A matte tapper is burning open a matte tap hole necessary to drain smelted matte out of the furnace bath. During the smelting process inside the furnace the matte settles to the bottom of the bath where, after reaching a predetermined level (bath levels are measured hourly), it can be tapped off. The slag floats on top of the matte so consequently the physical location of the matte tap holes relative to the slag tap holes is a critical consideration in the furnace design. The furnace is routinely fed over 200 tons of material per hour so the timing of the tapping processes is extremely important to keep the bath within proper levels. Wait too long to start tapping off the matte and matte levels will reach the slag holes, tap too long and slag will begin to flow out the matte holes. Both occurrences can cause difficulty in the process including possible lengthy shut downs of the furnace.