Hindustan Zinc Limited is an Indian integrated mining and resources producer of zinc, lead, silver and cadmium. It is a subsidiary of Vedanta Limited. Earlier it was a Central Public Sector Undertaking, sold by Government of India to Vedanta Limited when Atal Bihari Vajpayee and Bharatiya Janta Party Government was in power in the year 2003. HZL is the world's second largest zinc producer. Wikipedia