Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
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ANALYSIS OF THE VALUE – ADDED FOR TAYAN BAUXITE ORE AND CHEMICAL GRADE ALUMINA
No full textResearch conducted at PT. ANTAM and PT. ICA (Indonesia Chemical Alumina) Tayan, West Kalimantan was aimed to compare the amount of company value-added from selling the bauxite ore as a raw material and the chemical grade alumina as a processed goods. This research showed that company value added from selling 850.000 tons raw meterial US 692.42 thousand, royalties, CSR and insurance US 150.00 thousand, other services 1.64 million, Bank interest US 5, 73 million was. Of the US 10.49 per ton. Selling the chemical grade alumina up to 300,000 tons or equivalent to 850,000 tons provided the value-added to the US 3.85 million. 50.75 billion, royalties, CSR and insurance of US 16.50 million, corporate income tax 1.21 million and corporate profits to the US 190.44 per ton. It is indicated that selling the chemical grade alumina provides a greater profit than that of selling the raw material
COMPOSITION AND CHARACTERISTICS OF RED MUD: A CASE STUDY ON TAYAN BAUXITE RESIDUE FROM ALUMINA PROCESSING PLANT AT WEST KALIMANTAN
No full textBauxite residue emerges as the major waste material during production of alumina from bauxite by the Bayer’s process. An alumina refinery built in Tayan, West Kalimantan has a production capacity of 300 thousand tons per year. It means that it will produce red mud or bauxite residue approximately 300 – 350 thousand tons per year and washing residue around 200 thousand tons per year. Right now, it is stored in a nearby disposal area. This paper focuses on the characteristic study of the bauxite residue to evaluate the potential pollution risk to the surrounding environment. This experimental-based study is conducted to get appraisal and description of the residue regarding its utilization. Some characterization tests were conducted in the laboratory to find the properties of bauxite residue coupled with the previous study. It is found from the study that bauxite residue shows radioactivity elements. It comprises of oxides of iron, titanium, aluminum and silica along with some other minor constituents in the form of heavy metals and rare earth elements. Hazardous elements such as As, Pb, Cr and Hg were found in bauxite residue samples. But, the toxicity test showed that bauxite residue samples were not classified as hazardous material. Some rare earth elements such as Ga, Ce, Sc, Pr, Gd, Tb etc., were also detected in the samples
UPGRADING OF INDONESIAN LOW RANK COAL BY STEAM DRYING METHOD
No full textExperiments were carried out to produce upgraded coals with low moisture content by steam drying method. An Indonesian low rank coal, Berau coal with moisture content of 16.13% and calorific value of 5324 cal/g in air dried basis (adb) was treated by steam drying at temperature of 225 - 300°C in an autoclave to study process temperature effect. The results of proximate and ultimate analyses show that moisture content decrease by increasing the temperature process. The moisture content reduces to 0.86% and the calorific value increases up to 6760 cal/g in adb when the coal has been treated at the temperature of 300°C. Furthermore, the specific surface area and combustion characteristics of coals were influenced by the upgrading process
STUDY ON BASICITY IN DIRECT REDUCED IRON SMELTING
No full textPig iron as raw material for steel production, can be prepared by smelting a Direct Reduced Iron (DRI)/sponge iron. The smelting process needs optimum conditions to obtain such a high recovery likes basicity, which measures the ratio of alkalinity or acidity by adding the exact quantity of flux (CaCO3) and quartz sand to input materials to generate the reduction process running well. In this study, smelting process was conducted using DRI sample mixed with varied flux (CaCO3), quartz sand and coal. Then a mixture was fed to a resistance furnace. The reduction process was carried out at a temperature of 1600°C, for 1-2 hour. Pig iron as product and slag were analyzed to obtain its chemical composition. Afterward, recovery products was calculated. The results showed that the best conditions in these experiments were achieved at 1.18 basicity with pig iron recovery was reached up to 95.79%, contented of 95.84% Fe, 3.52% C and 0.0024% SiO2. These data of this study can be used as reference of flux (limestone), quartz sand and carbon addition as input to resistance furnace in smelting process of sponge iron on a larger scale
BENEFICIATION OF SAMBIROTO SILICA SAND BY CHEMICAL AND BIOLOGICAL LEACHINGS
No full textThe commercial value of silica sand significantly affected by the presence and content of iron, aluminium and other metal impurities that can have detrimental effects on the manufactured product. A leaching technology on Sambiroto silica sand had been studied using chemical (HCl and H2SO4) and biological (Aspergillus niger’s metabolite) methods to remove undesired metal impurities and obtain a high purity silica. The rates and extent of chemical leaching and bioleaching were different depending on the leaching agents used and their concen- trations. The results showed that the laboratory experiments improved the silica sand sample to a high grade purity. The major and minor impurities of Fe, Al, Ca, Cr, Ti, Zr and Cu were reduced significantly by acid leaching with HCl and H2SO4 4M at 90°C, 30% pulp density for 4-hours process. The chemical composition of the silica sand improved with the SiO2 content increased from 97.24 to 98.77%, on the other hand, the sum of impurities decreased from 1.148 to 0.237 %. These changes bring the beneficiated product very close to a feedstock of metallurgical grade silicon for advanced materials. Among the tested methods, chemical leaching is the most efficient in terms of both increasing percentage of SiO2 and metal impurities removal compared to biological leaching. Nevertheless, bioleaching process is sufficient to produce silica sand with a desired minimum value of Fe and Al contents for high quality glass industries. Both process characteristics could facilitate their industrial applications
ECONOMIC FEASIBILITY ANALYSES OF COAL- BASED ACTIVATED CARBON PLANT IN INDONESIA
No full textTechnology to make activated carbon from coal has been developed from laboratory to pilot plant scales with capacity of 1 ton/day. The results of previous experiments showed that the quality of coal activated carbon has complied with the standard of quality activated carbon from coconut shell (SNI). In addition, the result of coal utilization process showed that activated carbon can be used for water purification on hatchery, and waste water treatment in textiles and rubber industries. Although the technology and the quality have been reached, but for the production it still needs economic feasibility analysis. Economic feasibility analysis is necessary for coal- based activated carbon plant at commercial scale by giving an indication about economic value of the project. The indicators used in the analysis are Net Present Value (NPV), Return on Investment (ROI), Internal Rate of Return (IRR) and Payback Period. Calculation of financial indicators for the activated carbon project produced Rp 49.17 billion NPV, 50% ROI, 68,25% IRR and 1 year 4 months Payback Period. Based on that calculation, it can be concluded that the coal-based activated carbon plant would be economically feasible under certain operational scenarios. This study is expected to become an economic reference material and can attract inves- tors to construct the commercial plant