105 results about "Ammonium phosphate" patented technology

The preparation method comprises the following steps: S1, preparing a phosphoric acid solution, a hydrogen peroxide solution, a Ti salt, a phosphor salt solution and a ferrite solution; s2, Ti salt and the ferrite solution are mixed, and a titanium iron salt solution is obtained; mixing the phosphoric acid solution and the phosphorus salt solution to obtain a phosphorus source solution; s3, adding the titanium iron salt solution into a reaction kettle, and adding the hydrogen peroxide solution; s4, adding the phosphorus salt solution into the reaction kettle to obtain yellow slurry; s5, after the color of the slurry is heated to be white, white slurry is obtained; s6, carrying out solid-liquid separation on the white slurry to obtain an iron phosphate dihydrate filter cake; and S7, drying and calcining the iron phosphate dihydrate filter cake to obtain the Ti-doped battery-grade anhydrous iron phosphate. The titanium-doped iron phosphate is firstly prepared by a one-step method, the pH value of the reaction system is controlled by controlling the molar ratio of the iron element to all phosphorus elements in total phosphorus, ammonium phosphate and phosphoric acid in the reaction system, and the retention of the Ti element in the finished product and the regulation and control of the iron-phosphorus ratio in a specified range are ensured.

The invention provides a preparation method of grain size grading iron phosphate and high compaction type lithium iron phosphate. Removing impurities from the titanium dioxide byproduct ferrous sulfate, and filtering to obtain a purified ferrous sulfate base solution; the method comprises the following steps: reacting phosphoric acid with ammonia water to prepare ammonium phosphate solutions with different reaction pH values and phosphorus molar concentrations, respectively mixing the ammonium phosphate solutions with a certain amount of hydrogen peroxide, and sequentially adding an iron source, a first phosphorus salt solution, a second phosphorus salt solution and a third phosphorus salt solution into a tubular reactor for reaction to obtain iron phosphate slurry; and sequentially converting, filtering, washing, drying and calcining the completely reacted slurry to finally prepare the anhydrous iron phosphate. According to the invention, a mode of controlling solution nucleation and growth is adopted, nucleation and growth rates are controlled by preparing phosphorus salt solutions with different concentrations, size grading of precursor particles is directly realized in a synthesis reaction section, and slurry grading uniformity is further realized through aging crystal transformation. Lithium iron phosphate prepared from the iron phosphate precursor has high compaction density.

The invention belongs to the technical field of magnesium desulfurization wastewater treatment, and particularly relates to a magnesium desulfurization wastewater ammonia nitrogen and heavy metal ion cooperative treatment system which is characterized by comprising a vertical flow sedimentation tank, a stirring reaction device and a cyclone separator, and an outlet of the vertical flow sedimentation tank is connected with an inlet of the cyclone separator through a material transfer pipeline; a bottom outlet of the cyclone separator is connected with a stirring reaction device, the stirring reaction device is connected with an inlet of the vertical flow sedimentation tank through a seed crystal pump and a seed crystal pipeline, the stirring reaction device is connected with an automatic phosphate dosing feeder, the bottom of the stirring reaction device is connected with a blow-off pipeline through an automatic blow-off valve, and the treated desulfurization wastewater enters a downstream sewage treatment plant or is subjected to slag flushing. The method has the advantages that denitrification efficiency is high, reaction is stable, ammonia nitrogen and heavy metal ions in the magnesium desulfurization wastewater are synergistically removed, separated magnesium ammonium phosphate (struvite) precipitate crystals are used as seed crystals to return and adsorb, excessive addition of phosphate agents is reduced, and the effect of mixed reaction can be guaranteed.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a method for separating nickel and cobalt from a nickel-containing solution and preparing nickel salt, which comprises the following steps: 1) chelating and precipitating impurity metal ions in the nickel-containing solution by using ammonium polyphosphate with the polymerization degree of more than 1000 as an impurity removal agent, thereby removing copper, iron, zinc and aluminum to obtain an impurity-removed solution; 2) extracting the impurity-removed solution by using a diluent, alpha-hydroxyoxime, carboxylic acid and alkyl alcohol as an extraction organic phase to obtain a nickel-loaded organic phase; 3) washing the nickel-loaded organic phase by using nickel-containing washing water; and (4) reverse extraction is conducted on the washed nickel-loaded organic phase through reverse extraction liquid containing acid and nickel ions, nickel-rich liquid is obtained after reverse extraction is completed, nickel salt in the nickel-rich liquid is crystallized, and nickel salt solids are obtained after phase separation. According to the method, nickel is selectively extracted through the compound extraction system after impurity removal, the extraction rate of nickel reaches up to 99.8%, nickel is separated from metal ions such as cobalt and lithium, and the method is simple in process, low in equipment manufacturing cost and low in manufacturing cost.

The invention provides a biological organic fertilizer and a preparation method thereof. The biological organic fertilizer is prepared from the following raw materials in parts by weight: 10 to 15 parts of rice husk, 8 to 12 parts of peanut shell, 10 to 15 parts of bagasse, 15 to 20 parts of straw, 20 to 25 parts of livestock manure, 5 to 10 parts of pond sludge, 3 to 5 parts of plant ash, 5 to 10 parts of oil meal, 5 to 10 parts of ammonium phosphate, 2 to 5 parts of low-temperature complex microbial inoculants, 3 to 6 parts of seaweed oligosaccharide, 5 to 10 parts of modified vermiculite powder and 10 to 20 parts of photothermal conversion microspheres. According to the invention, waste is taken as a basic raw material and is matched with ammonium phosphate to rapidly supplement available nutrients, and meanwhile, the low-temperature complex microbial inoculant, the modified vermiculite powder and the photothermal conversion microspheres are introduced to form a synergistic interaction system. Vermiculite powder is modified, so that the nutrient adsorption and slow release capability is improved, a carbon source and low-temperature protection are provided for microorganisms, and the cell membrane stability is enhanced. The photothermal conversion microspheres efficiently absorb sunlight and convert the sunlight into heat energy, a local and mild heat island effect is formed around the fungicide, the microenvironment temperature is increased, breeding of the fungicide is remarkably accelerated, and therefore organic matter decomposition and nitrogen conversion are accelerated.

The invention belongs to the technical field of coal chemical industry grey water treatment, and particularly relates to an advanced treatment method and system for coal chemical industry grey water circulating water. The method integrates pretreatment, complexing cracking, fractional crystallization and deep deamination, and is characterized in that a chelating structure of an organic phosphorus dispersing agent and calcium and magnesium ions is thoroughly destroyed through an advanced reduction-advanced oxidation combined process, target ions are released, and the core problems that hardness removal is hindered and phosphorus pollution is caused are solved; then, calcium and magnesium are respectively converted into calcium carbonate and magnesium ammonium phosphate particles for resource recovery by utilizing a secondary crystallization technology, so that the bottlenecks of high alkali liquor consumption and salt accumulation of a traditional high-pH magnesium ion precipitation method are broken through; and finally, the residual ammonia nitrogen is deeply removed by adopting a pollution-resistant PTFE hydrophobic membrane, so that the residual ammonia nitrogen is efficiently and stably removed, and the problem that a traditional polypropylene material membrane system is easy to pollute and block, easy to oxidize and difficult to apply to the field is solved.

The utility model relates to an ammonium phosphate evaporation and concentration system and belongs to the field of chemical engineering. The system comprises a concentrated ammonium phosphate pump, a concentrated ammonium phosphate storage tank, an I-effect evaporation chamber, an I-effect heater, an I-effect circulating pump, an I-effect charging pump, an II-effect evaporation chamber, an II-effect heater, an II-effect circulating pump, an II-effect charging pump, an III-effect evaporation chamber, an III-effect heater and an III-effect circulating pump. By adopting the system and the method, low-pressure saturated live steam is utilized to indirectly heat dilute ammonium phosphate to generate secondary steam and tertiary steam to continuously heat the dilute ammonium phosphate to produce concentrated ammonium phosphate. Compared with a two-effect evaporation concentration process flow which is widely used at present, the three-effect countercurrent evaporation concentration process flow saves energy by 47%. The utility model aims at saving energy, reducing consumption, reducing carbon emission of a production device and protecting the environment.

The utility model relates to the technical field of organic wastewater treatment, and discloses a magnesium-carbon primary battery reaction tank which comprises a reaction tank, a water inlet pipe is arranged inside the left side of the reaction tank, a water outlet pipe is arranged inside the right side of the reaction tank, and a first slag discharge tank and a second slag discharge tank are arranged inside the upper side of the reaction tank. A negative plate magnesium plate and a positive plate carbon plate are arranged in the reaction tank, a sludge scraper is arranged in the reaction tank, and the bottom end of the water inlet pipe is fixedly connected with a sludge accumulation hopper. According to the utility model, magnesium ions react with ammonia nitrogen and phosphate in the wastewater to generate magnesium ammonium phosphate precipitates, so that multiple purposes are realized, the content of hydrogen ions in the wastewater is reduced, the acidity of the wastewater is relieved, the content of ammonia nitrogen and phosphate ions is directly reduced, and the production cost is reduced. The burden of nitrification, denitrification and biochemical phosphorus removal of a subsequent biochemical system is relieved, and meanwhile, the dosage of phosphorus removal in deep treatment is reduced.

The invention belongs to the technical field of sewage treatment, and discloses a DO-ORP coordinated regulation artificial tidal food web sludge in-situ reduction and phosphorus recovery method. Aiming at the problems of high energy consumption, serious phosphorus resource loss and the like of traditional sludge treatment, a multi-stage food chain consisting of microorganisms, protozoa and metazoan is implanted by constructing an artificial tidal environment with periodic alternation of wetting and drying; according to the method, the metabolic activity of sludge hydrolysis flora and phosphorus-accumulating bacteria is activated by utilizing cooperative regulation and control of DO concentration and ORP, microbial extracellular polymeric substances are triggered to be depolymerized by adopting tidal periodic oscillation, in-situ reduction of sludge biomass is realized by combining a food web cascade predation effect, and phosphorus is synchronously removed by virtue of an anaerobic phosphorus release-aerobic phosphorus uptake coupled struvite crystallization process. The method is suitable for treating the excess sludge of a municipal sewage treatment plant, and the high-purity magnesium ammonium phosphate fertilizer is produced while the dehydration energy consumption is reduced by 40%.

A method of recovery of ammonium phosphate comprises providing a start material (100) comprising struvite into a first aqueous process liquid (101) comprising monoammonium phosphate. The first aqueous process liquid (101) is mixed. Thereby the start material (100) comprising struvite is converted into monoammonium phosphate and / or diammonium phosphate in solution and a residue (103) comprising newberyite as a precipitate. The residue (103) is separated from the first aqueous process liquid (101), thereby giving a second aqueous process liquid (104) comprising monoammonium phosphate and / or diammonium phosphate. At least a part of said second aqueous process liquid (104) or a part of an aqueous process liquid (107, 112) emanating therefrom is returned into the first aqueous process liquid. Phosphoric acid (110) is added. A method for extracting nitrogen from reject water, an arrangement (1) for recovery of monoammonium phosphate and a system for extracting nitrogen from reject water is also disclosed.

The present application relates to the technical field of manganese industry wastewater treatment device, and particularly discloses a comprehensive treatment method for electrolytic manganese production wastewater containing medium and high concentration ammonia nitrogen, which comprises the steps of removing manganese, solid-liquid separation of manganese removal wastewater, adding a precipitant for precipitation reaction, etc.; according to the characteristics of electrolytic manganese production wastewater containing manganese, ammonia nitrogen, calcium, magnesium, sulfate ions, etc., by fully utilizing the magnesium ions in water, more than 95% of the manganese ions and all the phosphate radicals in water can be selectively removed by using slurry of quicklime, without introducing excessive calcium ions, effectively reducing the dosage of magnesium salt and phosphoric acid reagent, reducing the treatment cost, so that the electrolytic manganese production wastewater containing medium and high concentration ammonia nitrogen with ammonia nitrogen > 50 mg / L can be completely treated to reach the standard by using the ammonium magnesium phosphate precipitation method, and the indexes of manganese, ammonia nitrogen, phosphate radical and pH value after treatment can all reach the first standard limit value requirement of the Comprehensive Sewage Discharge Standard (GB 8978-1996), and the manganese, ammonia nitrogen and magnesium resources in the wastewater can be recovered.

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.

The application discloses a compound fertilizer for promoting cotton high yield and a preparation method thereof, relates to the technical field of cotton fertilizer, and comprises first mother liquor A, second mother liquor B and third mother liquor C which are prepared, stored and packaged separately; the first mother liquor A contains urea phosphate, monoammonium phosphate, anhydrous citric acid, malic acid and manganese sulfate monohydrate; the second mother liquor B contains commercial 11-37-0 liquid ammonium polyphosphate, ammonium salt type polyaspartic acid solution, purified fulvic acid clear liquid and tri-potassium citrate; and the third mother liquor C is a mixed system of polyol complex state boron clear pre-liquid and medium complex state zinc pre-liquid. The application can improve the effective state stability of phosphorus, zinc and boron, reduce the risks of precipitation fouling and dripping head blockage, alleviate the risks of local salt peak and root injury in the seedling stage, promote the uniform emergence and young root growth of cotton, and improve the yield.

The application discloses a phosphorus recovery method and system in phosphogypsum leachate, and relates to the technical field of environmental protection. The phosphorus recovery method comprises the following steps: adding calcium oxide into the phosphogypsum leachate, adjusting the pH value to 4, removing filter residues, removing COD through sand filtration and ultrafiltration; adjusting the pH value of the ultrafiltrate to 4, producing water through first nanofiltration, adjusting the pH value of the permeate to 10, collecting reaction generated gas into a second sedimentation tank for dissolution, continuously producing water through second nanofiltration, and obtaining concentrated water as phosphorus recovery liquid; collecting the first nanofiltration concentrated water and the second nanofiltration permeate, adding phosphate into the second sedimentation tank to obtain magnesium ammonium phosphate precipitation, and performing reverse osmosis treatment on the filtrate. The phosphorus recovery method provided by the application is simple in operation, low in cost, and can make the phosphorus recovery rate reach more than 90%, has a high removal rate of impurities such as F and S, and the obtained products in the treatment process can be recycled, and have high economic value.

The invention discloses a method for synergistically preparing magnesium ammonium phosphate by treating ammonia-nitrogen wastewater with phosphate tailings, which comprises the following steps: roasting the phosphate tailings at high temperature to obtain roasted ore; the obtained roasted ore is subjected to digestion treatment, CO2 is introduced into ore pulp for carbonization, and the CO2 comes from roasting waste gas CO2 and carbon-containing flue gas; performing solid-liquid separation to obtain a first filtrate and a first filter residue, using the first filter residue to recover calcium, and using the first filtrate to treat ammonia-nitrogen wastewater; adding a phosphorus source and ammonia-nitrogen wastewater into the first filtrate, adjusting the pH value, and filtering after reaction to obtain a second filtrate and a second filter residue; the ammonia nitrogen content of the second filtrate is detected through Nessler's reagent spectrophotometry, and the ammonia nitrogen removal standard is met; and drying the second filter residue at low temperature to obtain a magnesium ammonium phosphate product. The method is low in production cost, high in product value and high in resource utilization rate, ammonia nitrogen in the wastewater can be efficiently removed, the environmental wastewater discharge standard is met, efficient value-added utilization of industrial by-products is achieved, and meanwhile the prepared magnesium ammonium phosphate product meets the industrial standard.

The invention relates to the technical field of coal gangue treatment, in particular to a method for preparing high-purity mullite through coal gangue pretreatment-calcination coupling. The high-purity mullite is prepared by the following steps: crushing, grinding and sieving, adding soluble salt, phosphoric acid and ammonium salt in an alkaline hydrothermal reaction, roasting and removing impurities, modifying by using a composite mineralizer, coating by using silicon-aluminum sol, carrying out suspended three-stage calcination and the like. The method solves the technical problems of insufficient activation of the coal gangue, difficulty in deep removal of impurities, low purity of mullite and low resource utilization efficiency of the coal gangue in the traditional process, and realizes efficient resource conversion of the coal gangue. Through the synergistic effect of all process links, the crystal phase purity and structural compactness of mullite are effectively improved, the obtained product has good application performance, a feasible path is provided for preparation of high-value mullite from coal gangue, and the method is suitable for the related fields of high-temperature structural materials and the like.

The invention relates to the technical field of battery material preparation, in particular to anhydrous iron phosphate and a preparation method and application thereof, and the preparation method comprises the following steps: S1, mixing ammonium phosphate with an alcohol polymer and / or a carboxyl polymer to form an ammonium salt premix; s2, mixing hydrated iron phosphate with the ammonium salt premix to prepare a mixed material; and S3, calcining the mixed material to prepare the anhydrous iron phosphate. The alcohol polymer and / or carboxyl polymer and the ammonium phosphate firstly form an ammonium salt premix, then the ammonium salt premix is mixed with the hydrated iron phosphate, calcination is combined, and the heating rate, the temperature and the time in the calcination process are accurately controlled, so that decomposition of the ammonium phosphate can be effectively delayed, stable and uniform small pores are formed, and the specific surface area of the iron phosphate is increased; therefore, when the composite material is applied to lithium iron phosphate, the rate capability and the cycle performance of the composite material are obviously improved.

This invention relates to a method for the graded utilization of wet-process phosphoric acid and the co-production of food-grade phosphoric acid and ammonium phosphate, belonging to the field of phosphoric acid chemical technology. The method first purifies the raw phosphoric acid, with the main process involving multi-stage extraction and back-extraction to obtain food-grade phosphoric acid. For the byproduct raffinate acid, no complex purification is required; instead, a slurry process is used directly to prepare fertilizer. When producing diammonium phosphate, the final neutralization pH is controlled at 8.0-8.5, and the degree of ammoniation is 1.8-2.0. When producing monoammonium phosphate, the raffinate acid is mixed with slag acid and filter solids, and a small amount of raw material acid is added to neutralize to a pH of 4.0-4.5, with a degree of ammoniation of 1.0-1.1. This invention overcomes the problems of high slurry viscosity, equipment blockage, and low product grade caused by the direct fertilizer production of raffinate acid with a simplified process. Furthermore, it coordinates with the disposal of system waste in monoammonium phosphate production, truly achieving high-value utilization and clean production of all components of wet-process phosphoric acid.

The invention discloses a method for preparing feed-grade calcium hydrophosphate from raffinate acid, which comprises the following steps of: mixing alkali liquor D and raffinate acid, reacting, filtering after the reaction to obtain filtrate A and a filter cake E, and using the filter cake E for producing compound fertilizer, ammonium phosphate, superphosphate or rich calcium, and reacting the filtrate A with the calcium slurry, filtering after the reaction is finished to obtain a filtrate B and a filter cake C, returning the filtrate B to prepare an alkali liquor D, and finally drying and packaging the filter cake C to obtain the feed-grade calcium hydrogen phosphate. The method is simple in process, the value of the raffinate acid is increased, and the method is very convenient for actual production.

Disclosed is a fertilizer containing a mixture containing i) calcium ammonium phosphate (CaNH4PO4), magnesium ammonium phosphate (MgNH4PO4), or a combination of CaNH4PO4 and MgNH4PO4 and ii) a mixture of calcium sulfate and ammonium sulfate ((NH4)2Ca(SO4)2), a mixture of magnesium sulfate and ammonium sulfate ((NH4)2Mg(SO4)2), or a combination of the (NH4)2Ca(SO4)2, and the (NH4)2Mg(SO4)2. Methods of making and using the fertilizer are also disclosed.

The application provides a preparation method of a manganese iron ammonium phosphate precursor and a lithium manganese iron phosphate. The preparation method of the precursor comprises the following steps: preparing an ammonia water solution; preparing a mixed metal salt solution containing manganese and iron; preparing a phosphorus source solution; adding a small amount of the ammonia water solution as a reaction bottom solution, adding the remaining ammonia water solution, the mixed metal salt solution and the phosphorus source solution into a reaction kettle in parallel flow to perform a reaction, maintaining the pH at 5-5.5, then increasing the reaction temperature to 90 DEG C, aging, and obtaining a manganese iron ammonium phosphate monohydrate precipitate; and then performing solid-liquid separation, washing and drying to obtain a manganese iron ammonium phosphate precursor powder. The ammonia water solution is used as the bottom solution, the yield of the manganese iron ammonium phosphate precursor is improved, a secondary phosphorus source is added in an acidic environment, the proportion of P elements in the precursor is increased, the iron-phosphorus ratio is closer to the theoretical value, and the yield is higher. The process is simple, the yield is high, the method is more suitable for large-scale production, and has great market prospects.

The invention relates to the field of lubricating oil, in particular to a nonferrous metal-friendly gear oil composition as well as a preparation method and application thereof. The gear oil composition comprises the following components in parts by weight: 100 parts of wind power gear oil and 0.5-2 parts of ammonium phosphate, wherein the wind power gear oil contains alkyl polysulfide with medium and low activity, and the content of trivalent sulfur of the alkyl polysulfide is 50-100%. The wind power gear oil composition provided by the invention is excellent in performance, the compatibility of an oil product and a sliding bearing, especially a copper part, can be improved to a greater extent, and the metal corrosion with a fan gear box is reduced; the wind power gear oil composition provided by the invention has the advantages of simple components, easily available raw materials, simple preparation method and wide large-scale application prospect, and can meet the requirements of customers on extreme pressure wear resistance of wind power gear oil.

This invention discloses a method for preparing and applying algal hydrothermal char material. Algae are mixed with a reaction medium at a solid-liquid ratio of 50-100 g / L. After thorough stirring, the mixture is reacted under autogenous pressure and at a temperature of 130-150°C for 3-5 hours. After the reaction, the mixture is filtered, washed, dried, and ground to obtain the algal hydrothermal char material. The reaction medium is a mixed solution of ammonium phosphate and ammonia. The prepared algal hydrothermal char material can be used to improve the saline-alkali geochemical properties, reduce pH and salinity, and ultimately increase crop yield.

Gel-based subterranean formation hardening compositions and methods thereof may comprise introducing an aqueous carrier fluid comprising a gel and an ammonium phosphate salt into a subterranean formation comprising a carbonate mineral; and interacting the carbonate mineral with the ammonium phosphate salt to convert at least a portion of the carbonate mineral into a hydroxyapatite mineral; wherein the subterranean formation has an increased hardness after forming the hydroxyapatite mineral.

A method of forming a granular fertilizer product, the method comprising: forming a first mixture of phosphoric acid and ammonia; adding the first mixture and a halite powder to a granulator to form a second mixture; and providing ammonia to the second mixture to complete the formation of ammonium phosphate within the second mixture while the granulator processes the second mixture to form granules.

The invention discloses a method for producing a high-phosphorus-content calcium magnesium phosphate fertilizer by using an industrial byproduct magnesium ammonium phosphate, which comprises the following steps: drying and screening magnesium ammonium phosphate, adding phosphorite, dolomite or serpentine and coke or anthracite, feeding the materials into a smelting furnace according to a ratio, melting and smelting at a high temperature, blowing air or oxygen by an air blower at the smelting temperature of 1400-1600 DEG C for 2-3 hours, and cooling to room temperature to obtain the high-phosphorus-content calcium magnesium phosphate fertilizer. The smelting time is 0.5-4 hours, discharging molten slag from a slag opening of the smelting furnace, and carrying out water quenching to obtain the calcium magnesium phosphate fertilizer; gas generated in the process enters a hot-blast stove along with smelting furnace gas, at the moment, the temperature of a hearth of the hot-blast stove reaches 900-1000 DEG C due to gas combustion, and ammonia reacts with nitrogen oxide in the tail gas to obtain nitrogen and water, and reacts with sulfur dioxide to finally obtain ammonium bisulfate. According to the invention, resource utilization of the industrial byproduct magnesium ammonium phosphate can be realized, the calcium magnesium phosphate fertilizer with high phosphorus content can be obtained, and nitrogen oxides and sulfur dioxide in the tail gas in the production process of the calcium magnesium phosphate fertilizer can be more effectively removed.

The invention relates to the technical field of ammonium oligomeric phosphate fertilizers, and discloses a method for regulating and controlling polymerization distribution of oligomeric APP and an ammonium oligomeric phosphate fertilizer, the method is characterized in that a blocking agent is added in the process of preparing the oligomeric APP through a urea condensation method, the blocking agent is a dilute solution of alkali metal hydroxide, and the addition amount of the blocking agent is 6-20% of the use amount of a condensing agent. In the process of preparing ammonium polyphosphate through urea condensation, the blocking agent is added to terminate the polymerization reaction, so that the polymerization distribution of the product can be controlled. The blocking agent is added in the reaction process, so that the reaction temperature can be increased, the dosage of the condensing agent can be increased, target polymerization distribution can be quickly achieved, the reaction time is greatly shortened, and the efficiency is improved. On the basis of the regulation and control method provided by the invention, the ammonium oligomeric phosphate fertilizer prepared by the urea condensation method is distributed towards oligomers (n is equal to 2-3 and the content is high), the highest polymerization degree is not higher than 9, and the ammonium oligomeric phosphate fertilizer is high in water solubility, fast in hydrolysis and high in chelating capacity.

The present application relates to resource recycling and wastewater treatment technical field, disclose a kind of method for lithium precipitation mother liquor coproduction lithium phosphate and ammonium magnesium phosphate.Utilize the method, which includes: (1) lithium precipitation mother liquor is separated by nanofiltration membrane, and nanofiltration permeate is obtained;(2) the nanofiltration permeate and phosphorus source are mixed, and the mixture obtained is adjusted to 11.5-13 by lye pH value, carries out first precipitation reaction, and obtains lithium phosphate and phosphorus-containing wastewater;(3) the phosphorus-containing wastewater, magnesium salt and ammonium salt are mixed, and the mixture obtained is adjusted to 9-10.5 by lye pH value, carries out second precipitation reaction, and obtains ammonium magnesium phosphate.The technical scheme realizes the comprehensive resource utilization and harmlessness of lithium precipitation mother liquor, avoids the scaling of lithium carbonate in membrane system, and guarantees the long-term stable operation of membrane system;And create a feasible reaction environment for ammonium magnesium phosphate precipitation method, solve the problem of failure in high carbonate wastewater due to competitive precipitation.

The application belongs to the field of aquaculture, and particularly relates to an ammonia-nitrogen removing agent for aquaculture and a preparation method thereof. The ammonia-nitrogen removing agent is composed of the following components in parts by weight: organic chlorine 8-10 parts, peroxide 6-8 parts, oxygen supplier 0.2-0.5 parts, catalyst 0.5-1 part, pH regulator 2 parts, and stabilizer 4-5 parts. The organic chlorine is sodium dichloroisocyanurate and cyanuric chloride, or cyanuric chloride. The catalyst is ferrocene. The pH regulator is sodium bisulfate and phosphate, or phosphate. The stabilizer is anhydrous sodium sulfate and anhydrous magnesium sulfate, or anhydrous sodium sulfate and anhydrous magnesium chloride. The application slowly releases hypochlorous acid through organic precursors, and degrades ammonia-nitrogen in water by combining with the ammonium magnesium phosphate method, so that the concentration is controllable and the effective period is long. While the ammonia-nitrogen removing agent of the application efficiently degrades ammonia-nitrogen, the problem of excessively high initial effective chlorine concentration is avoided, and the safety and stability of the treatment process are significantly improved.

This invention discloses a method for recovering fluoride from white fertilizer while simultaneously preparing slow-release nitro fertilizer, belonging to the field of clean processing and utilization technology of phosphorus resources. This invention uses nitric acid to perform staged acid hydrolysis of white fertilizer. The phosphorus-containing filtrate after preliminary acid hydrolysis has a low impurity content and can be used to prepare water-soluble ammonium phosphate. The remaining acid hydrolysis residue undergoes complete acid hydrolysis to completely leach phosphorus and fluoride elements, followed by defluorination. Fluorine precipitates as fluorosilicates, which can be further separated to obtain fluorosilicate products. The defluorinated liquid is neutralized and dried to obtain the slow-release nitro fertilizer product. This method comprehensively utilizes the phosphorus and fluoride resources in white fertilizer, achieving clean processing and utilization of phosphorus resources. The overall process of the method described in this invention is simple to implement, has low production costs, and fully utilizes the phosphorus and fluoride resources in white fertilizer.