Effect Of Different Driving Forces On Filtration Dewatering Of Fine Coal

In recent years,with the increased mechanization of coal mining,mining of fine coal in coal increased,coal washing and processing before using is effective means to reduce economic pollutant emissions,in the coal washing process,for coal and gangue dissociation and coal pulverizing,which is more big content in the fine coal preparation plant.The loss of fine coal is not only a waste of resources,but also pollute the environment,so it is necessary to strengthen the recovery of fine coal;coal preparation plant in China at the present stage,basically are used in wet coal preparation technology to carry on the separation of coal products,water is an important index to evaluate the quality of coal.Increase the content of fine coal washing process,will lead to serious deterioration of the dehydration effect,moisture index of the product is difficult to guarantee,therefore,to explore the fine coal dewatering effect optimization is of great importance to economic and practical significance with the current.A new type of vacuum-this paper designed and made the two stage combined pressure filtration dehydration equipment,coal were optimized conditions of fine coal dewatering process optimization,vacuum dehydration process conditions of fine coal pressure filter dewatering process optimizationand vacuum pressure combined with two stage filtering on the test,find out the optimum conditions in the filter form,and compare them to.At the same time,this paper selects 7 different types of surfactants,6 kinds of polyacrylamide and polyaluminium chloride respectively in the form of filtering the optimal operation conditions of fine coal dewatering test,and compare the effect and regularity of optimum medicament type and dosage of additives in various types;and the a typical type of agents selected,two or three combined filter and compared in various forms through filtration;new compound additives made,explores the form of the filter filter.Finally,through the measurement of the contact angle and the surface tension of each filter aid,the filtering effect of fine coal is studied from the microscopic mechanism.The results of the study and the research shows that:1.Through the single factor test,vacuum dewatering of fine coal optimal operating conditions: the concentration of coal slurry is 300g/L,vacuum degree of filtration for 0.06 MPa,filtration time 4min,fine coal treatment capacity is150 g,the moisture content of filter cake: 26.08%;fine coal pressure filter dewatering process conditions optimization results are as follows: the concentration of coal slurry 450g/L,pressure size 0.6MPa,press 3min,fine coal treatment capacity is 240 g,the moisture content of filter cake: 22.03%;fine coal vacuum pressure combined with two stage filtration dehydration process optimization results are as follows: the concentration of coal slurry is 550g/L,by the vacuum degree of 0.06 MPa 3.5min and 0.6Mpa vacuum filtering.Pressurefilter 2.5min,fine coal processing capacity of 300 g,by the above conditions can get the moisture content of filter cake is 18.37%.2.Whether it is in the fine coal vacuum and pressure filtration and vacuum pressure of two stage combined dewatering under the action of surface active agent on the selection of test filter effect of coal sorting are: nonionic surfactants>anionic surfactants>cationic surfactants,and seven kinds of surfactants in the best effect the Span-80 amount is only 60g/t;selection of polyacrylamide by filter to test the effect of coal sorting are: anion > cation > nonion,and in polyacrylamide filter each of different molecular weight,molecular weight of 15 million is better than filter a molecular weight of 6 million was better than that of filter the lower moisture content of the cake after filtration;the optimum mixture ratio of Span-80: compound additives in self-made kerosene is 1:30,and the compound medicament components had a synergistic effect.3.Combined filter test in the operating conditions of each filtering optimum form respectively with typical pharmaceutical optimized show that in pairs agents combined filter,Span-80+HPAM(15 million)composite filter optimization;three typical combined agents than combination filter effect of two kinds of typical agents are better than any.4.The two stage of the vacuum pressure combined with reagent on fine coal dewatering test limit inquiry shows that when using two stage vacuum pressure combined with appropriate reagents or their combination,fine coalslurry dewatering limit can reach the moisture content of filter cake to about13%.