A production improving agent and chemical improving method for concentrated production of wet-process phosphoric acid

Abstract

The invention relates to an improved medicament and a chemical improvement method for the wet method phosphoric acid concentration production. The improved medicament suitable for the wet method phosphoric acid concentration production is characterized by comprising the following components in percentage by weight: 69-75% of an efficient scale inhibition and dispersion agent, 0.1-0.2% of polyacrylamide, 23-30% of a solubilizer and 0.5-2% of an oxidizing agent. According to the chemical improvement method, the improved medicament suitable for the wet method phosphoric acid concentration production in the claim 1 is added into wet method phosphoric acid concentration production. The improved medicament is used for the improvement of the wet method phosphoric acid production, not only can prevent scaling substances from adhering to or depositing on phosphoric acid concentration equipment or the inner wall of a pipeline, but also can accelerate the settlement of suspended impurities in a concentrated phosphoric acid product, remove chromophoric groups in the concentrated phosphoric acid, and improve the quality of the concentrated phosphoric acid product.

Description

technical field [0001] The invention relates to the improvement technology of wet-process phosphoric acid concentration production, which is used to prevent fluorosilicate and secondary precipitation salt in phosphoric acid from adhering and depositing in equipment and pipelines in the process of wet-process phosphoric acid concentration production, and at the same time accelerate the suspension of product concentrated phosphoric acid Impurity precipitation, production improvement agent and chemical improvement method for removing chromophoric groups in concentrated phosphoric acid. Background technique [0002] During the concentrated production process of wet-process phosphoric acid, the cations dissolved in dilute phosphoric acid mainly include Ca 2+ , Mg 2+ 、Al 3+ , Fe 3 + 、Na + 、K + , Zn 2+ , Pb + etc., the anions are mainly SO 4 2- 、SiF 6 2- , SiO 3 2- , F - etc., they are extremely unstable in phosphoric acid, and are easy to deposit or crystallize on t...

AI Technical Summary

Problems solved by technology

[0002] During the concentrated production process of wet-process phosphoric acid, the cations dissolved in dilute phosphoric acid mainly include Ca 2+ , Mg 2+ 、Al 3+ , Fe 3 + 、Na + 、K + , Zn 2+ , Pb + etc., the anions are mainly SO 4 2- 、SiF 6 2- , SiO 3 2- , F - etc., they are extremely unstable in phosphoric acid, and are easy to deposit or crystallize on the inner wall of equipment or pipelines. In addition, during the concentration process of wet phosphoric acid, as the water in phosphoric acid evaporates rapidly, the impurities originally dissolved in it will appear supersaturated These crystals are mainly fluorosilicate and some secondary precipitated salts, which are attached or deposited on the wet-process phosphoric acid concentration production equipment and the inner wall of the pipeline to cause blockage, which seriously affects the continuous and stable operation of production. It takes as little as five or six days, and as many as fifteen to twenty days, to stop and clear the blockage due to serious fouling, which not only brings a lot of cleaning and maintenance costs and labor costs, but also seriously affects the performance of the equipment due to frequent parking. shorten its life

The traditional method of cleaning dirt is generally to use a high-pressure water gun to clean first, and then pickle. The high-pressure water gun cleaning process will inevitably cause damage to the graphite tube and affect its service life. Improper operation may cause the graphite tube to rupture, which is not a long-term solution.

[0003] At present, many chemical methods for scale inhibition in the production process of wet-process phosphoric acid concentration have been reported at home and abroad. Generally, agents containing traditional scale and corrosion inhibitors or scale and dispersants are added to the concentration system, which to a certain extent It can delay the fouling of the concentration system and prolong the start-up period of the system. However, in practical applications, the start-up period can only be extended by 5 to 10 days, and it has no effect on other aspects of the production process. The graphite tube of the heat exchanger is seriously blocked, and the scale is dense and hard, which reduces the concentrated production of phosphoric acid. 2 o 5 The average unit hour output, thus bringing the application effect that the gain outweighs the gain