Block Model of Laterite Nickel Reserve in the Sorowako Village Research Area, South Sulawesi Province

S


INTRODUCTION
Nickel is a versatile metal with a very unique combination of properties that make it suitable for use in a variety of different functions. A deposit can be known its thickness if it has carried out systematic drilling activities and determination of grades. It does not stop there, the results of the drilling of laterite nickel deposits can be visualized in the form of 3D modeling with the help of computers to process field data, so that mining planning can be carried out as well as possible (Akhsanul et al., 2018;Rafsanjani, 2016;Thamsi, 2017).
Block modeling techniques are widely applied in the modeling and calculation methods of mineral resources in the mining industry. This technique has generally been done computerized (Anshariah, 2016;Ramadhan et al., 2022;Thayib et al., 2017). The distribution of resources/reserves in these blocks is able to make it easier for us to do quality assessments so that a quality distribution can be produced with location details (coordinates) and block unit volumes that are adjusted to the mining dimensions (Afriandi, 2015;Mustika, 2016).
The purpose of this study is to create a model block for laterite nickel reserves based on the data from the drilling results in the area. The purpose of this study was to determine the tonnage value of an estimated resource of saprolite and limonite ore deposits in the drilling area.

METHODS
The research method consists of 4 (four) stages, namely research preparation, data collection stage, data processing stage and data analysis.
Copyright © 2022, Journal of Geology & Exploration, Page: 19 Research Preparation This preparatory stage includes work: Literature study and preparation of field equipment used. The data collection method is basically a method of carrying out field work, which includes a survey of the area to be drilled, tools and materials used in drilling production. The data used in this study are: 1. The assay data is in the form of nickel content analysis data. 2. Collar data in the form of total drill point depth data. 3. Survey data in the form of coordinates and elevation of the drill point. 4. Lithological data in the form of laterite nickel profile lithology data. From all the data that has been collected, starting from assay data, coring, field surveys and geological data, then these data will be processed using Microsoft Office Word, Microsoft Office Excel and a backup model block is made using Surpac 6.5.1 software. After processing, we will get the value of volume and tonnage. Then the results of these calculations obtained are a block image of the 3D model of laterite nickel reserves in the study area.

Topography of Laterite Nickel Distribution Area
In the research stage of making this laterite nickel reserve model block, the data used is data from exploration drilling. Drilling carried out in the area starts from 200m spacing, 100m space, 50m space, 25m space, to the smallest space depending on the level of confidence. The number of drill points from the data obtained from the company is 275 drill points. For more details, see the image in the appendix on page 56.

Saprolite Zone Vertical Correlation Section
The next step is making block model boundaries based on the limonite and saprolite layers, generated from the Digital Terrain Model (DTM) file, which is a 3-dimensional shape obtained from string data. Where the String data is the point that correlates the top and bottom points of the saprolite zone in the form of a line for each layer. In the picture below, the yellow color shows the limonite zone, the red color shows the saprolite zone and for the blue color shows the bedrock zone.
For the cross-sectional image of the saprolite zone A-A' below the connecting line in the saprolite zone, it does not follow the topography of the study area, which can be seen from the several hole ids in the image below whose thickness is different so that it passes the existing topographic boundary line.

Resource Estimation of Laterite Nickel Deposits in Region X
The important parameters used in the estimation of laterite nickel reserves include following the 2011 KCMI code. In this area, the economic block size for mining is 12.5 x 12.5 x 1 meter. In addition, the material density factor also plays an important role in the estimation of ore resources. This is because the density of the material is a parameter used to` get the number tonnage of a resource