Before revision: Small prills of pig iron dispersed in slag are produced in all iron furnaces, but the phase transition of the iron into liquid in the furnace was an avoided phenomenon: these globules are not malleable so can't be hammered in a single piece , and .
After revision: Small prills of pig iron dispersed in slag are produced in all iron furnaces, but the phase transition of the iron into liquid in the furnace , as the prill globules or any resulting pig iron are not malleable so can't be hammered in a single piece operator of a bloomery had to avoid conditions causing the .