RATE OF CHLORINATION OF METALS AND OXIDES .1. FE,NI, AND SN IN CHLORINE

The rates of chlorination of Fe (528 to 921 K), Ni (890 to 1249 K), and Sn (340 to 396 K) in Cl//2-He and Cl//2-Ar mixtures were measured. The overall reaction products are gaseous (FeCl//3)//2, NiCl//2, and SnCl//4, respectively. In the high temperature ranges for iron ( greater than 680 K) and nickel ( greater than 993 K) as well as for the entire temperature range studied for tin, the transport of Cl//2(g) through the gas film boundary layer to the surface of the sample controlled the chlorination rates. The transport of NiCl//2(g) controlled the rate of the Ni-Cl//2 reaction at lower temperatures. The rate of the Fe-Cl//2 reaction at lower temperatures is controlled by a slow surface reaction between Cl//2(g) and FeCl//2(s) which covers the surface of the iron.