Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
Not a member yet
1014 research outputs found
Sort by
ALTERATION OF MONTMORILLONITE CLAY TO SOLID ACID CATALYST BY HEATING AND ACID SOAKING
No full textCommercial biodiesel production nowadays still uses sodium hydroxide solution as homogenous catalyst. This catalyst has some weaknesses, which cannot be reused and difficult on its separation from the product (methyl esther). Therefore, alternative catalyst is necessary to be sought to solve the problem and solid catalyst from clay has a possibility to be applied. Montmorilonite clay is widespread mineral in Indonesia and its layer structure is potential to be used as solid catalyst. The alteration processes consist of upgrading montmorillonite content followed by activation and esterification to review its performance. Previous activa- tion was carried out using aqueous sulphuric acid of 0.05; 0.5; 5 and 10 M and settled in each solution for two weeks. To obtain shorten activation time, modified method has been done with similar acid strength range but using preheating 60°C for 6 hours and settled within a week. Clay’s performance was observed by esterification reaction using Palm Fatty Acid Distillate (PFAD) of fried oil production waste as raw material. Its initial and final acid number were then reviewed. The conversion of PFAD to esther was measured from deviation of initial of final acid number. Previous method’s result of 2 weeks settlement showed maximum conversion of 91.6% at 5M acid strength of activation, while modified method reached maximum conversion only 67.63% at similar acid strength of activation. Both results were not yet resemble the 5M sulphuric acid solution as homogenous catalyst which is able to convert PFAD to esther as much as 98.73%. However, the method of 2 weeks settlement could be developed further to gain the optimum conversion
PRODUCTION OF OXALIC ACID BY ASPERGILLUS NIGER
No full textOxalic acid has been suggested to be essential in the metal leaching processes by Aspergillus niger. The ability of Aspergillus niger strain to produce a high amount of oxalic acid on glucose and sucrose media was investigated. The experimental results show that glucose is favorable for oxalic acid biosynthesis which can produce 14.47 g/L oxalic acid compared to 7.09 g/L oxalic acid on sucrose medium. The production pattern, however, were identical on both substrates. The main drawback of this fermentation was the low yield attained (75.47 % from theoretical yield) probably because some of glucose was oxidized to gluconic acid at the beginning of fermentation, and due to some limitation of growing the A. niger in shake flask condition because pH of the culture cannot be fully controlled in shake flask system. Therefore, batch culture in fully controlled fermentor can be carried out as further steps of experiment after shake flask
OCCURRENCE OF PHILLIPSITE MINERAL IN SUB- SEAFLOOR OF ROO RISE-INDIAN OCEAN : A TECTONIC EROSION SYNTHESIS
No full textA single deep-sea core (MD982156) of 30.30 meters long which is obtained during the MD III-IMAGES IV Expedition from Roo Rise - Indian Ocean in 1998 was studied. Down to 30 meters of the core length, the sediment consists of abundance planktonic foraminiferas. Below 30 meters, it is mostly composed of phillipsite mineral-rich sediment that is associated with nannoplanktons.The Paleocene authigenic phillipsite minerals associated with nannoplanktons is separated from Late Miocene to Holocene planktonic foraminiferas rich-sediments by hiatus. This hiatus or non deposi- tional in Roo Rise suggest be triggered by long Cenozoic tectonic erosion
THE USE OF CYCLONE COAL BURNER TO SUBSTITUTE OIL BURNER IN ALUMINUM SMELTER USING REVERBERATORY FURNACE
No full textThe increasing of oil price forces the industries to alter their fuel from oil into a cheaper fuel. Undoubt- edly, coal is a promising energy alternative in Indonesia. To save the cost, altering the fuel oil into coal in industries may be accomplished just by altering the oil burner with coal burner, therefore the exist- ing equipment still can be used without much modification. The coal combustor employed should have nearly the same characteristic with the oil combustor, so that the performance of the kiln or other equipment served by the combustor is not change significantly. R & D Centre for Mineral and Coal Technology (TekMIRA) has developed cyclone combustor for coal with particle size of less than 30 mesh. The combustion is stable at the rate of 50 – 180 kg/hr coal with excess combustion air of 22 – 26%. The length of cyclones is ranged from 120 up to 220 cm, the internal diameter is 60 up to 80 cm and the combustion temperature is 1200 up to 1325°C. This combustor characteristics are nearly the same with oil combustor such as: the combustion flame may be directed; high intensity combustion, long flame; and it is not difficult to match the energy output of previous oil combustor. In this experiment the cyclone combustor was used to replace the oil combustor in a reverberatory furnace to refine aluminum from aluminum scrap by melting the material at 1000 – 1060°C. For 500 kg aluminum, the oil consumption was 47.5 litre for 2.5 hour or the average was 19 lt/hr and the energy efficiency was 29.2%. Using high ash bituminous coal with cyclone burner, the coal consumption was 129 kg for 1.8 hour or the average was 71.6 kg/hr and the energy efficiency was 17.9%. A higher efficiency was obtained by using low ash sub bituminous coal, that the coal consumption was 82 kg for 81 minutes or the average was 60 kg/hr and the energy efficiency was 29.0%. Therefore it is a good opportunity for coal to substitute fuel oil in this reverberatory furnace and many other oil fuelled processes such as in boiler, lime calcination, mineral drying etc
STUDY OF IN SITU CYANIDE DETOXIFICATION ON GOLD PROCESSING TAILING AT PONGKOR GOLD MINE
No full textCurrently, gold processing unit at Pongkor mine processes cyanide-containing waste at the end pipe or known as final process. Due to the increase of environmental awareness from the community, such a process needs to be re-evaluated. This relates to tight regulation regarding safe waste prior to releasing to the nature. Conflicts will arouse when population at surrounding area increases fast. To anticipate such conflicts, the gold processing unit of Pongkor mine proposes a scenario dealing with waste processing improvement from the end pipe process to the whole one. It includes reagent use optimization and waste minimization including its recycle. In situ cyanide detoxification is one of waste minimization processes conducted at Pongkor mine. In terms of comparing which one of the methods is the best in reducing cyanide within wastes, a series of cyanide reduction tests employed Inco’s and Degussa methods at a laboratory scale. To reduce high cyanide concentration of the wastes, the used reagents in Inco’s method include Na2 S2O5, CuSO4.5H2O and pressured by the air while Degussa method applied H2O2 and CuSO4.5H2O. The results from this experiment suggest that Inco’s technology is able to detoxify cyanidation effluents better than that of Degussa technology
PRODUCTION OF SYNTHESIS GAS FROM INDONESIAN LOW RANK COALS USING FLUIDIZED BED GASIFICATION REACTOR
No full textIn relation to the objective of securing energy and raw material supplies for industries and increasing of low rank coal utilization; research on the production of synthesis gas from Indonesian coal has been carried out. Low rank coal samples and a fluidized bed reactor which was equipped with gas purification system have been used. The coal samples used were Adaro coal (sub bituminous), Mulia and Gunung Bayan (lignitic coals). Gasifying agent was also varied and consisted of oxygen, oxygen/ steam mixture and steam. Stoichiometric ratio of oxygen/carbon was kept at one half and oxygen/ steam ratio was one. The gasification temperature was kept constant at 900ºC. The composition of gas products were analyzed using a gas chromatograph with molsieve and porapak columns. The results showed that there was a good correlation between gasifying agent, coal used, quality and quantity of synthesis gas
THE EFFECT OF DISPERSING AND STABILIZING ADDITIVE ON THE STABILITY OF UPGRADED COAL WATER MIXTURE
No full textThe upgraded brown coal water mixture (UBCWM) stability with several dispersing and stabilizing additives was studied based on coal sedimentation time history. UBCWM was filled up in a settling column; which has four holes in the upper, upper middle, bottom middle and middle side to take samples. Results indicate that the addition of Naphthalene sulfonate formaldehyde condensate (NSF) as dispersant together with S-194 some kinds of bio polysacharide with long branches produced by Dainippon Pharmaceutical Co. Ltd. as stabilizer, produces UBCWM with the best stability compare with that by using polystyrene sulfonate (PSS) and polymethacrylate (PMA) together with carboxyl methyl cellulose (CMC) and S-60 also some kinds of bio polysacharide, but without branches pro- duced by Dainippon Pharmaceutical Co. Ltd . Even the addition of S-194 results UBCWM with good stability, from the economical point of view, the addition of S-194 is a problem. The price of S-194 is expensive, whereas CMC is abundant and cheap. Therefore, the use of CMC as stabilizing additive was also effective in preparing stable UBCWM according to the stability of the UBCWM by using S- 194 and CMC is not significantly different
