Study on Phase Transfer Catalyst Used in the Synthesis of Sodium Isobutyl Xanthate

• Main Authors: Zhijun Ma, Liang Cheng, Xingyuan Weng, Ye Gao, Jiuxing Huang
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Minerals
• Subjects: phase transfer catalyst; sodium isobutyl xanthate; solvent method; orthogonal experiment; weight matrix
• Online Access: https://www.mdpi.com/2075-163X/11/8/850

Xanthates are by far the most widely used collectors in the froth flotation beneficiation of sulfide ores. However, the xanthate production process suffers from low yield, low productivity, long reaction time and environmental pollution. To address these issues, an effective method was developed for the synthesis of xanthates using phase transfer catalyst. Sodium isobutyl xanthate was synthesized from isobutyl alcohol ((CH₃)₂CHCH₂OH), sodium hydroxide (NaOH) and carbon disulfide (CS₂) with dichloromethane (CH₂Cl₂) as solvent and cetyltrimethylammonium bromide (CTAB), cetyltrimethylammonium chloride (CTAC), tetrabutylammonium bromide (TBAB) and tetrabutylammonium chloride (TBAC) as phase transfer catalyst. The compound was characterized by elemental analysis, infrared spectrum, ¹H NMR and ¹³C NMR. The influencing factors on the content and yield of sodium isobutyl xanthate including phase transfer catalyst type, phase transfer catalyst dosage and reaction time were studied by single-factor experiments. The influencing factors on the product purity and yield including reaction temperature, solvent volume, material ratio and rotating speed were studied by orthogonal experiments. The results showed that when the amount of TBAC was 3.0%<i>m</i>_alcohol, the reaction temperature was 35 °C, the solvent volume was 3.5 <i>V</i>_alcohol, the rotating speed was 180 rpm, the reaction time was 4 h and the material ratio was n[(CH₃)₂CHCH₂OH]:n(NaOH):n(CS₂) = 1:1:1.10, the product yield could be up to 86.66% and the product purity reached 82.56%.