Estimation of geological coal reserve by structure modeling for Vinacomin coal seams

Abstract

The structure of coal seams in Vietnam is quite complex with tectonic disturbances and inseam rock partings. Determining the geological structure, calculating reserves and especially the geological reserves of coal seams is a common but rather difficult task for mining engineers. The traditional method in Vietnam is linear interpolation and calculating reserves by parallel cross-sections. But now, with the support of computers, the modeling method is being widely applied, and moreover, it also helps to accurately describe the structure of the coal seam and eliminate the rockpartings located between the roofs and floors in the seams, which is very necessary for calculating coal reserves. At the same time, new criteria for coal reserves have also been introduced, such as T, T1, T2. This newly applied method of calculating coal reserves not only increases the accuracy, but also shortens the time and even increases the calculated coal volume compared to the traditional method, has many scientific and practical meanings, and can be effectively applied to geological and surveying works such as calculating geological reserves and calculating mining excavated volume.

The main content of the paper is to introduce the method of calculating reserves by combining structural modeling and thickness of coal seam. This method is applied to calculate all major coal seams in large open-pit mines of Vinacomin, but the typical case study presented in the paper is the case of Caoson and Hatu mines, using data from boreholes in Vinacomin's geological exploratory reports. 

In order to have good results of reserve estimation, the article also introduces the creation of relational geological databases of coal deposits for mines. The modeling results demonstrate the effectiveness of these PC applied works, including establishment of coal seam structural maps such as elevation isolines of roof, floor and thickness of coal seams, as wel as tectonic zone planes. These modeling results can be served as the basis for mine design, mine planning, mine scheduling, mine optimization and economic efficiency calculation... on computers in a continuous and intergrated way.