A study on the characteristics of the slurry water at Burtai Coal Preparation Plant

Because of the difficulty for the slurry to settle down,Buertai Coal Preparation Plant is facing the problem of a high consumption of reagent. To avert the situation,analysis is made of the mineral composition,size consist and particle surface potential of coal slurry by using XRD,lazer size analyser and micro-cataphoretic apparatus. Result of study indicates that: the main mineral matters in coal slurry are kaolinite and montmorillonite which as a sort of clay substance are liable to undergo degradation in water and finally become micron size particles,making it very difficult for the slurry to settle down; the slurry water fed into the thickeners of the coarse and small coal washing system all contain a high proportion of minus 0.045 mm fine materials which are 45.8% and 47.1% respectively; and the absolute values of the zeta-potential of the slurry feed to the abovementioned 2 thickeners are all over 20 m V,making the slurry system to remain in a stable state and uneasy to undergo settlement even with the aid of flocculant because of the presence of a large interparticle electrostatic expulsive force.