108results about "Phosphorous acid" patented technology

The invention discloses a highly selective novel reaction with an important application value in organic phosphorus synthesis methodology. The reaction can be applied in important pesticide commodities of acephate, glyphosate, glufosinate-ammonium, chloramine phosphorus, profenofos, and the like. With the reaction, innovative technical synthetic routes can be designed. With the reaction, standards of clean production technologies can be satisfied, and the production cost is greatly reduced compared to existing technical routes.

A process for the manufacture of an aqueous composition that is a combination of a fungicide and fertilizer comprising the following steps:

• • (1) dissolving phosphorous acid in phosphoric acid to form a solution of an acid mixture;
  • (2) reacting the acid mixture of step (1) with an aqueous hydroxide solution creating an exothermic reaction under pressure; and,
  • (3) cooling the reaction product to between about 35° C. to about 65° C.

The reaction product prepared according to the above process can also be used as a bactericide.

The invention relates to a process of extracting phosphorous acid from sodium hypophosphite slag, wherein a high purity phosphorous acid product is obtained specifically by a cation exchange method through decompression, distilling and crystallization. The process comprises the following steps: extracting calcium phosphate solid from a calcium phosphate in a calcium phosphate workshop and reacting with sodium carbonate; separating and purifying to obtain a sodium phosphite liquor; decompressing, evaporating and crystallizing the sodium phosphite liquor after cation exchange through D001 resin to obtain the high purity phosphorous acid product. The process is simple in process, less in energy consumption and high in product purity, and does not cause secondary pollution at the same time.

The invention relates to a method for continuously synthesizing phosphorous acid, comprising the following steps of: fully filling phosphorous acid water solution in a first stage reactor, and then adding phosphorus trichloride and water for reaction at the same time; controlling the temperature to be 10-90 DEG C, and simultaneously leading the reaction material to overflow into a second stage reactor from the first stage reactor for heat preservation reaction; and controlling the temperature to be 10-90 DEG C, and then leading the finished product phosphorous acid water solution to overflow into a finished product storage tank from the second stage reactor. The method has the characteristics of simple technique, stable product quality, good yield, high safety performance, low production cost and the like.

A modified phosphite fine anti-rusting pigment and its production are disclosed. The pigment consists of organic sulfonate with long straight chain as catalyst D 0.1í½1.0wt%, phosphorous acid or its solution, zinc oxide, calcium hydroxide or theirs mixture in proportion=1:1í½1:4 and with mass concentration=10í½20%. It is prepared by catalyst D surface modification or combination with catalyst D surface modification and calcium modification, which fines the pigment. It can be used for industrial production, pigment and plastic industries and is no need for grinding.

The invention discloses a method for synthesizing highly dispersed aluminum orthophosphite crystals from an aluminum salt and hypophosphorous acid. The method is characterized in that the method comprises the following steps: (1) using the aluminum salt to prepare an aluminum hydroxide gel, filtering and washing till a washing solution has no anions of the aluminum salt; (2) adding distilled water into the gel after washing, stirring to get an aluminum hydroxide sol, adding the sol into the hypophosphorous acid while stirring, and continuously stirring to realize full reaction after dripping; and (3) filtering and heating an obtained solution, separating out aluminum orthophosphite, filtering, and drying to get the uniform and well-dispersed aluminum orthophosphite crystals. Compared with the prior art, the method disclosed by the invention has the advantages of simple process, energy conservation, environmental protection, high product yield and purification and short production period, and is suitable for industrial production.

The present invention is the production process of phosphorous acid and lower alkane halide with phosphorous trichloride and alkyl alcohol (phenol) as material. Phosphorous trichloride and alkyl alcohol (phenol) are reacted to produce phosphorous acid and lower alkane halide. The lower alkane halide is separated via proper method and the product is concentrated and crystallized to obtain phosphorous acid, with the mother liquor being circularly used. The phosphorous acid is used in producing other product. The production process is simple and low in cost.

The invention provides a recovery method of a rectification residual liquid of dimethyl phosphite. The preparation process comprises steps as follows: methanol and phosphorus trichloride are sprayed to an esterification reaction kettle slowly; a proper amount of ammonia is added to crude dimethyl phosphite in a neutralization tank slowly for neutralization; materials in the neutralization tank are sent to a rectifying tower to be rectified, dimethyl phosphite is completely distilled off, and a rectification residual liquid of dimethyl phosphite is left; the rectification residual liquid of dimethyl phosphite is transferred to a reaction kettle; the rectification residual liquid is subjected to activated carbon decoloration; the decolored liquid is filtered; a proper amount of hydrochloric acid is dropwise added to the filtered liquid, the mixture is sufficiently stirred until acidolysis is sufficient; tail gas generated in the acidolysis process is sent to a chloromethane recovery pipeline in a workshop; after acidolysis is finished, a phosphorous acid water solution in the kettle is concentrated and crystalized. Clean production is realized, discharge of three wastes is reduced, the recovery rate of byproducts is increased, and the production cost is reduced.

Disclosed is a process for any productions that involve reacting or mixing two or more substances to form one or more new substances under low supersaturation. However, the specific process used to exemplify the present invention is the “wet process” phosphoric acid production, in which this process is achieved through dissolving the phosphate ore and dispersing the sulfuric acid separately and simultaneously with the gypsum slurry that has roughly stoichiometrically balanced calcium and sulfate ions in the solution and is also at considerably low supersaturation. The slurry carried out digesting the phosphate ore and the slurry accomplished dispersing the sulfuric acid then mix together to form the said gypsum slurry that has roughly stoichiometrically balanced calcium and sulfate ions in the solution and is also at considerably low supersaturation. The slurry for filtration is drawn from the sulfuric acid dispersion compartment, and the sulfate level for this slurry is maintained suitable for the product separation.

The invention provides phosphorous acid titanium with a three-dimensional open-framework structure and a preparation method thereof and belongs to the technical field of phosphorous acid titanium with a three-dimensional open-framework structure. The preparation method is characterized in that an open-framework crystal compound of the phosphorous acid titanium without an organic template is synthesized by adopting a strong acid method in a hydrothermal system, the morphology of a product is regulated and controlled by adjusting the quantities of phosphorous acid and hydrofluoric acid in reaction gel, and the phosphorous acid titanium compounds with the three-dimensional open-framework structure, which have the identical structure and are different in morphologies, are synthesized. The phosphorous acid titanium compound does not contain an organic template agent. Compared with other metal phosphorous acid salts, the phosphorous acid titanium compound has relatively good heat stability, thus favorable conditions are provided for the research of the property of the phosphorous acid titanium compound. The photovoltage research shows that the compound has the property of a p-type conductor. The invention has the beneficial effects of providing a simple, convenient and effective method for preparing the phosphorous acid titanium crystal material with the open-framework structure.

The invention provides a method for preparing phosphorous acid and hydrogen chloride in an inner circulation tower by using phosphorus trichloride. The method comprises the following steps of: intermittently or continuously adding the phosphorus trichloride to the inner circulation tower, and then making the phosphorus trichloride react with a water solution in the tower to prepare a phosphorous acid water solution and a hydrogen chloride gas with large scale and high efficiency and yield and smoothly export the hydrogen chloride gas and heat. The method has the advantages of high reaction conversion rate and yield, steady reaction, high safety and the like and can be used for continuous production.

The invention provides a method for producing waste acids to prepare high-content phosphorous acid. The method comprises the following steps: concentrating most of the hydrogen chloride in the waste acids by performing falling film evaporation, adsorbing metal ions by activated carbon, extracting to remove the chloride ion after tertiary amine and kerosene complexing, and performing vacuum spray drying, thereby obtaining the finished phosphorous acid. Aiming at recycling of the waste acid, the phosphorous acid and hydrochloric acid which can be directly utilized are refined from the waste acids, and synergetic development among the economy, society and environmental protection is realized.

The invention provides a method for preparing potassium dihydrogen phosphite. The method comprises the following steps: solid potassium hydroxide is dissolved in an alcohol solvent, solid phosphorous acid is added, the materials are subjected to neutralization, a product is subjected to solid-liquid separation, and high-purity potassium dihydrogen phosphite is prepared after drying, wherein alcohol is recovered from a liquid obtained after solid-liquid separation through distillation, the recovered alcohol is recycled, and distilled mother liquor returns to neutralization for recycling. Crystallization of potassium dihydrogen phosphite is omitted by means of the difference between alcohol solubility and water solubility, high-purity potassium dihydrogen phosphite can be prepared, and production procedures are simplified; no wastewater, waste gas or solid waste is discharged, alcohol recycling is realized, and the effect of circulating and clean production is realized.

The present invention discloses a crystalline aluminum phosphite, a preparation method thereof and an application thereof as or for the preparation of a flame retardant or a flame retardant synergist. The preparation method has the following processes: 1, reacting aluminum hydrogen phosphite with an aluminum-containing compound in water at 80-110° C. to obtain a precipitate in the presence of no strong acid or a small amount of strong acid; 2, washing and filtering the precipitate; 3, drying the precipitate at 100-130° C.; 4, continuously heating the dried solid step by step at a low speed, where the material temperature is increased to not exceeding 350° C. from room temperature at about 5-10 h, with a temperature rise rate not exceeding 5° C./min. Compared with amorphous aluminum hydrogen phosphite, the crystalline aluminum phosphite has a higher thermal decomposition temperature, lower water absorption and weaker acidity, and can be synergistic with diethyl aluminum hypophosphite to achieve better flame retardant property and thus, is used for a halogen-free flame retardant component of high polymer materials.

The invention relates to a method for preparing phosphate fertilizer from waste liquid containing phosphoric acid ester and phosphite. The steps are as follows: S1) decompose the alkyl group in the waste liquid containing phosphoric acid ester and phosphorous acid ester under acidic conditions; S2) pass the solution obtained in S1 through alkali or carbonate neutralization; S3) evaporating the solution obtained in S2 for the first time and separating phosphate by cooling crystallization; S4) evaporating the solution obtained in S3 for the second time and separating phosphite by cooling crystallization. The invention provides a waste liquid utilization method with easy operation, safety, high phosphorus recovery rate and comprehensive waste utilization.

The invention discloses a continuous crystallizing and centrifuging system for producing phosphorous acid. The system comprises a concentration kettle, a condenser, a crystallizer, a centrifugal machine and a circulating pump, and is characterized in that the concentration kettle is connected with the condenser by virtue of the circulating pump; the condenser is connected with the crystallizer by virtue of a pipeline; the crystallizer is connected with the centrifugal machine by virtue of a pipeline. According to the system, the defect of the prior art is overcome, the crystallizing time is greatly shortened, the production efficiency is improved, the energy consumption is reduced, the equipment investment is reduced, the pollution to human, equipment and environment in the operation process is reduced, and the system is safe and environment-friendly.

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 relates to a method for preparing calcium phosphite from industrial sodium hypophosphite waste residues. According to the technical scheme, the method comprises the following steps: firstly, reacting the sodium hypophosphite waste residues, water and sodium carbonate, and separating to prepare a filter cake I and filter liquor I; secondly, reacting the filter cake I with hydrochloric acid, and separating to prepare filter liquor II; thirdly, enabling the filter liquor I to pass through an active carbon adsorption system, adding the filter liquor I and the filter liquor II into a continuous reaction crystallizer, ageing, separating and drying to obtain calcium phosphite crystals with the purity of more than 99.0% and crystal mother liquor II; and finally, evaporating and crystallizing the crystal mother liquor II to obtain crude sodium chloride salt and crystal mother liquor III, and returning the crystal mother liquor III to the reaction crystallizer for circulation. According to the method, a continuous reaction crystallization process is adopted, calcium phosphite is prepared from the industrial byproducts-sodium hypophosphite waste residues used as raw materials, the sodium hypophosphite waste residues are recycled during solid waste treatment, and waste liquid is not generated in a production process; moreover, the method has the advantages that the process is simple, the operating condition is mild, the energy consumption is low, the product quality is stable, the industrialization is facilitated, and the like.