History and Development of Slag and Dross Pressing

The hot dross pressing technology was first invented for the lead industry in 1896. This early patent was later followed by the hot pressing of zinc slag. The first commercially marketed pressing systems using this 1896 patent as a reference for aluminum, were available in the early 1980’s and manufactured by Pechiney in France and Showa Aluminum in Japan. In the mid 1980’s Anaconda Aluminum also developed a dross press system internally that was used in several of its operations. The first commercially successful dross presses were developed and marketed by Altek International in the early 1990’s. Since that time there have been many commercial manufactures and home made versions of the dross press found around the world. Some have been successful performing the process and some have not been successful. Dross pressing is the most widely used system for hot dross processing used through out the aluminum industry today. The original developing industries of lead and zinc do not widely use this process to recover liquid metals from their slags.