Flocculation Sedimentation Experiment of Highly Muddy Slime Water and Its Application Research in Coal Preparation Plant

Aiming at the problems of low sedimentation efficiency, poor clarified water quality, and heavy system load in highly muddy slime water of the coal preparation plant of Shangshe Company, the analysis finds that the content of fine particles with a particle size less than 0.045 mm in the slime water reaches 83.39%, with an ash content of 56.59%, enriched with kaolinite, quartz, and montmorillonite, which severely restricts the sedimentation performance. For the first time, the research introduces the identification of mudification characteristics and mineral composition analysis into the flocculation process optimization, the optimal parameter combination is determined by adopting orthogonal experiment method: flocculant 5 mg/L, coagulant 900 mg/L, slime water concentration 30 g/L, and an integrated optimization and transformation technology path suitable for highly muddy slime water is constructed. The application results indicate that the sedimentation speed is improved from 8.5 m/h to 11.2 m/h, the turbidity of the clarification layer is decreased from 610 NTU to 370 NTU, the bottom flow concentration is improved from 380 g/L to 460 g/L, the suspended solids in the circulating water are decreased from 1350 mg/L to 1050 mg/L (with a decrease of 22.2%), and the equipment failure rate is decreased by over 30% compared to before optimization. The research effectively improves the processing efficiency and stability of the system, and the economic benefits are significant.