Study of the effect of the MgO/Al2O3 ratio on viscosity of blast furnace slag Lu Yao, Shan Ren, Guoqing Liu, Qingcai Liu, Ming Kong and Jian Yang Metall. Res. Technol., 112 6 (2015) 602 Published online: 26 October 2015 DOI: 10.1051/metal/2015036