Magnesium sulfate heptahydrate production method utilizing waste sulfuric acid from production of cation exchange resin

Abstract

The invention relates to a magnesium sulfate heptahydrate production method utilizing waste sulfuric acid from production of a cation exchange resin. The method is characterized by comprising steps of: mixing magnesium oxide and waste sulfuric acid until a PH reaching 6-7 at a reaction terminal point; adding a flocculating agent into a mixed solution, stirring and standing; removing a supernatant liquid after flocculation, conglobating and sinking of minimal carbides; adding acid; crystallizing and removing free water to obtain a qualified magnesium sulfate product. The invention has beneficial effects that pioneering thinking is utilized to creatively select the waste sulfuric acid from production of the cation exchange resin to produce the magnesium sulfate product, and specific feasible operations and parameters are figured out through tests. On the one hand, a problem of waste sulfuric acid processing in the resin industry is solved; on the other hand, enterprise benefits are increased as well. In addition, the whole production process generates no secondary pollution or waste water.

Description

technical field [0001] The invention relates to a method for producing magnesium sulfate heptahydrate by using waste sulfuric acid, which is especially suitable for waste utilization in the resin industry. Background technique [0002] In the production process of cation exchange resin, the concentration of waste sulfuric acid produced after sulfonation reaction is between 45% and 75%, and its main component contains a large amount of carbides in addition to sulfuric acid, which are very small and cannot be separated by physical methods. . [0003] At present, almost all ion exchange resin enterprises in China are faced with the problem of how to deal with the waste sulfuric acid in the production of cation exchange resins. Many enterprises have used various means to increase the concentration of waste sulfuric acid as much as possible, so as to achieve the sales volume. purpose, but because the waste sulfuric acid after sulfonation reaction contains a large amount of ca...

AI Technical Summary

Problems solved by technology

[0003] At present, almost all ion exchange resin enterprises in China are faced with the problem of how to deal with the waste sulfuric acid in the production of cation exchange resins. Many enterprises have used various means to increase the concentration of waste sulfuric acid as much as possible, so as to achieve the sales volume. purpose, but because the waste sulfuric acid after sulfonation reaction contains a large amount of carbides, the color is as black as ink, basically no customers are willing to accept it, even if it is given away, it is difficult to find users (except for local calcium magnesium phosphate fertilizer enterprises, such Enterprises can accept part to reduce fertilizer cost)

However, the cation exchange resin production enterprises adopting the current technology can recover less than 30% of the waste sulfuric acid that can be directly used no matter what means are adopted, and more than 70% of the dilute waste sulfuric acid needs to be neutralized with lye to meet emission standards

Because enterprises spend a lot of money on the treatment of waste sulfuric acid, which increases the production cost of enterprises, resin production is basically no profit after the waste acid is completely disposed of, so sneaking is the only choice for many enterprises, and many enterprises are Under the pressure of local environmental protection, enterprises were shut down

At the same time, the current cation exchange resin production enterprises do not produce sulfate by themselves with recycled waste sulfuric acid.