Based on Kuster's expression for the elastic moduli of composite materials, the pore aspect ratio spectrum of granite is estimated.
The three conditions given below are assumed to generate 3640 types of pore aspect ratio spectra.
1) Aspect ratio (α) ranges from 10⁰ to 10^-5 and the distribution of the value of α is expressed with discrete line spectrum.El even values of aspect ratio are used to divide in equally spaced intervals a logarithmic scale.
2) The distribution of aspect ratio has the normal distribution.
3) A spectrum of pore shapes has a unique maximum.
The longitudinal wave velocities are calculated for 3640 models with the limitations mentioned above, and the pore aspect ratio spectra of granite are investigated by fitting the calculated velocities of rocks in dry and saturated states to the laboratory data.
The results show that the variation of longitudinal wave velocity with respect to water content can be quantitatively illustrated by the use of a pore model with mixeci asnect ratios instead of a single aspect ratio model, and that the most suitable model explaining velocity increase due to water saturation is that containing pores ranging from sphere to cracks (aspect ratio 10⁰ to 10^-5). Compared with the data of crstalline limestone, the relative amount of very thin cracks (aspect ratio<10^-3) contained in granite is less than that of crystalline limestone.

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This paper describes a new method for estimating the focal mechanism of microseismic event in mining panel, and also demonstrates a few illustrative results obtained from the analysis of the microseismic events induced by underground coal mining. This method gives formula of the radiation patterns of P, SV and SH waves emitted from a point source at which the major, intermediate and minor principal stresses change simultaneously. The formula imply that there are two potential stress paths during fracture at focal region. One is accompanied by increase of the minor principal stress during fracture process beyond the strength failure. This type of stress path will take place if the elastic resiliance of surrounding rock is greater than the load bearing capability of failed region. On the other hand, second one is characterized by decrease of both the major and minor principal stresses. This type will be undergone in rock adjacent to underground opening when the confining pressure is removed or reduced by enlargement of the opening.
The illustrative analysis showed a few features of microseismic event in an active longwall panel:
(1) At ribside of the panel, microseismic event seems to take place when the ribside losses effective confining pressure.
(2) At mined out area, microseismic event appears to occur under the major principal stress that is normal or parallel to the seam plane depending on the condition of caving behind the coal face.
(3) At the zone adjacent to pre-existing fault, microseismic event seems to be associated with the fault movement.

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The orientation of hydro-fracture is usually determined from stress condition on the basis of the theory of isotropy. However, the strength of anisotropic rocks in hydraulic fracturing shows orientation dependance from the results obtained in 1st report. The purpose of this report is to discuss how to account for rock anisotropy on the mechanism of hydraulic fracturing. Some laboratory hydraulic fracturing tests were conducted for the influences of stress condition, inclination of borehole and pre-existing fracture in Inada granite and Kofu andesite.
The permeation factors obtained from the relationship between the breakdown pressure and confining pressure are shown as the following equations.
Inada granite; P_b=0.57 (3_σh-σ_H) +T_HF
Kofu andesite; P_b=0.65 (3_σh-σ_H) +T_HF
Hydro-fractures in Inada granite were recognized to be created in the direction of the rift planes under the condition that the stress normal to the rift planes excessed the other stress by about 20 kg/cm2 (Figs. 7 and 11). This result suggests that the influence of rock anisotropy must not be negligible problem in stress analysis by using the data of hydro-fracture orientation.
It is suggested from the results of hydraulic fracturing tests in inclined borehole that the orientation of hydro-fracture is liable to be more influenced by borehole inclination than rock anisotropy and stress condition (Fig. 10).
The results of fracture intersection tests show that the hydro-fracture must not be created far from 8 mm across the pre-existing fracture under condition of this report.

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In this paper, the dynamic behavior of a submerged pipe string, which was hanging from a ship and equipped with a buffer at its lower end, was theoretically analysed for the design of a mining system in the deep ocean.
The main results obtained are as follows:
(1) The relative displacement of the pipe string to the ship continues to increase just as a pendulum even in the towing period of a constant velocity, which follows the period of acceleration, and then it approaches to the steady-state value after a considerably long time.
(2) The bending stress induced in the pipe string is much smaller than the tensile stress at the top of the string. Hence, the bending stress does not play an important role in designing the above-mentioned mining system.
(3) When the maximum towing velocity is constant, the variations of acceleration and deceleration times in towing have a little effect on the relative displacement of the pipe string. However, both the relative displacement and the time required for it to reach the steady-state value increase remarkably as the maximum towing velocity increases.
(4) From the practical sense, it can be said that the flow velocity of fluid in the string does not affect the displacement of the string for the mining system considered here.
(5) When the other quantities are constant, both the relative displacement of the string and the time required for it to reach the steady-state value increase remarkably as the mass of the buffer decreases or as its projected area to the vertical plane increases. Furthermore, a larger ratio of height to diameter of the cylindrical buffer leads to a smaller displacement of the string.

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In general, it had been well known that the energy efficiency of grinding process decreases with decrease of produced particle size or with increase of grinding time or with increase of input energy.
In this study, we defined the size reduction energy as the elastic strain energy which is stored up to fracture in the solids. The relationship between particle size and fracture energy or impact velocity required for fracture quantitative based on the single particle crushing was referred.
As a result, it was found that the increase of probability of collision between particles and grinding media is effective for ultrafine grinding. The above has been verified experimentally by the ball milling.

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A precipitation separation method has been investigated at ambient temperature to recover Cu, Ni and Co from sulfurous acid leach liquor of deep sea manganese nodules.
The Cu, Ni, Co and Mn values are completely leached out of the nodule byusing a slight excess amount of sulfurous acid for reducing MnO₂ in nodules to Mn²⁺, whereas 30% of Fe is undissolved. Fe²⁺ is oxidized by aeration and precipitated as Fe (OH) ₃ by adjusting pH of the leach liquor to 4.2-4.4. Subsequently, Mn is precipitated as MnCO₃ by adding (NH₄) ₂CO₃ when Cu, Ni and Co in the solution are stabilized as ammine-complexes in the presence of NH⁺₄ added as ammonia-water, (NH₄) ₂CO₃, (NH₄) ₂SO₃ or (NH₄) ₂SO₄. After several trials, over 90% recoveries of Cu, Ni and Co are obtained and about 97% of Mn and 99.9% of Fe could be removed. The optimum conditions for recovering metal values will be discussed.

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As fundamental studies for the behaviour of antimony in reduction smelting and treatments of byproducts, the activities in a liquid Cu-Fe-Sb system and the distribution coefficients of antimony and copper between the speiss and slag phases were investigated. The activities were determined at 1423 K by using an isothermal-isopiestic method. The isocurves of antimony, copper and iron activities represented some characteristic features on a ternary Cu-Fe-Sb diagram. The distribution coefficients were measured at 1473 K by using three kinds of slag systems; iron silicate at silica saturation, calcium ferrite and barium ferrite. The compositions of antimony of the speiss phase equilibrating with slag ranged widely from N_Sb=0.25 at γ-iron saturation to N_Sb=0.6. The obtained distribution coefficients could be explained quite reasonably based on the fundamental thermodynamic quantities of the speiss and slag components.

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The solubility curves of sulfates in the systems CuSO₄-NiSO₄-H₂O-C₂H₅OH and CuSO₄-CoSO₄-H₂O-C₂H₅OH at 298K were determined and the possibilities of industrial application of fractional crystallization method was discussed. The results are summarized as follows:
(1) The solubility curve for the system CuSO₄-NiSO₄-H₂O-C₂H₅OH can be devided into 2 portions which are characteristic to crystallization of CuSO₄.₅H₂0 and NiSO₄.7H₂0, respectively. Each crystalline phase contains only minute amount of other sulfate. The solubility of CuSO₄ at eutectic point decreases with increase in the concentration of ethanol from 0.78 to nearly zero, while that for NiSO₄ ranges from 2.18 to nearly zero.
(2) A similar solubility curve can be obtained for the solution system of CuSO₄-CoSO₄-H₂O-C₂H₅OH. However, the solid phase equilibrated with a saturated CoSO₄ solution was identified to be a mixed crystalline phase of (Co, Cu) SO₄.7H₂0.
(3) The separation of CuSO₄ from the saturated CuSO₄ solutions containing NiSO₄ up to 1 mole is possible to produce almost pure crystals of chalcanthite with the yield ranging 70 to 98%. The required amount of ethanol for the crystallization of chalcanthite ranges from 0.23 to 0.43 kg per kg of water, leaving the resultant solution whose CuSO₄ concentrations are 0.35 to 0.01 moles per kg of water.

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