Usiminas resumes production of Blast Furnace 1 in Ipatinga
After structure refurbishing, the company adds nearly 2 thousand tons per day to its pig iron production in the Steel Valley, recovering the production of plates at full load in the Plant
On Tuesday, April 17, Usiminas held an event that marked the resumption of company´s BF1, after 34 months deactivated. With the equipment return to operation, Ipatinga Plant accounts for an increase of 2 thousand tons to its pig iron daily production. Together, BFs 1, 2 and 3 add up to a production of 10,800 tons/day. The reactivation of BF1 is another indication of the company's upward recovery curve, a process started in mid-2016 which has been marked by successive positive results. For Usiminas CEO, Sergio Leite, it is also a message of optimism and reinforces a commitment to the future of Usiminas and the country.
Usiminas faced the most complex period of its history between 2015 and 2016, as a consequence of the severe crises in the international steel market and the domestic economy. After a phase focused on results building, started in the third quarter of 2016, the company is now working to recover its benchmark position in the market. The company registered positive balance sheets over the past year, had its credit rating raised by the three major global risk assessment agencies and its shares led the “Ibovespa” valuation ranking last year.
“We have reached a new level in which Usiminas can think about its future. It is the reflection of a new stage, with established management goals, focused, mainly, on the generation of results and the search for excellence in customer service and improvement of the organizational atmosphere. We are already in the process of building a new strategic plan for the next five years, we have made three advances of payment of our debt and internally we are reinforcing the initiatives and programs for our team valorization”, says Mr. Leite.
In operation since 1962, when it was inaugurated, Blast Furnace 1 followed the development of Usiminas and the Steel Valley. Over the decades it produced more than 29.5 million tons of pig iron until its halt in 2015. Sergio Leite highlighted the work of the team involved in the BF-1 refurbishing and the symbolism of the resumption of its operations. “Although we still have great challenges ahead, that date deserves to be celebrated. We are celebrating, in the same month of April, 62 years of Usiminas' start up, at an important moment, when we put Ipatinga Plant in pig iron full load and plates production, after recent extremely challenging years”, he points out.
Usiminas invested about R$ 80 million in the BF-1 refurbishing. The work, which lasted for about 11 months, generated 600 jobs and was led by “Usiminas Mecânica”, a capital goods company with strong operations in metallic, naval and offshore structures, oil and gas, plant assembly and industrial equipment, casting and railway wagons.
How does it work?
After the blast furnace blow-in, the internal heating is practically immediate. The furnace begins its operation filled with load and large amount of fuel (coke), mainly in the lower areas. The first pig iron run takes place approximately 24 hours afterwards and 3 days later the pig iron produced is already in chemical and temperature conditions to be consumed at the melt shop. The blast furnace is a counter current reactor. The metallic load, composed of sinter, granulated ore and pellet, together with the fuel (coke), are charged, in a controlled manner, on the top.
Hot air, enriched with oxygen, is injected into the lower area. Air oxygen reacts with coke carbon, producing the CO reducing gas and a large amount of heat. The reducing gas (CO), produced in the lower areas, rises countercurrent to the lowering of the load, favoring the metallic load reduction and melting.
As a result, the pig iron and the slag are obtained. The first one is directed to the melt shop, constituting the raw material to obtain steel. The slag is benefited and used in other economic activities and social investments.
After passing through the entire load column, the reducing gas (CO) undergoes dry and wet cleaning processes, giving rise to blast furnace gas (BFG). Some of this gas is reinserted into the production process, reused in the hot air regenerators, where the air to be injected into the blast furnace is heated to 1,200 ° C. The rest is directed to other units, such as the coke and rolling units, reducing energy consumption from other sources.
Blast furnace 1 refurbishing activities took place in regenerators 1,2,3 where more than 3,000 tons of refractory material were used. More than a thousand tons of refractory were used on the BF-1 body for reconstitution of its internal profile, besides replacing part of the carcass around the perimeter in the area of the ramp, above the tuyeres. In the same area, the shutter and perforation guns were repaired, as well as the peripheral ones, such as slag granulation, dedusting and gas cleaning systems, furnace loading system (composed by the system of silos of ore, coke and sinter, skip car, skip ramp) and top oven equipment.
In the area located at the base of the equipment and responsible for accumulating the pig iron and slag produced, known as crucible, the replacement of carbon blocks and a general reform throughout the furnace refrigeration system was carried out.