As a product line based on hot-rolled coil pickling, the pickling unit used by cold rolling factory of Meishan Iron and Steel was fully completed and put into production in July 2011, adopting the most advanced and mature shallow tank hydrochloric acid pickling technology. The pickling products are mainly used in automobile industry, compressor industry, electric water heater industry, mechanical hardware industry, among which pickling enamel steel accounts for about 70% of the national market.