モノアミン, ジアミンおよびトリアミンによるヘマタイトからの脱珪浮選に関する基礎的研究

抄録

Flotation experiments of fine particles (-10μm) of quartz and hematite were carried out as a function of pH using mono-, di-, and triamine acetates as collectors by Denver-type laboratory flotator. Amines used were dodecyl amine (C12H25NH2), dodecylpropylene diamine (C₁₂H₂₅NH (CH2) 3NH2), and dodecyldipropylene triamine (C12H25NH (CH2) 3NH (CH₂) ₃NH₂), respectively. Dissociation constants of diamine and triamine were determined by pH titration according to the Schwarzenbach's method. Reverse flotation of quartz from an artificial mixture (1: 1 by weight) with hematite was also carried out by varying the collector concentration in both acidic and alkaline media.
1) As dissociation constants, pK_α1 10.2 and pKa2 11.3 for diamine, and pK_α1 9.0, pK_α2 10.1, and pK_α3 11.3 for triamine were obtained, respectively.
2) Individual flotation tests showed that, in acidic media, flotation recovery of quartz increased with the increase of the number of amino radical of collectors, while no appreciable difference in flotation recovery of hematite was indicated. In alkaline media, flotation recoveries of quartz were enhanced with diamine and triamine, and floatability of hematite increased with increasing the number of amino radical of collectors.
This flotation behavior was explained by an electrostatic interaction between surface charges of minerals and positive charges of collectors resulting from their dissociation.
3) Reverse flotation of quartz from an artificial mixture was impossible in acidic media (pH=5) because of heterocoagulation of quartz and hematite.
Better results of reverse flotation were obtained in alkaline media (pH=10) using diamine and triamine in comparison with those using monoamine.
Reverse flotation tests at pH=10 and at a collector concentration of 5×10^-5M showed that the flotation rate of quartz increased while that of hematite decreased with increasing the number of amino radical of collectors.