The present environmental problems, such as global warming, toxic chemicals and waste recycling, have the distinct feature that their impact is global in the world and lasts well into the future. The focus of the measures for the waste recycling problem has shifted from the specific industrial activities to our ordinary lives. In the past, the main measure for waste problems was the regulation for specific factories. However, presently, in the new concept, it has become a general opinion that we should review not only industrial activities, but also ordinary life styles and the role of government. In Japan, this new concept is called “Establishment of Recycling Society”. Japan is intending to shift from the former 1R (Recycle) policy to 3R (Reduce, Reuse, Recycle) policy, in other words, to focus on not only recycling waste but also not producing as much waste by means of waste reduction and re-use of waste.
In this paper, reviewing the current status of Japanese waste problems, the Japanese policy and specific approach for the establishment for recycling society is considered.

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Cobalt-rich manganese deposit (CRMD) have a significant advantage of developing projects, when they can be separated the metal-bearing crust from the accompanying rocks by introducing the mineral processing. Using the mineral processing experimental data given by the Deep Ocean Minerals Association (DOMA), the authors evaluated the cost of the total system for CRMD development.
We tried to elaborate an economic improvement in considering influences upon the system combination and the apatite / basalt ratio contained in basement rocks. Comparing further the respective economic evaluation, we could obtain the profit and loss curve for a promising CRMD condition.
As a result, an optimized development method was proposed as follows: it was to use robotic miner for mining, gravity concentration for mineral processing and smelting and chlorine leaching process for metallurgical process in the Co : 0.41 %, Ni : 0.35 %, Mn : 14 %, Cu : 0.07 % overgrade basaltic sites.

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The permeability of a fracture may decrease with time due to time-dependent closure under in-situ normal stress. Estimation of the long-term permeability of a fracture is necessary for designing facilities for nuclear waste disposal and geothermal energy extraction. In this study, by using specimens of a hollow cylinder, which contained a hydraulic fracture perpendicular to the axis, the changes with time in the closure and permeability of the fracture under constant normal stress were measured for normal stresses of up to 25 MPa for granite and up to 15 MPa for sandstone. The power spectral density of the aperture showed that the fractures used in this study had the surfaces strongly correlated to each other. Main results obtained in this study were summarized as follows:
1) The time-dependent closure increased to be constant at 50 to 70 hours for the both rocks. The ultimate time-dependent closure did not depend on the normal stress when the elastic closure curve obeyed the Goodman's formula as for granite, while it increased with the normal stress when the elastic closure curve did not obey the Goodman's formula as for sandstone. The difference in the elastic closure curve between the two rocks was due to that in the increase rate of the contact area, which was related to the initial part of the cumulative probability distribution function of the aperture.
2) The hydraulic aperture decreased with time to be constant at about 50 hours for the both rocks. The hydraulic aperture was very small, 2.2 to 3.5 μm after the elastic closure and was finally 1.3 to 1.8 μm. The larger the initial hydraulic aperture was, the more the hydraulic aperture decreased with time. The ultimate hydraulic aperture was 40 to 75 % of the initial value.
3) The hydraulic aperture did not decrease according to the Darcy's law with the time-dependent closure for the both rocks. The decrease in the hydraulic aperture was small in comparison with the increase in the time-dependent closure. This was because the fractures used in this study were all well mated and, accordingly, the contact between the two fracture surfaces was developed well.

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For the safety of the transportation system of a slurry pipeline, it is very important to catch the behavior of the flow in the pipe. Hydraulic pressure, mean velocity, and delivered concentration are, in general, measured for monitoring the settling slurry flow. However the flow patterns in the pipe at any moment can not directly be shown with these data. A video camera system for the monitoring is probably not useful for the opaque pipelines, or even the pipelines with transparency parts, because the flow becomes muddy under practical transport conditions.
In this study, we provided a method for predicting the solid particle motion and the distributions of in-situ concentrations of the solid based on collected measurements. The method was capable of displaying the flow modes on a monitoring screen by using the random model associated with the concentration distribution of solid particles. Comparison of predicted and experimental images indicated that the proposed system was effective for monitoring solid-water mixture flows.

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The effect of capillary suction potential on the agglomeration of coal in water was investigated at various concentrations of added surface active agent and addition ratios of bridging liquid. Agglomeration was carried out by injecting castor oil as a bridging liquid into the suspension, which consisted of disperse medium and ground coal. An aqueous solution of 10^-2 mol · l^-1-NaCl was used as the disperse medium, and sodium oleate was added to the solution as an additive surface active agent. The main results of this work are as follows:
1) The addition of sodium oleate to the disperse medium modified both the contact angle of the bridging liquid on coal particles and the interfacial tension between the bridging liquid and the disperse medium and therefore affected the agglomeration phenomena.
2) The equilibrium agglomerate diameter increased as the capillary suction potential increased. Based on a model in which the equilibrium agglomerate diameter is determined by the balance between the cohesive force caused by capillary suction potential and the destructive force caused by agitation, an empirical equation to determine relationship between the equilibrium agglomerate diameter and the cohesive force was obtained.

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The air separation of PET and PVC was carried out by taking advantage of the different crushing resistance of two plastics. PET bottles and a sheet of PVC (0.5 mm in thickness) were shredded to small square pieces (5 mm × 5 mm). Both shreds were treated with a shear-type crusher. The PET shreds were bent and twisted by the crush so that they were blown up easily, but the PVC shreds were not. After the crushing for 90 sec, 100 % of the PET shreds were blown up at the air flow rate of 3 m/sec whereas the PVC shreds were not. The increase in initial shred size of PET up to 14 mm × 14 mm resulted in increasing the yield of PET at low air flow rate.

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Restoration of contaminated soils to an environmentally acceptable condition is important. Various methods currently used have advantages and limitations in remediating contaminants in soils. In fact, most successful in-situ remediation technologies are restricted to soils with relatively high hydraulic conductivity so that they can not be used for fine-grained deposits. One of the newer techniques in soil remediation is a method based on electrokinetic phenomena in soils. Electrokinetic soil remediation is an effective in-situ separation and removal technique used for extraction of heavy metals and some organic compounds from fine-grained soils. The technology uses electricity to affect chemical concentrations and water flow through the pores of soils.
In the present study, the distributions of cadmium in the electrokinetic processing of kaolinite under the condition of constant applied voltage and pH of cathode reservoir kept at neutrality are predicted using a theoretical model that incorporates equilibrium chemistry and the results are compared with experimental findings. The results obtained in this study are summarized as follows:
The pH was reduced to the strong acidity throughout most of the soil with an increase in the processing time. Cadmium migrates toward the cathode without accumulation of cadmium near the cathode and is successfully removed at the cathode reservoir. From experiments, it was also found that the progress of electrokinetic processing of cadmium could be grasped to a certain extent by monitoring the local voltage and the current density.

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This paper describes a new bacterial strain which is able to efficiently oxidize arsenite (As(III)) to arsenate (As(V)) in diluted ferrous ion-free 9k medium. The bacteria were isolated from a mine drainage containing arsenic using an arsenite (about 200 mg/l)-containing 9 k medium agar plate. The Bacteria were gram-negative and rod-shaped (0.8 ∼1.4 μm). The oxidation rate of arsenite depended on the cell concentration. Arsenite was oxidized in the pH range from pH4.2 to pH7.5, but the bacteria did not oxidize arsenite below pH3.0. The bacteria derived the energy for the growth from arsenite oxidation and the growth was enhanced with yeast extract.

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Phase equilibria and activities of the components in the liquid lead-antimony-oxygen ternary system have been investigated at 1,173 and 1,223 K to discuss the recovery of lead and antimony from an used lead-battery thermodynamically.
The two liquid phases of metal and oxide were observed at the temperatures studied, and the tie lines indicating isoactivities were determined. The activities of PbO, SbO_1.5 and Sb₂O₃ in the PbO-SbO_1.5 and PbO-Sb₂O₃ pseudo-binary systems were then calculated by applying the Gibbs-Duhem equation to the phase relation of metal-oxide equilibrium. Both in the pseudo-binary systems the activities exhibit negative deviations from Raoult's law. The vapor pressures of lead, antimony and lead oxide, antimony oxide were calculated by using the activities of the components in the lead-antimony-oxygen ternary system. As a result, an oxidation of antimony in the anode slime concentrated from an used lead-battery followed by evaporation as antimony oxide (Sb₄O₆) was found to be considerably effective for the recovery of lead and antimony.

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Ignition temperature was measured for five kinds of copper concentrates in air and pure oxygen gas flows. In the air oxidation, no significant difference was observed in the ignition temperatures for the concentrates. In contrast, the ignition temperature in oxygen flow depended on the kinds of major minerals contained in respective concentrate. The ignition temperature increases when the concentrate contains higher quantity of Cu₅FeS₄ or FeS that have lower dissociation pressure than CuFeS₂. However, the concentrates mainly composed of Cu₉S₅, that has a lower pressure of sulfur than CuFeS₂, or FeS₂ exhibited the lowest ignition temperature. This suggests that Cu₉S₅ in the concentrate may have a composition of high sulfur pressure, because the dissociation pressure of Cu₉S₅ changes significantly with minor variation of its composition.

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