Geochemical Characterization of Silica Sand in the Sidenreng Rappang Area Based on X-Ray Diffraction Analysis and X-Ray Fluorescence Analysis

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INTRODUCTION
In the framework of the implementation of regional autonomy which will soon take effect, local governments are encouraged to be independent in managing their regions. One of the mainstays of the region is mineral resources. The mineral resources or mining sector, especially industrial minerals, nationally the mining industry plays a very important role in the development of domestic industry (Galih, 2017;Prayogo & Budiman, 2012). If managed properly, the mining sector can even contribute more. Mining has a regional role or mission, namely to improve the regional economy, open new areas and minimize the gap in progress between regions (Langi et al., 2020).
However, the national mining sector is still fixated on traditional commodities that have been relatively the same for a long time, such as nickel, iron ore, gold and copper. With the development of the world, it is time for Indonesia to look at other potential mining commodities, according to the momentum of the direction of industrial development and the global market (Yusnidah, 2021).
One potential commodity that deserves attention is quartz sand or silica sand. Silica sand is one of the mineral materials whose existence in nature is very abundant and can be utilized in various applications (Rachman et al., 2012;Ratnawulan et al., 2018). Quartz sand is an excavation material consisting of silica crystals (SiO2) and contains impurity compounds that are carried during the In the Sidenreng Rappang area of South Sulawesi, there are abundant deposits of silica sand. The existence of silica sand in this area is expected to provide new income contributions, both to the local community and to local revenue. Before further mining is done, the character of silica sand needs to be known. Therefore, this study was conducted with the aim of knowing the geochemical composition of silica sand in the Sidenreng Rappang area using X-Ray Diffraction (XRD) X-ray fluorescence (XRF).

METHODS
The research was conducted by combining qualitative research with inductive research, namely combining field data and laboratory analysis data Firdaus et al., 2022) . The literature review stage was first carried out before the field data collection stage and the laboratory analysis stage so that conclusions were obtained from the results of the analysis of these three stages. Silica sand samples came from the western part of Sidenreng Rappang, South Sulawesi.
Silica sand sampling was carried out using the channel sampling method, taking samples in three different locations that were considered representative of the entire study area. Each was taken as much as 5 kg/sample and physically described. The sampling process can be seen in the figure below ( Figure 1).

Figure 1. Sampling
Sample preparation was carried out at the UMI Mining Engineering Mining Materials Processing Laboratory. Preparation starts from weighing, size reduction and sieving. The three silica sand samples that passed the 200 mesh sieve were then reweighed before geochemical analysis. Geochemical analysis was carried out by X-Ray Diffraction (XRD) method to determine the mineral composition and X-ray fluorescence (XRF) to determine the level of mineral elements contained in the silica sand samples of the study area. The sample sieving process can be seen in the picture below ( Figure 2). Sample 1 has a larger percentage of quartz minerals than sample 2 and sample 3, but the percentage of albit minerals in sample 1 is smaller than sample 2 and sample 3. The percentage of pyroxene minerals is almost the same between sample 1 and sample 3, but different in sample 2. Based on the results of XRD analysis of the three samples, the average content of SiO2 carrier minerals is obtained, including quartz minerals by 52.76; albit by 31.16% and pyroxene by 16.03%. The mineral composition of the three samples can be shown in the figure below (Table 1).  The average results of the percentage of mineral content of the three samples obtained (SiO2) 69.14%; (Al2O3) 22.92%; (Fe2O3) 3.04; (K2O) 2.55%; (CaO) 1.63% and minerals with levels below 1% (RuO2; TiO2; SrO; MnO; V2O5; Cr2O3; Rb2O; and ZnO). It can be estimated that the main impurity minerals present in the sample are aluminum minerals and iron minerals. The percentage of mineral content and its average can be shown in the table below (Table 2). Based on the above tables (Tables 1 and 2), it can be explained that silica is the main and dominant mineral that makes up the composition of silica sand while aluminum and iron are impurity minerals. The content of impurity minerals in silica sand is thought to be transported and deposited with valuable minerals, this is because they have almost the same specific gravity. Therefore, further research needs to be done, so that its utilization can provide added value to the economy and local revenue.

CONCLUSION
Based on the results of XRD analysis of the sample, the average content of SiO2 carrier minerals is obtained, including quartz minerals, and pyroxene, while the average results of the percentage of sample mineral content are obtained (SiO2) 69.14%; (Al2O3) 22.92%; (Fe2O3) 3.04; (K2O) 2.55%; (CaO) 1.63% and minerals with levels below 1% (RuO2; TiO2; SrO; MnO; V2O5; Cr2O3; Rb2O; and ZnO). It can be estimated that the main impurity minerals present in the sample are aluminum minerals and iron minerals.

ACKNOWLEDGMENT
The author is grateful to all parties involved so that this research and article can be completed, especially to the local government for permission to take samples and fellow researchers for all their thoughtful contributions. Hopefully in the future the author will always be given the opportunity to continue this research.