Laboratory measurements on coal matrix swelling were carried out during CO₂ injection, by monitoring strain and P-wave velocity changes. Cylindrical Coal samples were drilled from large blocks collected from Kushiro Coal Mine, Hokkaido. Fractured and intact samples were used to investigate swelling behaviors and its effect on permeability, respectively. Swelling strains are much larger due to CO₂ adsorption compared to N₂ adsorption at the same coal sample. Results of the intact coal sample show that the sample permeability decreased by about 50% associated with CO₂ adsorption. Both P-wave velocity and amplitude increased significantly caused by the coal matrix swelling. Our results suggest that coal matrix swelling due to CO₂ adsorption caused cleat closure and the cleat closure reduced coal permeability.

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In this study an arsenic plate adsorbent was prepared in two stages. Initially a Fe(III) bearing high molecular solid particle adsorbent was made from a ferric salt. Finally the solid particle was evenly spread on a plastic plate by using a special treating process to become an arsenic plate adsorbent. The mechanism of arsenic adsorption on this adsorbent is a kind of ion exchange process. It can adsorb both arsenic(III) and arsenic(V) from the wasted water. The arsenic removal was about 99%. In a solution contains 20mg/L arsenic at pH6. 99% of arsenic was removed in 2 hours by a l0g/L solid particle adsorbent and the final arsenic concentration was reduced to below 0.05mg/L arsenic. Furthermore, it was found that the re-adjustment of solution pH and temperature might cause the elution of arsenic and let it return back to the solution. The activity of the adsorbent was not reduced after elution. Thus, it can be re-used several times without producing the contaminated mud. The cost of the contaminated mud treatment can be reduced or completely avoided. The recovery and recycling of arsenic metal for re-use are feasible. Under the condition of high alkali solution (pH13), 363K and 2 hours, a plate adsorbent was re-used for five cycles with the arsenic elution was 80-99%.

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Column leaching experiments for two chalcopyrite concentrates agglomerated on supporting particles were performed with sulfuric acid solutions under various conditions. The results of the column leaching were compared to results of shaking flask leaching experiments reported previously.
Factors such as solution composition, coexisting minerals like pyrite, and presence of iron-oxidizing bacteria affected chalcopyrite dissolution, causing a significant variation in the copper extraction fraction vs. time plots. However, copper extraction rate from unit surface area of chalcopyrite could be determined simply from the normalized redox potential proposed previously, a function of the ferric, ferrous and cupric ion concentrations. The copper extraction rate vs. normalized potential plot for the column leaching data fitted well with the plot obtained by shaking flask experiments, and the copper extraction rate has a maximum at normalized potentials of 0.4 to 0.5. These results suggest that the normalized potential could be used to assess and optimize chalcopyrite leaching with different methods and under various conditions.

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Needle-like nickel powder with high aspect ratio was synthesized by the thermal decomposition of the precursors consisting of nickel ammine oxalate precipitated from aqueous solution. Nickel precursors of c.a. 1 μm in length and 50 nm in width were obtained by falling two solutions in drops simultaneously into distilled water at pH 9.5. One is a solution containing nickel chloride hexahydrate and ammonia, and the other is a sodium oxalate solution. The morphology of particles changed from granular to needle-like with the increase in pH. Large and size-dispersed needle-like particles were obtained at 363 K. The shape of metallic nickel particles changed from needle-like at 613 K to chain-like at 673 K depending on the heating treatment temperature of nickel precursors.

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The characteristic temperatures and structure of BaS-Ga₂S₃-GeS₂ (BGGS) glasses in a series of (100-x)[65BaS-35Ga₂S₃]-xGeS₂ in molar ratio are studied. Glass samples were prepared by a melt quenching method using vitreous carbon crucibles in an inert atmosphere and using vacuumed silica ampoules. Variations in glass transition temperature T_g and onset of crystallization, T_x, with GeS₂ concentration are evaluated. The addition of GeS₂ enhances the thermal stability evaluated by the temperature difference of T_x-T_g. Raman spectroscopy suggests that mixed-anion networks of GaS₄ and GeS₄ with the possibility of GeO₂ quartz structure for an impurity are formed, which contributes to a good thermal stability of these glasses with T_x-T_g >200°C. The BGGS glass fiber with an optimized composition could be continuously formed.

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