Research on washing water treatment process of fast-opening diaphragm filter press in coal processing plant

introductory

Zhangcun Mine Coal Processing Plant was put into operation in June 1998, which is a mine-type anthracite coal processing plant with a design capacity of 400,000 t/a. , After technological transformation, the washing capacity is increased to 600,000t/a, and the main products are washed lump coal, final coal, screened blended coal and other 7 varieties. The process of coal separation is as follows: 100 ~ 0.5mm particle size is selected by jettison, and -0.5mm particle size is concentrated by a 030m peripheral drive rake thickener, and then recovered by direct filtration. After repeated discussions, a KM250/1600 type coal sludge recycling plant was adopted.Fast and efficient diaphragm filter pressesAfter two years of production and operation, it has recovered 136,900 tonnes of coal slurry and realised more than 10 million yuan of additional income, creating good economic and social benefits.

Necessity of Coal Slurry Water System Modification

Before renovation, the process of coal slurry water system of the plant was simple, and the overflow of jigging fine coal hopper pit directly entered the coal slurry sedimentation pond on the east side of the jigging workshop to carry out natural sedimentation and recovery. There are 3 sedimentation ponds in total, with a total sedimentation area of 1160m2 .²_oThe results of small sieving test of coal slurry overflow from the pit are shown in Table 1, the overflow concentration is 53.08g/L, the overflow water volume is 300m.³/h, wash water concentration 36.57g/L_oDue to the high concentration of washing water, the coal slurry water must be discharged externally, which not only pollutes the environment, but also leads to a large amount of coal slurry loss. In order to realise in-plant recycling of coal slurry and achieve a closed loop of washing water, it was decided to carry out a technological modification of the coal slurry water system by adopting the KM250/1600 fast and efficient diaphragmfilter pressTreatment of fine-grained primary coal sludge.

data analysis

(1) With the prolongation of the operation time, the single cycle time is gradually reduced, which shows that the operators are familiar with this new equipment, for example, the coal slurry water dosing system is gradually rationalised and perfected, which plays a certain role in promoting. In the actual production process, when the concentration of thickener bottom stream>550g/L, the single cycle time dropped to 12min._oDue to the high content of fine particles in the coal slurry (-0.075mm particles accounted for 83.81% of the total amount of coal slurry), and containing kaolin and other viscous impurities, the single-cycle time did not reach the design time of 8 - 15min.₀

(2) The single cycle capacity is reduced to 4.62t, which is adjusted according to the fine particle size and high viscosity of the coal slurry in this plant, if the feeding time is too long, the dewatering efficiency will be greatly reduced. It is proved that it increases the hourly processing capacity.

(3) Due to the special nature of coal slurry in Zhangcun Mine Coal Processing Plant, the hourly processing capacity of the equipment did not reach the design value, and the actual amount of dry coal slurry processed was 10.72t/h.

reach a verdict

After two years of production practice, KM250/1600 type fast-opening diaphragm filter press runs smoothly and reliably, after-sales service is in place, and there is no big quality accident. With advanced structure and reliable quality, the equipment has reached or exceeded its design capacity in the coal processing plant of Hebi Coal Group, Gaoshuang Coal Processing Plant of Zaozhuang Mining Group and Dongtan Coal Processing Plant of Yankuang Group. The shortcomings of this equipment are mainly the unstable quality of filter plate and the short service life of feeding hose, which should be improved in the future.