ALISON LEWIS
University of Cape Town

RETHINKING PRECIPITATION PROCESSES: THE ART OF THE STATE

Abstract

From the initial efforts of alchemists, who sought to turn base metals into gold, precipitation as applied in the field of hydrometallurgy has always been a combination of art and science.  This talk will explore the roots of precipitation processes in hydrometallurgy, as well as provide an overview of the modern Industrial Crystallisation and Precipitation Research at the University of Cape Town. The challenges in the research area are many – from developing the science behind the art, to being able to measure processes that are governed by multiple factors across multiple scales.
Some case study examples will be explored, including re-engineering platinum and rhodium precipitation processes, elemental nickel precipitation and palladium salt precipitation. Some of our initiatives in mine water treatment will also be explored, including metal sulphide precipitation, iron hydroxide precipitation and Eutectic Freeze Crystallization.

ALISON LEWIS has a BSc (Chem Eng), MSc (Eng) and PhD, all from the University of Cape Town. She is a registered Professional Engineer, a Fellow of the University of Cape Town and a Fellow of the South African Academy of Engineering. She spent two years working as a Process Engineer, during which time she was involved in design and commissioning for South African Nylon Spinners’ Polymer Plant. Since 1996, she has been a full time academic in the Chemical Engineering Department at the University of Cape Town, mainly focussing her teaching on the fourth year design courses. She also initiated research into Industrial Crystallization and Precipitation and was promoted to full Professor in 2006. In 2003, she received an EPSRC fellowship and spent a year as a visiting Research Fellow at the University of Sheffield. In 2009, she spent six months as a Visiting Professor at the University of Mauritius. She is an NRF rated scientist, with a B2 rating i.e an internationally recognised researcher. She is currently the Head of the Chemical Engineering Department, as well as Director of the Crystallization and Precipitation Research Unit, an accredited Research Unit at the University of Cape Town. The Research Unit works nationally and internationally as specialists in the field of Industrial Crystallization and Precipitation. Water and brine treatment have become an increasingly important focus of the Unit’s activities.

For more info: www.chem-eng.utoronto.ca/news.htm

Websites of Interest

• University of Toronto
• Faculty of Applied Science & Engineering
• Department of Chemical Engineering & Applied Chemistry