閃亜鉛鉱のザンセート吸着に関する実験的研究 (第2報)

銅活性閃亞鉛鉱に対する吸着

抄録

Samples of sphalerite used in this experimental work and experimental procedures were same as in the experiments on unactivated sphalerite previously reported (the report I).
From the results of this investigation the following conclusions were obtained:
(1) In the solution in 'which pH value was not regulated, adsorption isotherm of KEtX well fitted the Freundlich equation when its equilibrium concentration was less than 100 mg per 1. On applying the data obtained to the Langmuir equation, it appeared that multimolecular adsorption of KEtX or chemical reaction of some unknown mechanism may have occurred at the surface.
(2) The amount of KEtX adsorbed decreased with increase in pH value of solution or decrease of hydrogen ion concentration [H+] in the solution and was given by the following equations logΓ=logΓ₁-k (pH) or Γ=Γ₁ [H⁺] Kwhere r is the amount adsorbed, F1 is the amount adsorbed at pH=O or [H⁺] =1, and k is a constant depending on total xanthate concentration or the xanthate ion concentration. But it was concluded that influence of xanthate ion concentration on its adsorption predominated over the concentration of hydroxyl ion.
(3) If the amount of KEtX adsorbed was equal, there was always a correlation between xanthate ion concentration [X^-] and hydrogen ion con concentation [H⁺] expressed by the following empirical equation [H⁺] ^0.15·[X^-] =mwhere m is a constant depending on the amount of KEtX adsorbed. This fact indicates that the correlation proposed by Barsky can be generally applied to the case above mentioned.
(4) Within the limits of the experiment, it was ascertained that alkali regulating agents such as KOH, NaOH, Ca (OH) ₂ and Na₂CO₃ did not cause different effect on the adsorption of KEtX.
(5) Experiments on adsorption rate of KEtX was carried out in the cases of different concentrations of KEtX and pH values respectively. From these results, the rate of adsorption with time t was generally given by the following equationsΓ=Γ₁+K log t or Γ=Γ₁t^1/nwhere k and 1/n are constants. And it was found that at a fixed pH value these constants increased linearly with increase in KEtX concentration and at the same KEtX concentration had a relation with hydroxyl ion concentration [OH^-], expressed by the following equations k [OH^-] ^α=b or [OH^-] ^α/n=bwhere a and b are constants depending on the KEtX concentration.
(6) The adsorption rate and the total amount of KEtX adsorbed both increased with rise of temperature. This fact suggested that chemical reaction of some unknown mechanism was implicated in adsorption of KEtX and it is presumed that oxygen in solution may have played an important role.
(7) It appeared that zinc xanthates behave themselves for adsorption quite as well as potassium