Calcutta - Tata Metaliks Ltd, the largest pig iron manufacturer in the country, is poised for a quantum jump in business. The company, which is now a subsidiary of Tata Steel, has set a target to double its turnover in two years. Apart from betting big on pig iron — it has two plants, one at Kharagpur in Bengal and the other at Redi in Maharshtra — the company expects ductile iron and casting to contribute…