| 摘要 |
PURPOSE:To obtain the titled slurry having a high degree of deashing and a desired particle diameter distribution, by mixing a first froth obtd. by making use of a first floating machine with a third froth obtd. by grinding a second froth and recovering the third froth by making use of a second floating machine and kneading the mixture after addition of a dispersant. CONSTITUTION:Raw coal 11 which has been ground so as to have a max. particle diameter of 3mm or less is fed together with water into a wet mill 12, where it is pulverized so as to have a particle diameter of 300mum or less. Water is added to the pulverization product to prepare a raw coal slurry 13 having a concn. of 2-15wt%. The raw coal slurry is fed into a first floating machine 14. A given amt. of a floating agent is added to the slurry, and a first froth 16 in an amt. corresponding to 50-70wt% of the fed coal and contg. low-ash coal having a relatively small particle diameter is recovered therefrom. The floating agent is further added to the residual slurry to obtain a second froth 17 contg. medium-ash coal having a relatively large particle diameter. The second froth is optionally pre-dehydrated and fed into a wet mill 18, where it is pulverized so as to have a particle diameter of 30-50mum. The pulverization product is then fed into a second floating machine 14', where it is deashed again in the presence of a floating agent to obtain a third forth 16' composed of a low-ash coal slurry. The third froth is concentrated together with the first froth 16 by means of a dehydrator 19 to have a water content of 25-35%. The dehydration product is kneaded with a dispersant by means of a kneader 20 to obtain the titled slurry 21.
|
