Removal of minim iodine ion from brine liquor which is material of caustic soda produced by ion membrane method

Abstract

The removing method for micro iodine ion in brine comprises: in acid condition, using one or more of H2O2, NaClO, FeCl3, and NaClO3 as oxidant to oxygenate the I- into I2; using one or more of active carbon, molecular sieve, carclazyte and diatomite as sorbent for adsorption. This invention reduces the iodine-content from 0. 1-5mg / L to less than 0. 05mg / L and meets the production request (less than 0. 2mg / L) for NaOH with ion film method.

Description

Technical field [0001] The utility model relates to a method for removing trace amounts of iodide ions in brine as a raw material of ion-exchange membrane caustic soda. Background technique [0002] At present, the raw materials used in soda production by ionic membrane method include industrial salt, raw brine plus brine and whole brine. The whole brine soda production is valued by all countries in the world because of its low cost and simple process, but the original brine often contains a relatively high amount of iodine Compounds, these iodides will precipitate in the form of iodate during electrolysis, resulting in reduced current efficiency and shortened ion membrane life. The data show that when I - When the content is greater than 0.4mg / L (or even 0.2mg / L), the life of the ionic membrane will be greatly reduced. There is no good solution to this problem. The article QUALITY: REMOVAL OF BROMIDE, IODIDE AND CHLORATE' introduces a method of using anion resin to remove ...

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Problems solved by technology

[0002] At present, the raw materials used in soda production by ionic membrane method include industrial salt, raw brine plus brine and whole brine. The whole brine soda production is valued by all countries in the world because of its low cost and simple process, but the original brine often contains a relatively high amount of iodine Compounds, these iodides will precipitate in the form of iodate during electrolysis, resulting in reduced current efficiency and shortened ion membrane life. The data show that when I - When the content is greater than 0.4mg / L (or even 0.2mg / L), the life of the ionic membrane will be greatly reduced. There is no good solution to this problem. The article QUALITY: REMOVAL OF BROMIDE, IODIDE AND CHLORATE' introduces a method of using anion resin to remove iodine by ion exchange. This method is to use sodium hypochlorite to remove I - Oxidized to I 2 , I 2 with Cl - Combined generation (I 2 Cl) - , and then removed by anion resin exchange

Its shortcoming is that the resin is expensive, the equipment investment is large, the operating cost is high, and the regeneration of the resin requires a large amount of regeneration liquid, which produces a large amount of waste water and waste liquid, causing environmental pollution, and the adsorbed I 2 Not easy to recycle

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