Sumitomo Metal Mining Co., Ltd. (SMMC) has been producing nickel and cobalt by MCLE process at Nickel Refinery in Niihama, Japan. Coral Bay Nickel Co. (CBNC), which is a subsidiary company of SMMC, has been producing the mixed sulfide of nickel and cobalt (MS) at Rio Tuba in Palawan, Philippines. The project that utilizes high pressure acid leach (HPAL) process was commenced in 2000. The construction of the plant was completed in September 2004. Since then, the HPAL plant of CBNC has been commissioned and the production rate of nickel at CBNC was exceeded over 10000 Ni-ton in 2007, which is the design capacity. This is the first track record in the laterite nickel operations. The mixed sulfide of nickel and cobalt produced at CBNC, is further refined to electrolytic nickel of 99.99% purity at Niihama Nickel Refinery of SMMC. The technology for production high purity nickel from low-grade laterite ore has been established and commercialized by the Coral Bay Nickel Project.
The exploitation of copper in Ancient Western Asia has a long history. Already in the Neolithic period malachite was used as raw material for bead and pigment, and then native copper was shaped into small objects by hammering and annealing. Based on the evidence from copper objects and workshops found in Iran and Anatolia, smelting and casting were carried out in the 5th millennium B.C. In the early copper production it is likely that the oxide ores such as malachite were used as raw material which was smelted in the crucible set on the shallow pit furnace with the aid of blow pipes. The advent of alloy in the late 4th millennium B.C., another significant development in early metallurgy, might make casting easier and more successful. The first copper alloy was arsenical copper which continued to produce until the end of the Middle Bronze Age along with bronze, an alloy of copper and tin. By the second half of the 3rd millennium the copper production in the vicinity of the sources became prevailing. The Late Bronze Age shipwrecks in the Mediterranean provide good evidence for the long distance trade of copper and tin in the shape of ingot.
This paper presents recent development regarding China's export restrictions on raw materials, which brought a strong response from Japan, the U.S. and the EU under the annual Transitional Review Mechanism (TRM) in the WTO. China is a dominant producer of various kinds of raw materials. China produces more than 90% of the world's rare-earths. For this reason, it is vital for major consumers such as Japan, the U.S. and the EU to secure a stable supply of these materials from China. However, China has recently been strengthening export restrictions on raw materials. The measures taken for this purpose include export quotas and export taxes. In 2007, this issue was discussed intensively under the TRM in the WTO. Japan, the US and the EU respectively expressed concern about China's export restrictions on raw materials. They also raised a lot of questions in conjunction with the consistency of China's policy with the WTO rules. China has provided some information, but the three parties still regards China's response as insufficient. Having described the above discussion in the WTO, this paper attempts to investigate whether or not China's policy is consistent with WTO rules. Also, the paper takes a look at the global demand for raw materials to consider why the three parties have particular concern about China's export restrictions. Lastly, the actions we need to take are presented. Mining development, recycling, and R&D activities for material substitution are essential to ensure a stable supply of raw materials.
A method to evaluate the regional stresses and the Young's modulus by analyzing mining induced deformation of the ground is proposed. Mining induced deformation is interpreted as the deformation due to the geometrical change of the ground surface caused by mine activity and it is classified in two types, i.e., the displacement increment induced by gravity and that by the horizontal regional strain. It is pointed out that both the regional strain and Young's modulus can be estimated by analyzing the mining induced deformation, because the displacement induced by the regional strain is independent of the Young's modulus and the displacement induced by the gravity is inversely proportional to the Young's modulus. The relative displacement due to mine excavation in Torigatayama mine were measured by GPS (Global Positioning System) and the regional stress state and Young's modulus were estimated by a back-analysis using three dimensional finite element method. It is shown that the maximum principal direction of regional stresses is almost NE-SW and Young's modulus of the ground is 3 to 6GPa in the present field.
Resources development projects including the early stage of exploration usually consist of multi-stage investments. Managers of such project have an option to invest or wait to a further stage at appropriate timing in each stage. These options have to be integrated into a comprehensive option as a compound option. In this study, we develop MSSA (Multi-stage SSA) method to evaluate multi-stage compound option by improving ordinary SSA (Stratified State Aggregation) method. MSSA which is one of the numerical computation technique based on Monte Carlo simulation has a flexibility to evaluate various uncertainties on a project. In a case study, project value of a crude oil development which has price and geological uncertainties has been evaluated by MSSA method. Geological uncertainties are decreased according to progress in the project stages as the result of exploration investment. Consequently, the project value and investment timing distribution considering compound option are calculated. Critical value maps for decision making are also obtained by varied initial crude oil price and expected oil reserves.
The time-dependence of molecular weight of gelatin, the cathode potential and the morphology of deposited Zn were investigated during long-term electrolysis of Zn to evaluate the degradation of gelatin and polyethylene glycol (PEG) added to the electrolyte for Zn electrowinning. Gelatin and PEG acted as a polarizer for Zn deposition, shifting the cathode potential to less noble direction. The polarization caused by the additives gradually decreased with increasing the electrolysis duration. The effective duration of additives significantly depended on the molecular weight and was longer in PEG-containing solution than in gelatin-containing solution. Gel permeation chromatography revealed that the molecular weight of gelatin in electrolyte decreased with increasing the electrolysis duration. The decrease in molecular weight of gelatin by electrolysis brought about the shift of the cathode potential to noble direction, showing that the molecular weight of degraded gelatin was related with the deposition potential of Zn. Even in the case without electrolysis, the molecular weight and polarization effect of gelatin decreased with increasing the lapse of time. On the other hand, the morphology and the crystal orientation of Zn obtained by long-term electrolysis corresponded to the change of the cathode potential with time regardless of the kinds of additives. With an increase in the cathodic polarization, the deposits showed the smaller grains with preferred orientation of (10-10). The morphology and the crystal orientation of deposited Zn became close to that in the additive-free solution when the polarization was decreased as a result of the degradation of additives.
The oxidation of phosphite in acidic solutions with dissolved oxygen under UV irradiation was investigated. The oxidation rate of phosphite obeys 1/2-order for phosphite and pO2, first-order for UV intensity. The pH of the solutions controls the concentration of the main reacting species, H2PO3-. A activation energy was found to be 41.3kJ• mol-1 , suggesting that the overall reaction rate was controlled by a chemical reaction. Furthermore, the applicability of the oxidation reaction of phosphite to the treatment of spent electroless plating solutions was studied using artificial electroless plating solutions. Oxidation above 80% was readily achieved within 120 minutes at 333K and 1 atm oxygen partial pressure. From the findings of this study, we can expect to use the oxidation reaction step of phosphite as part of the flowsheet of spent electroless plating liquor treatment.
Rare and noble metals contained in electric and electronic devices were analyzed by a commercially available energy dispersive X-ray fluorescence spectrometer. Several kinds of rare and noble metals such as nickel, cobalt, tungsten, zirconium, gold, silver, and bismuths were detected by analysis of the samples at inside part after removal of the package or crushing. Both bromine and antimony were detected in the most electronic part which contains plastics. The classification of elements contained and the procedures for identification of emission peaks in X-ray fluorescence spectrum were explained.