Geological risks assessment during mining of carbonate rocks deposits in Ukraine

Abstract

This paper offers an overview of methods for assessing geological risks in the development of domestic deposits of carbonate rocks and an example of calculation for one of the deposits of the Kherson region. Conducting geological exploration at each stage of deposit development is accompanied by certain risks, which by their characteristics belong to geological and investment risks, which together make up the group of risks of the mining business. The purpose of determining geological and economic risks when carrying out geological exploration works is to take into account those negative characteristics of the subsoil area, which can objectively reduce the quantity or affect the quality of the mineral. The listed methods of taking risks into account are possible for use at the final stages of geological and economic assessment during detailed exploration of deposits. Geological risk is defined as the probability of not confirming the quantitative and qualitative characteristics of the deposit's reserves. The degree of uncertainty is quantified through the coefficient of variation of resources. For relatively well-studied objects, it is small – 0-0.2, for medium-studied ones – 0.1-0.4, for poorly studied ones – from 0.3 to 1 and more. Intervals of values overlap because they depend on the complexity of the geological structure of the object. According to the results of calculations, the assessed area has low risks of quality loss, which is ensured by the even distribution of the useful component. Fluctuations in the contents of SiO₂ and MgCO₃ can have negative consequences, because for this deposit the increased amounts of mass for SiO₂ + Al₂O₃ if we evaluate the raw material as flux. By lithological varieties, the greatest risks of non-confirmation of quality were recorded for oolite limestones and pelitomorphic shell limestones.

Keywords

• carbonate raw material
• limestone
• geological risk