浓度和粒度对细粒煤滤饼结构影响的研究

Study on the structure of fine coal filter cake based on concentration and particle size

为了研究浓度和粒度对细粒煤滤饼结构的影响,对不同条件下的细粒煤进行真空过滤脱水,并采用电子显微镜和计算机图像处理技术对形成的滤饼进行孔隙结构分析,得到滤饼的孔隙率和分形维数,结合过滤速度、滤饼水分和干滤饼密度分析滤饼结构对过滤脱水的影响规律。结果表明:随着煤浆浓度的增加,滤饼的孔隙率减小,从而使过滤速度减小,滤饼水分和密度增大。同一滤饼从底层到上表面,孔隙率减小,分形维数增大。同时物料粒度越细,滤饼分形维数越大,孔隙率越小,特别是当粒度为-0.045mm时,滤饼孔隙率只有5%左右,给细粒煤过滤脱水带来了很大的困难。

In order to study the effects of concentration and particle size on filter cake structure of fine coal,vacuum filtration of fine coal in different conditions was carried out,and the porosity and fractal dimension of the cake were obtained by electron microscopy and computer image processing technology.At the same time,the effects of the filter cake structure on filtration dewatering was investigated combined with the filter velocity,moisture content and density of filter cake.The results showed that with the increasing of the slurry concentration,the porosity of the filter cake reduced which led to the lower velocity and higher moisture content and density of cake.On the other hand,the results also proved that the porosity declined and the fractal dimension increased from bottom to top of a cake.And the finer particle size led to greater fractal dimension and smaller porosity.Especially,the porosity of cake was only 5.2%when its particle was-0.045 mm,which brought a lot of difficulties in filtration dewatering.