Overview of the injection of powders and dusts into molten metals

The science and technology of powder injection has evolved from its start in the desulphurization of iron over 20 years ago. The inherent advantages of powder injection are: rapid reaction rate, good mixing, the ability to handle fine materials, flexibility and low capital cost. The fundamental engineering science related to the fluid mechanics of injection, and the associated thermodynamics and kinetics of the processes will be reviewed. Due to the above advantages, this technology finds application in the refining, smelting and the recycling of in-plant dusts and other secondary materials, in both the ferrous and non-ferrous industries. Some of these developments will be highlighted.