The role of sodium tripolyphosphate in wet grinding process of magnesite

The grinding process urgently needs to address the technical challenges of high energy consumption and low efficiency. In this paper, in order to improve the efficiency of magnesite grinding process, sodium tripolyphosphate (STPP) was selected as a grinding aid. Grinding tests showed that STPP significantly improved the mass fraction of − 0.074 mm in grinding products by 6.8% points. The mechanism of STPP on grinding process was analyzed by Fourier transform infrared spectrum (FT-IR) measurement, contact angle detection, zeta potential test, specific surface area and scanning electron microscopy (SEM) tests. The FT-IR and contact angle measurement results indicated that STPP had chemical and physical adsorption on magnesite surface, which improved its hydrophilicity, and promote water wetting action furtherly. So it can improve the grindability of magnesite. It can be seen by zeta potential detection that STPP increased the absolute value of magnesite to increase the electrostatic repulsion energy between particles (UE). And then, the dispersion of particles was improved. In addition, specific surface area and SEM tests indicated that STPP can increase the specific surface area of grinding products, and extend the defects and cracks of magnesite surface.