Electrowinning Principles and Practice: A Brief Introduction to the Electrochemistry and Engineering Behind Modern Electrowinning Plants

Electrowinning, or electroextraction, is the oldest industrially applied electrochemical process, and the backbone of the production of many metals, both precious and otherwise (aluminum, copper, zinc and lead, among others), as well as industrial gases (e.g. the chlor akali process).  In the US alone electrowinning processes consume on the order of 1 to 2% of total electricity produced, and many of the most energy intensive processes are have much room for improvement of efficiency.  In this tutorial we will broadly examine the theory and practice of both the electrochemical processes as well as the supporting mining and extraction operations.  Beyond a discussion of the basic operating principles, we will examine issues of feed purity, flow control, and rate sensitivity.  Finally, experimental and R&D scale approaches to efficiency improvements will be covered.  While the aluminum, copper, and chlor-alkali systems will be systems of focus in this talk, the principles discussed will be applicable to any modern electrowinning process.