BLEND VECTOR MODELLING AND RESERVE MAXIMISATION
Blend Vectoring is an approach to maximise the conversion of mineral resource to saleable product, where that product is a trade-off of conflicting specifications (e.g. grade vs. contaminants). A blend vectored model effectively utilises a variable product / contaminant grade criteria that trades off material with varying qualities to end up with the highest convertible resource. The video below provides a graphical representation of the process for a simple two contaminant real-world case developed by ORELOGY.
ORELOGY undertake open pit optimisation on the blend vectored resource to generate pit shells with the maximum tonnage of “potentially convertible resource”. However trading off the various material properties to sustain a marketable blend over the longest period of time will maximise the conversion of the in-ground resource to a saleable product. The key to ORELOGY's approach is the utilisation of Maptek EVOLUTION® (EVO) scheduling software, which is a highly sophisticated next-generation scheduling program that was primarily developed as a blending tool to accomplish precisely this. It utilises the forward looking capability of an Evolutionary Algorithm (EA) heuristic to maximise conversion of a potentially convertible resource to a scheduled ore inventory, which in turn can be classified as an Ore Reserve. It does this while minimising the amount of ex-pit stockpiling and rehandling required. As such it is the only tool currently available that can practically and effectively schedule a blend vectored model.
This process can be undertaken within a pit design or an optimal shell. In addition, if a higher value product can be produced earlier in the mine life without adversely affecting overall project value or sustainable mine life, then this potential can also be examined.
ORELOGY developed the EVO tool in-house over a five year period prior to it being acquired by Maptek in 2014. As a result ORELOGY are the acknowledged power user of this tool world-wide.