At present, coal accounts for nearly 25 percent of the world's primary energy supplies. Coal demand is expected to continue increasing in the world, particularly in the Asia-Pacific region, where dynamic economic growth is progressing. At coal mines in those coal-producing countries, mining sites are being shifted from open-pit mining to underground mining to meet increasing coal demand. Moreover, underground working places are becoming deeper. Therefore, securing safety at coal mines is an important task that must be tackled by these coal-producing countries.
On the other hand, Japan relies on overseas suppliers for 97 percent of its coal requirements. In addition, Japan is the world's largest coal importer. As such, the Japanese energy policy assigns top priority to securing a stable supply of foreign coal. In these circumstances, Japan is urged to answer a growing need from foreign coal producing countries for the coal mine safety technologies that had been developed and accumulated under the Japanese difficult mining condition. Considering that joint project is an important responsibility that Japan must perform in the international community, the Japanese government will continue to lay emphasis on coal mine safety projects.
Japan Coal Energy Center (JCOAL) has commenced information exchange program in 1982 based on the agreement between Australian and Japanese government. JCOAL and CSIRO had joint R & D projects on coal mine safety since 1993. The performance of gas drainage has been improved at the model mine as a typical result of the project. JCOAL also conducted cooperation projects on prevention technology of gas outburst and spontaneous combustion since 1992 with China. Occurrence of spontaneous combustion has been reduced dramatically at Chinese model mine by the end of the project. JCOAL had one joint R & D project on mine monitoring system in Indonesia.
Japanese government have a plan to continue and expand joint R & D projects on coal mine safety with coal producing countries in Asia Pacific region, and to set up the ICCR international R & D cooperation.

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No matter whether much more resources extracted from the deposit due to advances in technology, it is clear that the amount of metal resources is finite as long as they are non-renewable. To suppress resources consumption through recycling and substitution is effective way to retard the depletion of resources.
This study is concerned with substitutions of non-ferrous metals. Consumption model of copper, lead, and zinc is constructed considering the substitutions.
The end uses of the metals are classified into 18 categories. Demands for each categories are decided exogenously. Those demands are satisfied with the ordinary metals and seven kinds of substitutive materials. In this model, linear programming is used to decide the consumption of materials for each period. The objective function is the total extraction cost of these resources.
Sensitivity analysis for several parameters has been performed in connection with extraction cost and R / P of respective metals in the last period. As the result, in most cases substitution mitigates the depletion of metals as well as the increase of extraction cost. Especially, the substitution by aluminum and iron promotes the final R / Ps of copper increase. However, this is only true for copper and zinc, not lead. As initial reserve of lead is scarce compared to other base metals, lead will gradually be exhausted.

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A multi-period planning model for underground cut-and-fill operations was constructed for the purpose of maximizing discounted profit under given production constraints. The ore grades were estimated through geostatistics for minimizing the estimation errors, and production costs were calculated on the basis of the practical operation data. A sequential planning algorithm based on dynamic programming (DP) was then developed to specify the most profitable mining sequence, and applied to a Chinese copper-iron mine employing cut-and-fill stoping. Calculation results showed that the proposed DP-based sequential planning strategy can produce larger discounted profits than those obtained by the advance and retreat mining sequences.

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In order to deal with the uncertainties regarding ore grade estimations, production rates and metal prices during overall planning periods, a Chance-constrained programming combined with a dynamic programming was developed to incorporate these uncertainties. Four cases of the Chance-constrained programming formulation were proposed under different uncertainty assumptions of ore grades, production rates and metal prices. Simulations were conducted by taking the magnitude of the Chance-constraint and objective function violations into consideration. Simulation results with respect to the studied mine clarify that the increase of the confidence levels of Chance-constraints can lead to the decrease of NPV of the planning project, whereas the increase of the given probabilities of maximizing the allowable limit of the fluctuation of metal prices can lead to the increase of the NPV.

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Caking of powder-products in food, chemical and medical industries gives a serious economic loss if it happens during production, storage and transportation. For example, sodium bicarbonate easily forms cakes during the storage and distribution process after production due to the influence of the moisture in air, temperature, compaction and so on. Big burden is necessary in order to avoid this caking problem. Method for characterization of the weak caking is therefore required. Four types of equipment were made and examined for measuring powdering rate of clots and examined. An equipment consisting of a panting metal cylinder with lifters were finally developed. This device breaks the hardened cakes with the impact caused by rotating the cylinder for measuring the powdering rate. Strength of weak cakes can be evaluated with sufficient accuracy by using this method. Filling density of powder significantly affects on the hardening of the cakes. A new theoretical equation of powdering rate is proposed for evaluating the caking state and simulates very well the experimental process of powdering.

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Variously Mg-exchanged A-zeolites have been prepared and tested by the hydration calorimetry to clarify the characteristics as heat absorbents. 2Na⁺ → Mg²⁺ exchange in zeolites led to the decrease in number of cations to compensate the charge-balance providing space for water molecules in the structure. Various factors such as salt-concentration, temperature and repeating times of cation-exchange were optimized to obtain 89 % Mg-exchange of the Na-A zeolite. The Mg89-A zeolite containing 30.1 % of water was found to have the heat exchange capacity of 1 MJkg^-1, when it was dehydrated at 200 °C. The Mg89-A zeolite could be useful as a heat pump absorbent.

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The extraction of mercury (II) from hydrochloric and nitric acid solutions by trioctyl phosphine oxide (TOPO) in benzene has been investigated under different conditions. The organic extracts were examined by infrared, Raman and nuclear magnetic resonance spectroscopies. As the results, it was found that with increasing the concentration of aqueous hydrochloric acid solutions, the distribution coefficient for TOPO decreased below 1 mol dm^-3 HCl and rised to a maximum at about 4 mol dm^-3 HCl and then fell. The distribution behavior for the extraction of mercury (II) by TOPO from nitric acid solutions was analogous to that from hydrochloric acid solutions, while their extraction efficiencies were in the order of extraction systems HCl > HNO₃. Consequently the following equilibrium equations are proposed for the extraction of mercury (II) from hydrochloric and nitric acid solutions by TOPO : for HCl extraction system, HgCl₂ (a) + 2TOPO (o) ⇔ HgCl₂·2TOPO (o), HgCl₄^2- (a) + 2H⁺ (a) + 2TOPO (o) ⇔ H₂HgCl₄ · 2TOPO (o) and when mercury loading increases HgCl₂ (a) + TOPO (o) ⇔ HgCl₂·TOPO (o) ; for HNO₃ extraction system, Hg (NO₃)₂ (a) + 2TOPO (o) ⇔ Hg (NO₃)₂·2TOPO (o) and Hg (NO₃)₄^2- (a) + 2H⁺ (a) + 2TOPO (o) ⇔ H₂Hg (NO₃)₄·2TOPO (o).

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In processing starting sheets for copper electrorefining, the stainless steel cathodes are commonly replaced in one-day period to strip off the starting sheets. Half of the cathodes in cell are replaced without power cut, then, the cathode current density rises twice during the replacement. This operation sometimes results in the formation of gloss parts on a surface of the starting sheet, resulted from the deposition of some impurities such as bismuth. The cause and mechanism of the bismuth deposition were studied by the experiments using a plant cell, and measures for avoiding the deposition was discussed in this paper.
It was found that the content of bismuth deposited even in a short period of the electrolysis is so high as to give a serious effect to the quality of produced electrolytic copper and that the deposition is influenced by the current density and the electrolyte. To prevent the deposition of bismuth,the current distribution on the cathodes is to be uniform and the electrolyte is to be controlled for decreaseing the polarization. It was also found effective to replace the cathodes after they are covered with the deposited copper.

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The Study summarizes the consequences of comprehensive research on the mechanization of longwall faces which has been carried out at Taiheiyo Coal Mining Company's Kushiro Colliery since 1950 to this day.
Due to the crucial economical circumstances surrounded Japanese coal mining industry being affected by import of abundant and cheap priced crude oil from OPEC, the coal mining companies inevitably challenged to restructure their constitution by way of, for instance, mechanization of longwall faces and / or rejuvenation of underground structure.
At Kushiro Colliery, it was tried to introduce the powered supports to their thin seam(#2) and medium height seam(Lower Seam) on the experimental basis at the beginning, and as a final goal, it was also challenged to introduce multipass double wing mining method with 4 longwall faces where UU shaped Frame type with 12 legs powered supports were installed.
As a Part-1 of the report, the author describes mainly the results of measurement and analysis for roof lowering phenomena under heavy earth pressure. The results of analysis are reflected for the design of the powered supports, in particular, stroke of the hydraulic legs.

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As a fundamental study for treating fused oxides containing antimony and arsenic components relating to metallurgical and recycling processes, volatility, a, and vapor pressure of the oxide species evaporating from the CaO-SiO₂-FeO_1.5 slags with Q (%CaO / (%CaO + %SiO₂)) of 0.37, 0.53 and 1 were determined at 1,573 K in a range of mole fraction, N, of SbO_1.5 , SbO_2.5 and AsO_2.5 in the slag between 0.005 and 0.05 by using the transpiration method with a vertical volatilization chamber. It was found that the volatility of the antimony and arsenic components in each slag increases with decreasing Q and suggested that control and adjustment of the slag basicity are very important for eliminating these components from the slag by means of volatilization. The log α versus log N plots represented a nearly straight line with a gradient, which is very close to that predicted by the thermodynamic consideration, and it was concluded that Sb₄O₆ and As₄O₆ are the predominant gas species evaporating from the slags. Raoultian activity coefficients, γ, of SbO_1.5, SbO_2.5 and AsO_2.5 in the slags, which were derived from the measured volatility, decrease with increasing Q, and γ_SbO2.5 and γ_AsO2.5 are less than unity for the slags with Q of 0.53 and 1.

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