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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トリオクチルホスフィンオキシド(TOPO)のベンゼン溶液による塩酸および硝酸溶液からの水銀(II)の抽出が種々の条件により検討された。そして有機相への抽出物が赤外線，ラマン，核磁気共鳴のスペクトル測定により調べられた。その結果塩酸溶液からの抽出では，水溶液相中の塩酸濃度の増加により分配係数は1mol以下の酸濃度で減少し，それ以上の酸度で上昇し約4molで極大値に達し，また低下することが分かった。硝酸溶液からの抽出では，TOPOの水銀(II) の抽出能力は塩酸溶液からの場合よりも低いが，その抽出挙動は塩酸溶液へ類似している。それ故次のような抽出平衝式がTOPO による水銀(II)の抽出に対して提案される。すなわち塩酸溶液からの抽出では，HgCl₂ (aq) + 2TOPO (org) ⇔ HgCl₂·2TOPO (org), HgCl₄^2- (aq) + 2H⁺ (aq) + 2TOPO (org) ⇔ H₂HgCl₄·2TOPO (org)， 水銀の抽出濃度が増加するとHgCl₂ (aq) + TOPO (org) ⇔ HgCl₂·TOPO (org) ; 硝酸溶液からの抽出では，Hg (NO₃)₂ (aq)+ 2TOPO(org) ⇔ Hg(NO₃)₂·2TOPO (org), Hg(NO₃)₄^2- (aq) + 2H⁺ (aq) + 2TOPO (org) ⇔ H₂Hg (NO₃)₄·2TOPO (org).

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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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異なるQ(Q = %CaO / (%CaO + %SiO₂))値を有する3 種類の溶融CaO-SiO₂-FeO_1.5 系スラグ中のアンチモンおよびヒ素( モル分率0.005 ～ 0.05)の揮発度と蒸気圧を竪型流動法装置により1,573 Kの温度で測定した。流動ガスの単位容量当たりの揮発物重量で定義される揮発率は，アンチモン，ヒ素いずれの場合も，Q値の減少とともに増大した。スラグ中のアンチモンおよびヒ素は， それぞれ，Sb₄O₆ およびAs₄O₆ の形で揮発することが実験結果の熱力学的解析から窺われた。測定蒸気圧から導出されたスラグ中の5価酸化物SbO_2.5，AsO_2.5のラウール基準の活量係数は，Q値の増 加とともに減少した。

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