47results about How to "High main content" patented technology

The invention relates to a method for purifying lithium carbonate, belonging to the technical field of the preparation of high-purity lithium carbonate. The method is characterized by safe production process and high lithium yield. The method comprises the following specific steps: (1) washing lithium carbonate to be purified to remove impurities, and adding water to prepare lithium carbonate slurry; (2) introducing CO2 into the lithium carbonate slurry prepared in the step (1) to carry out hydrogenation reaction, stopping introducing CO2 when the concentration of lithium oxide concentration in a solution is 10-30g / L, and filtering the solution to obtain a hydrogenated solution, wherein the hydrogenation reaction is carried out at the pressure of 0.2-0.6Mpa and the temperature of 20-30 DEG C; (3) subjecting the hydrogenated solution obtained in the step (2) to an ion exchange resin to remove impurity ions in the hydrogenated solution; and (4) heating the hydrogenated solution in which the impurity ions are removed in the step (3) to 70-90 DEG C to carry out decomposition reaction, separating solid from liquid to obtain the wet lithium carbonate, and drying the wet lithium carbonate. The produced battery-level lithium carbonate has high main content, excellent quality and stable performance.

The invention discloses a preparation method of thiodicarb. The preparation method comprises the following steps: (1) dividing a solvent into two portions, dissolving methomyl in one of the two portions to obtain a methomyl solution, and dissolving 4-dimethylaminopyridine in the other portion to obtain a solvent which contains a catalyst; and (2) dividing sulfur dichloride into two portions, dropwise adding one portion of the sulfur dichloride in the solvent which contains the catalyst under a closed condition, meanwhile, dropwise adding the other portion of sulfur dichloride and carrying outdropwise adding reaction on the other portion of sulfur dichloride and the methomyl solution obtained in step (1), and carrying out insulating reaction after dropwise adding is finished to obtain thethiodicarb. The preparation method of the thiodicarb has the advantages that the reaction selectivity is high, the purity of the obtained product is high, the content of thiodicarb isomer is smaller than 0.4%, the yield is high and the like.

The invention discloses a preparation method of difluoro-sulfonyl imide lithium. The preparation method comprises the following steps: 1) under a protective atmosphere, adding a fluorizating agent into difluoro-sulfonyl imide to perform a fluorination reaction so as to obtain a mixture, wherein the fluorizating agent is one of or a combination of fluorine, a fluorine-containing mixed gas, anhydrous hydrogen fluoride, potassium fluoride, antimonic fluoride and rubidium fluoride; 2) performing reduced pressure distillation on the obtained mixture to obtain a di(fluoro-sulfonyl) imide intermediate; and 3) under a protective atmosphere, performing synthetic reaction on the obtained di(fluoro-sulfonyl) imide intermediate and a lithium source, and performing solid-liquid separation to obtain difluoro-sulfonyl imide lithium. According to the preparation method disclosed by the invention, the fluorination reaction does not need a solvent or other auxiliary agent, is less in types of adopted reagents, does not introduce a new impurity, is simple in operation, and is easy to control; the method is less in side reaction, good in fluorination effect and low in fluorination cost; and the purity and the yield of the product namely difluoro-sulfonyl imide lithium obtained by a subsequent synthetic reaction are improved on the whole, and the method has good economic and environmental benefits.

The invention provides a glyphosate continuous production device and method, specifically related to the continuous production of glyphosate synthetic liquid, pipeline reaction technology of hydrolyzed liquid and tail gas recovery technology. The purpose of the invention is to solve the existing shortcomings of intermittent operation, high labor intensity, high energy consumption and low purity of methyl chloride, improve the yield of glyphosate, the purity of methyl chloride and reduce energy consumption. The present invention increases the content of methyl chloride to 99.9%, increases the yield of glyphosate by 0.5% by realizing the continuous production of the whole process, reduces energy consumption, and is widely used in the field of glyphosate production.

The invention discloses a preparation method of boron carbide superfine powder. The preparation method is based on a boron carbide smelting device which comprises a smelting furnace body built with refractory bricks and a sunken cover plate buckled at a top opening of the smelting furnace body, wherein a positive pole and a negative pole communicating a power supply are inserted into the side wallof the smelting furnace body. The preparation method comprises the following steps: S1, mixing a boron source with a carbon source fully to obtain a smelting raw material; S2, fully filling the smelting furnace body with the smelting raw material and covering the furnace with the sunken cover plate; and S3, applying a voltage to heat the smelting raw material to 1500-1900 DEG C and keeping the temperature for 24-48h to obtain the boron carbide superfine powder. Boron carbide is prepared by means of a nearly closed high-temperature treatment method according to the preparation method disclosedby the invention, so that impurity pollution is reduced, the product is good in crystallinity, the primary content of the obtained boron carbide superfine powder is greater than 96%, and the productgraded meets the demand of an abrasive material, and meets the quality demand on boron carbide powder in the field of grinding industry or engineering ceramics.