PRELIMINARY STUDY OF THE EAST KOTAWARINGIN BAUXITE ORE CHARACTERISTICS AND ITS ESTIMATION EFFECT ON BAYER PROCESS

• Main Author: MUKHLIS (NIM : 12113089), ONRIA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/29887
• Institution: Institut Teknologi Bandung

The need and price of aluminum metal in the world market are both increasing and <br /> <br /> on the contrary, bauxite reserves as the primary source of aluminum metal decreases. <br /> <br /> Indonesia which is located in a tropical country is an ideal region for lateritic bauxite <br /> <br /> formation. However, the presence of various impurity minerals in bauxite will lower <br /> <br /> its economic value, especially during processing. This study aims to provide <br /> <br /> information on the characteristics of bauxite samples taken as well as estimate its <br /> <br /> effect in Bayer process. Three samples were taken and marked with BI-01, FMA-01, <br /> <br /> and FMA-02. This research was conducted with several methods, macroscopic <br /> <br /> observation, microscopic observation, XRD analysis and XRF analysis. The results <br /> <br /> show gibbsite, hematite, and goethite are the dominant minerals. Minor minerals are <br /> <br /> maghemite, quartz, eskolaite, and corundum. The maghemite minerals are only <br /> <br /> found in samples of FMA-01 and FMA-02, but eskolaite minerals are found in all <br /> <br /> samples. Quartz and corundum minerals are only found in samples BI-01. The <br /> <br /> gibbsite minerals in the FMA-01 sample are relatively rougher in size compared with <br /> <br /> in BI-01 and FMA-02 samples. The mineral hematite is found only in samples BI-01 <br /> <br /> and FMA-01. In the FMA-02, iron oxide minerals found only goethite and present as <br /> <br /> cement. The weathering of all samples is estimated to have reached the final stage, <br /> <br /> showed by low SiO2, Mg, and the absence of Na, Ca and K, but relic texture of the <br /> <br /> three samples can still be observed. Meanwhile, Al2O3 content of the three samples <br /> <br /> do not have a significant difference. Based on XRD analysis and microscopy <br /> <br /> observations, aluminum hydroxide minerals only present in gibbsite form. The silica <br /> <br /> minerals present in quartz form are only observed in the sample BI-01. Through the <br /> <br /> characteristics of bauxite ore and its chemical composition, it is estimated that the <br /> <br /> extraction temperature is between 140 °C&#61485;150 °C. The low SiO2 content both as free <br /> <br /> silica and as reactive silica in all samples gives expectation that the usage of NaOH <br /> <br /> solution during the extraction is very efficient and the product of sodium aluminate <br /> <br /> as the result of the extraction will also be perfect. <br />