The present situation of copper heap leaching is reviewed in this paper. Current techniques for improving copper extraction from sulfide ore are also discussed. Morenci mine (Arizona) has expanded its cathode copper production by the leaching-SX /EW process in parallel with the conventional flotation process since mid eighties. In March 2001, Morenci mine completed "Mine for Leach" project including closure of the concentrators and expansion of cathode copper production with a newly equipped crush-leaching system. Technical background of the conversion is discussed with efforts to improve metallurgical performance at the Morenci concentrators during last 10 years. Extraction of copper from sulfide ore is mainly decided by copper mineralization of the ore at the leaching-SX / EW process. One of the factors that made the conversion feasible at Morenci mine was chalcocite rich mineralization of the ore. Improvement in dissolution of chalcopyrite will be one of the biggest issues for future expansion of the heap leaching-SX / EW process.

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Geostatistics have been widely used for regionalized geologic data having spatial correlation structures. In some cases, these structures cannot be clarified by a semivariogram due to limited data and/or complexity of the data distribution. We applied a feedforward neural network to such kind of problem by choosing chemical content data in a kuroko-deposits area in the Hokuroku district, Akita prefecture in northern Japan as a case study. The content data of multiple chemical components were collected from 1917 sample points at 143 drillhole sites. The network structure consists of three layers: input, middle, and output. Input data of the network are coordinates of a sample point, Bouguer anomaly (gravity anomaly), and rock code. Contents of principal metals of kuroko, Cu, Pb, and Zn, and value of alteration index are estimated through the network. Numbers of neurons in the middle layer and training data vary with the location to improve the estimation accuracy and avoid overtraining of the network. Suitable numbers of neurons and training data were determined by repeating jackknifing at each point. Three-dimensional distributions of Cu, Pb, and Zn were successfully estimated by the proposed method, as shown by anomaly zones localized near the known kuroko deposits and the margins of depressions or uplifts in Pre-Tertiary basement rocks. Using the weights connecting adjacent neurons, sensitivity analysis of the neural network was carried out. Influence factors were obtained in this analysis to clarify geologic factors that affect the distributions of Cu, Pb, and Zn contents. Depth, the dacite in the middle-upper Nishikurosawa geologic stage, and Bouguer anomaly were found to be influenceable factors. Sensitivity vectors were also calculated through the analysis. Large vectors point toward anomaly zones near the kuroko deposits and express the anisotropy in the local distribution of the sample data. It is proved by semivariogram that the data have spatial correlation along the dominant direction of vectors. The sensitivity vector map contributes to infer flow paths of hydrothermal fluids that contained the sources of kuroko ores.

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The Hishikari Gold Mine has met a new challenge in choosing a mining method for the Keisen vein group in the Sanjin deposit. The deposit mainly consists of 2 veins. The KE-2 is a composite vein, extending over a width of a 15m, with an average grade of 20 g / t. The KE-3 has a 2 m width and a very high grade of around 100 g / t. They are too closely spaced to be extracted selectively by employing the conventional Hishikari mining method of bench stoping. Consideration was given on alternative mining methods in order to extract these veins efficiently. A modified bench stoping method with a larger width appeared to be economically feasible, but would involve stability difficulties due to increased stoping width. Numerical and empirical analyses were used to determine an appropriate mining sequence and stope dimensions. Numerical analysis was performed using a two-dimensional elastic-plastic finite element code. The results indicated that a conventional mining sequence caused increased stability issues. The "Stability Graph Method", which is a well known empirical approach, led to a new mining sequence and cable bolting patterns, which allowed improved stope stability and efficient mining of Keisen veins. Numerical analysis was also used to establish the dependence of stope stability on the properties of backfill materials.

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Much of high level coal mining technologies has been accumulated for over 100 years under high temperature, high pressure, gas and water emission and complicated geological conditions in Japan. Those technologies which have been developed based on safety concept consist of many elemental technologies such as exploration, extraction, support, transportation, ventilation, drainage, prevention of mining pollution, quality control, information technology and so on. The author has intended to apply those technologies to civil underground industries, especially targeted the mine ventilation technology, which developed for underground coal mine and reconstructed as "ventilation and disaster prevention technology".
In this paper, differences between mining and underground civil construction technologies have been discussed and some examples of this technology applied to civil construction field have been presented. Furthermore, large potential of this technology to wider underground industry and its problems have been summarized. The targets to be expanded field will be underground public construction such as shopping center or underpass, where unspecified people pass, dust control in the Geo-Space, and near future, surface construction such as dusty casting factory as semi-closed ventilation circuit will be focused. In those fields, handy CFD program and combination with ventilation network analysis will be required.

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Auxiliary ventilation is required to remove dust and gases generated at heading faces in underground coal mines. Currently, quantities of dust and gases are increasing due to high development rates and large cross sectional areas of the roadways. Combined ventilation system is being adopted in order to remove such dust and gases more efficiently. The optimum design of the location of ventilation ducts and of airflow volume is very difficult. The flow pattern in the surrounding face of roadway in the coal seam by using combined ventilation system is very complicated.
The authors have investigated the airflow patterns in combined ventilation system and the behavior of methane gas by visualization experiment with reduced scale models. This paper discusses the results of the examinations on optimum ventilation conditions to remove effectively methane gas generated in the heading faces where a cutting machine is working. During the experiment, additional forcing duct is set up with a view to preventing methane gas from concentrating at the overlapped zone and the effect of the forcing duct is investigated.

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A displacement monitoring system has been developed using the Global Positioning System. It has been applied to large slopes of limestone quarries, landslide slopes to monitor the slope stability. The system can measure the three dimensional displacements continuously and automatically. The accuracy of measurements is beyond the standard one of the GPS by applying the trend model to the measurement results.
This paper focuses on two topics. One is long-term continuous monitoring and the other is monitoring under the condition of the high height difference between the measurement points. The errors and the periodic characteristics of the measurement results are discussed through case studies. And then the standard deviation is shown in the relation to the distance and the height difference between measurement points. It will be available for planning the displacement measurement using GPS.

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It is well known that granite has orthorhombic elasticity caused by the orientation distribution of the pre-existing microcracks. Measurements of P and S-wave velocities propagating in various directions are indispensable to determine these elastic constants, because the orthorhombic material has nine independent elastic constants.
In this study, a new method to determine the elastic constants of granite is proposed. In this method, rock is assumed to be an elastic material which contains oriented cracks and random distributed cracks, and the effective elastic constants of rock are calculated by using New Self Consistent Scheme. From the calculated elastic constants, theoretical values of the elastic wave velocities are calculated and compared with measured values of them. The elastic constants can be back-analyzed by minimizing the difference between theoretical wave velocities and measured ones.
The proposed method is applied to three kinds of granite. It is confirmed that the theoretical values of wave velocities agree well with the measured values, and that the elastic constants as well as the crack densities can be evaluated. Furthermore, it is pointed out that the elastic constants of granite can be evaluated by measuring P-wave velocities in three principal directions.

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In Ground-Coupled Heat Pump (GCHP) systems, the thermal conductivity enhancement of grouting materials in heat exchange wells increases the heat exchange rate between formations and boreholes and hence greatly contributes the improvement of feasibility of the systems. In this paper, series of laboratory measurements were conducted to develop highly thermal conductive cement mortars to be used as grouting materials. Silica sand was mixed with cement paste for increasing the thermal conductivity, while bentonite was added to the mixture of cement and silica sand for establishing a uniform distribution of silica sand in the grouting materials. In the measurements, the relationship between the thermal conductivities of mortar samples with different recipes on silica sand / cement ratio, cement specific gravity, and bentonite mixture ratio were investigated under water-saturated conditions. After thermal conductivity measurements, permeability measurements were conducted to confirm the impermeable nature of the mortar samples. Viscosities of mortar pastes were also measured to confirm the easiness of grouting operation in well completions. The experiments showed (i) addition of silica sand greatly improves the thermal conductivity of grouting materials, (ii) addition of bentonite of 1.5 to 2.0 % (wt% to cement) maximizes the effect of silica sand, (iii) the permeability grouting materials proposed in this work was low enough to avoid any cross flow between aquifers.

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The aim of this paper is to derive a simple expression of the Reynolds number and an estimation method of the lower critical Reynolds number for the pseudo-plastic fluid flow in concentric annular tubes assumed the model of drilling mud flow in a well, because interpolation methods are used in the calculation of the Reynolds number and the theoretical estimation methods of the lower critical Reynolds number are needed.
Based on the theoretical function for the pseudo-plastic fluid flow given by Fredrickson and Bird(1977), the simple expression for the Reynolds number is obtained as Eq.(20) that is capable of estimating the theoretical value of one within 2% error at any rheology constant values where the values of the pipe diameter ratio are more than 0.2, and zero.
The estimation method of the lower critical Reynolds number by applying the flow stability parameter given by Masuyama and Kawashima(1977) is shown as Eq.(32) and Eq.(33). When the reciprocal number of the rheology constant is positive integer, the analytical solution of Eq.(32) is derived and shown as Eqs.(A-4) to (A-12) in the appendix. It appears from the comparison of experimental and predicted lower critical Reynolds numbers for pseudo-plastic fluid flow in concentric annular tubes that the estimated values show agreement with the experimental ones within 20% error.

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In hydrothermal treatment Cryptomeria Japonica (gymnosperm) was treated at temperatures of 270-330 °C in the presence of liquid water for 30 minutes using an autoclave of 10 L capacity. The solid product having heating values of 7,000-7,200 kcal / kg (dry basis) was obtained at yields of 48-55 %. The FT-IR, proximate and ultimate analysis results of this solid product were similar to those of the solid product obtained by hydrothermal treatment of Acacia Mangium (dicotyledonous angiosperm) reported in our previous paper. The liquid product is composed of mainly methyl alcohol, acetic acid, phenolic compounds such as catechol and guaiacol. It doesn't have 2,6-dimethoxyphenol which is in the liquid product obtained by hydrothermal treatment of Acacia Mangium.
The liquid product from hydrothermal treatment of Cryptomeria Japonica and Acacia Mangium were studied for their ability to reduce Cr(VI) to Cr(III) under pH2 and time exposures of 15 minutes. These results showed that the liquid products have the ability for the reduction of Cr(VI) to Cr(III) because of its components such as catechol and 2-methoxy-4-methyl-phenol which are essentially the phenols with electron-donating substituents. The reduced Cr(III) was removed by precipitation from the solution using CaO or Ca(OH)₂.

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The density, surface tension and viscosity of the (50-X)BaO-XZnO-50P₂O₅ (X = 0, 10, 20, 30, 40 and 50 mol%) glass melts have been measured over the range, 1,073 ∼ 1,623 K. The effects of ZnO on these properties have been investigated. The density of the melt was found to decrease with increasing ZnO content. The surface tension decreased with increasing ZnO content up to 30 mol% ZnO, and showing constant value at over 40 and 50 mol% ZnO in the temperature range of 1,323 ∼ 1,573 K.
The features of ZnO rich glass melts (X = 40, 50), that is high values of viscosity, and anomalous variation of surface tension, are related to the small oxygen coordination number of the Zn cations ( = 4) when compared with those of BaO rich glass melts (X = 0-30).

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We have developed the geo-environmental risk assessment model for heavy metals, which are considered both soil properties and exposure factors specific to Japanese situations. The exposure rates, the distribution of exposure paths and the risk level of soil content to the human have been evaluated by using this model.
Since the Japanese soil have the specific properties, i.e. high pH, high fraction of organic carbon content and high fraction of clay content, it is difficult to transport into the groundwater and the crops in comparison with other kinds of soil. The exposure rates of children are higher than those of adults. Especially, infants aged 1 to 2 are much exposed to the heavy metals. The major exposure paths of the human are different due to the kind of heavy metal. The human are mainly exposed to lead and chromium from direct ingestion of soil, whereas they are mainly exposed to selenium and cupper from intake of drinking water. The soil contents of exposure limit are estimated at 37 mg / kg for arsenic, 26 mg / kg for cadmium, 620 mg / kg for chromium, 4,600 mg / kg for cupper, 4.0 mg / kg for mercury, 120 mg / kg for lead and 1.6 mg / kg for selenium.

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