Platinum Group Elements Mineralogy, Beneficiation, and Extraction Practices – An Overview

Platinum group elements have become imperative to many modern industrial applications (automobiles, jewelry, pharmaceuticals, electronics, fuel cells, etc.) but are mined in only a few places. Characterization followed by beneficiation and extraction of these elements has many challenges for the applied mineralogist and mineral engineers due to its ultratrace concentration (2–4 ppm), small grain size (1–50 µm), and multiple associations (sulfides, tellurides, arsenides, antimonides, chromites, silicates, etc.). The important platinum minerals identified in different areas are sperrylite, sudburyite, braggite, hollingworthite, cooperite, laurite, geversite, kotulskite, michenerite, etc. This review critically discusses and gives an update on the classification and mineralogy of platinum group element ores around the world and also assesses the beneficiation practices and developed process flowsheets for recovery of platinum group element values. The extraction process routes to recover high purity of platinum group elements are also reviewed. The classification briefly describes the different types of ore deposits. The mineralogical analysis gives a general idea about the distribution and behavior of the platinum group element ores; also it helps to choose the beneficiation techniques. A brief summary of the different beneficiation and extraction techniques practiced at different places are discussed in detail. Flotation and enhanced gravity separation techniques used in some of the major platinum group metal producing plants for recovery of the platinum group of elements are also highlighted and conclusions are presented.