<報文>キサントゲン酸による硫化鉱物捕収に関する基礎的研究(第2報) : キサントゲン酸の重金属錯塩の生成反応

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Spectrophotometric studies were made on the formation reactions of Pb (II), Ni (II), Co (II), complexes with ethylxanthic acid and Co (II) complexes with methyl-, n-propyl-, n-butylxanthic acids in acetone-water (1 : 1) solution. The effects of various factors affecting the formation reactions of these complexes were studied and the compositions and formation constants were evaluated. Xanthic acid reacts with Pb (II), Ni (II), and Co (II) to form only one species of complex, respectively. The composition of Pb (II) complex with xanthic acid can be represented as 1 : 2,and that of other complexes are all 1 : 3. It may be considered that these complexes formed four-membered chelates with two bidentate ligands. The formation constants of PbX_2 and NiX_3^- complexes in acetone-water (1 : 1) solution were respectively determined to be 1.83×10^8 and 0.90×10^<14> at 25℃ and ionic strength of 0.5. The formation constants of CoX_3^- complexes were determined respectively to be 1.02×10^<12>, 0.98×10^<13>, 3.40×10^<13>, and 4.53×10^<13> for methyl-, ethyl-, n-propyl-, and n-butylxanthic acids. It was found that the values of pKa of xanthic acids vary linearly with the logarithmic values of the formation constants of their Co (II) complexes. And it was pointed out that the important relation exists between the effectiveness of xanthic acids as collector in flotation and the values of the formation constants of their heavy metal complexes.
1960-08-25