In this work, we intended to study on high expansion-foam plugs, and obtained the following results.
1) The conversion efficiency is a little affected by the spraying rate (at 4.7×10^-3and 6.5×10^-3m³/min), within the ranges examined.
The conversion efficiency is lowered by an unduly low airspeed, but in a small model roadway condition it would normally be about 70 percent.(see TABLE 1)
2) Effect of the airspeed on the wetness of a foam plug reaching a mark point in a model roadway. It has been observed that the wetness of a foam plug declines according to the equation.W_b^v=W_vexp (-Kl) an equation for the value (-K) is as follows;-K=b/lgl where, b=n^-1Σxy-n^-1Σxn^-1Σy/n-1Σx^2- (n^-1Σx) ²
3) Dependence is implied in Fig. 3-4, which shows that the plug's back-pressure rise is steeper when the plug is moving slowly.

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The comminutive function for the open-air bubbles on the impeller of Fahrenwald flotator is considered due to the hydraulic action of the pulp stream and the frother is said to be effective against the coalescence of reproduced air bubbles, but the comminuting strength and reduction ratio of air bubbles are not yet known- and the details of the effect of frothers are still unkown.
From this point of view the author made are exprimental studies on the above items by making use of the vertical type flowing channel consisted of cylindrical tubes, through the application of single air bubbles to water flow in the apparatus, and he obtained the following results:
1) The relationship of the equivalent diameter dmm of single air bubbles with the critical circling velocity U_ccm/sec of the impeller comminuting air bubbles can be represented by U_c=K/d^mwhere K and m stand for coefficients.
2) The ratio R of the diameter of the reproduced bubble to the original bubble can be represented by the following formula: R=d^-0.500-(2430-123d)(U-U_c) ^0.794·10^-6, where U>U_c, with a given circling velocity of the impeller.
3) The form of the bubble will not only influence on the degree of comminuting strength, but will vary the size of the reproduced air bubbles.
4) Along with the increase of the frother, the comminuting strength of the bubbles with the same diameter will be lowered (though the lowering rate is small) and simultaneously the size of the reproduced air bubbles will become smaller.
5) Accordingly high efficiency of the impeller as a pump will not essentially be great in comminutive function for air bubbles.

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To investigate the mechanism of the reaction between mineral surface and xanthate in flotation, the reactions between mercury and xauthate were thermodynamically studied with measuring the potential of the following cells: Hg|Hg₂X₂|X^-||Hg₂⁺⁺||Hg.(The abbreviation ‘X’ is used for xanthate.)
The standard potential, the free energy, the solubility product, and the reaction heat of the mercury xanthate were determined. Xanthates used in the experiments were ethyl xanthate, iso-propyl xanthate, and amyl xanthate.
The results obtained are as follows:-(1) The standard potentials of the cells, Hg|Hg₂X₂|X^-||Hg₂⁺⁺|Hg, are 1.066 volt for ethyl xanthate, 1.078 volt for iso-propyl xanthate, and 1.109 volt for amyl xanthate.
(2) The change of free energies for formation of mercury xanthate are -4.91×10⁴cal for ethyl xanthate, -4.97×10⁴cal for iso-propyl xanthate, and -5.11×10⁴cal for amyl xanthate.
(3) The solubility products of mercury xanthate are 1×10^-36for ethyl xanthate, 4×10^-37for iso-propyl xanthate, and 4×10^-38for amyl xanthate.
(4) The reaction heats of the formation of mercury xanthate are -5.46×10⁴cal for ethyl xanthate, -5.53×10⁴cal for iso-propyl xanthate, and -5.68×10⁴cal for amyl xanthate.
(5) The stable formation of metal was xanthate was considered on mercury surface contacting a dilute aqueous sloution of xanthate by comparing the potential of the cell, Hg|Hg₂X₂|X^-||Hg₂⁺⁺|Hg, with that of the cell, Hg|X^-||Hg₂⁺⁺|Hg.

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SiHCl₄gas carried by argon or hydrogen was introduced into the quartz tube heated from 700°Cto 1, 100°C, and the conditions of thermal decomposition and reduction were obtained. From the results of thermal decomposition in the large A/SiHCl3 ratio, it was assumed that 4SiHCl₃(g) =Si (s) +3SiCl₄(g) +2H₂(g) was the main reaction in this process. The percentage of silicon yield in argon was larger than thereaction in hydrogen between 700°C and 900°C, however, the yield more than 50% was found in the higher H₂/SiHCl₃mole ratio, Silicon was deposited in various forms, for examples, compact layer, powder, fine needle and polygonal forms. By the use of free energy of SiHCl₃formation and other values, the comparisons among experimental results and thermodynamical considerations were also obtained.

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Effect of iron, nickel, zinc and aluminium on anode potential has been studied. Iron exists of copper grain boundaries asα-Fe, so it reacts with Cu⁺⁺ ions to produce considerable amount of copper slime on anode surface. Consequently, anode potential of iron bearing copper anode is raised. Within the amount as impurities nickel, zinc and aluminium are dissolved in copper asα-solid solution. By the alloying of these elements standard electrode potentials of these alloys are raised, but these effects are very little. During electrolysis of nickel bearing copper anode nickel salt is produced in anode film solution. The presence of nickel salt increase electric resistance, so the anode potential is raised. Zinc atoms in copper anode react with Cu⁺⁺ ions to produce copper slime on the anode surface. The presence of copper slime yields raise of anode potential. The effect of aluminium is little.

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