Inhabitation Mechanism of Calcium Lignosulfonate on Serpentine During Ascharite Flotation
HAN En-ze1，LI Zhi-hang1,2*，CHENG Hong-fei1，XIONG Kun1
1. School of Earth Science and Resources, Chang’an University, Xi’an 710054, China
2. State Key Laboratory of Mineral Processing, Beijing 102200, China
Abstract：As a layered silicate mineral, serpentine is easy to slime. Fine serpentine particles can significantly deteriorate the flotation environment and have adverse effects on flotation indexes. Ascharite and serpentine are the most important non-metallic ores in paigeite ore. They are closely associated with each other and have fine particle size, so they need to be sorted under fine particle size. However, a large quantity of fine serpentine particles not only reduce the recovery of ascharite, but also flow into the concentrate with ascharite, leading to the low quality of the concentrate. Effective inhibition of serpentine is the key to solve the problem of ascharite flotation from serpentine. As an anion inhibitor, the effect of calcium lignosulfonate (CLS) on serpentine surface is rarely studied, and the inhibitory mechanism is not very clear. The inhibition mechanism of CLS on serpentine was discussed by flotation test, Zeta potential analysis, XRD and XPS. The inhibition mechanism of CLS on serpentine was discussed by flotation test, Zeta potential analysis, XRD and XPS, providing a novel method for efficient separation of ascharite from serpentine. The experimental results show that serpentine can significantly reduce the recovery rate of ascharite flotation when pH>8. As the pH value increased to 10, the recovery of ascharite decreased to 42.8% with the serpentine recovery of 17.6% in concentrate at the same time. However, the serpentine recovery was reduced to less than 5% and the ascharite recovery was up to about 66% when the 20~40 mg/L CLS was used in flotation. The mechanism analysis shows that the adsorption of CLS on the serpentine surface can reduce the Zeta potential of serpentine, which is attributed to influences of chemical adsorption and hydrogen bonding. The former is achieved by forming bond with Mg atom on the serpentine surface, and the latter is the result of the interaction between the phenolic hydroxyl group of CLS and the hydroxyl group in serpentine.
