Application of Advanced Digital Core Orientation Tool and Geo-Statistical Technique (Kriging) for Resource Modeling in a Structurally Complex Magmatic Chromite Deposit: A Case Study from Sukinda Chromite Mine, Tata Steel Limited

Abstract

Resource Modeling has been a challenging task in magmatic ore deposits, more specifically in Sukinda chromite deposit where the presence of shears and dykes intersecting the chromite ore have posed major structural disturbances. The conventional extrapolation of surface structural features with subsurface structures often gives inaccurate predictions. This paper discusses the role of Digital Core Orientation tool, its basic features, the process adopted and its advantage over the conventional one. The first section deals with the use of advanced core orientation technique to obtain the precise insitu structural disposition of the ore body at depth. The litho model prepared by adopting this procedure is a combination of all possible geological information which includes surface mapping, borehole litho information and their apparent subsurface behaviour. The second section discusses the use of - the method adopted for resource estimation for Sukinda-type deposit. The nature of disposition of ore body is anisotropic in nature; hence the conventional Inverse Square Distance (ISD) method has limited application in resource modeling due to variations in the chemical behaviour of the ore body. The ore mined is processed and converted to ferro-chrome. The distribution of chemical parameters viz Cr 2 O 3 , Fe, SiO 2 and Al 2 O 3 play a critical role in furnace while conversion to ferrochrome. Therefore, a precise estimate of these chemical parameters at run of mine stage is essential to control the feed to processing plant, which in turn produces the required band-width product to feed the furnace. Here Kriging is preferred over the ISD method under these circumstances.