Method for producing sodium periodate

Abstract

The invention discloses a method for producing sodium periodate. The method comprises the steps of preparation of trisodium dihydrogen periodate, preparation of sodium periodate, crystallization and separation, centrifugal dehydration and drying, wherein the preparation step of the trisodium dihydrogen periodate sequentially comprises the steps of preparation of sodium hydrogen iodate, preparation of sodium iodate and oxidation with sodium persulfate. The trisodium dihydrogen periodate is obtained by reacting sodium chlorate and iodine in an aqueous solution to produce the sodium hydrogen iodate, neutralizing the sodium hydrogen iodate by using sodium hydroxide to obtain the sodium iodate and oxidizing the sodium iodate in the sodium hydroxide solution by using the sodium persulfate, so that the method for preparing the trisodium dihydrogen periodate by using chlorine, iodine and sodium hydroxide in the prior art is abandoned, and the production method is stable in reaction, easy to control and high in production safety degree. Compared with a chlorine oxidation method, the method has the advantages of low consumption of raw materials, small amount of discharged waste liquor and environment friendliness.

Description

technical field [0001] The present invention relates to a kind of production method of sodium periodate, be specifically related to iodine, sodium chlorate (NaClO 3 ), sodium hydroxide, sodium persulfate (Na 2 S 2 o 8 ), nitric acid and water are the method for raw material production sodium periodate. Background technique [0002] Sodium periodate, or sodium metaperiodate, has the molecular formula NaIO 4 , which is a colorless or white tetragonal crystalline powder with a relative density of 3.865, melts and decomposes at 300°C, and is soluble in water (solubility in water: 0°C 4.17g / 100gH 2 O, 25°C 12.62g / 100gH 2 O), sulfuric acid, nitric acid, acetic acid, insoluble in sodium hydroxide and ethanol, its aqueous solution generates H due to hydrolysis + and H 3 IO 6 2+ And acidic. Sodium periodate is the main raw material in the pharmaceutical industry. It is used in the food industry and pharmaceutical industry. It can be used as an oxidizing agent, general analy...

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Problems solved by technology

[0005] The shortcoming of this method is: the consumption of raw material is big, and economic cost is high, and from reaction equation, the sodium periodate of producing 1mol needs to consume the sodium hydroxide of 10mol, the chlorine of 3.5mol, also can produce the chlorine of 7mol simultaneously sodium chloride, resulting in the discharge of a large amount of stock solution and high-concentration sodium chloride solution, causing great environmental pollution and increasing the difficulty of safe and environmentally friendly production. At the same time, a large amount of chlorine gas is used in the preparation process. It is a yellow-green toxic gas with a pungent smell. It must be used and stored very carefully. It has strict requirements on the conditions of use and storage equipment. Therefore, the use of chlorine gas oxidation to prepare sodium periodate has strict requirements on safe production. The method is cumbersome and complicated, the operation is difficult to control, and the safety degree is low

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