Abstract:

With the development of fine chemicals and intermediate products,the amount of various types of by-product waste salts continues to increase.Due to its large volume and difficult to be treated,it has become to be a critical bottleneck that hin-ders the development of the industry.The purification experimental study of phosphorus-containing waste salt produced as by-product of medicine was carried out.According to the generation method and characteristics of waste salt,methanol/ethanol mixed with activated carbon were used to remove organic matter and sodium chloride in waste salt by elution and recrystal-lization.When the volume to mass ratio of eluent to waste salt is 1 mL/g,the volume ratio of eluent methanol to ethanol is 4∶6,and the mass dosage of activated carbon to the waste salt is 0.4%,the organism in the waste salt has been removed effectively.Subsequently,the obtained mixed salt is recrystallized with the purity of phosphate more than 98%,which meets the industrial phosphate standard.The treatment cost of waste salt is about 174.24 RMB/t and 0.61 t of phosphate can be reco-vered by the above purification and recovery process,realizing the reuse of waste salt.

Key words: waste salt, phosphate, organism, purification