摘 要

黄铜矿是一种重要的铜资源。目前火法冶铜仍是最主要的获取铜的方式。随着矿产资源的不断开采，黄铜矿的贫、细、杂问题日益明显，加之近年来国家对环境保护的要求提升，湿法冶金成为继火法冶金后处理黄铜矿的重要方法。然而，湿法冶金过程中由于黄铜矿表面产生钝化层而导致浸出率低下。因此，减弱或消除黄铜矿浸出过程中的钝化现象成为了湿法炼铜处理黄铜矿过程中的技术难关。作为湿法冶金的新思路，微波因其独特的传热方式、选择性加热等优势被用来强化浸出黄铜矿，并且效果显著。然而在强化机理方面却仍然是模糊和有争议的。随着对微波浸出黄铜矿技术研究的不断深入，探索其强化浸出的机理更是尤为重要。

本文从微波对反应活化能、反应介质、反应物三个方面的影响对微波辅助强化浸出黄铜矿进行全面系统的分析，揭示了微波辅助浸出黄铜矿的强化机理，为微波浸出黄铜矿的技术应用奠定了基础。本文的主要研究内容和试验研究结果如下所述：

1）对微波辅助加热浸出黄铜矿的动力学进行研究。试验结果表明：在不同浸出温度下，两种浸出方式的铜浸出率基本相当。通过一个以表面反应控制速率的核缩模型以及Arrhenius方程拟合计算后发现，两种加热方式的反应活化能差异不大。也就是说微波辅助加热对黄铜矿浸出的活化能影响不大。

2）基于浸出溶液沸点提升的微波强化浸出研究。结果表明，浸出介质中硫酸的存在能有效地提高溶液沸点，并且相比于传统加热，微波辅助加热条件下相同成分的浸出介质沸点更高。由于微波的选择性加热特性，在微波加热条件下黄铜矿的温度可迅速上升到1000^oC，因此构建了两种加热方式的温度梯度原理图。根据模型分析得出，微波辅助加热的黄铜矿拥有高于浸出介质沸点的反应界面的温度，而常规加热条件下的结果恰恰相反。温度是影响反应速率的关键因素，因此沸腾的条件下，微波辅助浸出能够带来更高的铜浸出率。此外，浸出界面的温度超过钝化层硫的熔点，因此阻碍反应进行的硫层被溶解、剥离，从而促进黄铜矿浸出。

3）对微波辅助浸出过程中黄铜矿的反应历程研究。结果发现，在微波辅助浸出黄铜矿过程中产生了铜蓝新物相，而这一现象在常规浸出过程中却难以发现。经过分析论证后初步推断，微波浸出过程中黄铜矿通过转变为铜蓝等过渡态物质后再浸出成为铜离子。铜蓝更易被氧化从而溶解，因此微波能够促进黄铜矿浸出。

4）对微波辅助浸出过程中黄铜矿的反应行为研究。试验结果表明，常规加热条件下黄铜矿优先在有缺陷的部分浸出；而微波辅助浸出条件下，黄铜矿的表面出现许多小凹陷，浸出是在整个表面无差别进行的，因此微波扩大了黄铜矿的有效反应面积，提高了浸出率。

关键词：黄铜矿；微波辅助浸出；动力学；沸点；反应历程；反应行为

Abstract

Chalcopyrite is an important copper resource. At present, pyrometallurgy still is the main way to obtain copper. With the incessant exploitation of mineral resources, the problem of smelting becomes worsening on the poor and complex chalcopyrite. In recent years, hydrometallurgy has gotten more attention because of the higher standard for environmental protection. However, the principal disadvantage of hydrometallurgy is the low leaching rate of chalcopyrite due to the generation of passivation layer during leaching. Hence, it is the key of leaching technology on removing of the passivation layer. Microwave-assisted leaching, as a new processing, enhances the leaching rate of chalcopyrite with the unique way of heat transfer and advantage of selective heating, which works well. However, it is still vague on the mechanism of high recovery. With the deepening of the research on microwave leaching chalcopyrite, it is particularly important to research the leaching mechanism.

In this work, it is studied on the activation energy, reaction medium and reactants, which reveals the mechanism of enhancing leaching during microwave-assisted heating. It lays a foundation for the application of microwave-assisted leaching based on the results:

1) Study on leaching kinetics of microwave-assisted heating. The results show that the recovery of copper under microwave-assisted leaching is same with conventional leaching. After fitting calculation by a shrinking core model and Arrhenius equation, it shows that there is a little difference on leaching activation energy. In other words, microwave seems invalid on promoting leaching on the kinetics of chalcopyrite.

2) Study on enhancing leaching of microwave-assisted heating based on the high boiling point of solution. The results show that the leaching solution with sulfuric acid has a higher boiling point compared to normal, which is obvious with the effect of microwave-assisted heating. In addition, the temperature of chalcopyrite can rise to 1000^oC rapidly due to the selectivity of microwave heating. Hence, the principle diagram of conventional and microwave-assisted heating is modeled. According to the model, chalcopyrite under microwave assisted heating has a higher interface temperature than that of conventional heating. As we know, temperature is the key on leaching rate of chalcopyrite. Hence, it has a high recovery of copper at the temperature of boiling point under microwave-assisted heating. In addition, the passivation layer dissolves and removes from chalcopyrite due to the high interface temperature, which promotes the leaching rate.

3) Effect of microwave-assisted heating on the reaction pathway of chalcopyrite. The results show that covellite appears during microwave-assisted leaching, which is hard to find during conventional leaching. It can be preliminarily concluded that chalcopyrite dissolves through an intermediate product of covellite during microwave-assisted leaching. Covellite has a better leachability compared to chalcopyrite, which leads to a higher leaching rate of chalcopyrite.

4) Effect of microwave-assisted heating on the reaction behavior of chalcopyrite. The rasults show that the surface of chalcopyrite appears a lot of pits with the effect of microwave, which hints the leaching reaction. Chalcopyrite dissolves uniformly from the whole surface during microwave-assisted leaching, however, it begins firstly from the defect locations during conventional leaching. The unique reaction behavior promoted the leaching rate of chalcopyrite by creating a bigger and effective leaching surface with microwave-assisted heating.

Key words: chalcopyrite; microwave-assisted leaching; kinetics; boiling point; reaction pathway; reaction behavior

目 录

第一章 绪论 1

1.1 黄铜矿简介 1

1.1.1 黄铜矿性质及组成 1

1.1.2 铜资源现状 1

1.1.3 黄铜矿火法冶金处理 2

1.2 黄铜矿湿法冶金处理 3

1.2.1 氧化浸出 3

1.2.2 配位浸出 3

1.2.3 生物浸出 4

1.2.4 湿法冶金的新思路 5

1.3 微波在矿物处理中的应用 5

1.3.1 微波简介 5

1.3.2 微波在黄铜矿浸出中的应用 6

1.4 研究的目的及意义 6

1.5 研究的内容和技术方案 7

第二章 试验原料、药剂、设备和仪器 8

2.1 试验原料及准备 8

2.2.1 试验用黄铜矿样品的准备 8

2.2.1 试验用黄铜矿样品的分析 8

2.2 试验用试剂 9

2.3 试验用设备和仪器 10

第三章 结果与讨论 11

3.1 黄铜矿浸出动力学研究 11

3.2 基于浸出溶液沸点提升的微波强化浸出研究 15

3.2.1 黄铜矿在浸出介质沸腾条件下的浸出率 15

3.2.2 基于沸点提升的黄铜矿强化浸出机理 16