Preparation method of calcium thiosualfate

Abstract

The invention is applicable to the field of preparation of compounds and provides a preparation method of calcium thiosulfate. The preparation method comprises the following steps: taking oxidized filtrate of a sulfide dye and a hydrochloric acid diluted solution to react in a corrosion-resisting container at the mass ratio of 1 to 0.54; filtering a thiosulfuric acid and sodium chloride mixed solution generated at a low-temperature condition to obtain filter cake impurities and clarified filtrate; taking the clarified filtrate and calcium chloride to react in the corrosion-resisting container at the mass ratio of 1 to 0.97; filtering a mixed solution of the calcium thiosulfate generated by the clarified filtrate and the calcium chloride, hydrochloric acid and previous sodium chloride to obtain filtrate containing the calcium thiosulfate and the sodium chloride; putting the filtrate containing the calcium thiosulfate and the sodium chloride into a decompression distiller to obtain the calcium thiosulfate, the sodium chloride and distilled liquid. By reutilizing the oxidized filtrate of the sulfide dye, the oxidized filtrate of the sulfide dye is effectively managed and the environment is protected; the equipment cost is reduced and economic benefits are created.

Description

technical field [0001] The invention belongs to the field of compound preparation, in particular to a preparation method of calcium thiosulfate. Background technique [0002] Sulfur blue, also known as sulfur element or sulfur black, is the most consumed sulfur dye. Due to different production process conditions and user requirements, many kinds of sulfur blues with different colors can be produced. Domestically produced sulfur blacks BN (blue light), BRN (blue red light), RN (red light), BN double, BRN double and other varieties. [0003] The production of double sulfide blue BRN is made of dinitrochlorobenzene and sodium hydroxide as raw materials, which are hydrolyzed into 2,4-dinitrophenol sodium salt, vulcanized with sodium polysulfide, and then oxidized by air, filtered and dried. It is obtained by drying and crushing processes. [0004] The oxidation filtrate comes from the post-oxidation filtration process, which includes filtered wash water. The ratio of the pro...

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Problems solved by technology

[0006] The embodiment of the present invention provides a preparation method of calcium thiosulfate, which aims to solve the problem of the high cost of preparation of calcium thiosulfate in the prior art, the harm of the oxidation filtrate to the environment, and the waste of resources caused by the inability to effectively utilize its economic value The problem

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