A great paper written by Victor Patson Mutambo, Dilmurod Maxmudov, Yorqin Nurboboev, Asliddin Mahmadoliev and Feruz Pardaev.
Proper geological and economic assessment of ore dilution and loss is important both in the feasibility study of the mining design process and during mining operations. Production capacity and profitability of the mine directly depend on the indicators of loss and dilution of ore and are one of the main factors in assessing the prospects for the development of a mining enterprise.
The complexity of the mine structure, the instability of the ore and enclosing rocks, difficult hydro-geological conditions adversely affect the productivity of mining, causes the dilution of the ore to increase to 35-40%, and the ore loss to 25%.
Millions of dollars are invested each year in mining enterprises around the world to eliminate the consequences of damage of ore dilution and loss.
Planned and unplanned dilution
Planned dilution determined depending on the complexity of the ore body and selected mining method. In some cases, planned can reach up to 40%.
Unplanned dilution can be caused by the followings:
- blast overbreak, which may occur directly due to inadvertent fragmentation of rock outside the mining lines;
- instability of the rocks, located on the wall of the mining blocks;
- mining of filled chambers because of improper conduct of mining operations
Geological and technical factors of ore dilution
Various geological factors affecting the amount of the indicator of ore dilution:
- strength and stability of ore and enclosing rocks;
- size of ore bodies; v presence of tectonic disturbances and fracturing;
- clarity of contacts between ore and burden;
- roughness of the contour of ore bodies and the presence of useful components in the enclosing rock.
Mining and technological factors of ore dilution are the following:
- waste rocks can be mixed in different places and amounts from the roof and floor of the ore body
- waste rocks penetrate the broken and running ore from the overlying collapse
- mineral loss on rich parts of the ore in general, ore dilution is divided into planned and unplanned types.
Ore dilution consequences
All the factors of ore dilution listed above directly affect the quality indicators of the extraction of minerals and play an important role in the economy of the mining enterprise. Dilution, as well as loss of ore, causes economic damage, which consists of:
- unproductive expenses for underground and surface transport of mixed rock, for sorting the ore mass (if it must be resorted to) and for processing the rock at a processing plant;
- additional metal losses that usually occur during sorting and processing of diluted ore;
- reduction of the production capacity of ore processing factories or plants to produce final products (concentrate or metal), and sometimes also deterioration of the quality of these products.
Bibliography
Mutambo, Victor & Maxmudov, Dilmurod & Nurboboev, Yorqin & Mahmadoliev, Asliddin & Pardaev, Feruz. (2021). Impact of ore dilution on the technical and economic performance of a mining enterprise.
