Before revision: Anthracite iron or anthracite pig iron is the substance created by the smelting together of anthracite coal and iron ore, that is using anthracite coal instead of charcoal to smelt iron ores—and in iron smelting.
After revision: Anthracite iron or anthracite pig iron is iron extracted by the smelting together of anthracite coal and iron ore, that is using anthracite coal instead of charcoal in iron smelting.