Towards Environmentally Benign Pyrometallurgical Processes

过去，对现有提取方法的改进和新的金属提取工艺的开发都是由技术和经济因素决定的。最近，环境因素已成为决定一个过程的可行性的另一个重要因素。在这方面，对于本提案中描述的研究计划，主要目标是开发对环境影响较小的金属提取工艺。在矿物和金属开采过程中，一些主要能源仍以碳质或碳氢化合物为基础。最终，这些材料中的碳被转化为二氧化碳，从而导致全球变暖。为了解决这个问题，这项工作的一个主要重点将是研究微波处理技术。在这些微波过程中利用的电能可能是相对清洁的，而且还有其他潜在的优势，如减少气体吞吐量和粉尘产生。矿物的微波加工领域继续扩大，在理解这一复杂技术及其在提取冶金中的应用方面取得了相当大的进展。目前，火法冶金金属提取在某种程度上正被湿法冶金工艺取代，至少部分原因是湿法冶金更环保。拟议的研究解决了这一问题，并可能导致更绿色的火法冶金过程，并建立在这一新的金属提取研究领域十多年的经验基础上。在接下来的五年里，研究将集中在三个潜在的微波应用上：(1)微波破碎研究，(2)微波热真空处理和(3)煤的微波处理。此外，在对本研究计划中的拟议应用进行调查时，还将生成有助于确定其他潜在应用的信息。此外，我们将继续确定感兴趣的矿石、精矿和矿物的介电常数，并最终编制一份可出版的汇编。

In the past, improvements to the current extraction methods and the development of new metal extraction processes were determined by both technical and economic factors. More recently, environmental factors have become another significant feature in determining the viability of a process. In this regard, for the research program described in this proposal, the major objective is to develop metal extraction processes that have less of an impact on the environment. In mineral and metal extraction processes, some of the major sources of energy remain carbonaceous or hydrocarbon-based. Ultimately, the carbon in these materials is converted into carbon dioxide and this contributes to global warming. To address this issue, a major focus of the work will be to investigate microwave processing techniques. The electrical energy utilized in these microwave processes can be relatively clean and also there are other potential advantages such as reduced gas throughputs and dust production. The field of microwave processing of minerals continues to expand and considerable progress has been made in understanding this complex technology and its application to extractive metallurgy. Currently, pyrometallurgical metal extraction is being somewhat displaced by hydrometallurgical processes, at least in part because hydrometallurgy is more environmentally friendly. The proposed research addresses this issue and could lead to greener pyrometallurgical processes and also builds on over ten years' experience in this new research field in metal extraction. Over the next five years, the research will focus on three potential microwave applications as follows: (1) microwave fragmentation studies, (2) microwave pyrovacuum processing and (3) microwave processing of coal. In addition, to the investigation of the proposed applications in this research program, information will be generated which can help define other potential applications. Furthermore, we will continue to determine the permittivities of the ores, concentrates and minerals of interest and ultimately produce a publishable compilation.