Pore structure was analyzed by using two- and three-dimensional network model. In these models, the pore structures are assumed to be network systems of cylindrical segments of different diameters and different lengths.
The models were applied to analysis of experimental mercury porosimeter results of pore size distribution of rocks and coal.
The following results are obtained.
1) The theoretical results agree well with the experimental results.
2) The hysterisis curves of penetration and drainage can be explained by the model.
3) The network size and the linkage probability of the segments of comparatively large diameters have large effect on calculation results of penetration and drainage.
4) The pore volume fractions given directly from experimental results by using the “bundle of capillary tube” model are not correct, and the fraction of segments of comparatively large diameter is larger than that calculated from experimental results

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The bloating properties of sedimentary zeolites existing enormously in Green Tuff region of our country were investigated. Pelletized bodies (9-12mm diameter) prepared from pulverized zeolites were fired in the range of 900-1350°C. Then physicochemical properties, such as specific gravity, water absorption, crushing strength etc., of the pellets were measured. Moreover, 38 mixtures prepared from mordenite tuff, silica, alumina and ferric oxide were fired in order to make clear the optimum bloating range in chemical compositions.
The results obtained are summarized as follows;
In many cases, air dried pellets had high crushing strength enough to permit the firing by rotary kiln. Pellets started to bloat at temperatures above 1150°C and the bloating extent increased with raising the temperature. Most of the pellets fired at higher temperature than 1100°C were impervious and their specific gravity was about 2.3-0.4. Crushing strength of the fired pelletes whose specific gravity were about 1.2-1.3 were in the range of 120-170kg, and it was about 2 times that of artificial light weight aggregates commercially produced. By the results of X-ray analysis, chemical and thermal analysis, it was guessed that a common gas-forming component in sedimentary zeolites concerning with the bloating was ferric oxide.
From the firing tests of the above-mentioned mixtures, the optimum contents of silica, alumina and flux for the bloating were ascertained to be in the range of 60-70%, 10-25% and 10-20%, respectively.

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It is very important to keep good conditions of air flow rate in the deep and/or complicated underground roadway network of coal and metal mines in the both aspects of safety and economy.
In this paper, a method to analyze underground mine ventilation network concerning natural ventilation pressures, booster fans and regulators is explained, and some fundamental factors for mine ventilation control are discussed.
The main results are as follows;
1) To measure temperature at every intake and outlet node in a ventilation network is important for estimation of airflow rate through branches because natural ventilation pressures are dependent on the temperature at intake and outlet nodes as temperature distribution in the underground roadway network is constant.
2) To keep same condition of a branch having large energy cosumption in aerodynamic resistance is one of the factors for stable working of the main fans since when aerodynamic resistance of a branch ‘k’ in a network becomes twice, airflow rate at the main fans decreases, and the difference in airflow rate at the main fans between first condition and second one is proportional to energy consumption in the branch k at the first condition.
3) A relation between airflow rate Q_p through a certain branch ‘p’ and aerodynamic resistance R_q of other branch ‘q’ can be represented in the following experimental equation.Q_p=A (R_q/B+R_o/B) ^-n+Q_o whereA, R_o, n and Q_o are constant co-efficients having dimension (m³/s), (μ), (O) and (m³/s) respectively, and Bis 1μ for making values in round brackets dimensionless.

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The authors have considered to operate an ore dressing plant with a closed circuit for water dealing with mineral processing from a standpoint of reducing consumption of water and preservation of an environment from pollution by the waste water.
This study is concerned with water recycling of are dressing as well as the problems and the measures to meet those ones caused by the closed recycles.
A sample of kaoline are from Minami-shiraoi mine in Hokkaido was used for the experimental example. The pilot plants of closed circuit were constructed and experimented to recover pure kaoline to be used for a paper manufacture, the other minerals, pyrite, quartz etc., in that are being removal.
This paper presents the results of continuous water recycling operation conducted for a long period at about 50 and 90% recycling ratio of the waste water.
The kaoline processing system was consisted of the processes of are feed, attrition, flotation, classification, bleaching, thickening and waste water treatment. The operation tests were examined with an open circuit for comparison before the closed circuit had been conducted. The mineral balance and quality of concentrate were obtained from the results of the operation test.
The result also showed that there was little difference between the open and closed circuit for the quality and operating condition in 50% recycling ratio. However, in case of 90% ratio, the quality and condition were degraded.

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In this paper, the classification performance of the choking-free cyclone for waste mud have been investigated.
The main results obtained are summarized as follows.
1) The equation (1), which showes the size of separation for the solid particles suspended in paper slurry with the flow behaviour of Bingham plastic, can be applied to the solid particles suspended in waste mud slurry in the same manner. Therefore, it is suggested experimentally that the equation(1) can be applied to the prevailing Bingham plastic fluid.
2) As a result of comparing the classification performance of the choking-free cyclone with that of other cyclones, it is expected that the size of separation obtained by the cyclone is smaller than those by the others and the solid content in underflow slurry is larger.
3) This cyclone can be operated in the various conditions by controlling the rotational speed of the screw so that the size of separation are varied widely (20μm to 4mm)

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The leaching rate of a manganese nodule was discussed. The manganese nodule was crushed to 250 mesh under (-61μm) and leached with 1.0 N hydrochloric acid in the temperature range of 30 to 70°C. The results are summarized below.
The leaching rate can be represented by the volume reaction model, and the leaching rate of Ni and Cu are the second order with respect to each content remained in the sample. The dissolution of Fe ceases on the way of leaching, and for the soluble portion of Fe the leaching rate of Fe is also the second order. The leaching behavior of Co is analogous to that of Mn, i. e., both of them dissolve only slightly at lower temperature, but highly at 70°C. The leaching rates of Co and Mn at 70°C are also the second order.
The apparent activation energies for Cu, Ni and Fe leaching are 41.2, 81.1 and 43.3 kJ/mol, respectively, and the overall reaching rates appear to be controlled by the heterogeneous reaction.

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A certain heat treatment (annealed at 1, 000°C, followed by slow cooling) was employed to various kinds of commercial copper anodes in an attempt to increase their dissolution activity in a copper electrorefining electrolyte.
It has been observed that such heat treatment brings about a drastic change in the microstructure as well as a substantial disappearance of Cu₂O phase from the grain boundaries. Both electrochemical and X-ray diffraction analyses have confirmed that a phase conversion Cu₂O=CuO+Cu° surely occurs in the matrix of copper anode so heat treated.
The results of dissolution experiments also appear to indicate that;
1) The heat treatment results in a great enhancement in the dissolution activity of copper anodes to such an extent that it can hardly be passivated under conventional Cu ER conditions, and
2) The sole employment of annealing (with no subsequent slow cooling) increases the dissolution activity but a little.

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The distribution of Ag, Co, Ni, Zn, Sn, Pb, As, Sb and Bi between calcium ferrite slag and metallic copper was measured at 1250°C under controlled CO-CO₂ atmospheres, and the distribution measurements of Zn, Sn, Pb, As and Bi were also carried out for iron silicate slag.
By considering the relationship between the distribution coefficient and the oxygen potential, it was expected that the minor elements are present in the slags in the following forms: CuO_0.5, AgO_0.5, CoO, NiO, ZnO, SnO (SnO₂ in the range of high oxygen potential), PbO, AsO_1.5, SbO_1.5, BiO_1.5
The dissolutions of arsenic and antimony in ferrite slags are much more than in silicate slags. Lead and zinc are more soluble in silicate slags than in ferrite slags.

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This paper deal the source, production, and application of lithium. Lithium is the lowest atomic-weight alkali metal, lowest density among metals, and really active in an open atmosphere.
The sources of lithium are found as Spodumene, Lepidolite, Petalite, and Amblygonite mainly in Africa and North America. Of those ores, spodumene is only used for lithium chemicals. Brine welled from spar or lake is also the source of this element.
In the 2'nd World War, metal, hydroxide, and hydride of lithium were consumed for military use. Production of lithium hydroxide boomed up for a stock-pile of ⁶Li by US · AEC in 1950s.
There are two ways in production process for lithium chemicals. First is “acid-process”, in which the are (spodumene) is roasted with sulfuric acid to extract lithium value in followed stages and to recover as carbonate. Second is called “limeprocess” and currently not applied.
Two major producers of lithium carbonate in the Western World are Lithium Corp. of America and Foote Mineral Co., both in USA. Lithium carbonate is sold to other producers, as a starting-material for lithium chemicals. Brine-processing facilities at Atacama, Chile is reported to start in 1984.
The details of production in USSR and China are not disclosed. Lithium chemicals are widely used in many industries (ceramic, glass, flux, air-conditioning, alloy, brazing, aluminum, grease, organic synthesis, paint, battery, and electronics) and home-keeping (sanitary, bleach, and deodrant) at present, demonstrating its usefullness for these years and its potential in future.
Lithium can be used as a blanket material of nuclear fusion reactor to breed “Tritium” effectively.

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Land-based, cobalt reserves in the world are roughly estimated at 5. 9 million m. t. The recovery of cobalt is calculated approximately 1. 2 million m. t. by taking acount of the losses during the mineral dressing and smelting. Sea-bed nodules, though believed to be inexhaustible, are not still regarded as the substantial resources at present time.
The world production of cobalt counted 26 thousand m. t. in 1981. However the rapid rises in the price of cobalt and the shortness of the supply due to the cobalt crisis in 1978/79 lead to the substitution of cobalt and to the reduction in the consumption. The world production of cobalt dropped to 21 thousand m. t. in 1981. However, this decreasing tread seems to be stopped and the production is likely to increase.
From the view point of the raw materials, the cobalt refining processes are classified as follows;
(1) Recovery of cobalt from copper-cobalt concentrates.
(2) Recovery of cobalt through the nickel refining.
(3) Recovery of cobalt from the iron are (pyrite concentrates).
The first recovery route is adopted by the goverment refineries in Zaire and Zambia.
This processing route is described with the flow-sheets.
The solvent extraction processes by SMM or NMC (of Japan) and the pentammine process by Sherritt Gordon Mines Ltd. are both classified into the second route. Amax and Outokumpu also adopted this pentammine process.
Including these processes, eight processing routes are explained with their flow-sheets.
The world consumption shares of cobalt are U. S. A. 40% Japan 15% Europe 40% others 5%.
Enduses of cobalt are different depending on the countries. The break-downs of consumptions in the U. S. A. and Japan are given.

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Recent tungsten industry has been reviewed. In this review, tungsten are source, trend of recent production and comsumption in the world and Japan, characteristics and application of tungsten, and recent progress in production and material technologies were outlined.
The purification and recycling were discussed mainly among the production technologies.

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The state-of-the-art of the metallic molybdenum industry, briefly describing its raw materials, processing, products variables and their applications. Total molybdenum supplies as an industrial raw material to Japan were also reviewed in the frame of the supply/demand situation worldwide.

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Until the discoveries of huge pyrochlore deposits in Brazil and Canada in 1950's, both Nb and Ta had been extracted from Tantalite or Columbite using by solvent (MIBK) extraction technique.
Using by the above pyrochlore resources, more than 95% of niobium products, such as Fe-Nb, various grade of oxides (technical, optical etc.) and Nb-metal are produced at present.
The application of niobium to steels, optical glass, electronic component, superalloys, refractory metals, superconducting materials and catalysts are discussed in this paper. On the other hand, tantalum has no bright future even though Ta-condencer, cemented carbide and super-anti corrosive materials are stable and reliable markets, so that the total comsumption of Ta in the world to be remaining about 1, 600t in Ta₂0₅ during a few years. The consumption of niobium will increase in the field of electronics, superalloys, catalyst, however in true we cannot expect it too much in steel industry.

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The author summarized the rare earths industry. Items described are as follows.
1. What is Rare Earths
2. Chemical and Physical Properties
3. Resources
4. Separation and Purification
5. Its Applications
6. Future Aspects

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Based on high growth of IC, production rate of Silicon crystals has been increased by average 33% per year in these 5 years.
During this period, the diameterof Silicon crystals is shifted from 4 in. to 5 in., furthermore 6 in. diameter Silicon crystals will be required in the near future.
In connection with the technology of Silicon wafers for VLSI, the oxygen and carbon concentration must be controlled precisely to reduce its distribution in wafer. Also wafer flatness is required to be 3-4 microns in TTV (Total thickness variation).

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Compound semiconductors play complementary roles to Si in semiconductor electronics. Physical properties of the compound semiconductors are suitable for application to high speed devices and optoelectronic devices.
This paper will give areview on recent advances in compound-semiconductor technology with special emphasis placed upon both high speed devices and optoelectronic devices. It will be shown that development of material fabrication technology is crucial to bring a revolution in this technology.

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Important materials in titanium oxides are mainly divided into the three groups consisting of titanium dioxide, alkali metal titanates and alkaline earth metal titanates. Recent interests of titanium dioxide are a photocatalytic production of hydrogen from water, a black pigment and a sensitizer of color-copy using TiO₂semiconductor. In the alkali metal titanates, potassium hexatitanate fibers are used as a heat insulator, and a filler of plastics or various composite materials. The alkaline earth metal titanates include very important materials of electronic ceramics. Especially, the ferroelectric materials belonging tothe perovskite structure are improved to semiconductor, and they are applied to new electronic fields such as BL-condensers, varistors and various sensers etc.
Zirconium oxide materials also have various characters as the industrial materials. The characters are mainly generated by three states of materials. The one is created by the solid solution state such as the stabilized ZrO₂, ceramic pigments and an oxygen senser. In the cases of the material character of electromolding bricks, the textural state between ZrO₂ grains and the matrix of different materials plays a very important role. Recently, the partially stabilized ZrO₂ (or PSZ) is well known as a high toughness material. The character of this material is generated by the combined state of solid solution and texture as seen in an MgO (or CaO)- PSZ. The PSZ is expected to be one of the ceramic engine materials of automobile.

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The preparations (thin film, whisker, fine powder, sintered body and single crystal) of transition metal carbides, nitrides and diborides, electrical, superconductive, mechanical and oxidation resistance characteristics, and practical applications of these compounds are reviewed from the standpoints of material science. These refractory compounds are promising candidate materials for the following areas.
(1) Super-LSI technology and electronic device: field and thermal emitters, TiN as diffusion barrier in metallization to Si semiconductor, resistive thermoconductive humidity sensor with TaN film and Josephson turnel junction with NbN film.
(2) Energy related materials: solar-selective surface with ZrC thin film, emitter for thermionic generator, electrodes (ZrB₂ and HfB₂) for MHD generator and first wall coated with TiC or TiB₂ film for tokamak.

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