Effect of concentrated brine on coal slurry stability and sedimentation

Abstract

In order to solve the problem of comprehensive utilization of concentrated brine in coal chemical industry, the flocculating settlement test was carried out by using concentrated brine instead of coagulant in coal chemical industry, and the effect of pH and gangue content on concentrated brine was investigated. In this paper, the Turbiscan Lab stability analyzer is used to analyze the stability of coal slurry system with different concentration of concentrated brine. The sedimentation rate and supernatant turbidity of coal slurry are analyzed by image analysis method. The results show that the gangue minerals in this coal sample are mainly kaolinite and quartz, and the clay minerals are mostly kaolinite. The coal chemical concentrated brine is used as a coagulant.With the increase of its dosage, the stability of slime water first becomes weak and then stronger, and the settlement effect is the best when the stability is the worst. However, the addition of excessive brine will introduce too many cations, which will lead to the stabilization of slime water. The higher the waste rock content, the more difficult the coal slurry to settle. The coal slurry settlement effect gets better and then worse with the decreasing of pH value. The optimum settlement condition is pH=5.

Keywords

• coal slurry water
• concentrated brine
• sedimentation
• turbiscan stability index (tsi)