关键词: 磷石膏, 反浮选, 提纯, 脱硅

Abstract:

In order to solve the problem of low whiteness and the high silica content of phosphogypsum，the experimental study on removing organic matter and silicate in phosphogypsum was carried out by using single reverse flotation.SEM and EDS analysis were conducted on gypsum after reverse flotation with CM reagent（organic ammonium containing functional groups）.The results showed that the flotation performances of CM reagent were not significantly different at pulp pH ranging from 1.2 to 6.5.CM reagent had better purification effect on phosphogypsum compared with 2^# oil.When the pH of pulp was 3.5 and the dosage of CM reagent was 250 g/t，the calcium sulfate dihydrate content of gypsum in concentrate was 91.23% and SiO₂ content was decreased from 7.6% to 1.89%.The yield of concentrate and the recovery of calcium sulfate dihydrate was 89.53% and 95.08% respectively.The whiteness of concentrate after drying at 45 ℃ was 58%.CM reagent had better removal effect on silicate and organic matter on phosphogypsum surface.The Zeta potential test showed that CM agent not only produced electrostatic adsorption with silicate material in the pulp，but also formed hydrogen bond with it，which improved the selectivity of the agent.The use of CM reagent through a single reverse flotation process had achieved good beneficiation index，laying the foundation for phosphogypsum resource utilization.

Key words: phosphogypsum, reverse flotation, purification, desilication