Heavy rare earth elements (HREE) have been produced from ion-adsorption type deposits in southern China. Despite extremely low REE grades (0.2-0.05wt.%) of the deposits, exploitation of REE from this deposit type is very competitive because REE are easily extracted from the ores by ammonium sulfate solution. For the purpose of producing HREE outside China, a variety of sources are examined. They are 1) ion adsorption deposits outside China, 2) HREE-rich carbonatites, 3) alkaline rock complexes, 4) sediment-hosted phosphates associated with uranium mineralization, 5) xenotime associated with tin granites, and 6) iron-oxide apatite deposits. The major challenges for the production of HREE from these hard rock deposits are mineral beneficiation, REE extraction and treatment of radioactivity.

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This paper describes a proposal for easy self-dumping system by hopper barge loaded with soils. Utilizing the existing and widely applied versatile unit construct flotation system. For civil engineering purposes it is used in temporary applications to carry land based facilities such as excavators, cranes and pile drivers for marine works.

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There has been much attention paid to the utilization of complex ores due to decreasing the accessibility of high grade and easily extractable ores. In order to maintain the sustainable use of mineral resources, the effective beneficiation of complex ores is urgently required with the strong assist from mineralogical characterisation. In this paper, currently available characterisation and beneficiation methods of complex ores are reviewed and summarised to discuss the further development required for the sustainable utilisation of mineral resources for our society. Also, refractory gold ore beneficiation was discussed as an example.

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In order to selectively precipitate copper (Cu) and zinc (Zn) over iron (Fe) for recovery from an acid mine drainage (AMD) generated from an abandoned copper mine located in east Japan, the feasibility of a treatment process combining lime neutralization with sodium hydrosulfide (NaHS) sulfidization was investigated. First of all, lime neutralization was applied to the AMD to find the precipitation behaviors of Cu, Zn, and Fe. Next, NaHS sulfidization as well as the integration with lime neutralization were conducted to selectively precipitate Cu, Zn, and Fe from the AMD. The results show that by adding more than 20 mg/L NaHS into the AMD at pH 2.8 without pH adjustment, all of the Cu precipitated whereas Fe and Zn did not. Fe could be selectively precipitated over Zn afterwards by lime neutralization at pH 5; however, the addition of an oxidizing agent such as 0.02 vol.% H₂O₂ was needed. On the other hand, after Fe was fully precipitated previously by lime neutralization at pH 5, all of the Cu precipitated when 10-15 mg/L NaHS was added whereas Zn did not. After Cu and Fe were precipitated, Zn could be precipitated by lime neutralization at above pH 9.

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The recovery process of dysprosium from sewage by biosorption-desorption has been evaluated using low-cost biosorbents. Both dried and 450℃ carbonized mandarin-orange peels and ginkgo leaves were selected as biosorbents and used to evaluate the recovery process of dysprosium ions. Evaluating the effect of pH with respect to contact time indicated a rapid biosorption of dysprosium ions onto the surfaces of the biosorbents. Equilibrium was reached within 10 min of contact, with the best biosorption capacity of 25.64mg/g obtained with carbonized ginkgo leaves. The recovery process of adsorbed dysprosium was studied using hydrochloric acid, nitric acid, sulfuric acid and hot water. High recovery rates were obtained with acids but not with hot water. Hot water did not desorb dysprosium. Maximum recovery rates of 86.06% and 100% were obtained for dried ginkgo leaves and mandarin-orange peels, respectively, whereas 86.40% and 96.88% were obtained for 450℃ carbonized ginkgo leaves and mandarin-orange peels, respectively. This suggests that carbonization treatment has little influence on the desorption capacity of mandarin-orange peels but significantly improves the biosorption performance of ginkgo leaves and mandarin-orange peels.

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This study examined the fine grinding of limestone using a bead mill and a circular stirred media mill.Fine grinding characteristics of the bead mill using poly-sized grinding media with a volume mean diameter of 0.5 mm were compared with those observed by mono-sized grinding media with the same mean diameter.The median diameter of the ground particles and the mass of milled products below 1μm can be expressed as functions of the number of rotor revolutions, the mass of the grinding media, and/or the mass of the sample; these relationships were observed for both the poly-sized and mono-sized grinding media. This study showed that the median diameter of particles milled with poly-sized grinding media was more than 10% smaller than that obtained with mono-sized grinding media, and the mass of milled particles below 1μm produced with the poly-sized media was more than 10% greater than that milled using mono-sized media. The use of the poly-sized grinding media in the bead mill led to improvement in productivity of fine particles of limestone.

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We examined solubility differences on food surfaces according to salt particle diameter, which revealed that the salt diameter affects its solubility. Furthermore, we developed a new evaluation system uses electric impedance for non-destructive measurement of the dissolution state of salt on food.

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Poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) is a promising conductive polymer owing to its transparency, the high stability, and high conductivity. Previous studies have reported that the conductivity of PEDOT/PSS films increases on the addition of polar organic solvents to PEDOT/PSS water dispersion prior to film preparation. In this study, we report the conductivity enhancement in PEDOT/PSS films by solvent vapor treatment of the prefabricated film. In addition to dimethylsulfoxide, N,N-dimethylformamide and ethylene glycol, which are known effective additives for enhancing conductivity in PEDOT/PSS films prepared by solvent-addition method, methanol is also effective in enhancing conductivity by solvent vapor treatment. The conductivity of PEDOT/PSS films is enhanced from 5 to 384 S/cm after the solvent vapor treatment by methanol at 35℃. In this study, the effect of treatment conditions and the morphological changes after the vapor treatment have been investigated.

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Milling characteristics of dental alloys have been investigated and compared. The four differently configured tools used were made of cemented tungsten carbide. Most were uncoated but one was coated with a diamond-like carbon layer. The dental alloys studied were cobalt-chrome (Co-Cr) and cobalt-chrometitanium (Co-Cr-Ti) alloys, fairly strong alloys. There is a requirement for a reliable test to evaluate the properties of dental tools by measuring the cutting forces during milling. A full characterization of dental mills is a difficult task, because the geometry of the mills is complex, with conical multi-cutting surfaces. In this study a more comprehensive understanding of the effects of cutting rate on cutting forces was achieved by varying the tool cutting speed and measuring the force on the workpiece as it was driven into the rotating tool at a fixed feed velocity. It was observed that the cutting forces were changed by varying cutting speeds. Side milling required lower forces than central slot milling. After milling the surfaces of the dental tools and dental alloy specimen were analyzed by scanning electron microscopy.

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Heterogeneous materials such as rocks cannot be expected to have uniform quality and properties when used as structural materials. For example, in case of large rocks with a diameter greater than one meter that could be used to protection wall, measures should be taken to identify defects, such as internal cracks or fracture zones, whose adverse influence on material strength cannot easily be detected using traditional, destructive testing methods that rely on a few, small samples, such compression strength tests on cores taken from the rock. In these instances, the impact-echo method, which is simple enough for on-site tests and has good accuracy, could be used as a quick test method to evaluate material strength and detect internal defects in large rock specimens. In this study, measurements using the impact-echo method were performed on various types of rocks whose structural response was studied under large impact loads. The applicability of impact-echo method for estimation of rock strength was verified by comparing these measurements with those from other, more traditional, compression strength tests.

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In recent years, remote sensing data have been used for water quality analyses. Such data have favorable features, including instantaneousness, wide area of coverage and periodicity. In our previous studies, we analyzed the data collected from an Advanced Visible and Near Infrared Radiometer type-2 (AVNIR-2) optical sensor of the Advanced Land Observing Satellite (ALOS), and an active sensor of JERS-1 Synthetic Aperture Radar (SAR), using a fuzzy regression model with one input and one output. In this paper, to examine the usefulness of the fuzzy regression model for a water quality analysis, data from ALOS Phased Array type L-band Synthetic Aperture Radar (PALSAR) are used. A fuzzy regression analysis was performed using the Min and Max problems, and through fuzzy-level slice processing, maps of the estimated water quality were obtained from the ALSO PALSAR data. Furthermore, by comparing the results obtained using data collected from both ALOS AVNIR-2 and JERS-1 SAR, we examine the differences in the classification resulting from the differences in the sensors and resolutions.

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ADW is a fixed abrasive diamond saw wire manufactured by brazing diamond grains to a metal wire.Brazing makes it possible to firmly bond a diamond grain onto a metal wire. Therefore, ADW has a longer operating life compared with conventional electroplated diamond wire saws. However, it was found that when this tool is used on a single track with larger cutting force, there is the possibility of the tool breaking easily from the past experiments. Therefore, we developed twisted ADWs for improving the strength of ADW. In this study, good cutting conditions, such as cutting force, tension, wire speed, were investigated experimentally for high speed cutting performance with twisted ADWs. Observing the SEM photographs of used twisted ADWs for cutting, the contact state of diamond grains and brazing metal, the behavior of diamond grains in cutting were considered. As the result, the best cutting conditions (cutting force is 30 N, tension is 30 N, wire speed is 150 m/min) were found from two viewpoint of cutting performance and operating life.

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Friction stir welding (FSW) has been widely applied and studied intensively in recent times. The majority of FSW studies have been based on butt joint configuration. Joining with lap configuration is also widely used in rail, automotive and aerospace industries. Thus, various FS material flow related joint features and deformation and fracture behaviours of the joints under loading need to be better understood for FSLW to be more widely applied particularly for light weight structure applications. In this paper, features of hooking formed during FSLW of Al-to-Al and Mg-to-Mg will be quantified. These features are the results of two sequential material flows during FS which, as will be shown, are speeds dependent and alloy deformation behaviour dependent. Strength values of the welds will be presented and it has been found that hooking affects Al and Mg FSL welds very differently, due to the different modes of local plastic deformation. FSLW study has been extended to Al-to-Ti alloy, for which we will show that under a well controlled FSLW condition a thin and continuous interface intermetallic layer forms and this layer can bear a high shear load. As a result, the strength of the lap weld is very high.

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Rice hull, which is one of the agricultural wastes in Japan, is required to be reused from a viewpoint of recycling. The rice hull silica carbon (RHSC), made from rice hull is manufactured by mixing rice hull particles with a phenol resin, pressure forming, drying, and then carbonizing the mixture in the nitrogen gas environment at high temperatures. RHSC contains about 30 mass% of inorganic constituent and 70 mass% of organic constituent. The main inorganic constituent is silica (SiO₂), which content is more than 95 mass%. Silica has excellent corrosion resistance and oxidation resistance. Thus, it can be expected improvement of water resistance. In this study, focusing on the sliding friction and the water resistance, which are a core competence, the sliding friction was evaluated through wear amount and dynamic friction coefficient in air and pure water and seawater. The results showed that the dynamic friction coefficient of RHSC in each environment was low excellent value from 0.11 to 0.15. The wear amount in the air was about 50 μm in the 130 km running. By contrast, the wear amount in both pure water and seawater was reduced to 37 μm and 2 μm respectively. Thus, the use of RHSC can be expected in pure water and seawater.

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Recently, Japanese "tatami" mats are dumped about 1 million per year. Most have not been reused, they are incinerated. Therefore, effective using of dumped "tatami" mat which replaced of incineration disposal is needed. In this research, the adsorption properties for air pollutants and waste water contaminants of carbonized "tatami" were evaluated. Carbonized "tatami" is prepared by carbonizing the "tatami" waste in a nitrogen gas atmosphere for 12 h at 800℃. Rush grass which forms the "tatami" mat has a natural porous structure and it holds its structure after carbonizing. Water purification experiments of the adsorption properties of the carbonized "tatami", adsorption of 2,4-DCP was superior compared to the adsorption properties of activated carbon made from coconut shell residual chlorine. On the other hand, the carbonized "tatami" shows good adsorption properties for formaldehyde in the gas phase adsorption experiments, and the same results as activated carbon made from coconut shell were obtained. Therefore, the adsorbent which made from carbonized "tatami" can be available for the gas phase adsorption than the liquid phase adsorption.

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The paper presents a design procedure for horizontal pipeline systems, such as those used in bulk solids handling/transportation in mining operations.
The mean velocity as well as pressure drop are important parameters in the design of the slurry pipeline. Accurate prediction of the parameters is needed for the selection of pipe diameter and the type of pump suitable for the slurry system. The objective of this paper was to provide a pipeline design procedure, especially for mixed-sized slurry flows typically found in the coal mining industry.
This study covered the evaluation methods for determining flow regimes, concentrations, and optimum pipe diameter. Critical velocity and transport velocity of flow were also discussed. The innovated models for mixed-sized slurry flows by Seitshiro et al. were applied for the prediction of the hydraulic gradients.
In conclusion, the design procedure proposed in this study was verified with field data.

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In recent years, robotic applications have increased in many fields and robots are being actively developed for use in human environments. Robots need maps comprising geometric features such as obstacles. However, it is difficult to construct maps of human environments. Therefore, robots in such environments require autonomous mapping techniques. In this study, we aim to develop simultaneous localization and mapping (SLAM) to construct a detailed map based on sensor data acquired at constant intervals. We consider two types of environments: an office that contains many geometric features and a corridor that has few geometrical features. We describe the process for three online SLAM methods showing the maps developed using the acquired data and evaluations of the accuracy for each. As a result, we construct a map using SLAM with ICP scan matching. However, when a map is constructed for a large environment, the map is distorted by accumulated errors such as sensor and modeling errors. We examine a correction method for maps of large environments and evaluate it experimentally. We also evaluate the applicability experimentally. The results showed that the proposed method could correct both the office and corridor maps without distortion to produce a high-accuracy map.

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Cellulosic biomass, such as wood waste and rice straw, remains unexploited despite the high content of cellulose. Streptomycetes are producers of industrially important antibiotics and most of the antibioticproducing strains are unable to utilize cellulose. We have, therefore, aimed to breed streptomycetes that produce antibiotics from cellulosic biomass. Two cellulolytic streptomycetes, i.e. Streptomyces thermocarboxydus C42 and Streptomyces argenteolus M178, were selected on the basis of carboxymethyl cellulose (CMC)-degrading activity from approximately 1,000 soil-isolated streptomycetes. Shotgun cloning experiments of cellulase genes from these genomic DNAs were performed in Streptomyces lividans as a host to find putative four cellulase genes, i.e. cel9A_C and cel5A_C from the C42 strain and cel5A_M and cel12B_M from the M178 strain. The transformants of S. lividans harboring the four genes subcloned in an expression plasmid showed secreted CMC-degrading cellulase (CMCase) activities, thus demonstrating successful cloning and heterologous expression of the cellulase genes from the cellulolytic streptomycetes.

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In a previous study, we investigated the construction of an environmental map for autonomous mobile robots. We programmed a mobile robot to construct an environmental map using the information obtained from a laser range finder and rotary encoders. However, robot localization using an environmental map failed in homogeneous environments. To solve this problem, additional features from the environment in which the robot is operating must be extracted for use in mapping. For this study, a robot was programmed to acquire omnidirectional images and generate a localization classifier. This paper proposes a method of using special image information as a new feature of environmental mapping. The effectiveness of the proposed method was verified from results of an evaluation experiment for an indoor environment.

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A process for concentration of Cu from a Cu mine tailing by flotation has been investigated in this study. The flotation studies were carried out under varying conditions of pH (3.5~12), flotation time (0~20 minutes) and sulfurizing reagent (0, 1000 g/t) using two different pH regulators (NaOH, Ca(OH)₂). The results showed that the grade of Cu in froth concentrate was increased from 0.24 mass% to 0.81 mass% with the enrichment ratio of 4, whereas the Cu recovery reached 60% under the conditions (pH 10, sulfurizing reagent: 1000 g/t, collector of PAX: 100 g/t, frother of MIBC: 200 g/t and flotation time: 5 minutes). At the condition, the grade of Al and Fe were reached to 0.6 mass% and 6.6 mass% from 3.45 mass% and 3.51 mass%, respectively.

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Crystals of a yttrium complex composed from deprotonated p-sulfonatothiacalix[6]arene, [{Y(H₂O)₈³⁺}₂{p-sulfonatothiacalix[6]arene^6–}]･16H₂O (I), were studied by single-crystal X-ray diffraction analysis. In the present crystal system of I, the thiacalixarene molecule maintains an 'up-down' double partial-cone conformation possessing two pseudo-thiacalix[3]arene cavities, which act as a 'molecular container' towards guest water molecules. Interestingly, the aquated yttrium center does not directly coordinate to the thiacalixarene sulfonate groups. In contrast, the aquated yttrium cations act as a connector to the thiacalixarene molecules to establish a one-dimensional hydrogen-bonded polymer by hydrogen bonding between the thiacalixarene molecules and the yttrium cations. The extended structure of the complex forms a supramolecular assembly via mutually supporting intermolecular π−π stacking, S−π interactions, and hydrogen bonding between two differently oriented polymers.

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