The Fukazawa Kuroko deposit is situated in the almost central part of the Hokuroku basin. The Tsunokakezawa ore body dealt in this paper is the largest in the Fukazawa deposit and consists mainly of typical stratiform Kuroko ore body with several outlets of ore fluids forming siliceous ore bodies. The stratiform Kuroko ores are composed largely of sphalerite, galena and barite with pyrite, chalcopyrite, tetrahedrite, bornite, calcocite and covelline. Chalcopyrite and pyrite are commonly found in the coarse grained stratiform Kuroko ores which are distributed mainly in the western part of the Tsunokakezawa ore body. On the other hand, tetrahedrite, bornite, chalcocite and covelline are found in the fine grained ores with barite, and are commonly in the eastern part of the ore body. Colloform and framboidal textures are frequentry observed in the fine grained ores.
Filling temperatures have been measured for 104 fluid inclusions in sphalerite. barite and calcite. They range from 209°to 370°C. Most of them are ranged between 250°C and 340°C. The higher temperature values are obtained largely from the western part of the ore body and the lower values from the eastern. Inclusions in the Kuroko ores formed near the outlets of ore fluids yield higher filling temperatures than those in the outskirts of them.
From these temperature data, the depth of sea in the central part of the Hokuroku basin at the formation of the Fukazawa deposit is estimated to have been about 1440 meters at least. It is deeper than that proposed by SATO (1968). However, it is shallower than that supposed from the foraminiferal assemblage by GUBER and OHMOTO (1978).

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The Charpy impact test which is recognised as a fast, inexpensive and versatile method of obtaining meaningful data ond ynamic fracture of materials was carried out to propose the simple ways of obtaining the fracture energy, W, and the crackpropagation velocity.
The total absorbed energy, ΔE, in Charpy test contains, in addition to W, a considerable amount of loss energy, L, mainlyspent to accelerate the broken specimen and caused by friction between the specimen and its support. The test with a brokenspecimen slightly connected by cellophane tape, which may be called “Blank Test”, was performed to estimate L because theabsorbed energy in the blank test, ΔEblank, may be the summation of the kinetic energy of broken specimen and the friction alloss. Experimentally, it was verified that L can be equated with ΔEblank at the same counter angle of pendulum. Therefore, W can be calculated by (ΔE-ΔEblank).
In the second part of the paper, a new approach to crack velocity measurement was discussed. The very fine lines of conducting silver paint were applied to the side of the specimen, spaced at 3mm intervals. In the test, the subsequent failure of paint lines associated with crack propagation through the specimen was monitored as a series of small step voltage changein the recording circuit. The results showed that the crack velocity first accelarated and attained to the maximum near the centerline of the specimen, followed by the rapid decrease toward the end of the crack path. The maximum velocity measuredin this experiment was about 60% of the theoretical terminal velocity (=0.38 E/ρ).

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The longwall mining at Kushiro Colliery is characterized by highly mechanized face equipments and the majority of output comes from this coal winning method. The rate of face advance has, however, declined with increase of mining depth by a main reason why driving and successive maintenance of gate roads has been confronted with diffiulties. To secure a solution of this problem, a new type of gate road system investigated and adopted to retreat mining panels.
In the new system only one of gate roads is driven before winning coal, and another is extended with advance of coal face as if in advance longwall mining system (Fig. 1). At the situation the main gate road is driven in solidcoal by the same way as existing method, but the auxiliary road is constructed in goaf with ring or arch-invert support elements and tubular shield elements so that this gate road can be named as a liner road (Fig.10).
The structure and size of a liner road was determined so as to satisfy both requirements from ventilation and strucrural analysis. The preliminary design lead us to make use of the standard steel beam for the support element and a thin steel plate for shield element.
Up to the present this system has been adopted to five mining panels so that total coal production amounted to 550, 000 tons. In all cases liner roads were perfectly maintained during working of mining panels without any sort of trouble. The new system also revealed the economic feasibility through the result that the expenditure for gate roads in a mining panel could be reduced by about 27% in average comparing with existing longwall system.

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In this report, the natural frequencies, dynamic tensions and other characteristic values are derived for the winding rope with tail rope at work, and the analytical results are compared with some measured data in rope guided winding shafts.
Some results obtained are as follows;
(1) The portion of the winding rope between driving sheave and head sheave must be included into consideration to thel ongitudinal vibration of the winding rope.
(2) The natural frequency of the longitudinal vibration of the winding rope can not be calculated unless the weight of the tail rope is smaller than the weight of the cage, in which the weight of the tail rope may be an additional weight of the cage.
(3) The 2nd mode amplitude of the longitudinal vibration of the winding rope with tail rope is greater than the 1st mode amplitude, when the cage is disturbed near the pit mouth.

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Acid drainage from iron sulfide mine is neutralized by calcium carbonate or calcium hydroxide, after the oxidation of ferrous ions to ferric ions. And the precipitates formed, which mainly consist of ferric hydroxide and gypsum, are dumped to mill tailing dam. In order to utilize these precipitates, the separation of ferric hydroxide and gypsum by flotation method has been investigated. In the previous report, it was shown that synthetic mixture of ferric hydroxide and gypsum was satisfactorily separated each other in tne wide pH range by using dodecylammonium acetate (DAA) as a collector, where gypsum was floated and terric hydroxide remained in the solution.
This paper was concerned with the flotation separation of the precipitates formed by neutralizing an artificial acid mine water containing 1000mg/l of ferric ions and 6000mg/l of sulfate ions with calcium carbonate. It was indicated in the flotation tests of the precipitates without modifier by using DAA that the selectivity was affected by the rate of neutralization and that satisfactory results were obtained only when the aging process was introduced in the neutralization at pH 2.9. But it was found that starch acted as a selective flocculant as well as a depressor for ferric hydroxide and gave satisfying selectivity, even when rapid neutralization was adopted. These flotation products could be easily upgraded by washing with small volume of water or acidified saturated solution of gypsum.

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Floatability of zeolite with dodecylammonium acetate (DAA) has been investigated in order to recover cesium from high-level radioactive waste water by means of adsorbing particle flotation using zeolite as a adsorbing medium.
The results obtained are as follows:
1) Zeolite particles can be effectively floated with DAA at wide pH range from 4 to 10, especially when a frother (pine oil) is added. Short conditioning for about 30seconds gives sufficient floatability of zeolite and further conditioning reduces the floatability.
2) The rate of adsorption of DA⁺ ion against zeolite is more rapid than that of Cs⁺ ion, but the saturation amounts of the former are smaller than those of the latter.
3) The sign of zeta potential of zeolite is reversed from negative to positive by the adsorption of DA⁺ ion.
4) The specific surface area of zeolite is remarkably reduced by the adsorption of DA⁺ or Cs⁺ ion.
5) The amounts of DA⁺ ion adsorbed against Cs type zeolite are slightly small, compared to those against natural zeolite. The adsorption of DA⁺ ion against Cs type zeolite is accompanied by the elution of Cs⁺ ion. But, the amounts of Cs⁺ ion eluted are far smaller than those of DA⁺ ion adsorbed.
6) From the above results, it is concluded that the adsorption of DA⁺ ion against zeolite is caused by specific one rather than by ion exchange mechanism and it occurs not only on the surface, but also in the channels or carities of zeolite.

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The ternary miscibility gap and tie-line distributions in the copper-poor region of the Pb-Cu-S system were investigated at 1150°C and 1200°C. The result obtained at 1150°C was almost the same as obtained at 1200°C within experimental errors and it was concluded that the miscibility gap boundary rises sharply at the temperature range from 1150°C to 1209°C. Activities of lead, copper and sulfur were calculated from the tie-line distributions at 1200°C and were discussed in comparison with the data reported by other investigators.

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The equilibrium vapour pressure of synthesized arsenates (CaO·As₂O⁵ and 2CaO·As₂O₅) and arsenite (3CaO·As₂O3) has been measured respectively by transportation method. By x-ray and T. G. analysis, CaO·As₂O₅, 2CaO·As2O5 and 3CaO·As₂O₃ are found to decompose according to the following reactions and to start to dissociate vigorously at about 730°C, 950°C and 770°C respectively in the Ar atmosphere.
2 (CaO·As₂O₅)(s)=2CaO·As₂O₅ (s) +1/2As₄O₆ (g)+O₂ (g)
3 (2CaO·As₂O₅)(s)=2 (3CaO·As₂O₅)(s)+1/2As₄O₆ (g) +O₂ (g)
3CaO·As₂O₃ (s)=3CaO (s)+1/2As₄O₆ (g) When these reactions occur in the innert gas, 2P_As4O₆ is equal to PO2. Therefore, the equilibrium constant Kp of each reaction can be estimated by measuring the AS4O6 gas pressure. The relations between Kp and 1/T of each reaction obtained are as follows:
CaO·As₂O5:(905-988°C) logKp=-23.490×10³/T+16.37
2CaO·As₂O₅:(1017-1115°C) logKp=-26.590×10³/T+16.21
3CaO·As₂O₃:(811-891°C) logKp=-5815/T+4.03

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This cycle consists of a combination of sulfurization of ferrous sulfide with hydrogen sulfide and thermal decomposition of the sulfurization product under normal or reduced pressure.
Three types of ferrous sulfide, thermal decomposition product of natural pyrite, natural pyrrhotite, and synthetic ferrous sulfide were examined.
Both sulfurization product and thermal decomposition product in every case were identified as ferrous sulfide by X-ray diffraction analysis. But the formation of higher sulfide such as pyrite in sulfurization is not always desirable, because it gives thermodynamically very small hydrogen concentration. A representation for the two step process in this research can therfore be given in the following equations, provided that FeS1+x and FeS1+x+y indicate nonstoichiometric composition of the sulfide.
FeS₁+x+yH₂S=FeS₁+x+y+yH₂ FeS₁+x+y=FeS₁+x+yS/yH₂S=yH₂+yS
The thermal decomposition product of natural pyrite showed the most favorable results for obtaining not only higher concentration of hydrogen but also larger amount of evolved hydrogen. This may be due to the porous solid structure caused by the volume contraction under thermal decomposition.
In the cyclic experiments, the hydrogen concentration at the sulfurization increased with an increase in the decomposition temperature, whereas the temperature determined as optimum for sulfurization was in the range from 500 to 650°C. The latter result can be considered as resulting from the interplay of the temperature dependence of the reaction rate and the equilibrium concentration of hydrogen.

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