Technology Used
What is the benefit of mineral composition over elemental composition?

Ores mostly occur as minerals and very seldom as free elements. At most mines the ore deposit requires some form of treatment to separate the valuable components from the waste components.

The separation process always makes use of some physical or chemical property of the minerals in which the valuable component is captured. This may be the relative density, some magnetic or electrical parameter, grain size or surface characteristic. For the optimum operation of a mineral separation plant, the operator requires regular information about the mineral composition at the different stages of separation. As an example, different copper oxides can be differentiated from copper sulphides.

In addition, light elements may not be detectable by on-line elemental analysers. For example, silicon as element may be difficult to quantify, however silica as mineral can be quantified accurately.

Portfolio of minerals and metals:

Minerals and metals that have to date been successfully tested to be amenable to diffuse reflective spectroscopy are listed in the table below. Please note that this list only serves as a portfolio of what has been tested and does not exclude the possibility to successfully quantify metals and minerals not listed here.

Copper Sulphides Copper Oxides
Bornite Azurite
Chalcocite Cuprite
Chalcopyrite Malachite
Elements Other Minerals
Bismuth Arsenopyrite
Copper Azurite
Gold Biotite
Iron Calcite
Magnesium Chromite
Sulphur Covelite
Zircon Covelite
Phosphates Goethite
Fluor-Apatite Haematite
Lizardite Heazlewoodite
Phlogopite Magnetite
Coal Pentlandite
Ash Plagioclase Anorthite
Green Coke Pyrite
Pyrolitic Pyroxene
Heavy Minerals Pyrrhotite
Amphiboles: Hornblende Quartz (Silicate)
Corundum Spinel
Ilmenite Staurolite
Garnet Talc
Ilmenite Tourmaline
Kyanite Non-mineral values
Rutile Percentage solids
Ferrous vs Ferric oxide
Total Base Metal Alloys
How does the Blue Cube MQi technology work?

The Blue Cube MQi captures reflected light from a large number of ore particles presented to the scanner. It measures the relative amplitude of the different wavelengths received. This is referred to as the spectral profile.

In a specific mineralisation, each mineral species exhibits its own spectral profile. A mixture of minerals will show a combined profile that will contain a proportional summation of all the various mineral>
This combined spectral profile is referred to as the 'fingerprint' of the particular mineral mixture. By comparing the fingerprint of a mixture of unknown mineral composition with the fingerprints of other mixtures with known mineral compositions, its composition can be determined.

Diffuse reflective spectroscopy

Diffuse reflection is the reflection of light from a surface such that an incident ray is reflected at many angles that can be described as casual, rather than at just one precise angle, which is the case of specular reflection. If a surface is completely non-specular, the reflected light will be evenly scattered over the hemisphere surrounding the surface. A surface built from a non-absorbing powder, such as plaster, or from fibres, such as paper, or from a polycrystalline material, such as marble, can be a nearly perfect diffuser. (From Wikipedia, the free encyclopedia.)