A kind of purification production method of low-cost environment-friendly grade sodium salicylate

Abstract

The invention discloses a method for purifying and producing low-cost environment-friendly sodium salicylate, which comprises the following steps: step 1, putting the raw material of sodium salicylate into an airtight container, then adding pure water for stirring and soaking, and after soaking completely, Carry out dehydration treatment, and then dissolve with pure water; step 2, after the dissolution is complete, add ethylenediaminetetraacetic acid to the solution and keep stirring, and then keep warm for precipitation; step 3, after keep warm for precipitation, filter the solution, and then concentrate 1. Cooling and crystallization; Step 4. After the crystallization is complete, dehydration treatment is performed to obtain primary crystallization, and the product is finally obtained after drying the primary crystallization. The present invention improves the primary purification effect and reduces the number of recrystallizations by means of chelate removal and aqueous solution removal, so that the product meets the requirements of environmental protection, greatly reduces the production cost of the enterprise, improves the profit margin of the enterprise, and solves the problem of The deficiencies in the existing production methods have been eliminated.

Description

technical field [0001] The invention relates to the technical field of sodium salicylate purification, in particular to a production method for the purification of low-cost environment-friendly grade sodium salicylate. Background technique [0002] Sodium salicylate is a white scale or powder, soluble in water, glycerin, insoluble in ether, chloroform, benzene, mainly used for analgesics and rheumatism, also used as organic synthesis and analysis reagents, general sodium salicylate The preparation is: cross-add salicylic acid and sodium bicarbonate into distilled water, keep the temperature at 60°C, and keep it in an acidic state, and add appropriate amount of ethylenediaminetetraacetic acid (EDTA) and sodium bicarbonate at the same time. Raise the temperature to 85°C and react for half an hour. The qualified reaction solution is filtered and sent to the ebullating bed, and dried at 85°C to obtain sodium salicylate. [0003] At present, high-purity environmentally friendly...

AI Technical Summary

Problems solved by technology

This method replaces pure water with ethanol, and adsorbs precipitated particles with activated carbon. Although ethanol can be recycled, it has the following disadvantages: 1. The amount of ethanol used is large and energy consumption is large. Generally, 50 kg of sodium salicylate is used in industry The raw material is produced in one batch, and each batch needs to use 270L of 95wt% ethanol, which requires a large amount of use, and the energy consumption of water bath and distillation recovery in the later stage is large, and the ethanol itself is highly volatile, and the loss of ethanol in the production process is large, and its production cost is obviously high Recrystallization and refining in aqueous solution; 2. The mother liquor contains a lot of impurities, and repeated use will affect the purity. When ethanol is used as a solvent, some organic impurities and heavy metals will also dissolve in the mother liquor. These impurities are trace amounts, which cannot be removed by activated carbon adsorption. After the mother liquor is reused, the content of these impurities accumulates. When the crystallization is concentrated and crystallized in the later stage, these impurities will be entrained in the crystallization, resulting in an increase in the content of crystallized impurities. It is foreseeable that the purity of the final product will not meet the standard.

Therefore, this purification method cannot be used to solve the problem of low-cost production of high-purity environmentally friendly sodium salicylate by enterprises

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