The our copper prodution is mainly due to the ore-deposits of the cupriferous pyrite in the south-western part of Japan, the deposits are found in the region, whose geology is distinqushed as the zones of the Crystalline Schists, the Mikabu, the Paleozoic and the Mesozoic.
The deposits were pormerly considered to be the syngenetic sediments as beds with the country rocks, but the writer published that to be fissure filling deposits in 1910.
At the end of Cretaceous (Mesozoic) a great disturbance has happened to divide the part to the inner and outer zones by the medial structural line. The rocks of the outer zone were regionally altered by dynamo-metamorphism to show the Crystalline Schist System as a completely altered member, and the Mikabu system as a partly altered one while leaving the remaining portion of the Paleozoic, and Mesozoic zone in the normal state.
Moreover fissures arranged in echelon, parallel to the trend of the medial line are numerous in number, long along strike, . and broad in width in the region, of the Crystalline Gchist, and they were successirely in deereasing number, strike and width in the regions of the Mikabu, the Paleozoic and the Mesozoic.
The fissures served as passages for the intrusion of the ultrabasic laccoliths, such as serpentine and amphibolite, a port of which is now seen on the surface by erosion. The fissures were also supplied as room for cupriferous pyrite deposits as veins, and also as conduit to replace limeston lens, for mineral solution of high temperature and pressure from abysmal depth.
If the solutions were issued from several basic laccoliths, it would be impossible to slow the deposit in wide region of nuiform quality in Chalacter and abundant in number, at same time. Then it is nuturally to consider that the mineral solution would directly be issued from the magma of a deepest situation, as the writer indicated 43 years ago.

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When mineral particles, especially coal, are treated by jigs, the resulting separation is said to be due to only the differences of the specific gravity of the particles, and not depending on their sizes nor shapes. However this conclusion and the function of jig in the process have not been proved until now.
In this paper, the author intended to solve this phenomenon analytically and also prove by experiments.

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Kinetics of oxidation of artificial ferrous sulfide was studied with the aim of inquiring into some of the fundamentals of pyritic smelting in copper metallurgy and roasting of sulfide ores by means of a flow method. The initial stage of the reaction was autocatalytic, and the oxidation product consisted virtually of ferric oxide within a temperature range of 600 to 1000°C. The reaction rate increased with a rise in flow rate of gas for slower flow rate, but attained a certain constant value with an abundunt supply of gas. The reaction rate increased remarkably with increasing fineness of are particle, and the experimental equation indicating this relationship was derived. It also increased markedly with increasing temperature. The increase in oxygen concentration in gas mixture resulted in accelerating reaction rate especially at high temperatures. At over MCC 1000°C fusion of the ferrous sulfide occurred in the course of oxidation, resulting in rapid increase, in reaction rate. SO₂ content of the exit gas was represented as a function of reaction and flow rates.

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