The composition of iron ore can be monitored for process control purposes.

Composition of Iron Ore

The composition of iron ore can be monitored in a number of ways. One method involves measuring the natural radiation emitted from iron ore and using known correlations to derive the compositon. Another method involves the direct measurement of the elemental composition.

As an example of the natural radiation application, an Ironscan 1500 has been installed on the raw iron ore conveyor after the first stage of crushing to -90mm. Natural radiation emanates from the ore. The parameters of interest in the iron ore are Fe, Si, Al and P. Preliminary work in the factory allowed a performance guarantee for Si to be offered, and there with high expectations for Fe and Al. Not much success was expected with the measurement of P.

Not only is the customer extremely satisfied with the measurement of Si, Fe and Al, as was expected, but also with the measurement of P as well.

Direct measurement of the elemental compositon is performed using Prompt Gamma Neutron Activation Analysis (PGNAA) technology utilised by the GEOSCAN. In addition to the Fe, Si and Al, this technology allows measurement of elements such as Mn, Ti, Mg, Ca, K and others. The GEOSCAN is effective in monitoring the quality of lump and fines product streams as well as loadout operations. Blending can be controlled to ensure the product quality does not significantly exceeed the specification, hence maximising utilisation of the geological resource.  

Moisture Content of Iron Ore

Iron ore is usually sold on an as received basis. Traditionally it has been assumed that the ore is fairly homogeneous with respect to moisture content, and thus spot sampling of the ore was acceptable. Real time on-line monitoring has shown that this is not always so.

To ensure, for instance, a ship is loaded to the correct specification, a TBM can provide immediate information regarding the moisture content of the iron ore. This information may be able to be acted upon by an operator for process control purposes. The TBM can be integrated with water addition systems for dust management and optimised manual handling performance.