This paper deals with the life of Dr. W. Watanabe (1857-1919) and the history of the Nippon Kogyo Kai (Mining and Metallurgical Institute of Japan) during early 35years. Nowadays the name of Dr. Wataru Watanabe is widely known by virtue of the Watanabe Prize for metallurgy and mining engineering awarded from the Nippon Kogyo Kai. From 1873 to 1877 Watanabe studied chemistry at Tokyo Kaisei Gakko (the predecessor of University of Tokyo), then studied mining engineering at the University of Tokyo which was the first university of modern Japan. In 1879 he graduated from the department of science of the university, and was immediately placed in an assistant. teacher of the university. From 1882 to 1885 he had been abroad to study metallurgy and mining engineering at Bergakademie Freiburg. When Imperial University was established in 1886, he was appointed professor of it. From 1887 to 1896, he served concurrently as the manager of Sado gold mine, the most important one in our country from 16th century. He introduced many kinds of modern equipments and technics and founded Sado mining school for training miners and technicians, which resulted in great contribution to development of the mine. In 1898 Dr. Watanabe was elected vice-president of the Nippon Kogyo Kai, which was the firstinstitution, established in 1885, in the faculty of technology in modern Japan, and in 1907 became president of it. He had the post up to his death in 1919, and endeavored to develop mining industry in our country and advanced science and technology of mining and metallurgy promoting to hold a number of special and public lecture meetings.
Throughout of his life, he had been ardently concerned in education for young generations, not only as professor of the University but also trustee or advisor of other schools.

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The author describes in the above article the development of the “Super Dynamic SD System” (W-SDSystem), which is one of the most advanced coal mining methods in the world. The W-SD System is not only highly effiicient, but also has a remarkably high safety factor.
An English translation of the above article is available under the title of “Development of the Super Dynamic SD-Type High Speed Mining System.”

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Torigatayama Limestone Quarry has been developed with a view to securing abundant long-term supplies of high-grade limestone to meet the growing demand for raw material limestone from Japanese steel mills and cement manufacturers.
Torigatayama Limestone Quarry is on a mountain rising 1, 460 (one thousand four hundred and sixty) meters above the sea level, located in Shikoku, the smallest of the four main islands of Japan. The deposit exists above the 800 (eight hundred)-meter level. It has a length of 2, 300 (two thousand three hundred) meters, a width of 400 (four hundred) to 900 (nine hundred) meters, and a thickness of 300 to 500 meters. With proved reserves of 1, 500, 000, 000 (1 billion 500 million) metric tons, the quarry produces limestone of good quality with a calcium oxide (CaO) content of 55.5 (fifty-five point five) per cent.
Nittetsu Mining Co., Ltd. set about development of Torigatayama Limestone Quarry in 1969, aiming at an eventual annual production of 12 million metric tons. Two years later, or in 1971, production was begun at the rate of 6 million metric tons per annum. Output is being increased steadily in this largest-scale limestone quarrying project in Japan.
A striking feature of this project is found in the generous use of large-capacity modern equipment, notably a belt-conveyor transport system incorporating sophisticated automatic control techniques designed to minimize manpower requirements. In fact Torigatayama, where open-pit/bench-cut mining is adopted, is the first Japanese limestone quarry to employ large-size machines, which enable us to carry on operations at a high efficiency, despite the most unfavorable natural conditions, including the dense fog that persists throughout the year, the heavy rainfalls triggered by typhoons in the summer, and the heavy snow and ice in the winter.

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Akita Zinc Co. was established in 1971 as a joint venture by six zinc-producing firms of Japan. But The Dowa Mining Co., the major shareholder, exclusively undertook the design and construction work. Capital cost is 11, 300 million yen.
Although the main processes are based on the conventional “Roasting-Electrolysis Method”, a unique “Wet Method” was employed for residue treatment. This consists of four major steps: Leaching of residue under SO2 atmosphere, removal of Cu by H₂S, neutralization of free acid by lime and precipitation of ferrous ion as ferric oxide in autoclaves lined with Ti under O₂ atmosphere.
The present monthly production of electrolytic zinc is 6, 500t, but another expansion to double the capacity is scheduled to be completed in August 1974, After one year of construction period, full operation became on stream in March 1972.
The main features of the plant are:
(1) Almost complete recovery of the valuables in zinc concentrates, especially from the Black Ore, throughthe new residue treatment process.
(2) Applications of mechanical stripping and other mechanizations to save manpower.
(3) Careful prevention of pollutions both in air and water.

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The first Japanese Flash-Furnace started in 1956 at the ASHIO-Copper-Smelter of Furukawa Co., Ltd. The author has participated in works to introduce the Flash-Furnace process at the smelter and to establish the suitable and adequate operation of the furnace. Also, he has made improvement and perfection of the equipment.
The main contributions are as follows
1) Establishment of blending for copper-concentrates and flux in order to proceed adequate flash-smelting.
2) Improvement of the flash-drier with the object of drying concentrates without sulphur burning caused during the process.
3) Ditermination of shaft height for the suitable operation.
4) Design for the oil burner installed at the top of the shaft to keep the furnace atmosphere at required temperature.
5) Innention of the FlashE-lectric-Furnace, equipped with the arrangement of electrodes to the furnace, which serves effectively purpose of protection of bottom-up of, the Flash-Furnace, and at adopted the side-take for the waste gas to keep the good atmosphere around the furnace.
6) Decision of main specification for the waste heat boiler, such as dimention of a boiler matched withthe Flash-Furnace capacity, shape and arrangement of boiler-tube, removing method of boiler dust.
7) Device of the air-heater by steam of the waste-heat-boiler to prevent the heater from corroding by thgas of SO₃ and V₂O₅.

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In this paper we dealt with the shapes and mode of arrangement of inclusions observed in synthesized quartz and potash alum crystals. It appears that frequency of inclusion formation during the crystal growth is mainly controled by the supersaturated condition of the crystal forming solutions, but negligibly affected by the impurities in the solution. As the degree of supersaturation increases, the number of inclusion increases and the shape of inclusion becomes irregular.
In some cases, it is found that a micro-channel which interconnects the inclusion to the outside of the crystal is formed and that the channel allows a leakage of the contents through it.
It is found that the mode of arrangement of inclusions is affected significantly by the direction of crystal growth and flow of the forming fluids.
The formation of gas. bubbles on the surface of the growing crystal occurs not only under the boilling condition or chemical reaction, but also under the condition of lower temperatures than the boilling temperature.

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The removal of silica from kaolin mineral by amine flotation has been investigated by using dickite and quartz, as a kaolin mineral and a silica mineral, respectively, and dodecylammonium acetate (DAA), as a collector.
The experiments consist of measurements of cation exchange capacity of dickite, amine adsorption amounts and ζ potential, and flotation tests.
The results obtained have been discussed by taking account of the inherent surface properties of clay minerals due to their layer structure.
The conclusions are as follows.
1) In neutral or alkaline pH range, quartz can not float from dickite so selectively as would be expected from the flotation results of pure samples. In the case of small amounts of addition of DAA, flotation of, quartz does not occur, because the greater part of dodecylammonium ion (DA⁺) is consumed by entering into the interlayer of dickite, and if the amounts of addition of DAA increase, some portions of dickite float with quartz because DA⁺is adsorbed on not only the quartz surface but also the dickite surface.
2) In acidic pH range, dickite can float selectively from quartz. This may be caused by the reasons that hydrogen ion enters into the interlayer of dickite instead of DA⁺and DA⁺is adsorbed on the dickite surface rather than on the quartz surface because the layer surface of dickite is charged more negatively.
3) Flotation of dickite from quartz in the acidic pH range becomes difficult with the decrease of the sample size. This may be explained by the reasons that the floatability of quartz increases with the decrease of size in the acidic pH range where the frothing power of DAA is strong and the heteroflocculation occurs due to the interaction between the positive charge of the edge surface of dickite and the negative charge of the quartz surface.

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