关键词: 低温　, 油酸钠　, 组合药剂　, 磁铁矿　, 吸附机理

Abstract: To address the issue that sodium oleate (NaOL),an anionic collector commonly used in reverse flotation,suf fers from poor solubility and limited collecting performance at low temperatures due to its long carbon chain,which necessitates maintaining pulp temperature ≥35 ℃ in industrial flotation and significantly increases energy consumption,this study proposes a blending strategy of short-chain sodium decanoate (NaD) with NaOL to improve low-temperature flotation efficiency through molecular synergistic effects.The effects of combined collector ratio,pH value,and depressant dosage on the flotation behaviors of magnetite and quartz were systematically investigated at 10 ℃.The results show that at a NaOL-to-NaD molar ratio of 8∶2 and a total dosage of 20 mg/L,the quartz recovery reaches 91.12% in single-mineral flotation,while the magnetite recovery is only about 4.46%,indicating a significant difference in floatability between the two minerals.Based on these conditions,flota tion separation tests on artificially mixed ore (magnetite-to-quartz mass ratio of 3∶2) were conducted,yielding a concentrate with iron grade of 64.64% and recovery of 98.63%,which are respectively 12.24 percentage points and 8.86 percentage points higher than those obtained with NaOL alone under the same conditions,achieving efficient separation of magnetite and quartz.Zeta potential,contact angle,Fourier-transform infrared (FTIR) spectroscopy,and atomic force microscopy (AFM) an alyses reveal that NaOL and NaD undergo synergistic co-adsorption on the quartz surface,where NaD fills the gaps among NaOL clusters to form a dense and uniform mixed adsorption layer,significantly enhancing the surface hydrophobicity and re ducing the surface potential of quartz,thereby improving the collecting selectivity at low temperature.This study effectively o vercomes the low-temperature adaptability issue of fatty acid collectors through a molecular structure complementarity strategy, providing a new approach to reduce costs and improve efficiency in low-temperature flotation processes.