The authors have developed a method called'seismic moment method' to predict microseismicity induced by deep coal mining. The method is based on stress analysis and is applied to three cases in two deep coal mines in Japan, including two cases having experiences of rockbursts.
Through comparison between observation and prediction, it is clarified that the method is also effective for the three cases and that the rockbursts at longwall coal face tend to occur when microseismicity is being activated and when the width of relaxed zone in front of coal face is narrow. Criteria to evaluate rockburst danger area are also proposed.

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An approximated solution [Eq.(24)] to estimate rock surface temperature of underground airway with partly wet conditions has been provided. It is much simple and practical compared with previous methods or solutions. The solution is applicable to the range of airflow temperature from 0 to 32° or 10 to 40°(see appendix) and practical ranges of humidity, ventilation time, heat transfer rate, wetness, virgin rock temperature and rock thermal properties. Furthermore, an explicit function for the rock surface temperature is derived, then the rock surface temperature can be calculated by simple procedures without any iterative calculations. The short subroutine program in FORTRAN 77 to calculate the rock surface temperature is shown in the appendix.
The estimated value of rock surface temperature have been compared with Amano et al's numerical calculation results using two dimensional finite difference method.
Finally, a practical calculation system to predict airflow temperature and humidity along underground airways have been proposed using the practical solution of rock surface temperature. The system can consider the effects of airway inclination and wetness or wet area ratio upon airway surface. The calculation results of temperature and humidity along a single airway shows good agreement with the results of Uchino et al. using finite deference method for analysis of rock temperature distribution and some simulation codes reported by Danko et al.
Furthermore, it is pointed out that differences between calculation results of the simulation codes suggested by Danko et al. is probably caused by the difference between wetness and wet area-ratio (see Table 2).
The present prediction method for temperature and humidity in underground airways have been successfully applied to a general ventilation simulator named MIVENA run on the Microsoft Windows^TM which has been further developed and released by authors.

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The behaviour of rock in tension is considered to be as important as in compression for designing underground structures. But few results of tensile tests were reported. Especially, only very limited data are available concerning complete stress-strain curves in uniaxial tension test.
The testing method and the servo-controlled testing machine were developed for uniaxial tension tests in this study. Uniaxial tension tests were conducted on six rocks; Sanjome-andesite, Inada-granite, Kawazu-tuff, Tako-sandstone, Kimachi-sandstone and tage-tuff.
Complete stress-strain curves were successfully obtained. The experimental results indicate that the shape of complete stress-strain curve in tension is most similar to that in compression. Close observation of fractured surface by a CCD camera of 25-175 variable magnifications revealed very rough and rugged feature which may be induced by inhomogeneity of rock texture and could be related to post-failure behaviour such as advent of residual strength in final stage.

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An understanding of the time dependent behaviour of rocks is becoming increasingly important for long-term stability or durability of underground structures. However, data on the time dependent behaviour of rocks such as creep in tension are very limited. The object of the present investigation was to clarify the creep behaviour of Sanjome andesite in uniaxial tension.
Complete creep curves were successfully obtained, and experimental results were compared with previous results in uniaxial compression. The creep behaviour in uniaxial tension showed qualitatively similar trend to that in uniaxial compression. In primary creep region, the strain rate continuously decreases, followed by region where the strain rate changes little by little. Thereafter, the strain rate increases rapidly in tertiary creep region and is inversely proportional to the residual life time.
Also it is found that the life time depends on the normalized differential stress, (σ_F-σ_C)/σF where σ_F and σ_C denote strength and creep stress, respectively; the specimen under the sanne (σ_F-σ_C)/σ_F has the same life time, irrespective of compression or tension.
Finally, creep behaviour in uniaxial tension was analytically examined by the proposed mathematical model of crack growth. The result indicates that the model can be applicable to qualitative explanation of behaviour not only in primary creep region but also in tertiary creep region.

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In the ocean mining tests of manganese nodules, which will be done at offshore of Hawai, it is expected that concentration fluctuation will occur in a lifting pipe owing to collector's stick-slip movement.
In this paper amplitude of concentration fluctuation was studied experimentally.
And propagation properties of concentration fluctuation were calculated by the diffusion model that mean eddy diffusivity for mass at a cross section of pipe was estimated.
By using this model the amplitude and frequency of these fluctuations at an arbitrary point of lifting pipe could be estimated. Main results were as follows.
1) According to the results of the model-testings, collector's stick-slip movement introduced concentration fluctuation in a lifting pipe.
2) The amplitude of concentration fluctuation amounted to 60% of the time-average value in case the frequency of the oscillation of the collector model was 0.35Hz and that its amplitude was 0.50m.
3) As the frequency of the collector's oscillation became high and as its amplitude increased, the amplitude of concentration fluctuation increased.
4) According to the simulations of the concentration fluctuation's propagation, the amplitude of the concentration fluctuation decreased small with the distance from the outlet of the feeder.

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Phospholipids such as phosphatidylethanolamine and phosphatidylglycerol are detected as extracellular substances in cultures of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, but their effect on bacterial leaching is not well understood. In this paper, basic experiments on bacterial leaching of chalcopyrite by Thiobacillus ferrooxidans were carried out in the presence of phosphatidylethanolamine.
The copper extraction in chemical leaching of chalcopyrite with ferric sulfate increased slightly by the addition of phosphatidylethanolamine. In the medium containing ferrous sulfate as substrate, the ferrous oxidation by Thiobacillus ferrooxidans and its growth were not affected by the addition of phosphatidylethanolamine. In bacterial leaching, the addition of phosphatidylethanolamine had no effect on the copper extraction and bacteria adsorption on the mineral surfaces. These results were different from the results with phosphatidylglycerol.

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It is desirable to obtain high copper dissolution rate for relnoval of copper from ferrous scrap by ammonia leaching. In this study, a new ammonia leaching process using a injection. rnethod in a closed circuit system is proposed to improve copper dissolution rate and to prevent ammonia from vaporization loss. The copper dissolution. rate have been measured under injection of oxygen. The tests were carried out in a 24iter reaction flask under conditions of 30-40°C, oxygen flow rate 4-12 Nl/min, and concentration of cupric copper 0-50 g/l. It has been found that copper dissolution rate increases with increase in temperature, O₂ flow rate and concentration. of cupric copper. A kinetic model based on mixed reaction-diffusion controlhas been found to be in good agreement with the experimental results.

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Ammonia Leaching of copper has been studied in order to develop a hydrometallurgical process for removal of copper from automobile scrap. An air injection method in a closed circuit system, by which large flow rate of air can be injected into leaching solution without vaporization loss of ammonia, was introduced in order to obtain high copper dissolution rate. The leaching tests were carried out in a 200-liter tank under conditions of 40°C, air flow rate 100Nl/min, a nd initial concentration of cupric copper 16-18g/l. Pseudo-motor scrap, motor scrap and their mixtures with schredder scrap, and dynamo scrap were used as test samples. It has been found that shredder scrap has nothing to do with leaching rate of copper from pseudo-motor scrap or motor scrap. The copper dissolution degree from pseudomotor scrap, motor scrap and dynamo scrap was 100%, at 2.5 hours, about 85% at 5 hours and 80% at 5 hours, respectively. From above test results, it has been showed that ammonia leaching with the air injection method in the closed circuit system is effective for removal of copper from automobile scrap.

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The extraction of ruthenium (III) from hydrochloric acid solutions has been investigated by using high molecular-weight amines under various conditions.
The extraction isotherm shows a shape analogous, which has a minimum value at 1.5-2 mol dm^-3 initial aqueous hydrochloric acid solution. Hence, it is suggested that the extraction species varies in low acidity (≤1.5 mol dm^-3 HC1) and higher acidity (≥1.5 mol dm^-3 HC1). The order of the extractability of amines, with the exception of BDDA, TOA, CODA and CDDA, is quaternary ammonium compound>>tertiary amine>secondary amine, and the extractability is promoted by substitution of benzyl (electron donor) group.
Stoichiometric composition of the DOA and TOA complexes formed in the organic phase are deduced to be R₂NH₂Ru (OH) ₂ Cl₂·3H₂O at low acidity and R₂NH_·2RuOCl₂ 2H₂O at higher acidity and R₃NHRu (OH) ₂ Cl₂·0.5R₃NHCl·2H₂O at low acidity and R₃NHRu0Cl₂·R₃NHCl·H₂O at higher acidity, respectively.
In the examination of diluents effects, it is found that nitorobenzene is most effective for the extraction of Ru (III) with TOA.
The distribution ratios in the extraction with DOA and TOA decrease with increasing temperature.

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