Automatic Metal Skimmer
Altech SMV Ltd of Iceland supplies a proven, fully automatic Metal Skimming System designed to skim dross and bath material from transport crucibles with potroom metal.
Many primary aluminium smelters pre-treat metal immediately it is delivered to the Casthouse from the Potrooms. The procedure is normally a single skimming operation to remove bath debris. In some cases, this may be followed by additional processes to remove impurities - for instance, AlF3 or chlorine injection to reduce dissolved sodium - and a further skimming operation to remove resultant dross.
Skimming of floating bath material has a direct effect on final metal quality, and reduces both operating and maintenance costs in the Casthouse - skimming operations in the casting furnaces are reduced; less dross means less refractory attack and lower maintenance. Effective skimming reduces dross build-up on the transport crucible walls, maintaining a safe freeboard, reducing cleaning frequency and improving lining life.
Traditionally, crucible skimming is a manual process, labour-intensive and potentially dangerous. Whilst much floating debris can be removed manually, the relatively short sweep of a manual skimming tool means that some dross inevitably remains to contaminate the metal.
Automation of the metal skimming operation removes a person from a hazardous task, improving employee health, safety and environment (ISO 14000). Concurrently, skimming efficiency increases, further improving the metal and contributing to a higher overall quality standard (ISO 9000).
