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 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.