Research On Structure And Process Optimization Of Coal Preparation Products For Fenxi Mining Group

China is the largest coal producer and consumer country in the world, and coal in our country play an important role in our national economy and social development. The scarce coking coal such as fat coal, coking coal and lean coal in China should be the most important strategic resources. FenXi Mining Group owns a large number of high-quality coking coal, but bigger changes of coal quality and too much coal types, so that many problems in separation and sales. In order to promote the market competitiveness of enterprises and maximize the enterprise’s economic benefits, a lot of work was carry out in this paper.Product structure and process optimization of Fenxi Mining coal preparation were researched on basis of theoretical knowledge such as minerals processing, fluid dynamics, broken dissociation and numerical simulation. Crushing dissociation and suspensions rheological properties of the Fenxi coal was systematically analyzed. The separation efficiency of TBS was predicted by using the three-parameter normal integration model, and optimization program of process was obtained by combining with actual process system characteristics. The detail conclusions are as follows:(1) As for Fenxi coking coal, the effect of increasing cleaning coal yield and reducing sulfur by crushed dissociation is remarkable. When coal ash requested is 10.50%, 50 ~ 25 mm was reduced to-25 mm and-13 mm, corresponding theoretical yield were increased by 0.71 and 2.11% compared to the previous. 25 ~ 13 mm was reduced to-13 mm coal, corresponding theoretical yield were increased by 10.31 % compared to the previous. The sulfur content of coal was decreased by 0.04%, 0.20% and 0.41%, respectively, compared with the previous unbroken coal.(2) The Rosin-Rammler model is the optimal distribution model for Liuwan raw coal, while Gauding-Schuhmann model is the optimal distribution model for broken-level coal.The hyperbolic model for predicting cleaning coal yield and sulfur content of raw coal is better, and arctangent model for predicting cleaning coal yield and sulfur content of broken-level is better.(3) The measurement errors of particle settling was to maximize be eliminated, and the secondary measurement errors caused by flow state change using conventional mixing method, based on linear fitting of the viscosity versus time curve. Generally, pseudoplastic fluid model can be used to describe the heavy medium suspension in coal beneficiation. Consistency coefficient linearly increase, and power law index decreases with the increase of volume concentration of heavy medium suspension.(4) As the volume concentration Suspension is constant, with the increase of the slime content, the consistency coefficient decreases linearly, the power law index increases, that indicate slime is better in "lubrication" than magnetite powder.the mineral content in the suspension increase s, and the viscosity of the suspension increases, but the viscosity does not change. Clay mineral content does not affect the rheological model of the heavy medium suspension, only changes the rheological model parameters.(5) Consistency coefficient suspension of heavy medium coal preparation and the approximate calculation formula of power-law exponent is given, when the density is 1.45g/cm3-1.80g/cm3, and the slime content is 5%-30%, moreover the relative error is small.(6) In the first stage of the dense medium cyclone, the possible deviation E is 0.045 g ? cm-3, and the number of efficiency is 96.6%, so the separation efficiency is better. In the second stage,the possible deviation E is 0.095g/cm3, and the number efficiency is 88.83%, so separation efficiency is poor, moreover, the middings has the higher proportion in washing product yield, the lower ash, the larger re-election space.(7) By adjust the heavy medium cyclone, TBS sorting machine and the operating parameters of flotation machine, adjustment the coal ash level from 12(10.5%~11.0%) to 11(10.0%~10.5%). Although the clean coal yield decline, the yield of middle coal increased significantly, improve the overall economic benefits of the whole plant, then it improve the market competitiveness of coal products.(8) A mathematical model of partition curves was set up,which contained three parameters and the influences of the three parameters on the shape of the partition curve and the main separation indexes was analysed. Specifically, the parameters of a and b had an adverse effect on the high density part of the partition curves; however, the parameter of a still had an influence on the gradient of the curve, demonstrating a could influence the separation density as well as the probable error; the parameter of c only controlled the translation along the X-axis, indicating an influence on the separation density.(9) The mathematical models of the three parameter against separation density was still set up according to the industrial separation experiments of different flow rate of upward currents and a method of predicting the separation results under different separation densities for the TBS in Liuwan coal preparation plant was put forward, according to the models of the three parameters. The mathematical models of a, b and c about the separation density were determined as y=28.69e-1.489 x, y=2505e-2.957 x, and y=x, respectively.