A novel collector with wide pH adaptability and high selectivity towards flotation separation of scheelite from calcite

• Published in: Minerals engineering 2020-11, Vol.158, p.106606, Article 106606
• Main Authors: Ni, Chenquan, Liu, Chang, Fang, Xingzhong, Ren, Zhong, Yang, Liming, Shao, Penghui, Luo, Xubiao, Zeng, Guisheng, Duan, Limin, Liu, Tingxi
• Format: Article
• Language: English
• Subjects: Calcite; Flotation collectors; Gemini surfactant; Scheelite; Tungsten
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2020.106606

[Display omitted] •Conducted flotation of scheelite from calcite with HDDA as collector.•Obtained maximum scheelite recovery efficiency of 95.26% at pH above 9.•Obtained minimum calcite recovery efficiency of 13.68% at pH 7.•Examined recovery efficiency in a wide pH range of 6–11.•HDDA showed an obvious higher separation efficiency than conventional NaOL. In this work, we synthesize a new type of Gemini surfactant (hexane-1,6-didodecyldimethylammonium bromide, HDDA) to be used for the first time as a collector for the froth flotation separation of scheelite from calcite. Micro-flotation experiments with HDDA show the recovery efficiency of scheelite greater than 91% (maximum value of 95%), while recovery efficiency of calcite observes at smaller than 40% (minimum value of 14%) over a wide range of pH (6–11). The best separation pH is found as 7. Moreover, the separation process efficiency in presence of HDDA is greater than that of conventional sodium oleate in the flotation of binary minerals. The tungsten trioxide (WO3) grade of concentrate based on HDDA can reach to 65% at pH 7, which is obviously larger than that when sodium oleate is used (40%), which is in accordance with the single mineral flotation results. The results indicate the superior selectivity, outstanding collecting capacity and excellent pH adaptability of HDDA in the flotation separation process.