An effective process auditing program is an important part of maintaining consistent recoveries in mineral processing operations. Traditionally, process audits are completed using chemical and metallurgical methods to monitor recovery and elemental distribution. The development of automated mineralogy and more efficient process mineralogy analysis techniques means that mineralogy is now more accessible as an efficient and comprehensive auditing tool.
As operating costs increase and feed grades decrease it is important to maintain tight control of your process and ensure maximum recovery is maintained at all times. Just a few days of losses in recovery caused by changes in ore type or processing conditions can have a large effect on total metal recovery and profit. Mineralogical audits can be used to minimize these losses by monitoring the fundamental behavior of feed ore on a regular basis.
Smart use of mineralogical auditing can develop mineralogical and ore type benchmarks in a detailed initial audit that can be used in process control and monitoring. A detailed initial audit of geological ore types can be used to identify key mineralogical parameters that may be used in routine and cost effective analysis. Automated mineralogical systems like QEMSCAN are ideally suited to this because of the depth of information on everything from modal mineralogy to locking/liberation characteristics and mineral associations.
The advantage that automated mineralogy brings to auditing is the regularity of analysis that can be performed. Traditional intervals for audits are yearly or quarterly. However, the speed and cost effective nature of systems like QEMSCAN allow better mineralogical data to be collected at monthly or quarterly intervals. This provides greater options for use of mineralogy in monitoring of key process streams and opens the possibility to use auditing in control for aspects such as maintenance scheduling.
Whole process audits on targeted streams provide information on all aspects of the operation. It is possible to draw on other mineralogical information from ore characterization, tailings evaluation and risk reduction studies to build a comprehensive picture that is consistently developed upon. Subtle changes in ore type can be picked up quickly and key process parameters tweaked to compensate for the new ore type.
Mineralogical audits can equally be applied to specific unit operations within the process. This can allow more detailed information to be gathered on areas of the process that have been identified as critical. This can be especially effective for flotation or oxidation processes where process parameters can be very sensitive to small changes in mineralogy.
Overall, regular mineralogical auditing can provide targeted information for definition of inefficiencies over unit operations or the whole process. Smart use of auditing can establish trends in key process streams, define the effect of changing ore type and evaluate the effectiveness of ore blending from the mine. MinAssist can help with development, implementation and then monitoring of these programs through the virtual mineralogist program.
I encourage you to give us your thoughts on using process auditing. Larger mining companies use these techniques very effectively but the advent of automated mineralogy has meant that there is no reason why smaller operations cannot effectively implement very beneficial programs.