Study On Coal Water Slurry Technology Of Ningxia Sticky Coal

Lingwu coalfield mainly coking coal, its characteristics are low degree of metamorphism and difficult to prepare. In this paper, according to the different types of Lingwu coalfield non coking coal, the problem of poor slurry ability and large viscosity exist in the preparation process. To explore the relationship between coal slurry ability with coal structural characteristics and property, a method of coal petrography is put forward, it reveals that the coal structure and properties have closely relationship. It establishes an evaluation method for coal slurry preparation of Ningxia coal, it provides an important guidance for industrial production of coal water slurry in Ningxia. In this paper, according to test for 22 kinds of coal, including moisture, ash, grind ability index, the oxygen functional groups, contact angle and microstructure of petrography samples etc, the relationship between test data and slurry ability is studied. Get the following conclusion:1) The inner water is less than 4%, the coal slurry concentration is more than 60wt%, the inner water is between 6% and 10%,the slurry concentration below 60wt%.2) When the inner water is less than 4%, the higher of coal ash, the higher slurry concentration. Both the inner water and coal ash affect slurry concentration of coal water slurry.3) The results of surface tension of coal ash show that:by using approximate alternative elements calculation of coal samples in Si, Al, Fe, Ca, Mg, Na, K, the surface tension force is inversely proportional to slurry concentration, the trend is consistent with the actual industrial production.4) The D value is stands for the difficulty of slurry ability, the D value is less than 7, the coal is relatively easy to prepare, the slurry concentration is above 60wt%. The D value is more than 7, the coal slurry concentration is below 60wt%, it is not easy to prepare. This conclusion is in good agreement with the result of coal water slurry in the experiments.5) The coal with dense rock surface, few pores and cracks, its slurry concentration is more than 65wt%, the coal with average dense rock surface, a small amount of cracks, porosity, its slurry concentration is between 60wt% and 64wt%, oxygen functional groups of these coals are relatively less, the inner water is less, the slurry concentration is high. But the coal with soft rock surface, a large number of cracks, and developed pores, the oxygen functional groups with high contents, the inner water is higher, the slurry concentration is below 60wt%. Coal petrography microstructure analysis showed that the more rock fissures developed, the more holes, silk group of components, the more difficult to prepare.