Pyro Crew, 

Dross market has been quoted at 3 million TPY. This article has it higher as per paragraph below. 

“however, dross product is not entirely a waste material as it can be recycled and used in secondary steelmaking for slag deoxidation [5]. Approximately , four million tonnes of white dross and more than a million tonnes of black dross are reported throughout the world each year, and around 95% of this material is land-filled [6,7]. In the UK it is reported that the industry disposes about 200,000 tonnes of white and black dross [6, 7]. The quantities of dross land filled nowadays are expected to be lower, as a large chunk of it is being reprocessed to recover metallic aluminum as well as its oxides.”

http://article.sciencepublishinggroup.com/pdf/10.11648.j.am.20140302.11.pdf

HK