Mineralogical ore typing by QEMSCAN

Welcome back! I apologise for the long delay between posts. Things have been busy at MinAssist and the blossoming mining industry has kept demand for value added mineralogical analysis high and time for sharing our thoughts low.

Today I wanted to share some more thoughts on the usefulness of ore typing to mining and mineral processing operations. I have recently been working on a the beginnings of a geometallurgical program for an open pit operation where the whole processing chain from mining, through processing and to smelting is included. This has given me a unique opportunity to view ore typing from the perspective that although the mill is the direct customer of the mines ore types, consideration must be made for the effect that changing ore type can have on products fed to a smelter.

Examining this further I wanted to talk about some of the considerations that should be made when defining ore types on a mineralogical basis. The use of ore type definitions can provide vital information to a milling operation to ensure that variations in feed material do not adversely affect performance. Ore typing can be as simple as grade variations or definition of geological textures but I have been looking at taking it a step further and using fundamental mneralogical parameters as the basis.

It is now possible to use automated mineralogical techniques, like MLA or QEMSCAN, to quantify a huge number of process specific parameters within an ore sample and use these to group ores by type. This typing can be based on process specific parameters and elemental or mineralogical signatures can be used to differentiate these ore types at the blast hole and then track them through the process. The commerciLisation of infra-red logging technology, like GeoSCAN, will make this process even easier.

The key consideration in all this is which mineralogical parameters are best used to ensure that relevant information is fed to the mill. Mineralogical studies produce vast volumes of data for each sample and it is important to sift through and define what is really important for that specific application. For mineralogical ore typing I have found that definition of the key ore minerals, along with impurity minerals that may affect concentrate quality or general processing is the best starting point. For these minerals the most important parameter becomes the mean grain size and contextual setting of the mineral grains. Using this fundamental information it is possible to provide an ore type definition that is readily applicable for processing. From there it is simply a matter of identifying a suitable signature for that ore type that is easily measured and beginning to look at the process behaviour to draw correlations that can be used in predictive process control.

I realize this is only a very broad and brief introduction into the world of using mineralogical ore typing. I hope it helps you think on some of the possibilities having this type of information early in the mining cycle can bring. If you have any questions please don’t hesitate to contact us at MinAssist or leave a comment and stimulate some discussion.