Abstract
SYNOPSIS Electrowinning consumes a substantial amount of electrical energy, and owing to the ever-increasing unit cost of electrical power there is a need to improve current efficiency in the process. This research was carried out to design a continuous quality improvement framework for improving electrowinning current efficiency by applying statistical process control (SPC) on an online industrial copper electrowinning operation. A sequential mixed research methodology was applied and a statistical software package utilized for analysing data. It was concluded that metallurgical short-circuits (hotspots) had the most significant effect on current efficiency. Bringing hotspots under statistical control resulted in a 5.40% improvement in current efficiency, which is equivalent to approximately 74 t of 99.999% pure grade A copper cathode production over a period of 1.5 months. Keywords: quality, continuous improvement, continuous quality improvement, statistical process control, and current efficiency.
Highlights
The mining industry is a significant contributor to the Namibian economy, accounting for 9.3% of the GDP in 2019 (Chamber of Mines, 2019)
The root causes of hotspots were poor anode maintenance in terms of missing insulator replacement, old corroded anodes, poor spent electrolyte copper concentration control, and poor cathode smoothing agent (Magnafloc) control. These root causes were addressed by developing and implementing an out-ofcontrol action plan (OCAP) which resulted in the improvement of current efficiency from 89.64% to 95.04%, an improvement of
This translates to approximately 74 t of 99.999 % pure grade A copper cathode production over a period of 1.5 months
Summary
The mining industry is a significant contributor to the Namibian economy, accounting for 9.3% of the GDP in 2019 (Chamber of Mines, 2019). In Namibia, the mining industry produces a wide range of commodities such as special high-grade zinc, gold bullion, blister copper, grade A copper cathodes, uranium oxide, gem-quality diamonds, cement, dimension stone, semi-precious stones, salt, chemicals, tin concentrate, zinc, and lead concentrates. One of the state-of-the-art technologies used in the Namibian mining industry is the electrowinning (EW) process. This power-intensive electrical process is utilized for the production of refined copper cathodes (Parada and Asselin, 2009). In Namibia, the EW process is applied in mine-to-metal operations which are producing gold bullions, special high-grade zinc, and grade A copper cathodes. This research was conducted in Namibia’s only copper solvent extraction and electrowinning (SX-EW) plant that applies electrowinning technology to produce copper cathodes of 99.999% purity
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
