School of Chemical & Environmental Engineering，China University of Mining and Technology(Beijing)，Beijing ,China

为了解决煤泥水过滤速度慢、滤饼水分高和卸饼难的问题,基于滤饼孔隙结构的调控,提出了煤泥水分段过滤的工艺。利用煤泥水过滤装置和煤泥滤饼孔隙测量装置,研究了煤泥水分段过滤对滤饼水分、成饼时间、脱水速率和滤饼孔隙结构的影响。研究结果表明:与混合过滤相比,煤泥水分段过滤的滤饼水分低、成饼时间短和脱水速率大,且随着煤泥中-0.074 mm粒级含量的增加,煤泥水分段过滤对滤饼水分、成饼时间、脱水速率的影响先快速增加,达到最大后降低,影响最大的位置在-0.074 mm粒级含量20%~40%;煤泥水分段过滤减少了-0.074 mm粒级对大孔隙的填充,导致滤饼中孔径小于4μm的孔隙含量变化不大,孔径4~50μm的孔隙含量显著减少,孔径大于50μm的孔隙含量明显增大,滤饼的孔隙率增大。

In order to solve the problem of slow velocity of filtration,high moisture of filter cake and filter cake unloaded difficultly,the process of subsection filtration for coal slurry was proposed based on the regulation of pore structure of filter cake.Using coal slurry filtration device and pore measurement device for filter cake,the effect of subsection filtration for coal slurry on filter cake moisture,formation time for filter cake,dehydration rate and pore structure of filter cake were studied.The results show that compared with hybrid filtration for coal slurry,the moisture of filter cake is lower,the formation time is shorter,and the dehydration rate is larger.With the increase of -0.074 mm particles content,the effect of subsection filtration for coal slurry on filter cake moisture,formation time and dehydration rate increases rapidly,reaches the maximum and then decreases.When -0.074 mm particles content is between 20%～40%,the subsection filtration for coal slurry has the most remarkable effect.Essentially,the subsection filtration for coal slurry reduces the filling of -0.074 mm particles to large pores,with the result that the content of pores with size less than 4 μm is little change,the content of pores with size 4～50 μm is significantly reduced,the content of pores with size larger than 50 μm is obviously increased,and the porosity of filter cake for coal slime is larger.