Validation of the chosen cutoff grade value in open pit mine design

A cutoff grade in open pit mining is set based from the analysis of alternative design solutions with regard to geological, geotechnical and economic factors. In open pit mining, the minimum economically rational content of a useful component, or a cutoff grade is expedient to be found with allowance for a stripping ratio in an estimation ore block. The optimized cutoff grade is a function of the net present value of the open pit mine project implementation, and is to be periodically revised during adjustment of project documentation and open pit mining plans, in operational geological re-exploration, in amendment and updating of the block model of ore deposits, and upon modification of mineral mining and processing technologies. The implemented research proves that in the system analysis of parameters and performance of an open pit mine, the cutoff grade can only be adopted given the stripping ratio is taken into account. A lower cutoff grade allows higher NPV but reduced general income received from the product sales unadjusted for discounting.

Fomin S. I., Govorov A. S. Validation of the chosen cutoff grade value in open pit mine design. MIAB. Mining Inf. Anal. Bull. 2023;(12):169-182. [In Russ]. DOI: 10.25018/0236_ 1493_2023_12_0_169.

S.I. Fomin¹, Dr. Sci. (Eng.), Professor, e-mail: fominsi@mail.ru, ORCID ID: 0000-0002-0939-1189,
A.S. Govorov¹, Graduate Student, e-mail: s215078@stud.spmi.ru, ORCID ID: 0000-0001-9071-862X,
¹ Empress Catherine II Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

A.S. Govorov, e-mail: s215078@stud.spmi.ru.

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