Process for removing arsenic from diethylene triamine penta(methylene phosphonic acid) (DTPMPA)

Abstract

The invention provides a process for removing arsenic from diethylene triamine penta(methylene phosphonic acid) (DTPMPA). The process has the advantage of low production cost and comprises the following steps: adding 400-1000 parts by weight of DTPMPA which does not undergo arsenic removal treatment to a reaction kettle, pumping steam from the jacket of the reaction kettle to adjust the temperature of the materials in the kettle to 20-70 DEG C, then adding 0.1-1 part by weight of arsenic removing agent phosphorus pentasulfide, then adding 0.2-2 parts by weight of active carbon, washing the charging hole with 0.5-2 parts by weight of pure water after charging and then preserving the heat in the temperature range of 20-70 DEG C for 1-5 hours; and later filtering the DTPMPA, heating the clean DTPMPA after filtration to 80 DEG C, externally steaming the clean DTPMPA under negative pressure for 1-3 hours, before completing external steaming, firstly analyzing the activity, adding pure water for dilution according to the activity result, pumping cooling water from the jacket of the reaction kettle to cool the materials in the kettle to 40-50 DEG C and discharging the DTPMPA.

Description

A process for removing arsenic from diethylenetriaminepentamethylenephosphonic acid technical field The invention relates to a process for removing arsenic, in particular to a process for removing arsenic of diethylenetriaminepentamethylene phosphonic acid. Background technique Diethylenetriaminepentamethylenephosphonic acid, also known as diethylenetriaminepentamethylenephosphonic acid, has a molecular formula of C9H28015N3P5, and its English abbreviation is DTPMPA. It is an organic phosphonic acid scale and corrosion inhibitor. , zinc and other metal ions form stable complexes, dissolve oxides on the metal surface, and can still play a good role in corrosion and scale inhibition at 250 ° C, and is still very stable at high pH, ​​not easy to hydrolyze, and generally light It is not easy to decompose under hot conditions, and its acid and alkali resistance and chlorine oxidation resistance are better than other organic phosphonic acids (salts). It can form a six-membered ...

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Problems solved by technology

In the prior art, there is no process for dearsenic treatment of aminotrimethylene phosphonic acid, only a patent No. 200810230638.9 discloses a hydroxyethylene diphosphonic acid with an arsenic content ≤ 3ppm and its preparation process , the process uses ammonium thioacetate as the arsenic removal reagent in the production process of hydroxyethylidene diphosphonic acid, but ammonium thioacetate is expensive and difficult to purchase, and there are few domestic manufacturers, basically relying on imports, and the method uses The amount of ammonium thioacetate is too large, which greatly increases the production cost, which is not conducive to the practical application in industrialized production

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