Designing A Continuous Quality Improvement Framework For Improving Electrowinning Current Efficiency

ABSTRACT

The use of quality control techniques such as Statistical Process Control (SPC) has become essential for any business to thrive in the modern industry. Statistical quality control is one of the reasons why the Japanese had a significant advantage over their competitors. However, many organizations are still not yet applying this powerful quality control technique (Ben & Jiju, 2000; Helm, 2018).

In addition to that, although substantial research has been done to improve electrowinning current efficiency, no evidence of research done to improve current efficiency from a quality perspective by applying statistical process control was found in the reviewed literature (Moongo, 2020). This research/knowledge gap needs to be filled and this research has contributed to the body of knowledge by filling the above-mentioned research/knowledge gap.

In general, the electrowinning process requires substantial electrical energy to electroplate a metal of interest onto a cathode blank (Parada & Asselin, 2009). Unfortunately, the unit cost of electrical energy is ever-increasing (Nampower, 2019; Eskom, 2019). To make things worse, Nampower partly relies on Eskom to meet the electrical energy demand for Namibia.

However, Eskom has been struggling to supply the South African national grid with sufficient electrical power. This resulted in load-shedding (Eskom, 2019). Therefore, it is essential to utilize electrical energy efficiently. Hence, the need to improve current efficiency (CE), and the significance of this research (Moongo, 2020).

Despite the aforementioned facts, the electrical energy utilized in the electrowinning process can be applied more efficiently and cost-effectively by improving electrowinning current efficiency (Hongdan, et al., 2016; Moongo, 2020). A typical electrowinning process consumes approximately 60 % to 80 % of the total electrical energy at a mine (Gonzalez-Dominguez & Dreisinger, 1997). Consequently, there is an opportunity for substantial electrical energy saving and for increasing copper cathode production if electrowinning current efficiency is improved.