ABSTRACT

The extraction of nickel (Ni) from sulfide resources commences with flotation to produce a concentrate which is then smelted to produce a nickel-enriched phase called matte, and further refined to produce pure Ni products as well as by-products, such as cobalt (Co), copper (Cu) and precious metals. However, the traditional concentrate smelting-matte refining process, whilst technologically robust, is capital intensive and suffers from several environmental and technical issues such as sulfur dioxide emissions, poor recovery of cobalt and difficulty processing concentrates high in magnesia and arsenic without appropriate blending with high grade concentrates to dilute the concentration of these species. The direct hydrometallurgical processing of nickel sulfide concentrates and whole ores may be a remedy to these issues and hydrometallurgy offers several advantages over pyrometallurgy such as potentially lower capital costs, the ability to process lower grade materials and produce marketable metals or compounds directly from ore/concentrate. Despite the advantages of hydrometallurgy over traditional base metal sulfide smelting, the hydrometallurgical processing of nickel concentrates has been limited to a small handful of commercial operations, some of which only produce an upgraded intermediate for pyrometallurgical processing. In Part I of this three-part series, a comprehensive review of piloted processes for direct hydrometallurgical processing of nickel sulfide concentrates is presented, followed by a survey of industrial operations which have carried out direct leaching of nickel sulfide concentrates. A review of research activities and challenges/opportunities in the direct hydrometallurgical processing of nickel sulfide concentrates are presented in Part II and Part III of this series.

摘要

从硫化物资源中提取镍 (Ni) 首先通过浮选产生精矿，然后将其熔炼以产生称为冰铜的富镍相，并进一步精炼以生产纯镍产品以及副产品，例如钴 (Co)、铜 (Cu) 和贵金属。然而，传统的精矿冶炼-冰锍精炼工艺虽然技术可靠，但属于资本密集型，并存在一些环境和技术问题，例如二氧化硫排放、钴回收率低以及难以加工富含镁和砷的精矿，而没有与高品位精矿适当混合以稀释这些物质的浓度。硫化镍精矿和原矿的直接湿法冶金加工可能是解决这些问题的一种补救措施，湿法冶金比火法冶金具有多种优势，例如潜在较低的资本成本、能够加工较低品位的材料以及直接从矿石/精矿生产可销售的金属或化合物。尽管湿法冶金比传统贱金属硫化物熔炼具有优势，但镍精矿的湿法冶金加工仅限于少数商业运营，其中一些仅生产用于火法冶金加工的升级中间体。在这个由三部分组成的系列的第一部分中，对硫化镍精矿直接湿法冶金加工的试点工艺进行了全面回顾，随后对直接浸出硫化镍精矿的工业操作进行了调查。本系列的第二部分和第三部分介绍了直接湿法冶金加工硫化镍精矿的研究活动和挑战/机遇。