It has been known for a long time that a large quantity of high quality limestone occurs in Tosayama which lies at the central part of Kochi Prefecture along the boundary between the city of Kochi and the village of Tosayama. As for the actual development, a number of problems such as a hauling route of limestone and environmental measure existed. On the other hand, the limestone quarries in the outskirts of Kochi city which have supplied raw material to the lime industry, one of the major industries of Kochi Prefecture, have been gradually depleting their resources, and thus the development of a limestone quarry with a high quality has been an important issue for the industries of Kochi Prefecture.
The Tosayama quarry development group of Taiheiyo Cement Corporation divided the development works largely into two stages. In the first stage of small scale development works, the better understanding of local community on mining operation was gained as the clue for large scale development works of the second stage, and at the same time the various complicated problems such as securing of hauling route, development of hauling technology, and local environment were resolved step by step. During the large scale development works started from 1992 , the transportation route through the mountainous area, urban area, and paddy field was constructed by level excavation with shield driving method at paddy field and adoption of long distance curved conveyor and various tough problems were settled and finally a full-scale operation were achieved in 1997.
After a time over half century since the acquisition of the quarry site, the high quality of Tosayama limestone came at last to be supplied to relevant industries.

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Our production processes are predicated on the concept of inverse manufacturing / designing products from an all-encompassing perspective, from production through to recycling, based on the idea of the inverse factory. Reuse strategies to reduce environmental impact have featured as a core concept of the Fujicolor "QuickSnap" (along with functionality and quality upgrades) since its release in 1986. In particular, the use of recycling-oriented production systems supports the infinite reuse of QuickSnap components and contributes to the product development process.
The three concepts of recycling-oriented production system are as below;
1. "QuickSnap" is recycled to "QuickSnap.
2. Reuse and Recycling from the product design stage onward.
3. Fully-Automated reuse and recycling.

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Uniaxial compression tests, Brazilian tests and fracture toughness tests were carried out on dry and wet specimens of Shirahama sandstone at several loading rates. Effects of water in the uniaxial compression tests were as follows: (1) UCS and Young's modulus decreased by 42 % to 47 % and 42 % to 46 %, respectively; (2) Poisson's ratio increased slightly; and, (3) No obvious effects were observed on the critical strains. Effects of loading rate were as follows: (1) UCS and Young's modulus decreased as loading rate decreased; (2) No obvious effects were observed on Poisson's ratio; and, (3) Critical compressive strain and the absolute value of the critical extensile strain decreased as loading rate decreased. It was clarified in the fracture toughness and Brazilian tests that the fracture toughness / indirect tensile strength decreased by 70 % to 80 % / 52 % to 72 %, respectively, and that a positive linear correlation was observed between fracture toughness / indirect tensile strength and logarithm of loading rate, respectively. Mechanisms of the above observations were discussed based on the breakage of interlocking between such mineral particles as quartz and plagioclase. Breakage of cementing by illite was also considered.

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A scheme to estimate the global stress state from the local stress state evaluated by the field stress measurement is proposed. In the scheme it is assumed that the global stress is expressed by the superposition of the stress induced by the gravity and that by the horizontal movement of the upper crust.
The local stress state in the rock mass under the pit of Torigata-yama open cut mine, located in Shikoku Island, Japan, was measured by the Conical-Ended Borehole Technique. The local stress distribution in Mt. Torigata region was evaluated by the 3-dim. FE-analysis and the global strain and stress states were estimated by the proposed scheme. From the comparison between the local stress states measured and calculated, it is made clear that , in Mt. Torigata region, the stress state induced by the horizontal movement of the upper crust is nearly uni-axial compression and the direction of the maximum compression is ranging from N24E to N27E Furthermore, it is pointed out that the distribution of horizontal stresses are strongly affected by the Poisson's ratio of rock mass and that the high horizontal stress is acting at the floor of excavation of the mine.

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In this study, the behavior of upper and lower (permanent) shear displacements was investigated with cyclic shear loading tests for two kinds of rocks. The behavior of shear displacement obtained in this study may be classified into two processes. In one process, shear displacement is induced mainly by the closure of pores and cracks, the deformation within grains and sliding. In the other one, it is induced mainly by the growth of cracks. In case of neglecting the effect of normal stress, the slope of the equation expressing the relationship between the minimum rate of upper shear displacement and the number of cyclic loading on log-log graph is -1.02 for Kimachi sandstone and -0.92 for Tohoku marble. It is -1.09 for Kimachi sandstone and -1.00 for Tohoku marble when the rate of lower shear displacement is minimum. Upper shear displacement where the rate of upper shear displacement increases rapidly corresponds to shear displacement at the peak shear stress in the convenient direct shear test. Similarly, lower shear displacement where the rate of lower shear displacement increases rapidly corresponds to the permanent shear displacement at the peak shear stress.

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The reduction of the firing temperature for artificial aggregate has merit to decrease production cost.
Relating to the physical properties of fired products, the mixing effect of two kinds of ashes that have different properties and the additive effect of calcium carbonate as a flux were investigated.
As results, the partial replacement of a fly ash that is rich in flux elements to a fly ash that is poor in flux elements decreases the firing temperature to obtain maximum density of the latter one, and the hemisphericalizing temperature of ash compact can be estimated by the replacing ratio. The addition of calcium carbonate to fly ash that is poor in flux is effective to decrease the temperature to obtain maximum density, but not effective to the fly ash that is rich in flux.
The appropriate amount of calcium carbonate addition puts the chemical composition into a eutectic point of a CaO-Al₂O₃-SiO ₂ phase diagram. The species of forming mineral in a sintered body is almost the same as those in the diagram.
Though the strength of aggregates is roughly correlative to specific gravity, in detail, the better shape of bubble and the larger amount of melt phase, the stronger the aggregates.

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Leaching treatment of electrode materials has been studied to recover valuable metals in a used nickel-metal hydride rechargeable battery by a hydrometallugical process on the effects of sulfuric acid concentration, temperature, leaching duration and oxidizing agents (air, O₂ gas, H₂O₂ solution). The positive electrode materials were identified to be Ni(OH)₂ (active material) and Ni (current collector) by XRD analysis, and the active material of negative electrode to be LaNi₅. Leaching behavior was investigated by using positive electrode materials, active material of negative electrode, and reagents such as Ni(OH)₂ and Ni. The nickel hydroxide ,Ni(OH)₂, reagent was easily leached with diluted sulfuric acid, but leaching of the Ni reagent was difficult. Oxidizing agents were however effective in leaching metal Ni. The nickel hydroxide particles in positive electrode materials and the active material of negative electrode could be leached in 0.5 kmol·m^-3 of sulfuric acid solution, dispite no leaching of the current collector in positive electrode materials. The current collector was easily leached by adding oxidizing agents. Both O₂ gas and H₂O₂ solution were found to be effective. A practical process was tested to separate electrode materials from a used battery. The process contained the following treatments; cutting, heat treatment, magnetic separation and screening. NiO which is a product of heating treatment of Ni(OH) ₂ could be leached at a higher sulfuric acid concentration or higher temperature.

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Ferro-Nickel smelting of siliceous nickel ores by the Oheyama Process is carried out in a rotary kiln. Reduced metal in the kiln agglomerates to form particles of 0.5~20 mm in diameter, suspending in a partially fused slag. Although the melting condition of the slag is adjusted by ore blending and addition of limestone, the amount of anthracite in the slag also significantly influences it. The effects of anthracite amount as well as of gas atmosphere on softening temperature of the ores were investigated. The following results were obtained:
(1) The amount of anthracite influences Fe reduction fraction of ore to effect the melting condition of slag.
(2) The shortage of anthracite results in a lower Ni yield due to poorer agglomeration of Ni metals caused by a lack of the reduced Fe metals.
(3) Increasing gas velocity inside the kiln is apt to enhance the solution loss reaction rate by CO₂ in the gas.

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This report is written about the mechanism of making particles in colloidal solution. It was reported, believed that the numbers of nuclei and their growth rate were very important in deciding the process. However, it became clear that the nucleation process was more important for gold particles. The mass balance data of gold was successfully obtained by sedimentation field flow fractionation, and whole gold contents of chloroauric (III) acid became solid particles in the range of our experiment.
Chloroauric (III) acid was supplied to the gold becoming the particles and sodium citrate was a reducing agent. In this case, the numbers of nuclei were linearly proportional to the concentration of sodium citrate and the 2 / 3 power of chloroauric (III) acid concentration.

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Blasting to break the rock and structure using energy of explosive is one of the important operation for civil and mining engineering. In this research some test blasting using high-speed camera, high-speed video and precis blasting system were carried out to study the generation mechanism of fly rock caused by blasting. Seven full scale test blasts in the quarry with different quantities of explosives and burden were carried out to study the flying characteristics of fly rock caused by blasting. DDA (Discontinuous Deformation Analysis) was applied for numerical simulation of full scale blasting. The results are briefly summarized as follows;
1. Initial fracture in the model experiment using the glass material was caused by the Hopkinson effect. The separated fragment, considered as a fly rock, then is accelerated in the direction of a free face by the remained stress.
2. The flight distance of fly rock generated near the minimum resistance line have longer compared with other fly rock in the mortar block experiment. The reason is considered that fly rock near the minimum resistance line was influenced easily by the impact stress and the expansion gas generated by the detonator and detonating fuse. Moreover, it was shown to be able to control the flight distance of the fly rock by applying the precise initiation method.
3. The generation situation and the flying characteristics of the fly rock generated in the bench blasting were clarified from full scale test blasting. Moreover, it was shown that DDA was able to apply for the numeric simulation of bench blasting.

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In designing the long-term stability of deep underground structures in a rock mass, it is necessary to estimate the creep failure time of rocks under confining pressure. In the case of nuclear waste disposal tunnel, the creep failure time should exceed 10,000 years. In this paper, experimental results of tri-axial and multi-stage creep experiments are presented. Both kinds of experiments were conducted under confining pressures up to 40 MPa, including uni-axial stress state. In order to eliminate the loading rate dependency of strength in analysis, the concept of standardized strength is introduced. The Janach's failure criterion was successfully applied to explain the relation between standardized strengths and confining pressures. We introduce a new concept of normalized failure time that is thought to be most substantial value in determining the strength and / or creep failure time of a specific rock specimen. It is shown that the dispersion of normalized failure times, which was estimated from the experimental results, exhibited approximately a Weibull distribution. A conversion formula from normalized failure time to strength and / or creep failure time is presented. Using this conversion formula, we showed that creep stress level should be less than 79 % for survival of 99 % of test pieces after 10,000 years under the confining pressure of 40 MPa. It is also shown that not only the distribution of creep failure times, but also the strength distribution under any loading rate and confining pressure can be calculated from the normalized failure time.

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Double torsion tests in ambient air and liquid water have been used to establish stress intensity factor (K_I )-crack velocity (V ) diagrams for propagation of single tensile crack in dry or water-saturated sandstones, Kimachi sandstone and Shirahama sandstone. The following main results were obtained:
1) All the experimental data for dry specimens in ambient air and water-saturated specimens in water pertain to region I of the typical K_I-V curve, while even region II was clearly observed in K_I-V curve of dry specimens tested in water. The appearance of region was particularly clear in Shirahama sandstone.
2) No stress corrosion limit was encountered in the specimens tested in water even at nearly 20 % of critical stress intensity factor (K_IC ). But, dry Kimachi sandstone specimen tested in ambient air possibly exhibits the stress corrosion limit at nearly 50 % of critical stress intensity factor (K_IC ).
3) The K_I-V data of Kimachi sandstone were used to generate a diagram predicting the influence of strain rate on tensile strength. These predictions were in good agreement with the tensile strength determined by Brazilian experiments in ambient air and liquid water. Both the predictions and the experimental results are consistent with a monotonic reduction in tensile strength as strain rate is reduced from nearly 10^-2 s^-1 to nearly 10^-8 s^-1.

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In this paper, a newly developed double packer was introduced. In hydraulic fracturing operation, an opening and closing behavior of a fracture was related to in-situ stress state. A purpose of the new packer was to measure the fracture opening directly. The new packer consisted of two co-axial pipes that move independently. As sealing elements were fixed to each of two pipes, fracture opening could be measure by relative displacements of two co-axial pipes. Two types of sealing elements were examined. One was a rubber and the other was lead. The former was named rubber-seal packer, and the latter is named metal-seal packer.
A conventional double packer, the rubber-seal packer and the metal-seal packer were used in the Kamioka mine in 1998. In this mine, a hydraulic fracturing experiment in order to estimate in-situ stress was done using a borehole that was drilled horizontally from a gallery in 1996. The newly developed packers were used to re-open the pre-existed artificial fracture.
The result of the metal-seal packer experiments showed that relative displacements of two co-axial pipes had a good correlation with the wall expansion that was measured at vicinity of the borehole. It became clear that the metal-seal packer was possible to measure the fracture aperture directly. The shut-in pressure, that is thought to be equivalent to a magnitude of normal stress component, was estimated from the relative displacements of two co-axial pipes. This shut-in pressure estimated from the metal-seal packer agreed well with those from the Muskat method and Hayashi & Haimson method.

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