Oxides are classified into four types in terms of ionic radius and electric negativity for designing multicomponent oxide materials. The properties of molten oxide, e. g., slag, flux, and glass are determined by the activity of oxygen ions, whose volume fraction is near 50% in oxides. The activity of oxygen ions is quantified based on basicity. A calculated basicity parameter for multicomponent oxides is proposed using coulomb force between the cation and the oxygen ion. The valencies, oxygen-coordinationnumbers of metal ions and the polymerization degree of silicate anions in crystalline and vitreous oxides are disscussed using the basicity parameter.

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For the life cycle assessment (LCA) of coal, the authors investigated the life cycle inventory for coal mining in Japan. All energies, materials, equipment and facilities used for the coal production are listed for the assessment.
As the results, 109kg of CO₂ and 15.7kg of CH₄ are emitted par 1 ton of clean coal output. 92% of the total CO₂ emission is generated by the process of the production of energies needed for coal mining. CO₂ emission by the production of the materials used for the coal mining is about 7% of the total CO₂ emission. CO₂ emission by the production of equipment and facilities for the coal mining is less than 1% of the total CO₂ emission each.
For the reduction of the CO₂ emission, improvement of the efficiency of the domestic power generation by each colliery is essential.
By comparison with other countries'CO₂ emission data and transportation process, CO₂ emission from coal mining in Japan is almost as same level as main coal producing countries'emission.
Considering the higher global warming performance of CH₄ compared with CO2 and the emission volume of CO₂ and CH₄, the results of our investigation show that CH₄ gives larger effects for global warming than CO₂. Japan is facing difficult stage to reduce the amount of CH₄ emission. International co-operation to overcome the problem is important and urgent to prevent global warming.

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Evaluation of size distribution equation was carried out by eliminating some data that were obtained from a heap created along artificial and practical slopes, which has given the following results.(1) Simple sampling method from a heap becomes suitable when parameters of distribution equation are calibrated.(2) Deviation of rock size of 0.01% oversize estimated from calibrated distribution equation is 1.3-1.4 times larger than those estimated from distribution equation of feed.(3) This simple method is suitable to a practical heap in the field.(4) Size distribution equation can be used to estimate the maximum size of rocks under small probability by extending the distribution line.

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In Akabira Colliery, a decision was made to change the angle of influence for the cone-shaped shaft pillar from 60° to 80° in 1985. Mining in the former pillar areas started in 1986 and 2.2 million tons of coal was safely extracted before the mine closure in 1994.
Damages have been induced in four levels along the concrete block-lined shaft having length of 680m. It was concluded through observation of lining, monitoring of displacements along the shaft axis and three dimensional elastic stress analysis that the main factors which induced the lining damages are (1) fault slips due to increase of shear stress, (2) increase of vertical stress component or decrease of minimum principal stress in the horizontal plane and (3) stress concentration around roadways connecting to the shaft.
A consideration on a reasonable monitoring scheme for shaft damages was also shown.

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An orthotropic elastic spherical shell model has been presented to analyze the initial stress which varies with the location and with the depth below surface. The theory and the procedure to compute the vertical stress, the maximum horizontal stress and the minimum horizontal stress have been discussed as well as the necessary condition in which the analysis agrees with the measurement. The average horizontal stress is firstly investigated, and it has been shown that the distribution of the average horizontal stress with the depth is deeply depending upon the relation between the mean Young's modulus and the mean normal stress. Secondly, the ratio of the maximum shear stress in the horizontal plane to the average horizontal stress is analyzed and compared with the 83 measurements by means of the stress relieving method, and it has been concluded that the ratio is a function of the absolute of the vertical stress deviation. Finally, the case example shows a close agreement between the present analysis and the in-situ measurement by means of the compact overcoring method.

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A new three phase equation to explain the effective thermal conductivity of moist rocks has been derived by analyzing data obtained with eighteen kinds of porous rocks at various moisture conditions. The equation is mathematically based on the weighed geometric mean, and it is modified to take into account the effect of porosity.
In the equation derived, the effective thermal conductivity of the porous rocks is expressed as a function of the thermal conductivities of solid, liquid and gas and their volume fractions in the rock. Validity of the equation and degree of the influence of the affecting factors to the effective thermal conductivity of the three phased material have been also discussed.
The equation correlates the experimental data within ±22% in accuracy. When the effective thermal conductivity, porosity and water content of a certain rock at only one condition are known, the effective thermal conductivity of the rock at other various moisture conditions may be estimated using the equation.

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In the development of a continuous decomposition process of rare earth ores, the decompositionrate of bastonaesite by the alkaline hydro-thermal reaction was measured at 373-723K. The reaction was described by the dissolving core model. The apparent reaction rate constant, k', was proportional to the 3.9 power of NaOH concentration, which is given by the following equation.k'=2.79×10⁷·exp(-1.41×104/T)·C^3.9_NaOH

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There were mainly zinc and manganese as metal components in the roasting residue after the removal roasting of mercury from the used battery scrap. The recovery of zinc from the residue was studied. It was identified by X-ray diffraction that zinc was as ZnO and manganese as MnO and Mn₃O₄. The zinc and manganese completely could be dissolved by the leaching with the sulfuric acid solution keeping at pH 1. Because the pH range that zinc sulfide is stable is thermodynamically lower than that for manganese sulfide, the separation and recovery of zinc from the filtrate of the leaching solution was carried out by sulfide precipitation. However, even if in the sulfurization at a low pH, a small amount of manganese deposited with zinc. It was considered that the deposition of manganese was not sulfurization but coprecipitation.
Based on these fundamental experimental behaviors, the combination of the leaching with the sulfuric acid and the deposition by sulfurization was assumed as the treatment flow of the roasting residue. In the flow, 95% of zinc may be recovered as sulfide and the contents of zinc and manganese in the sulfurized deposit may be 62.5% and 3.7% respectively. Therefore, it may be considered that the sulfide could be utilized as the raw material of usual zinc extractive metallurgy.

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The production of fine gold powder with controlled particle size and shape is essential for electrical applications. In this study, the reaction mechanism of gold formation and the morphology of gold particles were investigated in order to establish the reduction of HAuCl₄ solution using Na₂S0₃ solution or SO₂ gas.
The experiments were mainly carried out at the concentrations of HAuCl4 solution ranging from 0.2×10^-3 to 0.01kmol·m^-3, at a pH from 0.5 to 10.0, and at room temperature or 343K.
When the Na₂SO₃ solution was added to the HAuCl₄ solution, the mixed solution rapidly changed from yellow to colorless solution. Afterwards, gold powder was produced at a pH below 3. It was considered that colorless Au (SO₃) ^5-₄ was produced by generated SO₂ in the mixed solution and its ion turned into Au⁰ at low pH.
In the reduction experiments using babbled SO₂ gas, the concentrations of AuCl₄^-, Au (SO₃)^5-₄ and Au⁰ vary with reaction time. The reaction curves suggested that the reaction progressed as an irreversible consecutive first-order reaction, as follows: AuCl₄-k1→Au (SO₃)^5-₄k2→Au⁰ (k1, k2: rate constant)
Based on the consecutive reaction model, the changes in the concentrations of the reactant and products were calculated with the reaction time. The calculated results using k1=0.028 sec^-1 and k2=0.019 sec^-1 agreed well with the experimental data.
According to the SEM observation and the analysis of particle size distribution, it was found that the gold particles formed by the Na₂S0₃ solutions were spherical at low pH and showed high dispersivility at high concentration of Na₂S0₃ and smooth surfaces at high temperature.

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The preparation of ferrite particles from Fe (OH)₂ aqueous suspension is studied in high temperaturehydrothermal condition accompanied with the Schikorr reaction. The well crystalized magnetite particle grew in larger size in this reaction system, compared to the usual co-precipitating or wet-oxidizing methods.
The addition of KNO₃ as an oxidizing reagent prior to the hydrothermal treatment was useful to control the nucleation of magnetite and this led to reduce the particle size. The addition of excess amount of KNO₃ led to hematite formation.
When Mn²⁺ or Ni²⁺ ion was mixed in starting ferrous solution, respective ion partially entered into spinel phase. In this case, manganese or nickel ferrite with stoichiometric composition was not obtained and the maximum value of x in the M_xFe_3-xO₄ (M: divalent metal ion) seemed to be 0.4 for Mn, and very small for Ni. The amount of H₂ generated during the reaction decreased by adding Ni²⁺. Also, Ni metal phase was observed by XRD in the series of Ni adding experiments.
Although, when KNO₃ solution was added into the starting solution, Mn²⁺ or Ni²⁺ were easily incorporated into the spinel phase to give respective stoichiometric ferrite.

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