Metalloid elements such as As, Sb, Bi, Se and Te in the molten metal, alloy, matte, slag and speiss phases are of great concern in the metallurgy of copper, lead, tin and nickel and the recycling of these metals. The activity data of these elements are very important for thermodynamically considering or evaluating the processes to recover or remove these valuable or detrimental elements. Based on the knowledge and experiences made by the authors in the past decades, the methods and techniques for determining the activity of these metalloid elements in the molten metallurgical systems, such as non-isothermal isopiestic, isothermal isopiestic, tranportation, Knudsen-effusion and electro-motive force measurement methods are briefly surveyed. Some applications of the activity data to derive the activity coefficients in the molten slags and to thermodynamically evaluate the behavior of As, Sb and Bi in the matte smelting of copper are also described in the present paper.
