Research Of Optimization And Monitoring Of Slurry System In Coal Preparation Plant

In the slurry treatment process, settling to clarify the effect of slurryaffected by a large number of fine particles. Adding flocculants or coagulant isthe most important, most direct and most effective technological measures.Rational drug use system is an important way to improve production efficiencyand reduce the cost of production. Achieve effective flocculation and settling inthe slurry treatment process is to ensure the quality of circulating water. Developa reasonable program of coal slurry, solve the problem of the difficulty of slurrypurification. At present agents added in the process of domestic coal preparationplant slurry treatment is mainly composed of artificial by feeling adjust theamount of flocculant. In the process of production testing device, lacking ofprocess parameters and operation parameters, and difficult to carry out areasonable reagent system, cause the turbidity in the circulating water is notstable, and drug consumption is high, but also affect the thickener underflowfilter efficiency. Due to the complexity of the mechanism of flocculation andsedimentation, meanwhile the characteristics of large inertia and large hysteresis.So using advanced monitoring and control methods, these measures to improvethe economic benefit of coal preparation plant is of great significance.In the paper, based on the concentration and dehydration of slurry ofphoenix mountain coal preparation plant, there appears the excesspharmaceutical consumption, the effluent of thickener overflow frequentblackwater, underflow pump often clogged filter press cycle length, filter press period is so long, owing to these problems, investigation and research wascarried out, collecting some slurry. In the study of slurry properties andflocculation settlement, on the basis of the flocculation sedimentationexperiment was carried out. First of all, the flocculation sedimentationobservation of a series changes in settling velocity, compression layer, turbiditysupernatant fluid volume, dehydration time and filter cake moisture forflocculation sedimentation evaluation index, determines the optimum flocculantfor phoenix mountain coal preparation plant types as XN12, the best reagent rateof240g/tdry slurry, the slurry system optimization of coal preparation plant, coalpreparation plant production efficiency to save reagent, reduce the cost.Secondly, according to the phoenix mountain ore slurry system present situationof coal preparation plant, the results of the washing water parameters monitoringagents was added automatically, it has a dosing model optimization andadjustment: put the different dosing system corresponding to different coalsamples result from the laboratory analysis into control system.⑴Through the size analysis of the thickener grain material, the results canbe seen that the-0.045mm material is more than65%, and according to the lawsof the subsidence of judgment, the settlement of the phoenix mountain coalpreparation plant is difficult. Analysis of XRD spectrum shows that the mainmineral in coal are kaolin, quartz, montmorillonite and pyrite. And the size ofquartz and kaolinite are bigger, their dissociation ability is poor, surfaceproperties is stable, so the impact on the settlement of slime water is not very big,but montmorillonite expanse under the influence of water, and has strongcapacity of ion exchange, so the slurry containing montmorillonite relativelydifficult when processing.⑵Through laboratory and coal preparation plant field slime settlingdehydration experiments, we can know that: comprehensive comparing of singleadding flocculating agent XN11, XN12, XN13, flocculant coal preparation plantused, and comparing with coagulant mixing experiment, we can know: flocculant XN12is optimal type, but the sedimentation effect decrease aftermixing with coagulant; Reagent dosage experiment contrast: when the dosage ofPAM is240g for1t dry coal slime, the sedimentation rate is faster, compressionlayer volume is55ml, supernatant turbidity is49.47, floccules has goodcompaction degree, dehydration time was8.26min, filter cake moisture contentis36.16%. Through the determination of the best reagent type and Dosage ofreagents the determination of the best reagent rate system reasonable reagentsystem, which can effectively reduce the coal preparation plant of use, costsavings, improve the production efficiency of coal preparation plant.⑶The research of slurry parameters monitoring, uses FB2300PKS which isa high stability, high precision, in the principle of polarization-time,environmental friendly, concentration detection instrument(Germany PTDCtechnique),the method of2point detecting turbidity and the variation of theturbidity along thickener depth direction, to instead of turbidity detection in theoverflow main, from the changes of detected turbidity, we can predictflocculating sedimentation trends early, and according to the trend, by fuzzycontroller, to implement timely and reasonable control. Using the controlstrategy of feed forward and feedback joint control in the slurry flocculatingsedimentation process, and using the principle of the fuzzy predictive control,have improved the stability of the control system.