Focusing on the desulfurization of high-sulfur coal for clean energy processdevelopment, we aimed to amalgamate the separate information relevant toeach field of coal geology and chemistry with chemical reaction engineering intoan integrated concept for efficient and earth-friendly process development incoal utilization.
Review was firstly on sedimentological interpretation of the total sulfurcontent and the distribution of sulfur forms in coal, then our early works forestablishment of the sulfur-forms analysis and formulation of a kinetic modelof desulfurization. Following review of the basic aspects of researh, we presentdata by rapid (hydro) pyrolysis, using a free-fall pyrolyzer, which examinedthe efficient performance of desulfurization of organic sulfur. A series ofstudies elucidated that proper selection of the operational conditions was possiblefor an effective means of desulfurizing organic sulfur which was resistivein conventional slow-heating treatments.
For the desulfurization process development in general, precise analyticaldata on coal, especially the forms of sulfur, are needed not only from chemicalbut also from geological view point, combined with precise processing data onphysical separation efficiency and pyrolysis which will be related to gasificationand combustion processes to follow.

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Behavior of structural defects in bulk GaAs during various heat treatmentprocesses was investigated. Results showed that the formation temperature ofAs-related dislocation loops and precipitates in an As-rich HB (HorizontalBridgman) GaAs is around 650°C, and their formation process is reversible andcritically affected by the cooling rate of crystals from high temperature. Inthe case of LEC (Liquid Encapsulated Czochralski) GaAs, precipitates formedon dislocations at the temperature range of 650°C-950°C, whereas point defectcluster around dislocations formed at 650°C-850°C. Based upon this observation, it was proposed that the excess As existing in GaAs crystals condenses as pointdefects, dislocation loops, and/or As precipitates, depending upon cooling ratefrom high temperature, presence of nucleation sites (dislocations), and degreeof nonstoichiometry. It was also observed that concentration of EL 2 defectsin the HB crystal tend to increase as the structural defects dissolve, indicatingthat the behavior of the structural defects can be closely related to that of theelectrically important EL 2 defects.

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The classical Drude-like optical conductivity tensor of the free electron systemin an uniform magnetic field is derived from the quantum mechanical Kuboformula. In the derivation, the exact solution for the free electron by Landauis used, although the interactions giving the scattering of the electron such asthe electron-phonon interaction are taken into account as a phenomenologicallife time effect.

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The liquid-liquid extraction of various metal ions by a couple new calix [4] arenes, which have aminobenzene carboxylic acid, benzothiazole, and benzoxazole, thiomethyl, and pyrazple group the upper rim of calix. These ligands ofextraction ability for metal cations including alkali and transition metal onesusing picrate counter ion have been examined. Benzothiazole and benzoxazolemodified calix [4] arene derivatives (4 and 5 respectively) were converted tothe phenol derivatives using BBr₃. The benzothiazole phenol derivative (6) shows high selective extraction ability for Cu²⁺ and Hg⁺, but the benzoxazolederivative (7) does show extractability for only Hg⁺. On the other hand, themethoxy calix [4] arene derivatives except thiomethyl appended derivative (8) show higher metal binding ability in this system.

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The rheology of suspensions of coarse particles in non-Newtonian fluidshas not been the subject of much investigation. There are distinct advantagesin using non-Newtonian carrier fluids in the transportation of solids, forexample in coal slurry transport. The objective of this work is to investigatethe flow behaviour exhibited by a concentrated mixture of coarse particles ina medium consisting of suspensions of fine particles. Steady state viscositymeasurements of suspensions of mono-sized coal, ballotini and styreneacrilonitrileparticles suspended in a non-Newtonian bentonite clay carrier fluid havebeen made using a Contraves Rheomat 115 rheometer. Measurements werecarried out with various particle concentrations and shear rates ranging from 2.22s^-1 to 345s^-1. It was found that variation of viscosity due to coarse particlesize did not follow any trend. It is thougth that this behaviour in due tothe interaction between the clay flocs and the coarse particles. Modellingwork assuming interacting coarse particles and flocs coexisting as in a bimodalmixture was shown to simulate this behaviour.

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Creosote is used commercially as a timber preservative. Previous studieshave shown that a modified Quemada model can be used to describe steadyshearflow behaviour creosote-in-water (O/W) and water-in-creosote (W/O) emulsions at moderate shear rates. This paper investigates the flow of O/Wemulsions in straight and square-wave capillaries at high shear rates, as a preludeto predicting timber treatability. This emulsion exhibits slip at the wallwhen flowing through a straight capillary, as is the case with some suspensions.A pipe flow equation based on the modified Quemada model has been develpedto predict flow rate against applied pressure drop. A modification of this equation, making use of a geometric parameter technique, can also be used to predictflow in square wave tubes.

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Adsorption of dispersants on coal particles in coal-water mixture (CWM) has been analyzed by use of ion-selective electrode based on a lipophilic diphosphoniumsalt. Naphthalenesulfonate-formaldehyde condensate (NSF), polystyrenesulfonate (PSS), and polyisoprenesulfonate (PIPS) are used as dispersants.The adsorption on coals increases in the order PIPS<PSS<NSF. These dispersantsare more adsorbed on Warkworth coal than on Chibori coal. Relationshipbetween the adsorption of dispersants on coal particles and fluidity of CWM is discussed.

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On the basis of analysing the structural characteristics and performance of CWM additive derived from coal (hereafter called ADC) in CWM preparation, this paper described the relationship between structure and property of ADC using bonding factor and hydrophobic/hydrophilic factor of CWM additive's structural activity, propounded two kinds of characteristic parameters for determining structural activity of CWM additive, and discussing their effects on the performance of additive in CWM preparation. As a result, the theoretical approach for designing or selecting more effective additives for CWM preparation has been developed.

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Dynamic stability and rheological characteristics of highly loaded coal water mixtures (CWM) with stabilizing additives were measured in aid of selecting suitable additives. Five stabilizing additives were tested. The experimental results show that some kinds of polysaccharides are effective to improve the stability of CWMs. These stabilizing additives have long sensible molecular chains and show high elasticity.

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The lattice expansion of a small piece of Ni (85wt%)-Cr (15wt%) thin film was measured by means of in-situ High Temperature X-ray Diffraction (HTXRD), referring to Ni-Cr plate of the same composition. The experimentally obtained coefficient of linear expansion of the film, β=1.42×10^-5/K, was consistent with the β-value of the reference plate. Furthermore, the derived value β=1.40×10^-5/K, based on the Vegard rule, was correspondent with the β-value of the film. It was confirmed that HTXRD is a remarkable technique for measuring β-values of tiny samples which cannot be measured by conventional dilatometry. The crystal structure, peak separation, and the factors of XRD peak transformation during temperature elevation of HTXRD are also discussed.

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The effect of Ar pressure during sputter-deposition of Co-Cr films on their magnetic properties and microstructures were studied in a wide pressure range (0.2-100 Pa) far beyond conventional sputterings. Films with higher coercivity than 600 Oe were obtained by increasing only the sputtering pressure up to three orders of magnitude higher than conventional ones even at room temperature, where any other special method such as reactive sputtering was not used. The films exhibited a typical clear columnar structure with physically separated grain boundaries. It was concluded that the high coercivity was attributed to the perpendicular anisotropy due to mainly a shape effect of the columnar grains and to the isolation effect between magnetic particles associated with the development of the physical separation between the columnar grains. The contribution fraction of the crystalline anisotropy to the total perpendicular anisotropy was estimated to be as low as about 20%. The performed ultra high Ar pressure deposition will be a powerful means for realization of a low temperature sputter-deposition for perpendicular recording media.

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Reexamination of the traditional status of metal/mineral processing engineering points to an increasing need for process development efforts to place greater emphasis on environmental concerns, both in terms of conserving the Earth's finite natural resources and in protecting the environment. This paper reviews some processes which exemplify thorough utilization of raw materials.

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Coal slurry is a mixture of pulverized coal and some adequate liquid medium. The use of coal slurry has various advantages because of its fluidity. In particular, the technology for the preparation, transportation, storage and combustion of coal water mixture (CWM) has been developed, and the commercial production of CWM is now started. However, the production rate of CWM is very small at the present stage. The use of CWM depends strongly on the oil price and the economical conditions. Also, various problems in CWM utilization technology are still open to question. The treatment of solid-liquid mixture is one of the most difficult problem in the field of chemical engineering. Thus, it may be valuable to review the present status of CWM technology. In this paper, recent investigations on the following topics will be reviewed. (1) Optimization of coal particle size distribution for CWM, (2) dispersion additives, (3) stabilizing additives, (4) rheology of CWM, and (5) transportation and storage of CWM.

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CWM demonstration tests such as Tomakomai project, Ube prtoject, etc. have been operated while accumulating various imformation data. In fact, present level of CWM for production, storage, transportation and combustion technologies, may be satisfactorily high for practical applications. However, users are less intereted in converting fuels to CWM at present because of the fall of oil prices since 1986 and recent recession in economy. Under these circumstances, a new test for CWM distribution relay system, or West Japan Project, has been launched since fiscal 1991 to appeal CWM to users as a more attractive commodity. On the other hand, a commercial project, or Nakoso project in which CWM is being used at a power station has been conducted since several years ago. And some feasibility studies to import large amount of CWM from China and Australia, are planning. Forecasting future aspect on energy in Japan where there are very few energy resources, CWM has been regarded gradually as one of the most important oil-substitute energy resources even if oil prices does'nt high enough. This paper describes CWM projects started from 1987 in Japan.

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The export of Hunter Valley coal and the Port of Newcastle are dependent, one upon the other. Coal is the lifeblood of the port. The 1990s have seen coal export infrastructure mature and strengthen as the result of a massive restructuring so that Port of Newcastle, in combination with the facilities of Port Waratah Coal Services, PWCS, now manages the largest capacity coal loading operation in the world. This requires an unique relationship ‘The Hunter Valley Coal Chain’ which links all the important elements the Port of Newcastle, Port Waratah Coal Services, the coal transportation services and the Hunter coal mines.

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