Mass Flow Determination
It is clear that a projected metallurgical performance of any gold operation must be confirmed with an appropriate and realistic mass balance, which is determined by taken good samples. The main objective of mass measurement for geometallurgical purposes is to establish the mass flow of the particular material or component present at a specific time, or the mass flow of that component over a defined time period, to a defined accuracy suitable for mass balancing, using appropriate methods based on acceptable practices.
Gold operations are exposed to financial risk related to its metallurgical performance to the extent that there is uncertainty in the evaluation of the quantities of precious metals sent to the recovery process and produced by it. Without any doubt, one of the first objectives in the design of a sampling procedure is to enable a gold operation able to quantify, manage and minimise the degree of risk to which it could become exposed, through problems detected in the mine or the processing plant. In this way, the main areas to which a gold operation could be exposed are misrepresentation of the performance of the operation and unknown losses such as gold concentrate, Merrill-Crowe precipitate or Dore bar.
For this reason is important for each operation to perform a risk assessment of its entire operation in order to establish and quantify the inherent risks or problems that affect the geometallurgical performance of the operation. Then, it is important that the sampling system or procedure must be updated to eliminate and minimize the risks when accounting discrepancies are identified between the projected and real mass balance. Basically, the use of statistical analysis, and check measurements and analyses provides a database, which becomes an essential component of the risk management process. The other fundamental component of the risk management process is regular and frequent management reviews, incorporating risk assessments, of the entire metal accounting system, supported by both internal and external audits performed by experience people. Obviously, the experience of metallurgists is important due to help to identify weak points and problems associated with the procedures selected.
It has been noted that a difference will normally appear between input and output due to measurement, sampling and analytical inaccuracies. Basically, this difference is considered as an unaccounted gain or loss and the metallurgist must perform the corrective actions to solve the problem. It is important to identify if the problem is on the ore or the processing plant. Potential differences must be compared with the estimated performance. If the projected was developed without a geometallurgical study, it must be included now.