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

Abstract

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 Na₂CO₃, (NaPO₃)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.

Keywords

low-grade magnesite / vertical roller mill / reverse flotation / positive flotation / new beneficiation process

References

[1] Bentli I, Erdogan N, Elmas N, Kaya M. Magnesite concentration technology and caustic-calcined product from Turkish magnesite middlings by calcination and magnetic separation. Sep. Sci. Technol, 2017, 52, 1129.

[2] Zhang H, Liu WG, Han C, Wei DZ. Intensify dodecylamine adsorption on magnesite and dolomite surfaces by monohydric alcohols. Appl. Surf. Sci., 2018, 444, 729.

[3] Misch D, Pluch H, Mali H, Ebner F, Hui H. Genesis of giant Early Proterozoic magnesite and related talc deposits in the Mafeng area, Liaoning Province, NE China. J. Asian Earth Sci., 2018, 160, 1.

[4] Zhao Z, Cui XL, Wang DH, Chen YC, Bai G, Li JK, Liu XX. Review of the metallogenic regularity of magnesite deposits in China. Acta Geol. Sin., 2015, 89, 1747.

[5] Brezáni I, Škvarla J, Sisol M. Reverse froth flotation of magnesite ore by using (12-4-12) cationic gemini surfactant. Miner. Eng., 2017, 110, 65.

[6] Teng Q, Feng YL, Li HR. Effects of silicate-bacteria pretreatment on desiliconization of magnesite by reverse flotation. Colloids Surf, A, 2018, 544, 60.

[7] Zhang H, Liu WG, Han C, Hao HQ. Effects of monohydric alcohols on the flotation of magnesite and dolomite by sodium oleate. J. Mol. Liq., 2018, 249, 1060.

[8] Sun WH, Dai SJ, Liu WG, Yu LT. Study on removing impurity from magnesite ore by two step reverse flotation. Bulg. Chem. Commun., 2017, 49, 678

[9] Yao J, Yin W, Gong E. Depressing effect of fine hydrophilic particles on magnesite reverse flotation. Int. J. Miner. Process., 2016, 149, 84.

[10] Sun QY, Yin WZ, Li D, Fu YF, Xue JW, Yao J. Improving the sulfidation-flotation of fine cuprite by hydrophobic flocculation pretreatment. Int. J. Miner. Metall. Mater, 2018, 25, 1256.

[11] Niu YP, Sun CY, Yin WZ, Zhang XR, Xu HF, Zhang X. Selective flotation separation of andalusite and quartz and its mechanism. Int. J. Miner. Metall. Mater., 2019, 26, 1059.

[12] Fu YF, Zhu ZL, Yao J, Han HL, Yin WZ, Yang B. Improved depression of talc in chalcopyrite flotation using a novel depressant combination of calcium ions and sodium lignosulfonate. Colloids Surf., A, 2018, 558, 88.

[13] Xu PY, Hu C, Gan M, Li J, Pan X, Ye HQ. Analyses on uniformity of particles under HPGR finished grinding system. J. Cent. South Univ., 2018, 25, 1003.

[14] Prziwara P, Hamilton LD, Breitung-Faes S, Kwade A. Impact of grinding aids and process parameters on dry stirred media milling. Power Technol, 2018, 335, 114.

[15] Little L, Mainza AN, Becker M, Wiese J. Fine grinding: How mill type affects particle shape characteristics and mineral liberation. Miner. Eng., 2017, 111, 148.

[16] Reichert M, Gerold C, Fredriksson A, Adolfsson G, Liebewirth H. Research of iron ore grinding in a vertical-roller-mill. Miner. Eng., 2015, 73, 109.

[17] Jensen LRD, Friis H, Fundal E, Møller P, Brockhoff PB, Jespersen M. Influence of quartz particles on wear in vertical roller mills. Part I: Quartz concentration. Miner. Eng., 2010, 23, 390.

[18] Boussu K, van der Bruggen B, Volodin A, Snauwaert J, Haesendonck CV, Vandecasteele C. Roughness and hydrophobicity studies of nanofiltration membranes using different modes of AFM. J. Colloid Interface Sci., 2005, 286, 632.

[19] Xie Z, Jiang H, Sun ZC, Yang QH. Direct AFM measurements of morphology and interaction force at solid-liquid interfaces between DTAC/CTAC and mica. J. Cent. South Univ., 2016, 23, 2182.

[20] Jaycock MJ, Parfitt GD. Chemistry of Interfaces, 1981, Ellis Horwood, Chichester

[21] Meng QY, Feng QM, Ou LM. Flotation behavior and adsorption mechanism of fine wolframite with octyl hydroxamic acid. J. Cent. South Univ., 2016, 23, 1339.

[22] Fu YF, Yin WZ, Yang B, Li C, Zhu ZL, Li D. Effect of sodium alginate on reverse flotation of hematite and its mechanism. Int. J. Miner. Metall. Mater, 2018, 25, 1113.

[23] Zhong CB, Xu CL, Lyu RL, Zhang ZY, Wu XY, Chi RA. Enhancing mineral liberation of a Canadian rare earth ore with microwave pretreatment. J. Rare Earths, 2018, 36, 215.

[24] Xie WM, He YQ, Li H, Zhang Y, Zhu XN. Investigation of the energy-size reduction and mineral liberation of raw coal in the Hardgrove mill. Energy Sources Part A, 2018, 40, 446.

[25] Wang XM, Miller JD. Dodecyl amine adsorption at different interfaces during bubble attachment-detachment at a silica surface. Physicochem. Probl. Miner. Process., 2018, 54, 81

[26] Cao XF, Liu CM, Hu YH. Flotation of kaolinite with dodecyl tertiary amines. J. Cent. South Univ. Technol, 2009, 16, 749.

[27] Li D, Yin WZ, Xue JW, Yao J, Fu YF, Liu Q. Solution chemistry of carbonate minerals and its effects on the flotation of hematite with sodium oleate. Int. J. Miner. Metall. Mater, 2017, 24, 736.

[28] Rahimi S, Irannajad M, Mehdilo A. Effects of sodium carbonate and calcium chloride on calcite depression in cationic flotation of pyrolusite. Trans. Nonferrous Met. Soc. China, 2017, 27, 1831.

[29] Liu C, Feng QM, Zhang GF, Chen W, Chen YF. Effect of depressants in the selective flotation of scheelite and calcite using oxidized paraffin soap as collector. Int. J. Miner. Process., 2016, 157, 210.

[30] Ramirez A, Rojas A, Gutierrez L, Laskowski JS. Sodium hexametaphosphate and sodium silicate as dispersants to reduce the negative effect of kaolinite on the flotation of chalcopyrite in seawater. Miner. Eng., 2018, 125, 10.

[31] Feng QC, Wen SM, Zhao WJ, Chen Y. Effect of calcium ions on adsorption of sodium oleate onto cassiterite and quartz surfaces and implications for their flotation separation. Sep. Purif. Technol, 2018, 200, 300.

[32] Zheng RJ, Ren ZJ, Gao HM, Chen ZJ, Qian YP, Li YB. Effects of crystal chemistry on sodium oleate adsorption on fluorite surface investigated by molecular dynamics simulation. Miner. Eng., 2018, 124, 77.

[33] Luo XM, Wang YF, Ma MZ, Song SX, Zhang Y, Deng JS, Liu J. Role of dissolved mineral species in quartz flotation and siderite solubility simulation. Physicochem. Probl. Miner. Process., 2017, 53, 1241

[34] Liu LY, Min FF, Chen J, Lu FQ, Shen L. The adsorption of dodecylamine and oleic acid on kaolinite surfaces: Insights from DFT calculation and experimental investigation. Appl. Surf. Sci., 2019, 470, 27.

[35] Xu PY, Li J, Hu C, Chen Z, Ye HQ, Yuan ZQ, Cai WJ. Surface property variations in flotation performance of calcite particles under different grinding patterns. J. Cent. South Univ., 2018, 25, 1306.

[36] Patwardhan A, Honaker RQ. Development of a carrying-capacity model for column froth flotation. Int. J. Miner. Process., 2000, 59, 275.

[37] Rahimi M, Aslani MR, Rezai B. Influence of surface roughness on flotation kinetics of quartz. J. Cent. South Univ., 2012, 19, 1206.

[38] Xu LH, Hu YH, Wu HQ, Tian J, Liu J, Gao ZY, Wang L. Surface crystal chemistry of spodumene with different size fractions and implications for flotation. Sep Purif. Technol, 2016, 169, 33.

[39] Hu YH, Gao ZY, Sun W, Liu XW. Anisotropic surface energies and adsorption behaviors of scheelite crystal. Colloids Surf., A, 2012, 415, 439.