Mining and metallurgy are fundamental activities of our human beings. These technologies have been uninterruptedly continuing and steadily developing since the beginning of human cultures.
Japan has also long and glorius histories of mining and metallurgy and in her recent years, these technologies had played important roles, particularly on her modernization in Meiji era and her rehabilitation after the World War II.
Nowadays, it is very hard to develop and operate a mine in Japan. However, the importance of technologies of mining and metallurgy is not in the least divested for our prosperities. Therefore, these technologies should be taken over without any cease to the following 21 Century.
Expect the bright restoration of our technologies in the global activities in near future.

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Since emissions of DXN's from incinerators of municipal waste has been one of the serious problems in recent Japan, new regulations have been decided and will be started from next year. The new regulations cover the emissions not only from incinerators but from some processes in metal production industries. Most processes covered by the new regulation in metal production industries are working in metal recycling which is supporting recycling society in Japan.
Inventory of DXN's emissions in non-ferrous metal industries were investigated and some technical problems were pointed out in the present review to show urgent scientific and technical research problems.

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Authors had proposed two types of constitutive equations which were developed based on the experimental data of some Japanese rocks. Since proposal of the equations, a lot of questions were asked us by researchers and engineers who took part in construction of tunnels, underground storages and so on.
Through the discussion with questioners, it was found that there were many common points in questions, especially on how to obtain the parameters in the equations, which arose mainly because explanations and assumptions concerning the constitutive equations were changed many times and it was hard for readers to understand the whole systems starting at experimental work, through determination of parameters, and ended at numerical simulation and evaluation of the calculated results.
In this manuscript, we tried to explain the present constitutive equations in the form of FAQ (Frequently Asked Question), which was chosen for convenience of busy readers. A variable-compliance-type constitutive equation is mainly stated, however, most questions and answers are also applicable to other types of equations with slight modifications.

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Design of the steel-reinforced concrete plug for the underground cavern to store high pressure compressed air and / or natural gas is focussed. It is confirmed, based on the finite element stress analysis, that in case of the double-conical shaped plug, the shear failure along the rock-plug interface in the rear part of the plug is most easily induced among the few possible failure modes ,which causes the loss of the resistance to the applied pressure. It is also proved that the plug whose angle of the conic rear part is 60 degrees exhibits the maximum resistance to the above-mentioned shear failure.
To effectively support the tensile stresses induced in the rear part of the plug, a steel-reinforced concrete structure is recommnended, in which the steel elements sustain the tensile load. A design procedure is proposed by modelling the plug as deep beam supported on the two points. Length of a newly designed plug is only one thirds of that based on the conventional design methods in Japan.
A series of two dimensional physical model studies were conducted to confirm the failure modes and the attainable maximum pressure of the newly designed plug.

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It is well known that uniaxial compressive strength of rock increases with loading rate. Loading rate dependency of Young's modulus has been also studied by many authors, however, only a small part are clarified.
In this study, testing method are slightly modified to reduce scatter of data. In the testing, Young's modulus at 50% of the peak strength is normalized by that at 10% of the peak strength which is preliminarily obtained under a predetermined loading rate. It was found that this testing method is effective and promising.
Seven Japanese rocks were examined. It was found that an andesite, a sandstone and two tuffs exhibited loading rate dependency of Young's modulus. For example, in case of Sanjome andesite, Young's modulus increased 2 % at every ten fold increase of loading rate. On the other hand, Young's moduli of a marble, a granite and a sandstone very slightly decreased with increase of loading rate.
With aid of constitutive equations, time dependency of modulus was discussed. It was found that irrecoverable strain delayed to extend when loading rate was high. That is possibly the main reason of increase of Young's modulus with increase of loading rate.

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The cement rotary kiln process involves the potentiality to utilize a variety of wastes as fuels. Therefore this process itself has been modified to adapt these conditions. Generally these processes are described by a distributed parameter model, therefore, these expressions are rather complicated and not suitable for control purpose. On the other hand the models developed exclusively for control purpose are too much simplified to reproduce the practical process. So it is necessary to develop an adequate model to estimate the dynamic behaviors and to be used in designing optimal control systems.
The aim of this paper is to present the local linear models based on mass balance, heat transfer for its control purpose by applying the method of weighted residuals. However, this method does not work favorably under such a condition introducing the mass of feed as a manipulated variable. To apply this method to its condition, both numeric and symbolic computation power were required in modelling.
Consequently some local linear models of reduced order were proposed for its control purpose. Especially, the model involving manipulated variables such as the mass of feed has been derived easily by using the MATLAB. Furthermore the authors have also conducted the comparison between the response from this model and that from the exact model. The good agreements between them have proved this approximation method to be adequate.

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Bactrerium inhabiting in Amarume crude oil of Yamagata prefecture was identified as Pseudomonas mendocina. In the first step, biodegradation experiments were conducted by using the bacteria of 0.510⁶ cells / ml and 300 ppm of chlorobenzene in aqueous solution under aeration and irradiation. After 6 hours, chlorobenzene was perfectly decomposed. Next, the mixtures of synthesized polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were degraded with the bacteria of 0.510⁸ cells / ml, where the initial total concentrations of PCDDs and PCDFs were 1,400 ppm and 180 μg-TEQ / ml. After 24 hours, about 70 % of PCDDs and 60 % of PCDFs were biodegraded. The biodegradation rates of PCDD / Fs were much faster than those reported in literatures with other bacteria.

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CO₂ emissions from the electrolytic copper production system were quantitatively evaluated using Life Cycle Assessment (LCA) technique. Electrolytic copper and sulfuric acid originated from the refining gas were produced in this system. In this study, inventories such as the fuel consumption of the unit processes and the in-house electricity were based on published papers and public statistical data. The following observations were made based on LCI analysis:
(1) CO₂ emissions from the electrolytic copper and sulfuric acid in the system are about 1.0kg and 0.4 kg / kg-product, respectively. The CO₂ emissions attributable to the transportation of copper concentrate correspond to 20 % of all emissions. This emission is higher than that of zinc, because the metal content in the concentrate is lower than zinc.
(2) The CO₂ emissions from the system decrease with the recycling of copper scrap to the converter process, because the consumption of copper concentrate is reduced. The reduction is estimated to be 0.2 kg-CO₂ / kg-Cu at the point of 0.1 kg / kg-blister Cu with scrap additive. This corresponds to 9 % reduction for the present system. However, recycling leads to the decrease of sulfuric acid by 450 kt at the point.
As a result, the recycling of scrap should be evaluated not only from the reduction of CO₂ emissions but also in terms of sulfuric acid demands.

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In order to assess the long-term stability of high-level radioactive waste form, various compositions of lithium and sodium borosilicate glasses containing cesium and strontium have been treated under a hydrothermal condition (200 C and 1.54 MPa) for maximum 6 months. The formed phases are tridymite, low quartz, Li₂SiO₃, Li₂Si₂O ₅ · xH₂O, Li₂Si₂O₅, Li₄₂O₅, searlesite (NaBSi₂O₅(OH) ₂), and veatchite (Sr₂[B₅O₈(OH)] ₂[B(OH)₃] · H₂O) including some unidentified phases. The behaviors of cesium and strontium are quite different on the hydrothermal process. Cesium is not included in any of the solid phases. In contrast, strontium is an essential constituent of veatchite. Natural veatchite occurs usually as a constituent of evaporite, and hence the mineral is inferred not to be stable, when groundwater flows into a disposal site. The results suggest, accordingly, that in order to incorporate cesium and strontium into some of forming minerals, another element must be added to the glass composition.

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Electrolytic removal of Se (VI) in waste water (15 ppm) is studied at pH 1 and 3 and at room temperature. Prior to electrolysis, there was a drop in concentration due to adsorption of Se onto activated carbon. In the initial half of electrolysis, the decrease in residual concentration followed the nucleation growth reaction without an increase in Se (IV). In the later half, plots were scattered, due to desorption of Se. The reaction has a maximum of removal rate; this was in accordance with those of data. Current efficiency was about 3 % at the maximum, owing to generation of hydrogen. The current density for particles suspended is compared with those for suspension electrolyses of the S-Cu system.

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Effect of some technological parameters on the rate of oxidative leaching of molybdenite in alkaline media (NaOH, Na₂CO₃ and NH₃ solutions) has been examined. Within the studied range of temperature (130 ~ 160°C), oxygen partial pressure (7 ~ 16 atm) and NaOH concentration (5 ~ 25 g / l) the oxygen mass transfer through the gas-liquid interface was found to control the rate of MoS₂ leaching. Effect of NaOH concentration has been observed only when low-grade MoS₂ containing sulfidic impurities of copper and iron was leached.

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