepared. The present application takes the by-product high-impurity raffinate acid generated in the production process of wet purified phosphoric acid as the only phosphorus source, realizes full-value utilization of the raffinate acid, the process is green and environmentally friendly, and is suitable for industrialized continuous production.

This invention relates to a system and method for preparing low-polymers and co-producing ammonium phosphate from nitrogen-containing oligomers in acrylonitrile wastewater. The invention aims to address the technical problems of high cost and environmental pollution associated with treating nitrogen-containing organic wastewater generated in acrylonitrile production through combustion. The system comprises a premixing tank, a raw material preheater, a reaction vessel, a neutralization tank, an oil-water separator, an extraction tower, an alcohol recovery tower, and a water recovery tower. This invention provides a method for converting wastewater containing nitrogen-containing oligomers generated in acrylonitrile plants into low-polymers, which can be used as a green fuel, by fully utilizing the oligomeric carbon chains. Simultaneously, nitrogen is removed, and ammonium salts are co-produced, which can be sold as fertilizer raw materials, thereby reducing costs. This invention provides a novel process for utilizing nitrogen-containing organic wastewater, improving the utilization rate of carbon and nitrogen resources.

The application discloses a crystal form regulator and application thereof in phosphogypsum byproduct of wet-process phosphoric acid, and belongs to the technical field of phosphorus chemical industry.The crystal form regulator is composed of a compound capable of forming aluminum-fluorine complex anions and iron-fluorine complex anions under acidic conditions.The crystal form regulator provided by the application can remove 100% of calcium ions in acidolysis liquid, and can also obtain phosphogypsum with good crystal morphology, and solves the problem that calcium ions in acidolysis liquid after decomposition of phosphate rock by nitric acid or hydrochloric acid cannot be completely precipitated and crystallized from the acid liquid.

This invention discloses a resource-based treatment method for acidic mother liquor wastewater from ferric phosphate, relating to the field of wastewater treatment technology. The specific process is as follows: the wastewater is pretreated with a ceramic membrane and then cooled using a heat exchanger; subsequently, it enters a primary acid membrane system for concentration under acidic conditions, with the concentrated water used to produce ammonium sulfate and ammonium phosphate; the primary permeate enters a secondary acid membrane system for deep purification, with the permeate reused and the concentrated water recycled. In this invention, the primary acid membrane is a polysulfonamide composite nanofiltration membrane prepared by interfacial polymerization, and the secondary acid membrane is a polyurea nanofiltration membrane prepared by interfacial polymerization with the addition of surfactants and catalysts. This method does not require pH adjustment and operates directly under strongly acidic conditions, achieving efficient separation, concentration, and resource recovery of sulfate and phosphate ions in the wastewater.

This invention discloses a low-temperature solid-phase synthesis method for manganese tetroxide, belonging to the field of inorganic functional material preparation technology. The preparation method includes: preparing a targeted organic ammonium salt surface modifier; preparing a composite precursor by high-energy ball milling of a manganese source (γ-type MnOOH) and a rhombohedral MnCO3, a modifier, and a composite auxiliaries; obtaining a crude product through a low-temperature solid-phase reaction at 220-350℃ under a nitrogen or argon inert atmosphere; and obtaining the final product through fluidized bed desorption, air jet milling depolymerization, sieving, acid washing, and vacuum drying. To address the shortcomings of existing solid-phase synthesis methods, such as high energy consumption, easy generation of impurities, and product agglomeration, this invention proposes a synergistic regulation and low-temperature solid-phase synthesis technology. Through specific manganese source formulation and the synergistic effect of modifiers and auxiliaries, pure-phase synthesis at 220-350℃ is achieved, solving problems such as high-temperature dependence and impurity phase formation. The product has a regular crystal structure, high purity, and good dispersibility, making it suitable for high-end lithium-ion battery cathode materials and other applications. The process is energy-efficient and environmentally friendly.

A lithium manganese iron phosphate positive electrode material and a method for preparing the same are disclosed, which belong to materials of lithium-ion battery. The method includes: mix raw materials and solvent to obtain a first mixture, the raw materials includes a phosphorus-containing compound, a manganese-containing compound, an iron-containing compound, a lithium-containing compound, and a carbon-containing compound; subject the first mixture to a first pretreatment and a first sintering process to form a first sintered material; mix the first sintered material, an additive containing phosphorus, and solvent to obtain a second mixture; subject the second mixture to a second pretreatment and a second sintering process to form a second sintered material, wherein the phosphorus in the additive distributes on particle surface of the second sintered material to form a phosphorus-rich shell layer; subject the second sintered material to post-processing to obtain the lithium manganese iron phosphate positive electrode material. The present disclosure can reduce the powder resistivity of the positive electrode material. Thereby the voltage plateau decay rate is slowed down during the cycling process, and the cycle life of the lithium manganese iron phosphate positive electrode material is improved.

The present application relates to the production process of battery-grade iron phosphate prepared from wet-process phosphoric acid and its related acid, and belongs to the technical field of wet-process phosphoric acid production. The present application solves the technical problem of providing a production process of battery-grade iron phosphate prepared from wet-process phosphoric acid and its related acid at low cost. The process obtains battery-grade iron phosphate through extraction, defluorination by concentration and chemical defluorination, preparation of NH4H2PO4 solution, reaction, oxidation, adjustment of pH and separation of precipitate, washing and drying. The method of the present application has low production cost and can realize the recycling of fluorine resources. By using specific extraction and stripping methods, or using specific two-step neutralization methods, NH4H2PO4 solution is obtained by extraction and separation from purified wet-process phosphoric acid. The process does not produce raffinate acid, the extractant can be recycled after stripping, and the production quality is not affected by the generation of difficult-to-dissolve substances such as ammonium magnesium phosphate. The two-step method is used to prepare battery-grade iron phosphate, and the cost of preparing iron phosphate by precipitation method is low, which meets the requirements of industrial production.

The positive electrode active material includes olivine lithium manganese iron phosphate. The olivine lithium manganese iron phosphate includes a dopant at a manganese-iron site. At the manganese-iron site, the dopant satisfies a relationship of "dFe-X < dMn-X". The term "dFe-X" represents a nearest-neighbor atomic distance between the dopant and iron. The term "dMn-X" represents a nearest-neighbor atomic distance between the dopant and manganese.

Process for extracting nickel from a feed ore comprising a mineralized form of iron and a mineralized form of nickel.

This invention relates to the field of water treatment technology, specifically to a sludge phosphorus release and phosphorus crystallization recovery device, comprising a phosphorus release mechanism and a phosphorus crystallization recovery mechanism. The phosphorus release mechanism includes a sludge thickening unit, a sludge breaking component, and a sludge dewatering unit; the sludge breaking component includes a sludge breaking unit and a pH adjustment unit; the phosphorus crystallization recovery mechanism includes an outer shell, a middle shell, an inner shell, a flow-pushing and stirring component, a baffle vortex component, a modular vortex component, an inclined plate component, and a micro-nano aeration disc. The outer shell, middle shell, and inner shell combine to form a unique circulation channel. Combined with the micro-nano aeration disc, small crystal particles enter the circulation channel as seed crystals, providing readily available nucleation sites for the solution, reducing the critical supersaturation required to form new crystal nuclei, reducing the probability of spontaneous nucleation, inhibiting the formation of irregular dendritic or needle-like crystals, and promoting the formation of denser, more uniform prismatic or plate-like large crystal particles, thus achieving efficient phosphorus release and phosphorus crystallization recovery.

A process for recovering phosphorus from ashes coming from combustion plants fed with solid fuel in the form of a renewable and / or waste material, comprising a step of mixing phosphorus-comprising ashes with a sulfuric acid solution, carrying out a solid-liquid extraction and thereby obtaining an acidic slurry comprising a supernatant and an exhausted precipitate, wherein the supernatant comprises phosphoric acid, as well as subjecting said supernatant to successive steps to obtain a concentrated, neutralized, phosphorus-containing mixture, possibly mixed with urea so as to obtain a soil conditioner in liquid form. A plant for carrying out said process and one or more products obtainable through said process are also described.

This invention provides a method for preparing high-purity trisodium phosphate from iron phosphate slag as a phosphorus source, including defluorination and solid fluoride roasting of raw materials; enhanced low-temperature alkaline leaching with composite flux; high-temperature solid-liquid separation and countercurrent washing; synergistic purification based on complexation and nanofiltration; evaporation concentration, cooling crystallization, and mother liquor or condensate circulation; enhanced low-temperature alkaline leaching with composite flux and utilizing the synergistic impurity removal mechanism of boron complexation-nanofiltration membrane to achieve efficient resource utilization of iron phosphate slag, solving the problems of high energy consumption, complex process, high product impurities, and low phosphorus yield in existing technologies.

The invention discloses a method for producing functional diammonium phosphate by using white fertilizer, and belongs to the technical field of diammonium phosphate production. Comprising the following steps that liquid ammonia and mixed acid (the mixed acid is phosphoric acid and waste white fertilizer in the filter pressing production process) react in a reaction chamber to generate slurry, and the reaction slurry is jointly sprayed and granulated on a material curtain of a granulator through a special nozzle and a functional additive conveyed by a functional additive conveying pump. The invention provides a method for producing ammonium phosphate by utilizing medium-low-grade phosphorite with relatively high impurity content. Waste white fertilizer which cannot be treated in the filter pressing production process is used as the raw material, so that the purposes of energy conservation and consumption reduction are achieved; by adding the functional additive, not only are nutrient elements added to crops, but also the soil is improved.