Profile

• Expert in hydrometallurgical process and cost modelling (chemical and vapor-liquid equilibrium modeling, mass/energy balancing, preliminary capital and operating cost estimation) and in the use of data reconciliation for extracting information from laboratory, pilot and operating plant data.
• Experienced at critical evaluation of processes, particularly before the expenditure of significant effort and money on development work.
• Skilled in hydrometallurgy, electrometallurgy and aqueous chemistry.
• Skilled in the application of chemical engineering principles.
• Experienced in the application of conventional and innovative circuits to the processing of ores, concentrates and wastes.
• Experienced at troubleshooting, composed under pressure, able to lead technical teams through difficulties.
• Over twenty years in hydrometallurgy, five years managing applied research (team >80 people).
• Superior research management abilities and people skills.
• Free to travel as necessary, own software licenses for Aspen Plus and other software.

Process Modelling

• Developed numerous mass/energy balances for circuits processing sulphides, laterites, gold, zinc, lithium, hazardous wastes, cobalt-manganese, magnesium, uranium and others.
• Developed numerous mass/energy balances for oil and gas processing (combinations of reaction, distillation, heat exchange, flash, compression, expansion unit operations)
• Unit operations represented in the various process models include comminution, flotation, size separation, atmospheric- and high-pressure leaching, laterite autoclaving, filtration, thickening, counter-current decantation, precipitation, solvent extraction, ion exchange, electrowinning, electrorefining, multi-stage evaporation, reverse and forward osmosis, heat exchange, pressure reduction, steam compression.
• Familiar with the aqueous chemistry of sulphate, chloride, nitrate, phosphate and fluoride systems.
• Also developed numerous mass/energy balances for oil and gas processing (various combinations of reaction, distillation, heat exchange, flash, compression, expansion unit operations).
• Trained a significant number of people in process modelling.

Experience

• Simulation of conventional and novel circuits (sulphate, chloride, nitrate, phosphate and fluoride systems, as well as mixed systems).
• Simulation of oil and gas processing circuits.
• Lithium extraction from geothermal brine, salar brine and hard rock.
• Simulation of waste water treatment processes, including sulphate removal from acid mine drainage.
• Base metal and sulphur balancing by reconciliation of operating plant data.
• Hydrometallurgical processing of magnesium ores and wastes.
• Hydrometallurgical recovery of gallium metal from wastes.
• Pressure acid leaching of laterite, downstream recovery of nickel and cobalt.
• Oxidative leaching of sulphide minerals (pressure and atmospheric).
• Pressure leaching of refractory gold-bearing materials.
• Recovery of gold and elemental sulphur from gold-bearing pyrite.
• Pressure leaching of nickel/copper/cobalt/iron concentrates, mattes, alloys.
• Pressure leaching of sphalerite.
• Oxidation/precipitation of iron from process solutions.
• Efficiency improvements in full-scale zinc electrolysis.
• Removal of manganese from zinc electrolyte.
• Electrowinning of nickel, cobalt, chromium, zinc and copper.
• Electrorefining of copper.
• Production of chromium metal and chromic acid from waste ferrochrome.
• Production of beryllium metal from beryl.
• Processing of PGM-bearing matte/alloy.
• Production of cobalt metal from converter slag.
• Ion exchange/electrowinning for recovery of nickel from bioleach liquors.
• Solvent extraction/electrowinning for recovery of nickel from bioleach liquors.
• Recovery of copper and cobalt from manganese-bearing ores and tailings.

Professional History

Self Employed                                                                                    Jan. 2003 to present

• Incorporated as Arithmetek Inc. in February 2008.
• Critical review and analysis of novel process routes via thermodynamic analysis and mass/energy balancing.
• Encapsulation of experimental results into numerically rigorous mass/energy balances for process design, engineering feasibility studies, process optimization, etc.
• Data reconciliation.
• Process modeling of existing circuits.

SGS Lakefield Research Limited, Lakefield, Ontario

• Recruited from Mintek by Lakefield Research Limited in 1999.
• Role of technical trouble-shooter, diagnosing and solving technical problems, leading technical teams through difficult periods.

Manager, Process Modelling                                                           Oct. 2001 to Jan. 2003

• Modeled unit operations and flowsheets; process chemistry, mass/energy balances and process economics.
• Enhanced the quality, scope and profitability of projects undertaken by SGS Lakefield Research Limited for various clients around the world.

President, Argento Plata Metals Limited                                         Feb. 2001 to Sep. 2001

• Substantially improved productivity by adding a critical unit operation; gallium recycling venture controlled by Lakefield Research Limited; short-term assignment to find and rectify the cause of low productivity.

Manager, Metallurgical Group                                                          May 2000 to Jan. 2001

• Technical management of laboratory and pilot-plant projects.  Used process modelling to solve a severe process problem during a major pilot-plant project on laterite processing; enabled the work to be completed successfully.

Assistant Manager, Hydrometallurgy                                            April 1999 to April 2000

• Introduced and applied process modelling in hydrometallurgy.
• Prepared proposals for laboratory and pilot-plant work, interacted with clients to define scope and to secure projects.
• Managed and participated in projects commissioned by various clients.

Mintek, Johannesburg, South Africa

Manager, Hydrometallurgy                                                           April 1994 to March 1999

• Introduced hydrometallurgical process modelling and trained staff in the technique; significantly enhanced the quality of project work and the efficiency of pilot plants via process modeling.
• Contributed technically to R&D and client-funded projects via theoretical and practical input, uncovering/removing obstacles, etc.; projects such as removal of sulphate from acid mine drainage; pressure leaching of various materials; efficiency improvements in zinc electrolysis; removal of manganese from zinc electrolyte; recovery nickel from low-grade feeds, recovery of copper and cobalt from wads.
• Collaborated with engineering companies on the production of feasibility studies.
• Managed the selection of appropriate projects, deployment of project teams, achievement of technical milestones, technical quality of the work done and the resulting technical reports, occupational health and safety, maintenance of facilities, budgeting, control of expenditure and securing of contracts for client-funded work.
• Managed the performance and development of about 80 professionals (Ph.D., M.Sc. and B.Sc. level), technicians and operators; developed engineers and technicians into high-grade technical professionals via appropriate technical challenges, support and promotions.
• Management style encouraged free thinking and expression of technical opinions; eliminated hierarchical culture by being accessible to all; regularly talked to everybody in Hydrometallurgy, particularly about technical issues; led by questioning and advising instead of commanding; encouraged and applied lateral thinking; earned respect by remaining calm and objective during heated debates.
• Maintained appropriate expertise bases for anticipated work; developed motivated, effective technical teams skilled in the various unit operations of hydrometallurgy.
• Maintained infrastructure and multipurpose laboratory and pilot-plant facilities for testing and continuously piloting hydrometallurgical processes and generating sound data for definitive cost estimates and feasibility studies; developed motivated, effective research teams.
• Maintained good relationships with the metallurgical industry; generated work that resulted in improved operation of commercial plants.
• Met revenue and expenditure targets; significantly reduced reliance on state funding.
• Balanced the needs of upper management and those of technical staff; consulted staff where necessary; compiled and provided forecasts, management reports, etc.
• Nurtured good relationships with universities and community colleges; assisted with formulation and supervision of postgraduate research, including M.Sc. and Ph.D. projects; examined M.Sc. and Ph.D. dissertations; selected students for undergraduate and postgraduate bursaries; supported vacation projects for undergraduate students; external examiner on hydrometallurgy for the University of the Witwatersrand.

Assistant Director, Base Metals Industry                                    Jan. 1992 to March 1994

Assistant Director, Sulphide Minerals Processing                        Jan. 1987 to Dec. 1991

Group Leader, Sulphide Minerals Processing                               Jan. 1986 to Dec. 1986

• Led the development of patented technology for the production of chromium metal and chromic acid from waste ferrochrome fines.
• Managed a major laboratory and pilot-plant program on the production of beryllium metal from beryl.
• Conceived, developed and motivated R&D projects; led and supervised the execution of approved projects.
• Developed proposals for client-funded work and supervised the execution of client-funded work.
• Supervised and participated in the production of technical reports emanating from client-funded and R&D projects.
• Pressure leaching, iron removal, electrolysis.

Principal Engineer/Senior Engineer/Engineer                              Aug. 1982 to Dec. 1985

Principal Scientist/ Senior Scientist                                               Jan. 1980 to July 1982

• Developed patented equipment and technology for recovering gold and elemental sulphur from gold-bearing pyrite.
• Promoted regularly in recognition of increasing technical competence.
• Carried out R&D and client-funded projects in hydrometallurgy; pressure leaching of sulphide minerals, refractory gold-bearing concentrates.

SASOL, Sasolburg, South Africa

Chemical engineer                                                                          Dec. 1975 to Dec. 1979

• Process engineering; process development and production experience in the conversion of coal to synthetic fuel.

Education and Training

• Ph.D., University of the Witwatersrand, 1984, Engineering.
• B.Sc., University of Cape Town, 1975, Chemical Engineering.
• Member of CIM Metallurgical Society, Hydrometallurgy Section Committee.
• Various management and professional development training courses.

Publications

• Environmental Evaluation of Making Nickel Sulphate. Alta Ni-Cu-Co Conference, May 2019, Perth, Australia.
• Lithium from Clay versus Lithium from Spodumene. Alta Lithium Processing Conference Conference, May 2019, Perth, Australia
• Extraction of Lithium from Brine – Old and New Chemistry. Processing of Critical Metals, Hydrometallurgy 2018, Extraction 2018, August 2018, Ottawa, Ontario, Canada.
• Modelling Synergistic Solvent Extraction of Nickel and Cobalt. Gordon Ritcey Symposium: Advances in Hydrometallurgical Solution Purification Separations, Hydrometallurgy 2018, Extraction 2018, August 2018, Ottawa, Ontario, Canada.
• Laterite and the Commodity Price Cycle. Alta Ni-Cu-Co Conference, May 2018, Perth, Australia.
• Aqueous Chemistry of Lithium Production. Alta UREELI Conference, May 2018, Perth, Australia.
• Is Alkaline Glycine a Contender for Dirty Copper Concentrate? Alta Ni-Cu-Co Conference, May 2017, Perth, Australia.
• A Broad Look at Lithium Extraction. Alta UREE Conference, May 2017, Perth, Australia.
• A Preliminary Evaluation of Alkaline Glycine as an Alternative to Cyanide for Gold Extraction. Alta Au-U Conference, May 2016, Perth, Australia.
• Technical & Cost Comparison of Laterite Treatment Processes Part 4 – Hydroxide to Metal. Alta Ni-Cu-Co Conference, May 2016, Perth, Australia.
• Evaluation of Established and Novel technology for Iron Control and Acid Regeneration in Chloride Hydrometallurgy Circuits. Iron Control 2016, IMPC 2016, September 2016, Quebec City, Canada.
• Technical & Cost Comparison of Laterite Treatment Processes Part 4 – Hydroxide to metal. Alta Ni-Cu-Co Conference, May 2015, Perth, Australia.
• Evaluation of Stabilised Bromine Technology for Gold leaching. Alta Au-U Conference, May 2015, Perth, Australia.
• Technical & Cost Comparison of Laterite Treatment Processes, Part 3. Alta Ni-Cu-Co Conference, May 2015, Perth, Australia.
• Technical & Cost Comparison of Laterite Treatment Processes, Part 2. Alta Ni-Cu-Co Conference, May 2014, Perth, Australia.
• Early Evaluation of Metal Extraction Projects. Alta Ni-Cu-Co Conference, May 2013, Perth, Australia.
• Nickel and the Three Mineral Acids. Alta Ni-Cu-Co Conference, May 2012, Perth, Australia.
• Development of a Novel High-Chloride Circuit for the Starfield Resources’ Ferguson Lake Project. TMS Annual Meeting, Feb 23 – Mar 3, 2011, San Diego, California, USA.
• Nickeliferous Pyrrhotite – Another Source of Nickel If it can be Extracted Economically; Alta Nickel, Cobalt, Copper Conference, May 2010, Perth, Australia.
• Treatment of Nickel Laterites by Chloride and Hybrid Chloride Sulphate Processes: COM 2009, August 2009, Sudbury, Ontario.
• Using Computing Power in Process Development; Mintek 75 Conference, June 2009, Johannesburg, South Africa.
• Water and Carbonate Balances in an Alkaline Uranium Extraction Circuit; Alta Uranium Conference, May 2009, Perth Australia.
• Modeling the Thermodynamic Behavior of Aqueous Magnesium Chloride at High Concentrations and Temperatures; 2009 AspenTech Worldwide User Conference, Houston, Texas, May 4-7, 2009.
• Aspects of Modelling a Complex Chloride leach Circuit: Starfield Resources’ Ferguson Lake Project; paper published in the proceedings of the Alta Nickel/Cobalt Conference, Perth, Australia, June 2008.
• Modelling the high pressure leaching of laterite using Aspen Plus and OLI; paper published in the proceedings of the 2005 Conference of Metallurgisys, Computational Analysis in Hydrometallurgy, Calgary, Alberta, Canada, August 2005.
• Process Modelling in Flowsheet Development – Concept and Case Study; paper presented at theAlta Nickel/Cobalt Pressure Leaching and Hydrometallurgy Forum, May 2001, Perth, Australia.
• The Purification of Polluted Mine Water; paper presented at the Second Southern African Minerals Symposium, October 1998, Cape Town, South Africa.
• Cu/Co Tailings Treatment Project, Democratic Republic of Congo; paper presented at the Alta Nickel/Cobalt Pressure Leaching and Hydrometallurgy Forum, May 1998, Perth, Australia.
• Testwork Conducted by Mintek for Bulong Nickel project; paper presented at the Alta Nickel/Cobalt Pressure Leaching and Hydrometallurgy Forum, May 1997, Perth, Australia.
• R&D Testwork: The Key to Successful Design; paper presented at the SAIMM Metallurgical Process Design School, November 1993, Randburg, South Africa.
• The Production of Particulate Manganese Dioxide during Zinc Electrowinning; paper presented at the 20th Annual Hydrometallurgical Meeting, International Symposium on Electrometallurgical Practice, October 1990, Montreal, Canada.
• The Prediction of Redox Potential in Concentrated Iron Sulphate Solutions; paper published in Hydrometallurgy, volume 21, 1988.
• The Effect of Flocculent in the Leach on the Precipitation of Iron During the Direct Oxidative Leaching of Sphalerite; paper presented at the International Symposium on Iron Control in Hydrometallurgy, October 1986, Toronto, Ontario, Canada.
• Oxidative Leaching of Base Metal Sulphides Avoids Air Pollution; paper presented at the Symposium on Air Pollution - Challenges in Southern Africa, November 1986, CSIR, Pretoria, South Africa.
• The Recovery of Gold from Refractory Ores; paper published at Gold 100, 1986, Johannesburg, South Africa.
• Kinetics of Leaching of a Low Grade Iron-Nickel-Copper-Cobalt Matte in Ferric Sulphate Solution; paper published in Hydrometallurgy, volume 18, 1987.
• Electrically Heated Fluidized Bed Reactor and Processes Employing Same; patent filed in South Africa (1991) and in United States, Canada and Australia.
• The Production of Chromium Hydroxide/Basic Chromium Sulphate and the Conversion thereof to Chromium Metal or Chromic Acid; South African patent (1991).
• The Treatment of Uitkomst Concentrate; declassified Mintek report M188D, 1984.
  Authored and co-authored over 70 confidential reports.

Last updated February 2020