Grade control digging involves performing tests on ground that is to be mined. Deposits of desired minerals are never evenly distributed and grade control digging can give mining companies a better idea of where to focus their efforts. A grade control drilling company Kalgoorlie provides equipment and services to perform this function.
Grade control is an process that is performed at a mine on a regular basis. It is essentially an economic function that is used to select the location of the best parcel for the material to be mined. Mistakes in grade control analysis are costly and often irreversible; they are measured in terms of cash flow losses and increased operational cost.
Grade control models are created using a large number of samples. In underground mines this data is usually provided through a series of tightly drilled holes, channel samples or short drilled holes to test production levels. In an open pit environment blast holes samples are obtained by taking samples based on closely spaced grids based on where blasting is conducted. Sometimes, though rarely, grade control drilling is performed separate from blast hole drilling; this occurs, for instance when using dedicated reverse circulation drilling.
Conventional grade control analysis methods include setting grade outlines and the use of inverse distance, polygonal estimation or kriging of blast hole grades. These methods do not account, however, for uncertainty in prediction. Other methods, such as simulation of multiple realizations, provides the data for different optimization algorithms, such as the minimum-loss/maximum profit method.
Improvements in the simulation-based methods are evident in more erratic grade distributions and where there are more marginal mixed ore-type zones. More complicated grade control scenarios, such as those that involve multiple processing options and stockpiling, can also lend themselves to grade control optimization through these simulation based methods.
Reliable production (or reconciliation) information is used to optimize the grade control model and also the resource model with actual mining results. Determining the degree of reliability of this information is key to understanding to what extent it is possible to optimize grade control models because the precision of such information is sometimes substandard. A grade control drilling company Kalgoorlie can assess the quality of the reconciliation information and thus determine the feasibility of using it for mining model calibration.
Grade control technology is used to improve the efficiency of a mining operation and to thus increase its productivity and overall profitability.