Improved wet dihydrate phosphoric acid producing process

Abstract

The improved wet dihydrate phosphoric acid producing process has sodium dodecanol sulfate and sodium dodecyl benzene sulfoante in certain ratio are first compounded into water solution of 2-30 wt% concentration, and then added into phosphoric acid, with the added amount being 30-300 ppm. The addition of the water solution of sodium dodecanol sulfate and sodium dodecyl benzene sulfoante in the extraction step and concentration step of wet phosphoric acid production can reduce the scaling in production apparatus and pipeline obviously, and can also raise concentration evaporating strength and apparatus capacity and lower concentrated steam consumption.

Description

Technical field [0001] The present invention relates to the production of dihydrate wet-process phosphoric acid. More specifically, the present invention relates to a method for preventing scaling of the dihydrate wet-process phosphoric acid production equipment, and capable of increasing the production capacity of the device and reducing consumption. Background technique [0002] With the depletion of phosphate rock resources, the content of impurities such as potassium, sodium, silicon, fluorine, iron and aluminum in the phosphate rock increases. The microcrystalline composite salt precipitated in the dihydrate wet-process phosphoric acid reaction and filtration and washing processes is supersaturated. Substances, serious scales on equipment and pipelines, often need to be shut down for cleaning, which seriously affects the operation rate and production capacity of the wet-process phosphoric acid reactor. Moreover, because the fouling layer is dense, the ...

AI Technical Summary

Problems solved by technology

[0002] With the depletion of phosphate ore resources, the content of impurities such as potassium, sodium, silicon, fluorine, iron and aluminum in phosphate ore increases, and the microcrystalline composite salts that are supersaturated and precipitated in the dihydrate wet phosphoric acid reaction, filtration and washing process Severe fouling on equipment and pipelines often requires shutdown and cleaning, seriously affecting the operation rate and production capacity of wet-process phosphoric acid reactors

Moreover, due to the dense scale layer, process cleaning does not work; manual cleaning is labor-intensive, time-consuming, labor-intensive, low-efficiency, and increases more cleaning costs

[0003] In the dihydrate wet-process phosphoric acid concentration process, the microcrystalline compound salts precipitated by supersaturation are suspended in the circulating acid liquid phase, which increases the solid content, viscosity, surface tension and boiling point of the circulating acid, reduces the evaporation strength, and Significantly increase the steam consumption, which seriously affects the operation rate, production capacity and production cost of the wet-process phosphoric acid concentration plant

[0004] In addition, in the process of separating the solid phase by the concentrated phosphoric acid clarification method to produce commercial wet-process phosphoric acid, it is also due to the fine crystal grain size of the microcrystalline compound salt precipitated by supersaturation, which is not easy to settle and difficult to separate, which seriously affects the production capacity of the production device