214 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 belongs to the technical field of soil improvement, and particularly relates to a sandy soil functional water and fertilizer retention agent and a preparation method and application thereof.The preparation method specifically comprises the following steps that 1, modified bentonite, humic acid nano-microspheres and amino acid chelated microelement powder are mixed and stirred; 2, adding sodium alginate-cellulose composite gel and a magnesium ammonium phosphate-urea compound, and stirring to obtain a primary product, and 3, putting the primary product into a granulator, and granulating to obtain the sandy soil functional water and fertilizer retention agent. Through the synergistic effect of multiple components, the performance bottleneck of a single material is broken through, the components have the advantages of being all natural and degradable, the process is simplified, the cost is reduced, and compared with the prior art, the prepared retention agent has remarkable progress in water and fertilizer retention efficiency, environmental compatibility and comprehensive functions.

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 discloses a method for recovering a lithium source and an iron source in a lithium iron phosphate battery positive plate, which comprises the following steps of: cutting a dried positive plate material into pieces, putting into a tubular furnace, calcining at high temperature, crushing, sieving and separating aluminum foil pieces to obtain lithium iron phosphate positive fine powder; the method comprises the following steps: mixing the lithium iron phosphate positive electrode fine powder with an acidic ingredient, separating and deslagging to obtain a filtrate, dropwise adding an H2O2 solution, adding a NaOH solution to generate a precipitate, and carrying out suction filtration to obtain a residue Fe (OH) 3 colloid and a filtrate Li (OH) solution; and further treating the separated slag by dissolving with dilute sulfuric acid, dropwise adding an ammonium phosphate solution into the generated ferric sulfate salt solution, and adding ammonia water NH3.H2O to adjust the pH value to be 2-3 to form ferric phosphate precipitate, thereby obtaining ferric phosphate powder. And introducing CO2 gas into the filtrate for 2 hours to form white emulsion, thereby obtaining the lithium carbonate. Recycling of the lithium source and the iron source of the waste lithium iron phosphate battery has important significance and wide prospects in the aspects of environmental protection, economy and resource sustainability.

The invention discloses modified ferromanganese ammonium phosphate, modified ferromanganese pyrophosphate and a preparation method and application of the modified ferromanganese ammonium phosphate and the modified ferromanganese pyrophosphate, and belongs to the technical field of battery materials. Adding an oxidizing agent and regulating the pH to form ammonium ferric phosphate, and carrying out ion exchange reaction on the ammonium ferric phosphate, manganese salt and doped metal salt to exchange iron elements in the ammonium ferric phosphate to form metal doped ammonium manganese ferric phosphate; meanwhile, the exchanged iron ions continuously react with phosphate radicals generated by converting manganese ions, doped metal ions and ferrous dihydrogen phosphate into iron phosphate in the system to form metal-doped manganese iron ammonium phosphate, so that manganese, iron and doped metal atoms can be uniformly distributed in a precursor crystal lattice at an atomic level; the generation of a non-solid solution impure phase and a solid solution phase with a non-target manganese-iron ratio and the introduction of anion impurities are effectively avoided, so that the ratio of metal to phosphorus in the metal-doped ammonium manganese iron phosphate obtained by the reaction is less than 1, and the electrochemical performance of the modified lithium manganese iron phosphate is favorably improved when the metal-doped ammonium manganese iron phosphate is applied to the positive electrode material.

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 invention discloses a cobalt-nickel raffinate comprehensive utilization method which comprises the following steps: respectively carrying out oil removal treatment on a cobalt raffinate and a nickel raffinate to obtain an oil-removed cobalt raffinate and an oil-removed nickel raffinate; mixing the deoiled nickel raffinate and the deoiled cobalt raffinate according to a molar ratio of ammonium to magnesium of (1-1.2): 1 to obtain a mixed solution; performing de-weighting treatment on the mixed liquid to obtain de-weighting liquid and de-weighting slag; and mixing the heavy-removed solution with an organic solvent and a phosphorus-containing solution, then adjusting the pH value of the mixed solution to be alkaline, and performing solid-liquid separation to obtain magnesium ammonium phosphate and a magnesium-precipitated solution after a precipitate is generated through a reaction. According to the method disclosed by the invention, the open circuit of the magnesium in the wastewater is realized, ammonium and magnesium in the wastewater are recovered while the accumulation of waste residues is reduced, 70-80% of ammonium and 99% of magnesium are converted into magnesium ammonium phosphate with economic value, and the resource utilization of the magnesium and ammonium in the wastewater is realized.

The invention belongs to the technical field of phosphate fertilizer production, and particularly relates to zinc-containing diammonium phosphate, a preparation method thereof and a fertilizer containing the zinc-containing diammonium phosphate. The zinc-containing diammonium phosphate is prepared by wrapping the outer layer of a solid zinc fertilizer with elemental sulfur to obtain sulfur-zinc-containing mixed slurry, and spraying the sulfur-zinc-containing mixed slurry onto diammonium phosphate for granulation, thereby obtaining the zinc-containing diammonium phosphate. Wherein the addition amount of the solid zinc fertilizer accounts for 30-100% of the total mass of the elemental sulfur; based on the total weight of the zinc-containing diammonium phosphate, the addition amount of the sulfur-zinc-containing mixed slurry is 1-10%. According to the preparation method, direct contact and antagonistic reaction of phosphate radicals and zinc ions are avoided, degradation of phosphorus and zinc nutrients is avoided, and a relatively good water-soluble zinc content ratio and a relatively good water-soluble phosphorus content ratio are kept.

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 relates to the technical field of compound fertilizer production, and discloses an ammonia-acid method compound fertilizer production system and process, the ammonia-acid method compound fertilizer production system comprises a raw material preparation unit, a reaction unit, a granulation unit and a drying unit which are communicated through pipelines, and the granulation unit comprises a dissolving tank, a primary mixing tank, a secondary mixing tank and a rotary drum granulator which are communicated; the reaction unit comprises an ammonium phosphate dissolving tank and a tubular reactor, the tubular reactor is provided with a plurality of inlets, and an outlet of the ammonium phosphate dissolving tank is communicated with one inlet of the tubular reactor; the raw material preparation unit is communicated with the ammonium phosphate dissolving tank, the dissolving tank, the primary mixing tank and other inlets of the tubular reactor; an outlet of the tubular reactor is communicated with the rotary drum granulator, and an outlet of the rotary drum granulator is communicated with the drying unit. According to the scheme, different types of raw materials are subjected to reaction treatment and then are sufficiently mixed in a liquid state for granulation, so that the mixing uniformity of various materials is effectively improved, and the stability of compound fertilizer granules obtained by granulation is further improved.

The utility model relates to the technical field of phosphorite treatment, in particular to a device and system for preparing ammonium phosphate and byproduct nitrophosphate fertilizer by decomposing phosphorite with nitric acid. The device comprises an acidolysis tank, the acidolysis tank is connected to a first separator, the first separator is connected to a first crystallizer, the first crystallizer is connected to a second separator, the second separator is connected to a decalcification tank, the decalcification tank is connected to a denitration tank, and the denitration tank is connected to a second crystallizer. The denitration tank is respectively connected to the repulping tank and the purification equipment; the re-pulping tank is connected to a neutralizing tank, and the neutralizing tank is connected to a first concentrator; and the purification equipment is connected to the second concentrator. According to the device disclosed by the invention, the mother liquor generated by the acidolysis tank is deeply processed to prepare monoammonium phosphate and purified phosphoric acid, meanwhile, a byproduct white fertilizer can be processed into a phosphorus (potassium) nitrate fertilizer, and a byproduct white gypsum is obtained.

The invention discloses a method for removing calcium and magnesium from a cobalt-nickel hydroxide raw material, and relates to the technical field of hydrometallurgy. The method comprises the following steps: slurrying a cobalt-nickel hydroxide raw material and deionized water, and washing the slurry to remove residual water-soluble calcium / magnesium at normal temperature in a carbon dioxide pressurized stirring manner, namely primary impurity removal; then, ferrous sulfate is used as an auxiliary rinsing agent for further washing and removing calcium / magnesium, and secondary impurity removal is achieved; the secondary impurity removal material is mixed and dissolved with sulfuric acid-ammonium phosphate, after the pH value is adjusted through ammonia water, most of residual calcium / magnesium ions are compounded to generate calcium phosphate / magnesium ammonium precipitate to be separated out, and at the moment, the filtered cobalt-nickel material is subjected to tertiary purification and impurity removal. The nickel-cobalt material subjected to three-time calcium / magnesium pre-removal can significantly reduce the impurity concentration of the acid-dissolved liquid, and lays a solid foundation for shortening the extraction stage number, reducing the extraction workload, reducing the extraction input cost and improving the product quality for a subsequent extraction production line.

The invention relates to chemical fertilizer production, and provides a multi-tube reaction-based ammonium phosphate drum granulation system, which comprises a granulator, a pre-neutralization tank and a tube reaction tank, the granulator is internally provided with an ammonia distributor, and a tube reactor A, a tube reactor B and a tube reactor C which are arranged below the ammonia distributor; the A pipe reactor and the B pipe reactor are both connected with a pipe reactor tank, and the pipe reactor tank is connected with a phosphoric acid cleaning agent; the C pipe reactor is connected with a pre-neutralization tank, the pre-neutralization tank is connected with an acid source, and the acid source comprises raffinate acid or sludge acid. The ammonium phosphate rotary drum granulation system based on the multi-tube reactor can effectively consume raffinate acid and sludge acid to produce DAP products.

The invention discloses a high-concentration multi-element slow-release blended fertilizer which is prepared from nutrient elements, plant hormones, ammonium bicarbonate, ammonium phosphate, potassium chloride, magnesium oxide, sub-volcanic rock, kaolin, urea, bentonite, calcium oxide, compound microorganism bacteria, diammonium hydrogen phosphate, potassium sulfate, crop waste residues, a fermentation accelerant and animal waste. The fertilizer comprises the following components in parts by weight: 2-5 parts of nutrient elements; 1-3 parts of plant hormones; and 10-15 parts of ammonium bicarbonate. The organic fertilizer and the inorganic fertilizer are combined, the product is green and environment-friendly, the utilization rate of the fertilizer is increased, the fertilizer efficiency is more remarkable, the effects of further activating soil nutrients and fertilizing soil can be achieved, root growth and cell division can be promoted, crop disease resistance can be improved, conversion and absorption of nutrient elements such as nitrogen, phosphorus and potassium in the fertilizer can be accelerated, and the fertilizer efficiency is improved. And moreover, the negative influence of the fertilizer on the environment can be effectively reduced after long-term use of the fertilizer, so that the fertilizer has good social and economic benefits.

The invention relates to the technical field of positive electrode material precursors, in particular to a method for preparing battery-grade iron phosphate by taking titanium dioxide waste acid as a raw material and application of the battery-grade iron phosphate. Hydrolysis waste acid in the titanium dioxide industry is selected as the raw material, ammonia gas is used as a pH regulator, and phosphorus salt and hydrogen peroxide are used as precipitants; the solubility product constants of aluminum phosphate and titanium phosphate are small, Al < 3 + > and Ti < 4 + > in the hydrolysis waste acid are precipitated by adopting soluble phosphate and then are filtered and removed, iron ammonium phosphate is precipitated by virtue of phosphorus salt and is fully washed, and the content of metal impurity ions can be reduced to be less than 100ppm; according to the method, ferrous sulfate is subjected to fractional precipitation, impurity removal, precipitation, washing and aging under different pH conditions, so that the use amount of alkaline substances is greatly reduced, and the problems of high liquid waste treatment cost and resource waste in the traditional titanium dioxide industry are solved.

The group of inventions relates to the chemical industry, and more particularly to the production of nitrogen fertilizers, and can be used for producing granules of fertilizers such as, inter alia, ammonium nitrate, urea and ammonium nitrate-phosphate fertilizers, by prilling. What is proposed is a method for forming nitrogen fertilizer granules by prilling using a closed air circulation loop, in which cooling air is fed into the lower part of a prilling tower, a nitrogen fertilizer melt is sprayed into the upper part of the prilling tower, and granules are removed from the lower part of the tower. By means of at least one closed circulation loop, air is removed from the upper part of the prilling tower for preparation by purification and cooling and is returned to the lower part of the prilling tower as cooling air, wherein before being returned to the prilling tower, at least a portion of the air is sent for additional preparation by aftercooling, with the separation and removal of condensate and subsequent warming of the air. Also proposed is an apparatus for carrying out the claimed method. The technical result of the group of inventions consists in increasing the efficiency of a prilling process entailing a closed loop for the circulation of cooling air by improving the quality of the fertilizer produced, increasing operational reliability and reducing the overall dimensions of the equipment used, while maintaining a complete absence of prilling process emissions and obviating the need for the inspiration of external air.

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%.

The invention relates to an iron ion inhibitor composition and application thereof. The iron ion inhibitor composition is prepared by combining 2 to 2.5 parts of soluble salt of oxalic acid, 1 to 1.5 parts of ammonium phosphate compound and 1.0 to 1.5 parts of triethanolamine. The iron ion inhibitor composition can be added in the ore grinding process, after ore grinding or in the flotation pulp mixing process of copper-lead-zinc oxide minerals, and then conventional flotation pulp mixing and flotation separation operation is carried out. The concentration of iron ions in ore pulp can be effectively reduced, iron species adsorbed on the surface of the ore can be stripped, accordingly, the flotation recovery rate and the concentrate grade of the copper-lead-zinc oxide ore are remarkably improved, agent consumption is reduced, and the method has the advantages of being simple in process, wide in applicability and the like.

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 provides a method for synchronously removing nitrogen and phosphorus in organic wastewater, which comprises the following steps: detecting the concentration of ammonia nitrogen and the concentration of phosphate in the organic wastewater, and adjusting the pH value of the organic wastewater to 8.0-9.5; adjusting the temperature of the organic wastewater to 20-30 DEG C; adding magnesium salt into the mixture; wherein the molar ratio of the addition amount of the magnesium ions to the ammonia nitrogen is (1.0-1.2): 1; the molar ratio of the addition amount of the magnesium ions to the phosphate is (1.0-1.2): 1. A chemical precipitation method is adopted, magnesium salt is added into the organic wastewater rich in ammonia nitrogen and phosphate to serve as an agent, magnesium ammonium phosphate precipitates are generated through a chemical reaction, and therefore the purpose of synchronously removing ammonia nitrogen and phosphate is achieved, and the problem of nitrogen and phosphorus pollution of the organic wastewater is effectively solved; the method for synchronously removing nitrogen and phosphorus in organic wastewater disclosed by the invention has the characteristics of high efficiency, economy and environmental protection, and is easy to popularize and apply.

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.