论文总字数：25564字

摘 要

细颗粒矿石浮选性能的优化长期以来都是矿物加工领域的研究热点。与大尺寸的气泡相比，微气泡具有上升速度慢、比表面积大等特性，有利于增加气泡与矿物颗粒的碰撞概率，减少气泡-颗粒的脱附，对于提高细颗粒的选择性浮选性能有重要作用。常规细颗粒浮选过程中遇到的主要问题之一是体系中缺少较小尺寸的气泡，导致浮选装置效率低下，不能选择性地回收细颗粒。本文采用多通道陶瓷膜分布器作为气泡发生器制备大量微气泡用于细颗粒磷灰石浮选过程，研究了捕收剂用量、浮选时间和表观气速等不同操作条件对细颗粒磷灰石浮选性能的影响规律，通过实验结果分析得到了浮选最佳操作条件。实验获得的精矿质量达到了磷矿浮选工业要求指标，即P₂O₅品位及回收率分别达到30％和60％。

另外，为了进一步提高浮选性能，本文针对浮选柱内大量微气泡被底流区液体夹带进入尾矿的问题，设计了一种由多个倾斜板组成的新型回流元件。采用欧拉-拉格朗日法对气泡在液相流中的运动过程进行计算流体力学（CFD）模拟，深入理解了浮选料液在含有回流元件的浮选柱中的流动机理。通过实验研究了回流元件在不同底流流量下的气液分离性能，测量了气泡的尺寸分布，探究了回流元件的加入对浮选柱内气泡流动的影响。结果表明，将多通道陶瓷膜分布器作为气泡发生器运用于强化磷灰石细颗粒浮选的研究中是可行的。回流强化浮选性能实验结果与CFD模拟结果相符，对浮选装置的优化设计具有参考价值。新型回流元件的加入促进了气泡-液体分离，对P₂O₅回收率的进一步提高具有显著作用。

关键词：浮选 细颗粒 膜分散 CFD 磷灰石

Study on Performance of Ceramic Membrane Distributor Used in Flotation of Fine Apatite

Abstract

The optimization of the flotation performance of fine-grained ore has long been a hot topic in the field of mineral processing. Compared with large-sized bubbles, microbubbles have the characteristics of slow rising speed and large specific surface area, which is beneficial to increase the collision probability and reduce the bubble-particle attachment, thus it plays an important role in improving the selective flotation performance of fine particles. One of the main problems encountered in the conventional flotation process is the lack of small-sized bubbles in the system, which results in low efficiency of the flotation device and the inability to selectively recover fine particles. In this work, a multi-channel ceramic membrane distributor was used as a bubble generator to prepare a large number of microbubbles for the fine apatite flotation. The effect of different operating conditions such as the dosage of collector, flotation time and apparent gas velocity on the flotation performance of fine apatite was studied. Through the analysises of experimental results, the best operating conditions were finally obtained. The quality of the concentrates obtained by the experiments had reached the requirements of industrial phosphate ore flotation, namely P₂O₅ grade and recovery in more than 30% and 60%, respectively.

In addition, in order to further improve the flotation performance, a new reflux component composed of several inclined plates was designed to solve the problem that a large number of microbubbles in the flotation column are entrained into the tailings caused by the excessive flow velocity in the bottom flow zone. The Eulerian-Lagrangian method was used for computational fluid dynamics (CFD) simulation. The movement of bubbles in liquid phase was investigated, so as to understand the flow mechanism of liquid in a flotation column containing reflux component. The bubble-liquid separation performance of the reflux component at different bottom flow rates was tested through experiments and the influence on the bubbles flow in the flotation column was studied. The size distribution of the bubbles was also measured. The results showed that it was feasible to use the multi-channel ceramic membrane distributor as a bubble generator to enhance the flotation performance of fine apatite. The experimental results were consistent with the CFD simulation results, which had reference value for the optimal design of the flotation device. The new reflux component designed in this work played a significant role in promoting bubble-liquid separation and improving the recovery of P₂O₅.

Keywords: Flotation; Fine particle; Membrane dispersion; CFD; Apatite

目 录

摘 要 I

ABSTRACT II

第一章 文献综述 1

1.1 磷灰石浮选研究现状 1

1.1.1 磷矿研究现状 1

1.1.2 磷灰石的组成及用途 1

1.1.3 磷灰石浮选工艺现状 2

1.2 浮选柱气泡回流技术 4

1.3 气液体系的CFD模拟 7

1.3.1 欧拉-欧拉模拟 7

1.3.2 欧拉-拉格朗日模拟 7

1.4 本文研究目标和内容 8

第二章 研究方法 9

2.1 磷灰石细颗粒浮选强化过程 9

2.1.1 实验原料和实验设备 9

2.1.2 实验系统 10

2.1.3 测量方法 12

2.1.4 实验过程 13

2.2 斜板强化气液分离过程研究 13

2.2.1 CFD模拟方法 13

2.2.2 模拟设置 16

第三章 结果与讨论 19

3.1 原料组成和粒度分析 19

3.2 磷灰石浮选条件优化 19

3.3 回流强化浮选的CFD模拟分析 22

3.4 回流强化浮选性能测试 25

第四章 结论 30

参考文献 31

致谢 34

第一章 文献综述

1.1 磷灰石浮选研究现状

1.1.1 磷矿研究现状

磷矿是化学工业生产过程中极其重要的不可再生矿物原料，也是磷的主要来源。地球上用作农业用浓缩固体磷肥原材料的磷矿大约占68%^[1]，其余矿产还可用于生产磷酸、黄磷、磷酸盐等磷酸盐物质，普遍应用于化工、制糖、医药、食品、冶金、国防等领域。

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