General scale inhibitor for salt and sodium sulfate co-production technology in salt-making industry

Abstract

The invention discloses a general scale inhibitor for a salt and sodium sulfate co-production technology in a salt-making industry. The general scale inhibitor comprises organic phosphorus and a high-molecular polymer, the high-molecular polymer comprises hydrolytic polymaleic anhydride with a molecular weight being ten million to twenty million, a terpolymer T15, and Antiprex.A, and the organic phosphorus comprises ATMP and EDTMP. By aiming at the technical problem of the salt-making scale inhibitor, the high-efficiency general scale inhibitor is provided for solving the fouling problem of heat exchange equipment of a salt and sodium sulfate co-production system, the product uses the efficient chelating capability of organic phosphorus and excellent dispersion capability of the high-molecular polymer, and can be simultaneously effected on a salt system and a nitre system.

Description

technical field [0001] The invention belongs to the technical field of salt making industry, and in particular relates to a general-purpose scale inhibitor for the salt and nitric acid co-production process in the salt making industry and its application. Background technique [0002] In salt production, scaling of heat exchangers and evaporating tanks is a common problem that plagues all salt production enterprises. Once scaling occurs on salt production equipment, it will reduce heat transfer efficiency, increase energy consumption, and shorten production cycle. At present, there are three methods to solve the equipment fouling problem in the salt making system: adding acid to neutralize, ultrasonic anti-scaling, and adding anti-scaling agent; through actual production inspection, adding acid and ultrasonic descaling have a certain degree of negative impact on production (adding acid It will increase the corrosion of equipment, and at the same time, the pH of the concentra...

AI Technical Summary

Problems solved by technology

At present, there are three methods to solve the equipment fouling problem in the salt making system: adding acid to neutralize, ultrasonic anti-scaling, and adding anti-scaling agent; through actual production inspection, adding acid and ultrasonic descaling have a certain degree of negative impact on production (adding acid It will increase the corrosion of equipment, and at the same time, the pH of the concentrated four-effect brine will reach 11, and the scaling phenomenon is still serious; ultrasonic descaling has no obvious anti-scaling effect on dense and hard calcium carbonate scale)

[0003] Chinese patent application 200910224621.7 discloses a composite scale inhibitor suitable for high hardness and high alkali industrial circulating water, which is composed of hydroxyethylidene diphosphoric acid, polyaspartic acid, polymaleic anhydride, and polyacrylic acid dispersant; this patent The invented product has passed the test, and its scale inhibition rate is extremely low under the condition of salt production. Since most of them are made of high molecular polymers, they have poor chelating ability for calcium and magnesium ions.

Chinese patent application 201210311210.3 discloses a salt scale inhibitor, which is composed of 2-phosphonic acid butane-1.2.4-tricarboxylic acid, diethylene triamine pentamethylene phosphonic acid, polymaleic anhydride, acrylic acid-sulfonic acid Salt-non-ionic terpolymer and deionized water; the formula disclosed in this patent has a high phosphorus content. After the salt factory uses it, the salt quality cannot meet the requirements of the chlor-alkali factory, and the voltage of the ionic membrane will gradually increase, shortening the ionic strength. Membrane service life (according to the actual production inspection, when the phosphorus content of the salt scale inhibitor exceeds 3.5%, the membrane voltage of the chlor-alkali plant will rise sharply and an alarm will be issued)

Moreover, due to the different production processes of the salt system and the nitrate system, the salt system mainly contains free calcium and magnesium ions, so the requirements for the chelation of scale inhibitors are relatively high; the nitrate system is at the end of the whole system, and the brine is continuously evaporated and concentrated , There are mainly glauberite scale and salt scale in the circulation system, so the antiscalant is required to have a strong dispersion ability. The polymaleic anhydride used in this patent has a molecular weight of only 6-8 million, and the dispersion ability cannot reach the requirements of salt-making enterprises. demanding

At present, there is no antiscalant product on the market that can be used in the salt and nitrate cogeneration system at the same time

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