Falcon离心选矿机矿浆的干涉沉降研究

发布时间：2018-07-25 10:27

【摘要】：随着矿产资源“贫、细、杂”问题的日益突出,微细粒矿物的回收一直是研究的难点和热点,Falcon离心选矿机作为一种进口的高效重选设备,打破了传统设备的回收下限,能够有效的回收微细粒矿物。本文以半连续设备Falcon SB机型为研究基础,对Falcon实验机中矿浆的干涉沉降进行沉降建模、模拟研究和实验研究,主要研究内容如下:Falcon离心选矿机的分选特征和应用现状的研究。分析三种Falcon离心选矿机的结构特点和工作特性,并分析新的结构特点对Falcon离心选矿机分选效果的影响;结合当前国内外对Falcon离心选矿机工业应用,分析其在提高选矿回收率、减少耗能等方面的优势。对Falcon离心选矿机沉降机理以及相应的参数进行研究和分析,为建立Falcon离心选矿机干涉沉降模型提供理论基础。首先,根据Falcon离心选矿机转鼓的分区和受力情况分析其沉降机理;然后,研究影响Falcon离心选矿机分选性能的矿浆物理参数、结构参数和操作参数;最后,根据Falcon离心选矿机沉降机理和分选性能,设计分析相应的设备参数值。基于对流扩散方程建立Falcon离心选矿机的干涉沉降模型。首先,根据矿浆在离心机内的运动特性,引入对流扩散方程;其次,考虑分选过程中固相浓度变化和速度的变化的非稳态过程以及不同粒度的沉降情况,建立各位置、各时刻、各粒度下的速度、浓度变化的干涉沉降模型。对建立的干涉沉降的数学模型进行求解。首先,采用有限差分方法求解对流扩散方程,运用中心差分的格式将控制方程离散化,以求解浓度,并根据第1单元与第N单元位置的特殊性,分别为这两个单元建立新的离散化方程;其次,将初始流化过程中的浓度分为三种不连续的情况,完善离散化方程的求解;然后,根据稳定性条件确定模型的时间、空间步长的大小。最后,根据建立的模型利用MATLAB编程求解浓度值。Falcon离心选矿机实验和仿真分析。首先,构建实验系统进行实验,将实验矿物的分配率与模型计算分配率进行对比分析,验证模型的可行性;其次,在不同的反冲水、离心力、进矿浓度情况下进行仿真分析;最后,以分选粒度d50和可能性偏差EP作为分配率曲线的评价指标,分析不同的操作条件给粒度分配率和分选效率带来的影响,结果反冲水流量增大粒度分配率降低,同时分选粒度d50增大,EP减小;初始进矿浓度的增加粒度分配率降低,分选粒度d50增大,EP减小;转鼓转速增大粒度分配率增大,分选粒度d50减小,EP减小。
[Abstract]:With the increasingly prominent problem of "poor, fine and miscellaneous" mineral resources, the recovery of micro-fine minerals has been a difficult and hot point in the research. As an imported high-efficiency gravity separator, Falcon centrifuge has broken the lower limit of recovery of traditional equipment. It can recover fine mineral effectively. Based on the semi-continuous equipment Falcon SB model, this paper models, simulates and studies the settlement of interference settlement of slurry in Falcon experimental machine. The main research contents are as follows: the separation characteristics and application status of the centrifugal concentrator. The structure and working characteristics of three kinds of Falcon centrifuge concentrators are analyzed, and the influence of new structural characteristics on the separation effect of Falcon centrifuge concentrators is analyzed, and combined with the industrial application of Falcon centrifuge concentrators at home and abroad, it is analyzed that they are improving the recovery rate of mineral processing. Reduce energy consumption and other advantages. The settlement mechanism and parameters of Falcon centrifugal concentrator are studied and analyzed, which provides a theoretical basis for the establishment of interference settlement model of Falcon centrifuge concentrator. Firstly, according to the partition and force condition of the drum of Falcon centrifugal concentrator, the settlement mechanism is analyzed. Then, the physical parameters, structure parameters and operating parameters of slurry which affect the separation performance of Falcon centrifuge concentrator are studied. According to the settlement mechanism and separation performance of Falcon centrifugal concentrator, the corresponding equipment parameters are designed and analyzed. The interference settlement model of Falcon centrifugal concentrator is established based on convection diffusion equation. Firstly, according to the movement characteristics of slurry in centrifuge, the convection-diffusion equation is introduced. Secondly, considering the unsteady process of the change of solid concentration and velocity in the separation process and the settlement of different particle sizes, each position and every moment is established. The interference settlement model of velocity and concentration variation at different particle sizes. The mathematical model of interference settlement is solved. Firstly, the finite difference method is used to solve the convection-diffusion equation, and the central difference scheme is used to discretize the governing equation to solve the concentration, and according to the particularity of the position of the first unit and the N element, A new discretization equation is established for the two units respectively. Secondly, the concentration in the initial fluidization process is divided into three kinds of discontinuous cases to perfect the solution of the discretization equation. Then, according to the stability conditions, the time of the model is determined. The size of the space step. Finally, according to the established model, the concentration value. Falcon centrifugal concentrator is solved by MATLAB program. Firstly, the experiment system is constructed to compare the distribution rate of experimental minerals with the calculated distribution rate of the model to verify the feasibility of the model. Secondly, the simulation analysis is carried out under different conditions of recoil water, centrifugal force and ore concentration. Finally, the granularity D50 and the possibility deviation EP are taken as the evaluation indexes of the distribution rate curve, and the effect of different operation conditions on the granularity distribution rate and separation efficiency is analyzed. As a result, the granularity distribution rate decreases with the increase of backwash water flow. At the same time, the particle size D50 increases and EP decreases, the initial concentration increases, the particle size D50 increases and EP decreases, the rotating speed increases, the particle size distribution rate increases, and the separation granularity d50 decreases.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD45

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