Research On The Preparation And Properties Of Oil-Water-Coal Slurry Of Shenfu Coal

Oil-water-coal slurry is a fluent consisted of shenfu coal, water and oil. Besides oil and water, shenfu coal is the primary constituent of the slurry. As a new kind of coal-based fuel, it has many advantages such as protecting environment, high combustion efficiency and low ignition point. Oil-water-coal slurry can be widely utilized as oil in industrial boilers and power plant boilers. With the development of society and high environment standards, it is imperative to speed up the pace of a clean and efficient use for coal. The main contents of this paper can be concluded as the following aspects.Firstly, the slurrying characteristics of the oil-water-coal slurry was studied. A suitable type of additives and the best amount of additives were found. The slurrying technology, slurried ingredient, particle size distribution influent to the apparent viscosity is analyzed. The results showed that the dry and wet slurrying method was superior to any other methods including dry slurrying and wet slurry and it was found that apparent viscosity increased with the content of either coal or oil increased.Secondly, the rheological properties of the oil-water-coal slurry was studied. The results indicated that the oil-water-coal slurry belonged to a yield-pesudo-plastic fluid and yield stress existed. The rheological curve was fitted by rheological model, and the achieved results shows that rheological properties of oil-water-coal slurry coincided with Herschel-Bulkley model.Thirdly, the stability of the oil-water-coal slurry was studied. Ash added directly into the slurry affected the stability of oil-water-coal slurry. Metal positive ions originated from ash made the particle surface potential reduced, but it reduced the repulsion among the solid particles and increased the slurry structured degree. Therefore, the stability of the slurry improved in the presence of the metal positive ions. When the ratio of thick and thin particle was 13: 1, the slurry remained uniform by standing method after 6 months. At the same time, the stability of oil-water-coal slurry was researched utilizing the size models, the results manifested that the stability of the slurry increased with the particle size distribution became wider. Using particle size distribution data model for theoretical calculations, it was found that the actual particle size distribution of the sample above 25μm particle size was closer to the size model, but the content of sample which size was less than 25μm was lower, and it was not suitable for the size mode. As the content of fine powder increased, the content of less than 25μm particle size enhanced, the friction force among the particles increased and for this reason, the relative sliding among the coal particles become difficult, which it prevented the coal particles sinking and improved slurry stability. The actual data of the theoretical distribution is closer to R-R model.