In order to efficiently operate a mining system, it is important to construct the computer aided mine design and planning systems. These systems, which require the information concerning topography and geology of planned site, estimate optimum mining method, investment effect and changes in scene with the progression of mining. This paper presents the methods to construct a highly precise terrain model and to estimate appearance patterns of rock discontinuities on the model for mine design.
In this study, a quarry located at the northern Kumamoto prefecture near the northern limit of Beppu-Shimabara Graben is chosen as the subject area. First, the characteristics of the five fracture zones observed in the planned site are revealed by the analysis of X-ray diffraction, summit levels, azimuth frequency of lineaments and joints. As a result, it is shown that clay minerals are conspicuous in the fracture zones, and that the strikes of the zones are parallel to the dominant trends of the fracture systems on several scales in the graben occurred in the regional tectonic stress field. Furthermore, the maximum gradient method is proposed to generate DTMs (Digital Terrain Models) with arbitrary dimensions of mesh intervals from the contour lines traced by a digitizer. Directions, dimensions and locations of center of the five fracture zones are used for an example of the mining simulation with information on rock discontinuities such as fracture zones. The changes in appearance of those fracture zones on mining slopes and floors with the progression of mining are simulated and clearly shown on the computer graphic screen.

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Stress relief method is widely used in coal mines in many countries to prevent the gas outburst and rock burst. It is one of the effective methods of relieving the stress to cut the slits in coal seams.
The author made a model experiment to investigate the effect of the slitting at the heading face on the stress relief. A three-dimensional model experimental apparatus of about 1: 80 geometrical scale was used. The dependence of slit thickness, number of slits and the strength of model coal seam on the effect of the stress relief was measured. As the model rock mass, the gypsum plate was used and as the model coal seam, an artificial seam made from the mixture of water, gypsum and diatomite was used. The scale factor of the stress and strength was 1: 40.
The effect of the stress relief was evaluated by the degree of stress relief defined by the author. A slitting standard for effective stress relief, such as to cut the several parallel slits and to cut the slits near roof or floor, was proposed.

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The pressure loss and the particle velocity profiles for ice-water slurry flows in a pipe were experimentally investigated. The pressure loss was larger than that for clear water flows at lower velocities. On the other hand, it was a little smaller than that for clear water flows at higher velocities. The particle velocity profile at lower velocities was distorted by the friction between the ice particle layer and the pipe wall. However, it approximately agreed with that of turbulent clear water flows at higher velocities.
A simplified model was proposed to examine the pressure loss for ice-water slurry flows in pipes at higher velocities. This model gave satisfactory results with experiments.

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It is important to investigate in detail the mineralogical properties of the mineral matters in coal, for the application of advanced coal cleaning techniques such as column flotation, oil agglomeration and chemical cleaning.
In this paper, existing state of mineral matters, including sulfur component in Miike coal is investigated for getting basic data to produce ultra-clean coal.
50% particle size of mineral matters is 5.4 μm in the Miike coal pulverized to -500μm. Quartz and albite exist mostly in the higher range of specific gravity in coal sample and concentrated in a part of degradinite. In contrast, montmorillonite, kaolinite and calcite exist in the middle and lower ranges. Although, the majority of the former two minerals could be rejected by commonly used physical cleaning methods, it would be necessary to apply some advanced coal cleaning techniques, in order to reject the latter three minerals finely dispersed in coal matrix.
Approximately 1/3 of total sulfur in Miike coal exist in the form of iron sulfide, which is composed of pyrite and marcasite. The iron sulfide particles of +100 μm almost consist of pyrite. The proportion of pyrite/marcasite is 4/3 and 50% particle size of these minerals is 20pm, in the fraction of-50 pm size range, which indicating that the physical cleaning could be applied to reject them with relative ease. Organic sulfur, occupying 2/3 of total sulfur, is uniformly dispersed in coal substance, then it is necessary to apply some chemical cleaning methods for the rejection.

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Manganese dioxide was precipitated by ozone oxidation from acidified sulfate solutions of sulfuric acid concentration ranging from 0.25 to 5.0mol/l at temperature varying from 25 up to 80°C at an ozone partial pressure of the ozone-oxygen mixture gas of 2.8×10^-2 atm. The precipitates were analyzed by X-ray diffraction using Cu-Ka line. The X-ray diffraction patterns consisted of the peaks indicating γ-MnO₂, α-MnO₂ or a mixture of the two, depending on the ozonation conditions. Based on the X-ray diffraction data for 52 MnO₂ -samples, a diagram was constructed to represent the ozonation conditions, the temperature and the acid concentration, for the formation of the individual types of manganese dioxide. At each acid concentration above 1.0mol/l, γ-MnO₂ was found to be an ozonation product below a border-temperature, where a mixture of γ-andα-MnO₂was produced. The border-temperature was gradually descending as the acid concentration was increased. Manganese dioxide of a-type in stead of 7-type was produced in high temperature-acid concentration region.
In the X-ray diffraction diagrams for 7-Mn0₂ formed under varying conditions, a rise in ozonation temperature led to increased intensity and slight shift toward higher angles of the peaks. And an increase in acid concentration gave rise to broadening of the diffraction peakes.
It was also demonstrated in the X-ray diffraction diagrams that the formation of MnO₂ by ozonation was not significantly affected by the presence of zinc sulfate in acidified sulfate solutions having similar composition as the electrolyte solution for zinc electrowinning.

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This paper describes a new practical method for predicting environmental airflow-conditions, such as temperature and enthalpy, in underground ventilation networks. The calculation code “MIVENA” for mine ventilation networks has developed by authors using with a nodal head method and the temperature-humidity prediction method. The equations and schemes fitted to the network calculations are presented clearly as a general form. The system was mostly compared with Amano et al.'s system and differences between two systems are discussed.
The prediction method is that the environmental airflow-conditions on nodes are calculated from inlet nodes to downstream nodes and ones on the fan node can be calculated at last. The environmental conditions of inflow airstream on airways connected to a node are calculated from upstream to downstream with a kind of one dimensional numerical-difference methods by dividing the airways to 5 m long spans before the calculations of the node.
The temperature and humidity on nodes consisting of the recirculation loop can be calculated by using a function which indicate a approximation degree of the calculation result. When absolute humidity in airflow becomes larger than saturation absolute humidity on airways or nodes, the methods and calculation schemes for revisions of temperature and humidity are also presented. These methods are effective for calculations on exhaust airways which are influenced by auto-expansion with temperature reduction.
The present calculation system was successfully applied to the Amano et al.'s network example, the Ezuri Mine and the Fukasawa Mine run by Hanaoka Mining Co. LTD. Fan driving maps for main fans controlled by thylisters, which indicate the total inlet airflow-quantity on several seasons against the thylister frequency, were made to find out the optimum driving thylister frequency on each season.

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Estimation of blasting vibration is important for the safety control in blasting work. In the previous report about the blasting vibration in tunnel excavation, the authors proposed a method to predict the amplitude spectrum of blasting vibration.
In the present paper, a method to predict the maximum amplitude of blasting vibration is proposed. Analyzing the time series of blasting vibration on the basis of the probability, it is made clear that the maximum amplitude of the waveform in time domain can be evaluated from the amplitude spectrum in frequency domain. Since the amplitude spectrum is theoretically calculated by the previously proposed method, the maximum amplitude of the blasting vibration can be also evaluated theoretically. It is shown that the proposed method gives good estimations for the maximum amplitude as well as the power spectrum of blasting vibration in tunnel excavation.

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Pacific Ocean manganese nodules were leached in dilute sulfuric acid solutions using hydrogen peroxide as a reductant. High grade manganese nodules were crushed to minus 200 mesh, and treated to extract metals under the conditions, where pulp density was 1g/l, sulfuric acid concentration ranged from 3.5×10^-3 to 3.5×10^-2 mol/l, hydrogen peroxide concentration ranged from 1.7×10^-3 to 2.6×10^-2 mol/l, and temperature from 30 to 90°C. The results obtained are summarized as follows.
Nickel, cobalt, copper and manganese can be extracted quickly from manganese nodules by leaching in dilute sulfuric acid solutions in the presence of small amount of hydrogen peroxide at a room temperature. The extraction percentages of metallic components depended on both concentrations of sulfuric acid and hydrogen peroxide, and satisfactory extraction was not attained in case of shortage of either concentration of these reagents.
Different from ordinary leaching, the extraction percentages of metallic components decreased with elevating leaching temperature in this method. Under optimum conditions, the extraction percentages of nickel, cobalt, copper, manganese and iron were 100%, 95%, 100%, 100% and 60%, respectively.

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The impact hardness of rock is normally determined by using a ‘Protodyakonov’ type drop hammer. However, this test cannot be applied to a wide range of rocks. Therefore, standardized impact hardness test using the ‘Protodyakonov’ type drop hammer was carried out and the correlati ons of the resulting values of impact hardness with the mechanical properties obtained from usual laboratory tests were investigated.
The results show that the impact hardness has, a generally good correlation with the tensile or the compressive strength of rocks. Therefore, the impact hardness can be used as a strength index in the estimation of rock properties. Moreover, the performance of rock drilling or machine roadway drivage can be predicted using the impact hardness of rock.

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In relation to the production of rare earth-transition metal alloys by the Reduction-Diffusion process, Nd and Sm were diffused into solid Fe to investigate the growth of intermetallic compounds. The diffusing elements, Nd and Sm, were supplied to a polished surface of an Fe block from the vapor phase. As had been expected from the phase diagrams, only the Nd₂Fe₁₇ diffusion layer was obtained for the Nd-Fe system, and the SmFe₃ and Sm₂Fe₁₇ diffusion layers were observed for. the Sm-Fe system. In the case of the latter system, however, the thickness of the Sm₂Fe₁₇ layer alone could be measured because the SmFe₃ layer had grown as an outermost layer and was so brittle that most part of it was lost while the section of the Fe block was polished. In either case, it was shown that the growth rate of the compound was controlled by diffusion. Apparent activation energies were obtained for the diffusion of Nd and Sm in the respective compounds through the Arrhenius plots. The resultant activation energies differed in higher and lower temperature ranges, particularly for the diffusion of Sm in the Sm₂ Fe₁₇ phase, though it is still ambiguous what change in the diffusion mechanism caused the difference.

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