Water in Sustainable Hydrometallurgy

随着全球对原材料需求的增加，加拿大金属工业正在扩大规模，并在世界各地投资新项目。湿法冶金利用水基化学技术，在广泛的温度和压力范围内采用各种化学条件，从天然矿产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该行业的水质，可回收性和使用。可持续发展要求工艺用水最少，分离效率高，排放最干净。我们的研究小组以实验测量为基础，建立了先前的理论进展，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，旨在改善工业过程水的净化、回收和利用。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，能耗低，将从海水淡化行业改编。第二种是共晶冷冻结晶（EFC），用于回收工艺用水和高可溶性盐，它们在工厂电路中积累，造成再利用/再循环问题。这项技术特别适合在寒冷的加拿大气候中实施。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，从天然或再生资源中分离和回收金属。MSH使用少量的水来提取金属，并有可能将湿法冶金领域转变为净用水最少的领域。本项目拟培养博士3名、本科生15名、博士后1名，研究方向为精密实验技术。这项工作通过研究矿产部门的新的可持续技术理念，为加拿大经济作出贡献，使金属生产商在全球市场上更具竞争力，以满足世界对以尊重环境和无害的方式生产的初级金属的需求。

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.