Research on new beneficiation process of low-grade magnesite using vertical roller mill

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2020-04, Vol.27 (4), p.432-442
• Main Authors: Li, Chuang, Sun, Chuan-yao, Wang, Yu-lian, Fu, Ya-feng, Xu, Peng-yun, Yin, Wan-zhong
• Format: Article
• Language: English
• Subjects: Anniversaries; Beneficiation; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Circuits; Civil engineering; Composites; Corrosion and Coatings; Dosage; Experiments; Fineness; Flotation; Glass; Magnesite; Magnesium carbonate; Magnesium oxide; Materials Science; Metallic Materials; Metallurgy; Mineral processing; Minerals; Natural Materials; Process parameters; Reverse flotation; Roller mills (grinders); Surface roughness; Surfaces and Interfaces; Thin Films; Tribology
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-019-1898-2

We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball mill. We conducted experiments involving the reverse flotation and positive flotation of low-grade magnesite to determine the optimum process parameters, and then performed closed-circuit beneficiation experiments using the vertical roller mill and ball mill. The results show that the optimum process parameters for the vertical roller mill are as follows: a grinding fineness of 81.6wt% of particles less than 0.074 mm, a dodecyl amine (DDA) dosage in magnesite reverse flotation of 100 gt -1 , and dosages of Na 2 CO 3 , (NaPO 3 ) 6 , and NaOL in the positive flotation section of 1000, 100, and 1000 gt −1 , respectively. Compared with the ball mill, the use of the vertical roller mill in the beneficiation of low-grade magnesite resulted in a 1.28% increase in the concentrate grade of MgO and a 5.88% increase in the recovery of MgO. The results of our causation mechanism analysis show that a higher specific surface area and greater surface roughness are the main reasons for the better flotation performance of particles ground by the vertical roller mill in the beneficiation of low-grade magnesite.