Water in Sustainable Hydrometallurgy

随着全球对原材料需求的增加，加拿大金属行业正在全球范围内扩大和投资新项目。湿法冶金使用水基化学，通过在广泛的温度和压力范围内采用各种化学条件，从天然矿物资源和无机废物中回收金属。目前的研究计划将我们的研究重点从提高金属提取效率转移到改善水质，可回收性和该行业的使用。可持续发展要求最小的工艺用水量、高分离效率和最清洁的排放。拟议的工作建立在我们研究小组的实验测量支持的先前理论进展的基础上，旨在开发在行业中找到出路的新应用。提出了三个相互关联的项目，旨在改善工业过程中的水净化，回收和使用。第一种是正向渗透（FO），用于从受污染的工艺流中回收水。这是一个自发的过程，具有低能耗，并将适应水淡化工业。第二种是用于回收工艺用水和高度可溶性盐的Eurocarbon冷冻结晶（EFC），这些盐在工厂回路中积累，造成再利用/再循环问题。这项技术对于在加拿大寒冷的气候中实施特别有吸引力。第三是进一步发展我们的新想法，使用熔融盐水合物（MSH）作为浸出剂，从天然或回收资源中分离和回收金属。MSH使用少量的水进行金属提取，并有可能将湿法冶金领域转变为最小净用水量的领域。拟议的研究计划将培养3名博士和15名本科生以及一名博士后研究员在复杂的实验技术。这项工作通过调查矿产部门的新的可持续技术理念，使金属生产商在全球市场上更具竞争力，以满足世界对以环保和无害方式生产的初级金属的需求，从而为加拿大经济做出贡献。

With increasing global demand for raw materials, the Canadian metals industry is expanding and investing in new projects around the world. Hydrometallurgy uses water-based chemistry to engineer metal recovery from natural mineral resources and inorganic wastes by employing a variety of chemical conditions within a wide range of temperatures and pressures. The present research programme shifts our research focuse from improving metal extraction efficiencies to improving water quality, recyclability and usage in this industry. Sustainable development calls for minimum process water usage, high efficiency of separations, and cleanest discharge. The proposed work builds upon previous theoretical advances backed by experimental measurements in our research group aiming at developing novel applications that find their way in the industry. Three interconnecting projects are proposed that aim at improving industrial process water purification, recycling and usage. The first is Forward Osmosis (FO) for the recovery of water from contaminated process streams. It is a spontaneous process, has low energy consumption and will be adapted from the water desalination industry. The second is Eutectic Freeze Crystallization (EFC) for the recovery of both process water and highly soluble salts, which accumulate in plant circuits creating reuse/recycle problems. This technology is particularly attractive for implementation in the cold Canadian climate. The third is the further development of our novel idea to use Molten Salt Hydrates (MSH) as lixiviants to separate and recover metals from natural or recycled resources. MSH use small amounts of water for metal extraction, and have the potential to transform the field of hydrometallurgy to that of minimum net water usage. The proposed research program will train 3 PhD and 15 undergraduate students as well as one postdoctoral fellow in sophisticated experimental techniques. This work contributes to the Canadian economy by investigating novel sustainable technology ideas in the minerals sector that renders metal producers more competitive in the global markets to satisfy the world demand for primary metals produced in an environmentally respectful and sound manner.