87results about "Hypophosphorous acid" patented technology

The invention relates to a method for preparing aluminum hypophosphite. The method includes the following steps of firstly, preparing sodium hypophosphite solution with concentration of 2-6mol/L, adjusting pH (potential of hydrogen) to be 3-5 preferentially within 3-6.5; secondly, preparing aluminum sulfate solution; and thirdly, subjecting the sodium hypophosphite solution and the aluminum sulfate solution to reaction by heating on the acid condition to generate aluminum hypophosphite. The aluminum sulfate is added into the sodium hypophosphite solution for reaction within a certain temperature range, so that harms caused by volatilization of hypophosphorous acid during preparing of the aluminum hypophosphite are avoided, operation is simplified, yield of products is high, cost is low and industrialization is easy to realize.

The invention discloses rare earth metal hypophosphite higher in density and high in thermal stability, and a preparation method and an application of the rare earth metal hypophosphite as a flame retardant in a polymer material. The formula of the rare earth metal phosphate is Ln(H 2PO2)3(H2O).The preparation method of the rare earth metal hypophosphite comprises the steps of dissolving hypophosphite in water, adding sodium hydroxide to the solution to allow the pH of the solution to be 3.0-4.0, adding rare earth metal nitrate or an aqueous solution of rare earth metal chloride salt to be solution, stirring for 3-4 hours at 40-60 DEG C, cooling, filtering and washing to a reaction product, and obtaining the rare earth metal hypophosphite after drying. A halogen-free flame retardant polymer composite taking the rare earth metal hypophosphite as the flame retardant comprises the following components by mass percent: 40-90% of polymer and 10-25% of rare earth metal hypophosphite.

The invention is a method for producing sodium hypophosphite, which is characterized in that the process steps include batching, reaction, filtration, first concentration, adjustment, second concentration, cooling and crystallization, and centrifugal packaging. Advantages: Put the measured liquid caustic soda into the lime milk tank, mix it with water and quicklime, and pump it into the reaction kettle together. In this way, it is not necessary to disassemble the liquid alkali pipeline frequently, thereby reducing the unfavorable factors affecting normal production; the reactor is emptied with nitrogen, which should be evacuated with steam, which is easy to operate and does not require additional equipment; replace the old-fashioned plate with a diaphragm press filter Frame filter. The water content of the filter cake is reduced from 45-50% to 35-40%, and the filter cake content of 1-1.5% sodium hypophosphite is reduced to 0.4-0.8%. The reduction of the water content of the filter cake not only improves the recovery rate of sodium hypophosphite, but also improves the operating conditions of slag unloading; the ratio of yellow phosphorus per kettle is changed from 90 to 100kg to 150kg, which greatly increases the output of a single device.

A flame retardant polymer composition is described. The composition includes at least one polymer and a hypophosphite salt, wherein the hypophosphite salt is heat stabilized so that when it is heated for 3 hours at 298° C. under a flow of argon flushing at rate 58 mL/min, it generates less than 0.5 mL of phosphine per gram of hypophosphite salt. The flame retardant polymer composition can also include at least one additive that improves the flame retardant properties of the composition.

The invention relates to a technique for preparing hypophosphorous acid through a bipolar membrane electroosmosis method. Sodium hypophosphite and deionized water are taken as raw materials; a sodium hypophosphite solution is put into a salt chamber of a bipolar membrane electroosmosis device; the deionized water is respectively put into an acid chamber and an alkali chamber; the liquid in the three chambers is pumped into the bipolar membrane electroosmosis stack for circulating; and the bipolar membrane electroosmosis device is started for performing bipolar membrane electroosmosis, so as to prepare the hypophosphorous acid and sodium hydroxide solution. The technique for preparing hypophosphorous acid, provided by the invention, is simple, low in energy consumption, mild in technical condition and free from secondary pollution, and multiple sets of grouping units can be repeatedly assembled and formed into a membrane stack between a pair of electrodes, so that the technique can be easily amplified industrially. The prepared hypophosphorous acid can be directly used as a product applied to the production raw material of sodium hypophosphite; the content of sodium ions in the hypophosphorous acid solution can be further reduced through refining; and the acquired sodium hydroxide solution can be used for adjusting the pH value in the production process of the sodium hypophosphite.

The method of manufacturing nickel hypophosphite from a solution of hexahydrated nickel sulfate and a solution of monohydrated sodium hypophosphite by an electro-membrane technique, consists:a) in introducing respectively the hexahydrated nickel sulfate solution and the monohydrated sodium hypophosphite solution into each of two dilution circuits of four-compartment electrodialysis cells formed by alternating stacks of cationic and anionic homopolar membranes in an electrodialysis apparatus having an anode and a cathode that are insoluble;b) in applying an electrical current from the anode to the cathode without regulating the pH of the solutions contained in the dilution and concentration circuits but regulating the electricity supply, either in voltage or in current; andc) in recovering a hexahydrated nickel hypophosphite solution from one of the concentration circuits.

The invention relates to a purification method of sodium hypophosphite product, which includes the following technical steps: (1) material proportioning, (2) chemical reaction, (3) filtering, (4) concentration for first time, the concentration being 26-28 Baume degrees, (5) base adjustment working section and acid adjustment working section, (6) concentration for second time, materials being concentrated to 48.6-48.7 Baume degrees after being heated by steam; (7) cooling, crystallization, centrifugation and packaging. The purification method of the invention has the advantages that: the quality of the sodium hypophosphite product is greatly improved by adopting cheap barium salt to remove the sulfate in feed liquid and the stability of product quality is also guaranteed; acid adjusting filtrate is filtered by a filter with the pore diameter of 5-15 microns instead of a cloth filter, thus eliminating the tiny impurities in the water solution of the product and further improving the quality of the product.

The invention discloses a method of using glufocinate byproduct waste residue to prepare aluminum hypophosphite. The method includes following steps: (1), slowly adding a glufocinate industrial byproduct into water, sufficiently stirring, filtering to remove filter residue, and taking filtrate for standby use; dissolving sodium hypophosphite in water to prepare a sodium hypophosphite solution, and adding hydrochloric acid to adjust pH value of the sodium hypophosphite solution to 3-6; (2), taking the filtrate and the sodium hypophosphite solution according to a reactant molar feeding ratio of sodium hypophosphite to aluminum chloride being (4-5):1; (3), putting the sodium hypophosphite solution in a container provided with a snake-shaped condensing pipe, heating to 30-50 DEG C, and dropwise adding the filtrate while stirring at a high speed; after dripping of the filtrate is finished, finishing reaction while slowly stirring; (4), subjecting a reaction product obtained in the step (3) sequentially to separating, washing and drying to obtain powdery white solid which is a product containing aluminum hypophosphite. Therefore, by optimizing the process of using the glufocinate byproduct waste residue to prepare aluminum hypophosphite, a reaction system has the advantages of mild reaction and high reaction rate.

The invention discloses a method for preparing aluminum hypophosphite. The method comprises the following steps that a certain amount of aluminum hydroxide is added to a reaction kettle with a stirring function, a certain amount of water is further added, the mixture is thoroughly stirred, and therefore the added materials are evenly scattered. An appropriate amount of hypophosphorous acid is dripped to the mixture at the temperature of 50 DEG C-100 DEG C and the reaction is kept for 3h-8h; the temperature of the mixture is reduced to the indoor temperature, the mixture is filtered and dried, and therefore the aluminum hypophosphite is obtained, wherein the volume of the water: the number of moles of the aluminum hydroxide: the number of moles of hypophosphorous acid = 1L: 1mol-2mol: 2mol-8mol. According to the method for preparing the aluminum hypophosphite, the yield is high, the technology is simple and easy to conduct, cost is low, the performance cost ratio is high, the obtained product is good in heat stability, and the application prospect is good.

The invention relates to a method for joint production of hypophosphite of calcium, magnesium and aluminum. The method provided by the invention employs sodium hypophosphite, a calcium salt, and a magnesium salt to carry out double decomposition reaction to prepare calcium hypophosphite and magnesium hypophosphite, and avoids the harm of using hypophosphorous acid as the reactant, also gives consideration to the technological shortcoming that after preparation of calcium hypophosphite and magnesium hypophosphite, a lot of hypophosphite still exists in waste liquid and cannot be completely extracted, after preparation of calcium hypophosphite and magnesium hypophosphite, a joint production technique is employed for the first time to prepare hypophosphite of aluminum. The preparation method has the advantages of mild reaction conditions, little pollution, pure product, high utilization rate of hypophosphite ions, high comprehensive yield, greatly reduced cost, and simple and practicable process route, and is convenient for mass production.

The present invention relates to a process for the preparation of phosphinic acids from alkali metal phosphinates, which comprises reacting alkali metal phosphinates in a polar solvent with an inorganic mineral acid and then separating off the phosphinic acid formed.

The invention relates to a method of producing hypophosphorous acid, which comprises the following steps: a. a portion of concentrated sulfuric acid is put into a reaction vessel, in which two portions of hypophosphorous acid are fed, and then the mixture solution is stirred and reacts for 1-2 hours; b. after the reaction is finished, residue and feed liquid are separated by a centrifuge, the feed liquid separated is 70-75 percent of the hypophosphorous acid by content and the residue is sodium sulfate; c. adequate barium hydroxide solution is added into the feed liquid of the hypophosphorous acid separated, which causes sulfate radical to generate barium sulfate deposition, and the barium sulfate is removed through filtration, thus obtaining the hypophosphorous acid; d. the concentration of the hypophosphorous acid obtained in the step c is adjusted to 50 percent by adding water and then the solution obtained is packed, thus obtaining the hypophosphorous acid product. The invention uses the concentrated sulfuric acid and sodium hypophosphite to generate the hypophosphorous acid and the sodium sulfate through reaction, and the technique process does not cause environmental problems such as wastewater, etc. Furthermore, the velocity ratio of double decomposition reaction is very fast, thus being especially applicable for mass production and greatly improving the production capacity of the hypophosphorous acid.

The invention provides a method for preparing high-purity sodium hypophosphite, which comprises the following processing steps: matching materials, wherein, the high-purity sodium hypophosphite is prepared from the following components according to proportioning by weight: 100 portions of yellow phosphorus, 70 portions of lime, 290 portions of ionic-membrane caustic soda and 500 portions of water; evenly mixing the components and reacting to obtain sodium hypophosphite solution and calcium phosphate precipitation; adding barium hypophosphate prepared from hypophosphorous acid and barium carbonate to the sodium hypophosphite solution, and evenly mixing the solution; improving the purity of the product solution by a method of adding powdered activated carbon for decoloring and adsorbing chloride ions; filtering with a membrane filtering machine with the pore diameter being 0.2 mum, so as to trap the tiny impurities; and additionally arranging a spraying system on a centrifuge and washing crystals with de-ionized water solvent. The invention has the advantages that the crystals are sprayed and washed at the time of centrifugal separation, and the mother solution adhered to the surfaces of the crystals can be washed away, thereby ensuring the obvious purification effect; the method can remove the cumbersome and low-efficiency preparation process, simplify the preparation process and reduce the preparation cost; and the content of the product can reach 103.56%.

The invention discloses a preparation method for nanometer aluminum hypophosphite, belonging to the technical field of preparation of nanometer materials. The preparation method comprises the following steps: a) adding an aqueous solution of sodium hypophosphite and cetyltrimethylammonium bromide into an organic continuous-phase solvent and carrying out a reaction at 50 to 95 DEG C so as to obtain a water-in-oil reversed-phase microemulsion containing sodium hypophosphite, wherein the microemulsion is named as liquid A; b) adding a water-soluble aluminum salt solution and cetyltrimethylammonium bromide in another organic continuous-phase solvent and carrying out a reaction at 50 to 95 DEG C so as to obtain a water-in-oil reversed-phase microemulsion containing a water-soluble aluminum salt, wherein the microemulsion is named as liquid B; c) mixing the liquid A with the liquid B, adjusting a molar ratio of sodium hypophosphite to the water-soluble aluminum salt at 80 to 95 DEG C and under atmospheric pressure, carrying out heating and refluxing, and then carrying out a reaction in a nanometer microemulsion reactor so as to obtain a nanometer aluminum hypophosphite colloid; and d) carrying out separation, purification and drying on the nanometer aluminum hypophosphite colloid so as to obtain nanometer aluminum hypophosphite powder. According to the invention, the method employs a reversed-phase microemulsion process to prepare uniform and stable nanometer aluminum hypophosphite so as to overcome deficiencies of the conventional methods and processes.

PCT No. PCT/FR96/01233 Sec. 371 Date Aug. 19, 1998 Sec. 102(e) Date Aug. 19, 1998 PCT Filed Aug. 2, 1996 PCT Pub. No. WO97/12836 PCT Pub. Date Apr. 10, 1997Nickel hypophosphite is prepared by ion exchange on a carboxylic between nickel sulphate and hypophosphorous acid. The product thus obtained, both in the form of an aqueous solution and of a crystalline salt, is intended in particular for the preparation of chemical nickel plating baths.

The invention relates to a method for treating waste slag in a yellow phosphorus production process, in particular to a heterogeneous catalytic oxidation method for treating high-concentration phosphine tail gas generated in a sodium hypophosphite preparation process from sludge phosphorus and belongs to the technical field of industrial waste gas purification treatment. The method comprises the following steps: heating the sludge phosphorus and lye in proportion to a temperature of between 75 and 95 DEG C under the condition of oxygen isolation, performing a reaction with stirring, collecting and washing the generated phosphine, absorbing the phosphine by using solution of hydrogen peroxide in the presence of a filter cake of a nitrate catalyst, wherein the mass ratio of the catalyst to the absorption liquid is 1-20 to 1,000, and reacting to form sodium hypophosphite and sodium phosphite products. The method can reduce the air pollution caused by the phosphine tail gas, have high absorption efficiency of the phosphine, and can increase the output of the sodium hypophosphite products.

The invention discloses a method for preparing hypophosphorous acid (salt) and gluconic acid (salt) from glucose phosphate serving as a raw material, which comprises the following steps of: (1) preparing raw materials: preparing subphosphate or acid phosphate and glucose, and taking water as a solvent; (2) heating: continuously heating mixed solution at the temperature of more than or equal to 100DEG C under the air pressure of more than or equal to 0.01MPa for more than 10 minutes; (3) separating: adding a separating agent, concentrating, and separating to obtain crude products of gluconic acid salt and hypophosphorous acid salt; (4) purifying: filtering to remove precipitates to obtain gluconic acid, adding a gas or a solvent capable of reacting with the hypophosphorous acid salt into aqueous solution of the separated hypophosphorous acid salt, and filtering to remove precipitates to obtain hypophosphorous acid; (5) preparing the hypophosphorous acid salt: reacting the hypophosphorous acid with basic oxide or hydroxide to obtain the hypophosphorous acid salt; and (6) preparing the gluconic acid salt: reacting the gluconic acid with basic oxide or hydroxide to obtain the gluconicacid salt. The production process is environment-friendly and harmless, raw materials are readily available, the cost is low, the yield is high, the period is short and the safety is achieved.

A process for stabilizing hypophosphite salt is provided, which comprises the following steps: a) washing the hypophosphite salt at least one time under a controlled pH value of 4-11, preferably 5-8, as the said hypophosphite salt in an aqueous solution and/or in a solid state; and b) drying the said hypophosphite salt under reduced pressure to remove the volatiles. The process can prevent or minimize the formation of a dangerous quantity of phosphine from hypophosphite salts, more particularly in the flame retardant of the application. The flame retardant polymer composition is also provided, which comprises a polymer and the hypophosphite salt stabilized by the above process.

The invention provides a phosphorus-containing wastewater recycling and waste resource utilization method, which comprises: adding a calcium-containing alkaline compound into phosphorus-containing wastewater, and neutralizing to obtain the mixture of a calcium phosphate salt and calcium halide; filtering the mixture to obtain a calcium phosphate salt precipitate and a calcium halide salt solution,adjusting the pH value of the calcium halide salt solution, returning the calcium halide salt solution as a decontamination agent to a decontamination tower, and continuously carrying out decontamination on a halogenated phosphorus compound; when the calcium halide concentration in the calcium halide salt solution reaches a set value, concentrating the calcium halide salt solution, and carrying out cooling solidifying to obtain a calcium halide hydrate; and collecting the calcium phosphate salt precipitate, carrying out a mixing reaction on the calcium phosphate salt precipitate and aluminumhalide, filtering, and drying to obtain an aluminum phosphate salt flame retardant and a calcium halide aqueous solution. The method of the invention has advantages of low cost, easy industrial production, turning of waste into treasure and other practicalities, and further has high value.

The invention relates to a method for preparing aluminum hypophosphite via a continuous reaction crystallization process. According to the technical scheme, the method comprises the following steps: continuously adding a 50-80wt% sodium hypophosphite solution and 50-60wt% soluble aluminum salt solution into a reaction crystallizer, controlling the average residence time of the materials in the continuous reaction crystallizer for 1 to 5 hours, further discharging a mother liquor I of aluminum hypophosphite from the bottom of the crystallizer and sending the mother liquor I of aluminum hypophosphite into an ager for aging 0 to 3 hours, then further discharging the mother liquor I from the bottom of the ager, and carrying out centrifugal separation, washing and drying so as to obtain an aluminum hypophosphite crystal with the purity greater than 99.0% and a crystallized mother liquor II; finally, evaporating and crystallizing the crystallized mother liquor II so as to obtain a coarse product sodium salt and a crystallized mother liquor III; returning the crystallized mother liquor III into the continuous reaction crystallizer for circulating. Based on the continuous reaction crystallization process, the method has the advantages of simple process, moderate operating condition, low energy consumption, stable aluminum hypophosphite quality and the like, and is easy to industrialize.

The invention discloses a sodium hypophosphite evaporation process. A sodium hypophosphite aqueous solution is evaporated by using a three-effect evaporation device. The process includes the followingconcrete process steps: sodium hypophosphite is added into a first-effect evaporator with an appropriate flow rate, secondary steam generated by evaporation is separated by a first-effect gas-liquidseparator in the first-effect evaporator and then enters a second-effect evaporator, the secondary steam generated in the second-effect evaporator is separated by a second-effect gas-liquid separator,enters a third-effect evaporator, is evaporated by the third-effect evaporator, is separated by a third-effect gas-liquid separator, enters a condenser for condensation and then is discharged; and aconcentrate of the first-effect gas-liquid separator is pumped into the third-effect evaporator through a first-effect discharging pump located at the bottom, a concentrate of the third-effect gas-liquid separator in the third-effect evaporator is pumped into the second-effect evaporator through a third-effect discharging pump located at the bottom, and a concentrate in the second-effect gas-liquid separator is pumped into a crystallization kettle through a second-effect discharging pump after reaching a prescribed concentration. The sodium hypophosphite evaporation process can realize continuous evaporation of the sodium hypophosphite and is simple in operation and stable in discharging concentration.

The invention relates to the field of ceramic tile production, provides a ceramic tile with copper metal texture and a preparation method thereof, and is used for providing a ceramic tile with copperimitation texture. The ceramic tile with the copper metal texture is prepared from 5-8 parts by mass of iron phosphate, 20-25 parts by mass of hybrid aluminum hypophosphite, 6-8 parts by mass of quartz, 40-60 parts by mass of albite, 1-3 parts by mass of calcined kaolin, 3-7 parts by mass of aluminum oxide, 2-5 parts by mass of calcined talc, 3-5 parts by mass of zinc oxide and 8-12 parts by massof high-boron frit. The materials are mixed and then subjected to ball milling to obtain glaze, and the glaze is applied to a green body to form ground coat; transparent glaze is applied to the groundglaze, firing is conducted for 20-24 h, and the ceramic tile with the copper metal texture is obtained. The metal texture can be improved, and particularly, the ceramic tile has the texture and colorsimilar to those of copper.