一种新型浮选柱的数值模拟及性能研究

发布时间：2018-05-31 01:10

本文选题：新型浮选柱 + 数值模拟　；参考：《贵州大学》2017年硕士论文

【摘要】：本文研制了一种能够扩大浮选粒度上限的新型浮选柱,在保证有用矿物已实现单体解离的情况下,其既能浮选矿浆中的细颗粒矿物,也能回收一部分矿浆中大于0.075mm的粗颗粒矿物。以普通浮选柱为初始模型,采用FLUENT软件对其结构进行优化模拟,根据模拟结果得到了一种新型浮选柱。该浮选柱主要由柱体、泡沫槽、给矿管、排矿管、气泡发生器、循环漏斗、循环管道以及循环泵组成。主要特点在于该浮选柱有六段循环管道,且呈对称分布在柱体两侧,每段循环管道都设有一个阀门。当进行浮选作业时,可以根据矿石性质及粒度组成,利用阀门自由控制矿浆循环高度,从而实现浮选。通过对浮选过程中矿粒与气泡的作用机理以及浮选效率影响因素进行研究,可知要提高浮选效率,可以从以下几个方面进行:减小气泡直径;选择适宜的湍流强度;增加气泡与颗粒的相对运动速度;缩短矿粒的上浮路径;增大气泡表面积通量、降低浮选柱高度和延长矿浆在柱体内的停留时间。而新型浮选柱的设计均符合以上要求,从而验证了新型浮选柱设计的合理性。选用贵州某低品位钙镁质磷矿石为试验矿样,在6种不同磨矿细度条件下,对循环管道高度、单边循环与对称循环进行了试验。循环高度试验结果表明:当磨矿细度在67.13%~81.34%范围内时,应该选用高位循环来提高磷精矿中P2O5的品位和回收率;当磨矿细度大于81.34%时,综合考虑精矿品位和回收率,应选用中位循环方法来提高其浮选效果。单边循环与对称循环的试验结果表明:当磨矿细度在67.13%~81.34%范围内时,应该选用单边循环方式;当磨矿细度大于81.34%时,应选用对称循环方式提高磷精矿品位和回收率。利用普通浮选柱进行了对比试验,实验结果表明:在磨矿细度-0.075mm占84.98%时,新型浮选柱所获得的精矿品位就已经达到了普通浮选柱的最佳指标,其精矿品位与普通浮选柱所获得的精矿品位相差不大,而回收率比普通浮选柱提高了0.43%。当磨矿细度为-0.075mm的含量占88.53%时,精矿中P2O5的品位比普通浮选柱提高了0.29%,精矿中P2O5回收率比普通浮选柱提高了0.07%。这说明新型浮选柱可以通过控制循环管道及阀门来扩大浮选粒度上限,使其既能浮选矿浆中小于0.075mm的矿粒,也能回收普通浮选柱难以选别的一部分大于0.075mm的矿粒。
[Abstract]:In this paper, a new flotation column which can enlarge the upper limit of flotation particle size has been developed. It can not only floatate fine granular minerals in pulp, but also guarantee the monomer dissociation of useful minerals. Some coarse grained minerals larger than 0.075mm in pulp can also be recovered. Taking the ordinary flotation column as the initial model, the structure of the column was optimized and simulated by FLUENT software. According to the simulation results, a new type of flotation column was obtained. The flotation column consists of a column, a foam tank, a feed tube, a discharge tube, a bubble generator, a circulating funnel, a circulating pipe and a circulating pump. The main characteristic of the flotation column is that the flotation column has six sections of circulating pipeline and distributes symmetrically on both sides of the column, and each section of the circulating pipeline is provided with a valve. When floatation is carried out, the circulating height of slurry can be controlled freely by using valve according to the property and particle size composition of ore, and thus floatation can be realized. Through the study of the action mechanism of ore particles and bubbles and the factors affecting flotation efficiency, it is concluded that in order to improve flotation efficiency, the following aspects can be carried out: reducing bubble diameter, selecting appropriate turbulence intensity, and improving flotation efficiency. The relative velocity of bubble and particle is increased, the floating path of ore particles is shortened, the surface flux of bubble is increased, the height of flotation column is reduced and the residence time of pulp in column is prolonged. The design of the new flotation column meets the above requirements, which verifies the rationality of the new flotation column design. In this paper, a low grade calcium magnesia phosphate rock in Guizhou was selected as the test sample. Under six different grinding fineness conditions, the circulating pipe height, single and symmetrical circulation were tested. The results of cycle height test show that when the grinding fineness is in the range of 67.13% or 81.34%, high circulation should be selected to improve the grade and recovery of P2O5 in the concentrate, and when the grinding fineness is greater than 81.34%, the concentrate grade and recovery rate should be considered synthetically. The median circulation method should be used to improve the flotation effect. The experimental results of one-sided and symmetrical cycles show that when the grinding fineness is in the range of 67.13% or 81.34%, the single-sided circulation should be used, and when the grinding fineness is greater than 81.34, the grade and recovery of phosphorus concentrate should be improved by symmetrical circulation. A comparative experiment was carried out with the ordinary flotation column. The experimental results show that the concentrate grade obtained by the new flotation column has reached the best index of the ordinary flotation column when the grinding fineness is -0.075 mm accounting for 84.98%. The concentrate grade is not different from that obtained by ordinary flotation column, and the recovery rate is 0.43% higher than that of ordinary flotation column. When the grinding fineness of -0.075mm is -0.075mm, the grade of P2O5 in the concentrate is 0.29 higher than that of the ordinary flotation column, and the recovery rate of P2O5 in the concentrate is 0.07% higher than that of the ordinary flotation column. This shows that the new flotation column can enlarge the upper limit of flotation particle size by controlling the circulating pipes and valves, so that it can not only flotation the ore particles in pulp less than 0.075mm, but also can recover the ore particles larger than 0.075mm that are difficult to be separated by ordinary flotation column.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD923

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