An investigation of the corrosive wear of steel balls in grinding of sulphide ores

Document Type : Research Paper

Authors

1 Department of Mining, Petroleum and Geophysics, Un iversity of Shahrood, Shahrood, 36199-95161, Iran

2 School of Mining Engineering, College of Engineering, University of Tehran, Iran

Abstract

Ball mills are common grinding equipment in mineral processing industries. Ball wear results from three mechanisms namely impact, abrasion and corrosion. Of these, the corrosion mechanism is the least investigated, due to its chemical-electrochemical nature. Therefore, the aims of this research were to investigate the grinding chemistry influence (slurry pH, solid percentage, water chemistry and gas purging) on corrosive wear of steel balls and to determine the contribution of corrosion mechanism to total wear of steel balls. The results indicated that the mass losses of steel balls could be reduced considerably by controlling the pulp chemistry inside the mill. In addition, the results showed that 73.51% of the corrosion products are generated from the oxidation of steel balls. It was also estimated that the corrosion mechanism accounts for 26.68% of the total wear of steel balls.

Keywords


[1] Mori, H., Mio, H., Kano, J. and Saito, F. (2004). “Ball mill simulation in wet grinding using a tumbling mill and its correlation to grinding rate”. Powder Technology, Vol. 143–144, pp. 230–239. [2] Ajaal, T., Smith, R.W. and Yen, W.T. (2002). “The Development and characterization of a ball mechanical alloying”, Canadian Metallurgical Quarterly, Vol. 41, pp. 7-14. [3] Wills, B.A and Napier-Munn, T.J. (2006). “Mineral Processing Technology”, Elsevier Science & Technology Books. 7th Edition. [4] Iwasaki, I., Riemer, S.C., Orlich, J.N. and Natarjan K.A. (1985). “Corrosive and abrasive wear in ore grinding”, Wear, Vol. 103,pp. 253–267.
[5] Jang, J.W, Iwasaki, I. and Moore, J.J. (1989). “The effect of galvanic interaction between martensite and ferrite in grinding media wear”, Corrosion, Vol. 45, pp. 402-407. [6] Bond, F.C. (1964). “Metal wear in crushing and grinding” Chememical Engineering Progress, Vol. 60, pp. 90-100. [7] Natarjan, K.A. (1996). “Laboratory studies on ball wear in grinding of a chalcopyrite ore”, International Journal of Mineral Processing, Vol. 46, pp. 205–213. [8] Heng-xing, X, Song-ren, L and Ding-huo, L. (2003). “Electrochemical corrosion of steel balls in wet grinding”, Transactions of Nonferrous Metals Society of China, Vol.1, pp. 958-962. [9] Chenje, T.W., Simbi, D.J. and Navara E. (2003). “The role of corrosive wear during laboratory milling”, Minerals Engineering, Vol. 16, pp. 619-624. [10] Moore, J.J., Perez, R., Gangopadhyay, A. and Eggert, J.F. (1988). “Factors affecting wear in tumbling mills: influence of composition and microstructure”, International Journal of Mineral Processing,Vol. 22, pp. 313-343. [11] Pitt, C.H., Chang, Y.M., Wadsworth, M.E. and Kotlyar, D. (1988). Laboratory abrasion and electrochernical test methods as a means of determining mechanism and rates of corrosion and wear in ball mills. International Journal of Mineral Processing, Vol. 22, pp. 361-380.
[12] Yelloji Rao, M.K. and Natarjan K.A. (1991). “Factors influencing ball wear and flotation with respect to ore grinding” Mineral Processing and Extractive Metallurgy Review, Vol. 7, pp. 137-173. [13] Pazhianur, R, Adel, G.T. and Yoon, R.H. (1997). “Richardson PE. Cathodic protection to minimize corrosive wear in ball mills”, Minerals and Metallurgical Processing, Vol. 14, pp. 1-7. [14] Peng, Y., Grano, S., Fornasiero, D. and Ralston, J. (2003) “Control of grinding conditions in the flotation of chalcopyrite and its separation from pyrite”, International Journal of Mineral Processing, vol. 69, pp. 87-100. [15] Greet, C.J., Small, G.L., Steinier, P. and Grano, S.R. (2004). “The Magotteaux Mill®: investigating the effect of grinding media on pulp chemistry and flotation performance”, Minerals Engineering, Vol. 17, pp. 891-896.
[16] Huang, G. and Grano, S. (2005). “Galvanic interaction of grinding media with pyrite and its effect on floatation”, Minerals Engineering, Vol. 18, pp. 1152–1163. [17] Huang, G. and Grano, S. (2006). “Galvanic interaction between grinding media and arsenopyrite and its effect on flotation: Part I. Quantifying galvanic interaction during grinding”, International Journal of Mineral Processing, Vol. 78, pp. 182-197. [18] Chen, G.L., Tao, D.and Parekh, B.K. (2006). “A laboratory study of high chromium alloy wear in phosphate grin ding mill”, International Journal of Mineral Processing, Vol. 80, pp. 35–42.
[19] Tao, D., Chen, G.L. and Parekh, B.K. (2007), “An electrochemical study of corrosive wear of phosphate grinding mill”, Journal of Applied Electrochemistry, Vol. 37, pp. 187-194. [20] Brukard, W.J., Sparrow, G.L.and Woodcock, J.T. (2011). “A review of the effects of the grinding environment on the flotation of copper sulphides”, International Journal of Mineral Processing, Vol. 100, pp. 1-13. [21] Azizi, A, Shafaei, S.Z, Noaparast, M. and Karamoozian, M. (2013). “Investigation of the electrochemical factors affecting the grinding environment of a porphyry copper sulphide ore”, Journal of Mining and Metallurgy A, Vol. 49, pp. 45–55. [22] Azizi, A, Shafaei, S.Z, Noaparast, M. and Karamoozian, M. (2013). “The effect of pH, solid content, water chemistry and ore mineralogy on the galvanic interactions between chalcopyrite and pyrite and steel balls”, Frontiers of Chemical Science and Engineering, Vol. 7, pp. 464-471.
[23] Rumball, J.A. and Richmond G.D. (1996). “Measurement of oxidation in a base metal flotation circuit by selective leaching with EDTA”, International journal of mineral processing, Vol. 48, pp. 1-20.
[24] Cullinan, V.J., Grano, S., Greet, C.J., Johnson N.W. and Ralston J. (1999). “Investigating fine galena recovery problems in the lead circuit of Mount Isa mines lead/zinc concentrator. Part1: Grinding media effects” Minerals Engineering, Vol. 12, pp. 147–163.
[25] Winter, G.and Woods, R. (1973). “The relation of collector redox potential to flotation efficiency: monothiocarbonates”, Separation Science, Vol. 8, pp. 261-267.
[26] Heyes, G.W. and Trahar, W.J. (1984). “The flotation of pyrite and pyrrhotite in the absence of conventional collectors”, In: Richardson, P.E., Srinivasan, S. (Eds.), Electrochemistry in Mineral and Metal Processing, The Electrochemical Society, America, pp. 219–232. [27] Woods, R. (1987). “Reagents in Mineral Technology”, In: Somasundaran P, Moudgil BM. (Eds.), pp.39–78. [28] Wadsworth, M. E., Zhu, X. and Li, J. (1993). “Electrochemistry of pyrite”, In: Hiskey JB, Warren GW. (Eds.), Hydrometallurgy: Fundamental, Technology and Innovation, pp.85–99. [29] Ailor, W.H. (1971). “Handbook of Corrosion Testing and Evaluation”, New York, John Wiley & Sons, Inc. [30] Jones, D.A. (1996). “Principles and prevention of corrosion”, 2nd edition, Upper Saddle River (NJ): Prentice Hall.
[31] Tao, D. and Parekh, B.K. (2004). “Corrosion protection of grinding mils in the phosphate industry using impressed current technology”, Final Technical Report Prepared for Florida Institute of Phosphate Research, University of Kentucky, Lexington, KY 40514 USA.