| Against the flaws like short operation cyclic, deficiency in economic in the field of traditional treatment of coal washing wastewater, a new approach of filter equipment packed by different materials was carried out to the disposal of coal washing wastewater. The turbidity of outlet suspended load could be highly decreased by filter unit with quartz sand or lime stone packing, the discharging water quality was increased and the environmental hazard was cut down.In this experiment, local quartz sand of which diameter is 0.8～1.2 mm and K80=1.48 is implemented as flitting material. Acryl glass filtration column supporter is also used with monolayer. Firstly, the filter capability of quartz sand and lime stone were compared by assaying the outlet turbidity variation under the conditions of changing the inlet turbidity of coal washing wastewater and the filtering velocity. The filtering period of lime stone was stayed in stable at 1.4 h when the filtering velocity was at 6 m/h, 8m/h and 10m/h; the filtering period of quartz sand was decreased gradually, and the shortest of which was 2.6 h. The outlet turbidity of quartz sand was 5 NTU compared to 30 NTU of lime stone; the highest removal ratio of quartz sand was 97.64% compared to 87.86% of lime stone. The intensity of backwash was 20 L/(m~2·s), the outlet turbidity was 2.5 NTU after 16 min backwashing of quartz sand in the comparison of 44 L/(m~2·s) in intensity, 2.5 NTU after 12 min. The conclusion indicated that, the quartz sand filter has the advantages of longer filtration period, smaller hydraulic pressure loss, higher turbidity remover rate, more equally impurity interception, less water consume in counter washing. Secondly, an orthogonal test experiment under the changing of speed, filter layer thickness, filer material diameter was taken and the optimal experimental parameter was concluded. The finding is when the percolation speed at 6 m/h, the filter layer thickness at 80 cm and the d10 at 0.83 mm the compositive capability is the best, and the biggest MSC and FPI value at 880.6 and 226.0, the smallest JP value at1.58 which indicated the best combination property was get. The water loss of pure filter layer was gained like equation 4.19. At last, the double layer filtering system with quartz sand and lime stone was studied basically. The removal ration of turbidity of coal washing wastewater was considered under the same filtering period between monolayer quartz sand system and double layer system packed with quartz sand and lime stone. The results showed that the double system had a longer filtering cyclic at 4 h and a higher turbidity removal ration of 99%.This paper evaluates power consumption, water consumption per year and the processing ability when quartz sand filter is used. After detailed analysis, a conclusion was made that quartz sand filtering system has a strong ability of dealing with coal waste water, which also has a good economy advantage and practical usage.
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