Our client's operational site in Ghana was experiencing losses of gold through the mine to mill process whereby the grade control parameters were not being achieved at final 'gold in circuit' reconciliation. This loss of recovered ounces significantly impacted the company's market value and ability to finance its growth strategy.
ORBIZ was engaged in conducting a comprehensive review of all gold room operating processes and identifying opportunities for improvement to rapidly improve gold recovery rates.
The process observation activity identified a significant amount of spillage at all stages of the gold room process (from electrowinning cells to pour) of both calcined and uncalcined concentrate. The spillages were being cleaned down at the end of each pour and collected in a sump. As the sump cleaning activity was difficult and hazardous, it was typically carried out every 4-6 weeks.
The sump cleaning process was analysed, and improvements introduced to eliminate the hazards and improve efficiency and meet all security requirements. With the addition of two new pieces of equipment (a submersible pump and a wet vacuum), the process was vastly improved, enabling the process to be completed weekly before any smelt so that the result can be included in that pour.
The new weekly gold room reconciliation process was standardised to enable it to be completed safely and efficiently on a repeatable basis. This new process now provides consistent grade control to mine to mill process. While the measures are taken have vastly improved the condition, they are temporary solutions, and long- term corrective actions will be put in place to eliminate most spillage in the process.
- 2000-ounces of gold recovered through initial gold room reconciliation activity realising $2.7m uplift in revenue
- Significant safety improvements delivered through new equipment and processes to support gold room reconciliation process
- Weekly gold room reconciliation process introduced enabling consistent grade control and increased Board and Shareholder confidence through consistently strong production and financial outcomes