Data_Sheet_1_Flotation Separation of Diaspore and Kaolinite by Using a Mixed Collector of Sodium Oleate-Tert Dodecyl Mercaptan.ZIP

Sodium oleate (NaOl), a collector in diaspore flotation, has been widely used for more than 30 years, while its low selectivity becomes an issue under today's process requirement. This study introduced tert dodecyl mercaptan (TDM) together with NaOl as a mixed collector to improve selectivity in diaspore flotation. We found that using the mixed collector of NaOl/TDM (total concentration 0.1 mM, the molar ratio 8:2 of NaOl: TDM) at pH = 9–10 significantly effectively separated diaspore and kaolinite. Comparing the recovery of Al2O3 and the ratio of Al2O3 to SiO2 (A/S) treated by NaOl/TDM (pH = 9) and NaOl (pH = 10), the Al2O3 recovery and A/S in concentrate for NaOl/TDM are 7.5% and 2.2 higher than that for NaOl in mixed mineral flotation. Also, surface tension measurements, Zeta potential measurements and Fourier Transform Infrared (FTIR) spectra analysis were used to examine its selectivity from a flotation mechanical perspective. Surface tension measurements show that mixed collector NaOl/TDM has stronger surface activity and hydrophobic association than NaOl. The results of Zeta potential measurements and FTIR spectra analysis indicate that NaOl and TDM can selectively co-adsorb diaspore through physical adsorption. Moreover, the adsorption of TDM promotes the adsorption of NaOl on diaspore. However, when NaOl/TDM treats on kaolinite together, TDM can hardly adsorb on mineral surface, nor can it promote the adsorption of NaOl.

油酸钠（Sodium oleate, NaOl）作为一水硬铝石浮选的捕收剂，已被广泛应用三十余年，但其选择性欠佳的问题在当前工艺要求下愈发突出。本研究将叔十二烷基硫醇（tert dodecyl mercaptan, TDM）与NaOl复配为混合捕收剂，以提升一水硬铝石浮选的选择性。研究发现，在pH值9~10条件下，使用总浓度为0.1 mM、NaOl与TDM摩尔比为8:2的NaOl/TDM混合捕收剂，可实现一水硬铝石与高岭石的高效分离。对比两种处理体系下的氧化铝（Al₂O₃）回收率与铝硅比（Al₂O₃与SiO₂的比值，A/S）：在混合矿物浮选体系中，采用NaOl/TDM（pH=9）处理时，精矿中的氧化铝回收率与铝硅比分别较NaOl（pH=10）处理时高出7.5%与2.2。此外，本研究通过表面张力测试、Zeta电位测试与傅里叶变换红外（Fourier Transform Infrared, FTIR）光谱分析，从浮选界面化学视角探究了该混合捕收剂的选择性机制。表面张力测试结果表明，相较于单一NaOl，NaOl/TDM混合捕收剂具备更强的表面活性与疏水缔合能力。Zeta电位测试与FTIR光谱分析结果显示，NaOl与TDM可通过物理吸附作用在一水硬铝石表面选择性共吸附；且TDM的吸附可促进NaOl在一水硬铝石表面的吸附。然而，当NaOl/TDM共同作用于高岭石时，TDM几乎无法在矿物表面吸附，亦无法促进NaOl的吸附。