New copper smelting and recycling process with “O-SR” Process, which is combined newly installed Mitsubishi Process S-furnace with the existing reverberatory furnaces and PS-converters has put into operation in December 2007. S-furnace has shown excellent performance since the start of operation. It is proven that S furnace has high adaptability with other processes. S-furnace which is directly connected to two reverberatory furnaces by launders, is solely used for copper concentrate smelting and reverberatory furnaces are dedicated to slag/matte separation and to treat combustible waste materials such as shredder dust (SD) generated from automobile, electrical home appliance and vending machine. After introducing of O-SR Process, amount of treated copper concentrates and combustible waste materials was increased. Furthermore, consumption of fossil fuel and generating CO2 was dramatically decreased at reverberatory furnaces. As a result, now Onahama Smelter & Refinery was revived as one of the most competitive copper smelter in the world by the combination of new technology and existing process.
Indonesia produced 306 Mt of salable coal in 2010 almost 100% by surface mining. Rapid increase in production by surface mining, however, has brought strong concerns of sustainable supply ability of coal with current quality level in future. Thus, development of underground mining has been recognized to be important by the government and the coal industry in Indonesia. Since 1980’s until 1995, only 3 underground mines had been operated, and currently, there are only two operating underground coal mines with small scale. However, several underground projects with fully mechanized mining system have recently started pre development work, such as exploration, feasibility study and so on. The author expects that development of underground mines with bigger production scale would become active within a few years. On the other hand, the underground mining condition in Indonesia is more difficult than it in other countries. This paper describes the history and outlook of underground coal mining in Indonesia from technical points of view, and then discusses the technical problems for future development of underground mining in Indonesia.
To better understand trapping mechanisms of CO2 in reservoir, we try to elucidate the effect of thin and low-porosity lamina in porous Tako sandstone on CO2 flow by experiments and numerical simulations. Tako sandstone is characterized by the well-developed and low porosity lamina, where the intergranular space is filled with precipitated iron-rich minerals. We measure P-wave velocities (Vp) in three channels which are crossing through high porosity zone (Ch.A), on a lamina (Ch.B), and beneath the lamina (Ch.C) during CO2 injection stage (drainage) and water re-injection stage (imbibition). In drainage, all channels show large Vp-reduction over 10 %. In imbibition, they indicate Vp-increases but different recovery patterns with injecting CO2-saturated water. After 250 ml water injection, Vp of Ch.A and Ch.B almost recover from Vp-reduction in drainage. On the other hand, Vp of Ch.C still has a reduction about 4%. We then try 2D core-scale flow-simulations by using TOUGH-2 to confirm the effect of lamina on fluid flow and pattern of CO2 distribution. In drainage, CO2 has large mobility and moves upward vigorously to the top-end of core at 20ml CO2-injection. After reaching the top-end, CO2 invades lamina zone and raises CO2-saturation during drainage. In enhanced case of difference between porosity-permeability relation, the result of simulation indicates the strong heterogeneity of CO2-distribution pattern, which shows clear low-CO2 saturation of the lamina zone and obvious high-CO2 saturation of the zone of direct beneath of lamina. In imbibition, CO2 saturation decreases rapidly after 40ml water injection. However, the zone of beneath the lamina keeps high CO2 saturation after 100ml water injection. These results suggest that the lamina in Tako sandstone behave as barriers of CO2 flow. This assumption is supported by results of Vp-measurement, because the channel of beneath a lamina still shows a Vp-reduction about 4% after 250 ml water injection.
There has been a focus on the effective utilization of sewage sludge ash from Iwate Prefecture as filler for asphalt mixture. This ash can partially replace limestone filler, and if it is used as-is after being expelled from a treatment facility, the optimum asphalt content increases as the replacement ratio increases, reducing various properties of the asphalt mixture. However, with a replacement ratio up to 45%, all criteria are met and it can be applied. On the other hand, reduced properties cause porous ammonium magnesium phosphate particles to generate eccentrically in the coarse regions. If these coarse areas are eliminated, the various properties of the asphalt mixture can be improved.
In order to recover and recycle the valuable metals, such as Mo, Ni and V on γ-Al2O3 supported catalyst, which has been used for desulfurization in petroleum refining process, three step process, i.e. air-oxidation roasting step at temperatures from 400 to 900°C, alkaline leaching step using sodium hydroxide and carbonate solution and hydrogen reduction-hydrochloric acid leaching step, has been experimentally conducted for its process feasibility. It has been known that NiAl2O4 spinel compound formation in the roasting step hinders the leaching of Ni, which leads us to the reducing-acid leaching step of the alkaline leach residue. It has been shown that (1) in the roasting step, better elimination of hydrocarbon and sulfur constituents is attained at temperature at temperatures, 700 to 900°C, with resultant formation of Mo and V oxides and Ni spinel compound, (2) better leaching rate of Mo and V, 97% and 89% respectively, and the least leaching rate of Al (around, 0.6%) using sodium carbonate solution and (3) high Ni leaching rate of 80% has been attained in the final step. Thus, using this three step process, reasonable rate recovery of Mo, V and Ni has been shown feasible and this process scheme could be applicable for recovery Mo, Co and V in desulfurization catalysis.