Mining Dilution: Variable Versus Fixed Factor

Anoush Ebrahimi
Monday, February 26, 2018
First presented: 

Mining dilution affects the economy of mining projects in many ways. For example, dilution increases costs and can cause reconciliation issues that are common in mining operations. A common approach to estimating mining dilution is to apply a fixed factor to the entire block model. The fixed dilution factor is usually driven by assumptions that are made based on experience and general knowledge. Mining dilution occurs in contact area of ore and waste, but not in the centre of the orebody. Because fixed dilution factor ignores the changes of values within an orebody, the designs driven by such studies can become suboptimal. The methodology described in this paper assures dilution factors are calculated on a block-size scale and honor the variability of values within the orebody. Applying a variable dilution factor enhances the accuracy of mining studies and subsequent economic evaluations. This will be demonstrated using a case study.

Feature Author

Dr. Anoush Ebrahimi

Anoush Ebrahimi has 24 years of mining experience and specializes in strategic mine planning, open pit mine design, mine evaluation, production scheduling, mine layout optimization, mine simulation and computer modeling. He has worked in Canada and abroad on mining projects at stages ranging from conceptual study to construction. Anoush’s diversified experience includes gold, copper, polymetals, coal, manganese, phosphate, bauxite and oil sand projects. Mines he designed that are now in operation include the Endako molybdenum super pit in Canada and the Gualcamayo gold mine in Argentina. 

Anoush is an adjunct professor at the University of British Columbia and a director of the CIM Vancouver branch. He has authored and presented numerous technical papers at CIM, SME and other conferences and seminars.

Principal Mining Engineer
PhD, MSc, BSc
SRK Vancouver
SRK Turkey