It is the purpose of this study to find out the mechanicl behaviours of rocks under various loading-rates which ranged from 1.0×10^-1kg/cm²/sec to 8.0×10⁷kg/cm²/sec. The high rates of loading for the rock specimen have been obtained by the use of a high-speed compressive testing machine.
In the case of the high-speed loading test, which is undertaken for the purpose of comparing with the low-speed loading test, the shock waves should be eliminated, so as not to expose the rock specimen to impact loading.
From the above consideration, a new high-speed compressive testing machine, which is applied the load to the rock specimen by using the underwater explosive, has been designed.
The results of this investigation, using 10 kinds of rocks and a kind of cementmortar, have been summarized as follows.
The compressive strength of rocks increases with the loading-rate, for instance, “AKIYOSHI” marble at the rate of about 2.6 in respect of the ratio of the high-speed compressive strength to that of the low-speed. In this case, the average loading-rate of the high-speed test is about 2.5-2.6×10⁷kg/cm²/sec, and the average loading-rate of the low-speed test is about 1.0×10^-1kg/cm²/sec.
For the reason of this rate effect, it may be concluded that the effect of the pore, which exists in the rock, should be considered for, the occurrence of the rate effect.

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This paper describes a theoretical study on the states of stress and deformation around the bottom of a circular vertical shaft by means of the finite element method.
The problem is solved by the application of linear analysis considering the ground as the media under conditions of plane strain and axi-symmetric strain.
From the calculating results, the swelling at the batholith and the deformation on the wall of shaft and the states of stress concentration around its bottom part are discussed.

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The purpose of this paper is to report the results of the plant experiments concerning the magnetic roughing concentrator for low grade iron ore which had been carried out since 1964 in theKamaishi mine.
The concentrator manufactured for trial have the construction illustrated in Fig. 1, Photo-1 and-2. It consists mainly of a shaking feeder having the same mechanism as a shaking table and a drum type magnetic concentrator being deeply immersed in water.
Ore particles are previously stratified by the shaking motion of the feeder, hence magnetic particles are reasonably attracted to the magnetic separator at the top of the drum. The predominating characteristics of this rough concentration process have been evidently recognized in the previous investigations.
The concentrator have the dimensions of a total height of 3, 115mm, a total length of 4, 450mm and a total width of 1, 130mm. The diameter of the separation drum is 1000.8mm, the effective span of the drum is 120mm and the maximum strength of the magnetic field on the surface of the drum is 1, 200 Oe.
The influences of feed rate, the revolution rate of the drum, the inclination and the shaking rate of thefeeder and its stroke length on the separation results are investigated. Experimental results are tabulated in tables 4, 5 and 6. In coarse ore separation (spiral separator tailing, table 4) the recovery of magnetic Fe remains about 65%. On the other hand in medium size (flotation tailing, table 5) and fine size (thickener spigot, table 6) the separation recoveries are keeping higher values of 80-94%.
Cleaning of the rougher concentrate of this separator is carried out by using a small scale Ferrogum magnetic separator. We obtained the final concentrate of magnetic Fe c=58% under the recovery of E=98%.

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Gadeau's bath, one of the electrolytes of the aluminum refining, is composed of the ternary molten salt mixtures of sodium fluoride, barium fluoride, and aluminum fluoride.
We have experimented the thermal analysis and the X-ray diffraction for the binary sodium fluoride-barium chloride system, which is one side of the above-mentioned ternary system, and discussed these, results applying the treatment of the reciprocal ternary system.
1) At first. we calculated the free energy change of the next reactions.
2NaF+ BaCl₂=2NaCl+ BaF₂ΔG°1000°C=-5kcal/mol (1)
NaF+ BaCl₂=NaCl+ BaFClΔG°1000°C -5kcal/mol (2)
As a result, we think that the displacement reaction (1) has priority to the reaction (2).
2) In the binary barium fluoride-barium chloride system, the composition of BaF₂ 45.8% (BaF₂: BaCl₂=1: 1 in mole ratio) shows the maximum melting temperature 1, 005°C, and this is assumed to be the melting point of the compound BaFCl (barium fluochloride) which is formed in this system
This binary system gives two minimum melting temperatures (e. g. 840°C at BaF₂ 13.6% and 930°C at BaF₂ 70%). The former is the eutectic temperature of BaCl₂-BaFCl system and the latter is that of BaFCl-BaF₂system.
3) As the results of the thermal analysis and X-ray diffraction, we concluded that the square of the Na, Ba/F, Cl reciprocal ternary system is divided into three triangles, i. e. NaF-BaF₂-BaFCl system, NaF-BaFCl-NaCl system and NaCl-BaFCl-BaCl₂system.
And then sodium fluoride-barium chloride system corresponds to the diagonal of the above-mentioned square, i. e. the pseudobinary system extending over three ternary systems.

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Thermodynamics of the copper mattes of FeS-ZnS and Cu₂S-ZnS-FeS systems were studied in the temperature range from 1, 200°C to 1, 250°V
The vapor pressures of ZnS at various compositions of these mattes were measured by the dew point method and from these experimental data thermodynamic functions were calculated.
In the FeS-ZnS system, activity curves of ZnS and FeS deviated positively from Raoult's law and the degree of deviation was represented by activity coefficient γ. The values of γ were 4-6 for ZnS and 1-1.05 for FeS. The points which ZnS in mattes precipitate, i. e. activity of ZnS eqval to unity, were about 0.23, 0.25 for molar fraction of ZnS at 1, 200°C, 1, 250°C respectively. Also by using these activity data, free energy, enthalpy and entropy of mixing were calculated.
From activity measurements of ZnS in the mattes of Cu₂S-ZnS-FeS system at 1, 200°C, iso-activity curve of ZnS and iso-free energy curve in the Cu₂S-ZnS-FeS system at 1, 200°C were obtained.

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