Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
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CHARACTERIZATION OF KARANGNUNGGAL KAOLIN AS RAW MATERIALS FOR CERAMIC
No full textKaolin from Karangnunggal had been characterized. This kaolin has a brownish white in color and is associated with tuff. To identify characteristics, the samples was analyzed by XRD, optical microscope, AAS, and SEM. The results showed that the kaolin consisted of kaolinite, halloysite, cristobalite, dickite, muscovite, illit and hematit while petrographic analysis describes halloysite, kaolinite, dickite, and quartz. SEM analysis showed the crystal forms such as kaolinite, halloysite and dickite; while chemical analysis confirmed that kaolin composition comprised SiO2 = 65.78 %, Al2O3 = 19.55 %, Fe2O3 = 0.90 % and LOI = 8.29 %. Based on characterization results Karangnunggal kaolin originated from tuff alteration. Referring to such properties, this kaolin can be used as raw material for white ceramic products such as sanitary, ceramic tiles and insulation
DISTRIBUTION CHARACTERISTICS OF FERRO-TITANIUM OXIDE MINERAL ON LOW-GRADE IRON SAND
No full textIron sand is known as one of the sources of TiO2 in the form of ilmenite or titanomagnetite mineral. Iron-titanium oxide mineral contained in Indonesia iron sand are classified as titanomagnetite. Indonesia possesses a lot of iron sand deposits such as at southern coast of Cilacap, Kebumen and other areas. The iron sand consists of magnetic and non-magnetic minerals as either loses or bound materials. Fractionation of Cilacap iron sand which employed three types of sieve (40, 60 and 80 meshes) showed that the iron sand is dominant in -40+60 fraction (68.38 g) while the most amount of iron and titania contents occurred at fraction of -80 mesh, namely 11.62 and 1.46%. Magnetic separation showed that the finer the particles and the higher the magnetic intensity, the higher the derived iron and titania. The process has also successfully increased the TiO2 content more than 5 times, from 0.325 to 1.67%
SYNTHESIS OF Na-A ZEOLITE FROM NATURAL ZEOLITES
No full textConversion of natural zeolites into Na-A zeolite by the two-step method has been achieved. Synthesis process was conducted at hydrothermal condition 90° and 100° C using alkaline silicates as silica source aluminate as alumina source. The silica was derived from zeolitic tuff and the sodium aluminate was obtained from chemical reagent. Dissolution on zeolitic tuff was made in order to obtain supernatant, Na2SiO3.nH2O. Reaction time for the synthesis ranged from 0.5 – 4 h. It is found that SiO2/Al2O3 molar ratio of 1.6, Na2O/SiO2 molar ratio of 4.41, and Na2O/H2O molar ratio of 60.70, and crystallization time of 4 h give maximum crystallinity. XRD and SEM showed that Na-A zeolite synthesis begins after 1 h and reaches its crystallization maximum. Then Na-A is substituted by Na-X and hydroxysodalite (HS) zeolite. The XRD pattern and SEM image show that microtextural are comparable to the reputed zeolite commercial
GEOLOGY AND CHARACTERISTICS OF LOW SULPHIDATION EPITHERMAL VEIN IN SENEPO AREA, EAST JAVA
No full textSenepo area is one of several epithermal mineralization prospects in Southern Mountains of Java Island. This study is aimed to investigate the geological framework and hydrothermal alteration of the prospect as well as to characterize the low sulphidation (LS) epithermal vein including vein textures, ore mineral, ore chemistry and hydrothermal fluid that are responsible for the formation of the quartz vein. Detailed field mapping was completed to understand the geological framework and hydrothermal alteration zones. Petrographic, ore microscopic, XRD and AAS analyses were applied to characterize the quartz vein. The study area is occupied by pebbly sandstone, andesite breccia, andesite units and alluvial deposit. Ore mineralization is mainly hosted by andesite of Oligo-Miocene of Watupatok Formation. The host-rock has been suffered by overprinted hydrothermal alteration and weathering. The epithermal veins are found as N-S-trending quartz veins with a thickness of 1-2 meters. These veins show massive texture, crustiform, cockade, druzy, comb, and disseminated sulphides, which is included in Crystalline Quartz Zonation (X). Optical microscopy and XRD analysis indicate that these veins contain several ore minerals such as chalcopyrite, sphalerite, galena, pyrite, hematite, covellite and malachite, associated with gangue mineral including quartz, felspar, chlorite and clay minerals. AAS analysis displays variable chemical composition of precious and base metals such as Au (17-37 ppb), Ag (8.1-32.6 ppm), Cu (122.1-81,450 ppm), Pb (35.4-883.6 ppm) and Zn (18.3-2,628 ppm). Gold and silver are relatively low compared to the base metals. Fluid inclusion micro thermometric analysis indicates that ore mineralization originated at temperatures of 187-263 oC and salinity of 0.18-0.53 % wt. NaCl eq. This salinity corresponds with a minimum hydrostatic pressure of about 10-55.1 bars. Based on those characteristic data, mineralized quartz veins in the study area are classified into a base metal horizon of LS epithermal system
PREPARATION OF METALLIC CERIUM BY METALLOTHERMIC REDUCTION USING CERIUM OXIDE AS RAW MATERIAL
No full textCerium is one of the rare earth elements (REE) which many are found in rare earth minerals of monazite. Cerium is widely used for metal alloys in stainless steel, permanent magnets and automotive industries. In Indonesia, researchs for cerium extraction from such minerals of monazite to procure metallic cerium have not been inten- sively carried out, although cerium is potentially promising as raw material for alloying. The present research aims to study the conditions of cerium oxide (CeO2) reduction process to yield metallic cerium (Ce). Cerium oxide reduction process was performed by a metallothermic method using a reductant of magnesium metallic powder and CaCl2 as a flux. The parameters studied during the experiments were the quantity of the reductant, the composition of the flux and temperature of the process. The best result of the experimental process obtains the yield of metallic cerium about 50%, while the metal purity is 91% Ce. The process took place under condi- tions of that the oxide sample and reductant ratio were 1 : 1, the flux addition was 1%, with temperature of the process at 1200°C for 3 hours
BIOSOLUBILIZATION OF PHOSPHATE ROCK BY Penicillium sp
No full textPhosphorus is an essential element that regulates soil fertility. Its deficiency is replenished by chemical fertilizer made from phosphate rock. An environmentally friendly and economically alternative to chemical processing of phosphate rock is the use of phosphate solubilizing microorganisms. In this research, a potential phosphate solubilizing fungi were successfully isolated from the surface of Cijulang phosphate rock and identified as close relative of Penicillium sp. The phosphate biosolubilization capability of the fungus was tested and the influence of leaching parameters such as particle size of mineral, ore concentration (pulp density), and initial pH of medium was investigated using a shake flask study to characterize the solubilization of phosphorus by Penicillium sp. The x-ray diffraction data indicated the presence of hydroxyl apatite Ca5(PO4,CO3)3OH as the main source of phosphorus.The fungal strains of Penicillium sp produced oxalic and citric acids during fermentation of glucose which resulted in a drop pH of the growth medium. The results also indicated a potential relationship between the phosphorus biosolubilization and the production of organic acids by the fungus. In addition, particle size, ore concentration and initial pH were also shown to have significant effects on the solubilization of phosphorus from the phosphate rock. The optimal speed of attack was obtained for a surface area of substrate of .-200 mesh. A concentration of 5% solid gave the highest speed of P biosolubilization. The optimum range of initial pH was 6-7 and initial pH began to show an inhibiting effect at 4. The maximum percentage of soluble phosphorus released of 42.8% was attained using -200 mesh particle size, 5% pulp density and initial pH 6 after 16 days of process
