METHOD FOR PRODUCTION OF CORROSION INHIBITOR Russian patent published in 2022 - IPC C23F11/167 

FIELD: power engineering; utility sector.

SUBSTANCE: invention relates to inhibitors of metallic material corrosion, as well as the formation of scale, in particular to metal corrosion inhibitors based on nitrilotrismethylene phosphonic (hereinafter – NTP) acid complexes with zinc; it can be used to protect metal parts of technological equipment in oil and gas, chemical, food industry, boilers, boiler auxiliary equipment, heat exchangers, pipelines and other equipment in power engineering and utility sector. The method includes loading 0.5-0.8 of the calculated amount of sodium hydroxide and the calculated amount of zinc oxide into the reactor, gradually adding the calculated amount of NTP acid, while after the gas release is stopped, the remaining amount of sodium hydroxide is added. The process is carried out at a temperature of no more than 80-90°C and an absolute pressure of 0.5-0.8 kgf/cm² with continuous boiling of the reaction mass and continuous pumping of released vapors and gases to maintain the specified pressure throughout the process. The resulting mixture of reaction products is transferred to a crystallizer and subjected to crystallization with constant mixing, and the separation of liquid and crystalline phases is carried out by centrifugation.

EFFECT: increase in the yield of the target product by preventing hydrolysis of NTP acid and reduction in the content of impurities in the target product of a crystalline form.

2 cl, 4 tbl, 5 ex