(Reuters) - International Steel Group Inc. will restart a second blast furnace at its ISG Weirton unit in response to strong demand for its coated steel products. The company said the new blast furnace will produce about 2,200 additional tons of iron per day. International Steel acquired bankrupt steelmaker Weirton Steel for about $253 million in May. ISG said restarting the second furnace at Weirton would allow it to call back 50 steelworkers to work at the facility.