MMK's oxygen converter shop celebrates its 30th anniversary
The transition in steel production from the open hearth to the oxygen-converter method was an important milestone in the history of MMK. In 1985, the Central Committee of the CPSU and the Council of Ministers of the USSR adopted a joint resolution to build and put into operation the first stage of the oxygen converter shop, which has a capacity of 5 million tonnes of steel per year, followed by the second stage, with a total capacity of 9 million tonnes of steel per year. In January 1986, the construction of the oxygen converter shop at MMK was declared an All-Union Komsomol construction site, and in April of the same year, the shop's first foundation slab was laid.
Installation of the first converter began in 1988. Construction of this large-scale production facility was carried out at a rapid pace. On August 27, 1990, the lining of the first converter was completed, and on November 2, converter No. 1, the steel finishing unit, continuous casting machine No. 1 and the cast slab preparation department was put into operation at the oxygen converter shop. The estimated cost of the first stage of the workshop was RUB 737 million, including RUB 400 million for construction and installation work.
The second converter and continuous casting machines № 2,3 and 4 were built by 1994. By this time, the first stage of the intensive development of converter melting and continuous steel casting technology was completed. In 1999, the third converter was put into operation at the oxygen converter shop.
Today, the oxygen converter shop is MMK's main steelmaking division, producing about 80 percent of all of MMK's steel. The oxygen converter shop consists of a charge preparation unit, a converter unit made up of three high-performance 370-tonne top-purge converters and cast iron de-sulfurisation units, and a continuous steel casting unit consisting of five continuous casting units. It also includes a non-furnace steel processing unit consisting of two steel vacuuming units, two ladle furnace units, two steel finishing units, an electric arc heating unit for steel and an average steel purging unit. The existing equipment at MMK's oxygen converter shop has the maximum capacity utilisation and produces a wide range of branded products. Last year, the shop produced 9,859 thousand tonnes of steel, and in total, the oxygen converter shop produced about 235 million tonnes of steel in its 30-year history. Steel produced by MMK's oxygen converter shop can be found in the pipes of the largest main oil and gas pipelines, in the bodies of the latest cars and in the hulls of modern sea and river vessels.
In recent years, MMK's oxygen converter shop has been upgrading its technology and mastering the production of new steel grades. In 2016, the oxygen converter shop implemented a major energy-efficiency project to modernise the smoke exhauster engine control systems, which cost about RUB 400 million and created an annual economic effect of more than RUB 100 million. As part of the modernisation project, a set of measures was implemented to save energy and increase the energy efficiency on the drive motors of the smoke exhausters in the converter gas utilisation system.
In 2020, MMK started implementing a project to reconstruct a complex of gas treatment plants for capturing secondary emissions from the oxygen converter unit. The main objective of reconstructing the gas and dust installations and exhaust paths at converters № 1, 2, 3, and the cast iron overflow unit at the oxygen converter shop is to reduce emissions into the atmosphere and into the oxygen-converter shop's work space to standard values through more efficient collection and cleaning of flue gases generated when pouring cast iron from the mixer into the bucket, pouring cast iron into the converter and when purging the smelter.
As part of the project, in February 2020, a contract was signed with Primetals Technologies Austria GmbH for the supply of basic engineering and equipment for the reconstruction of the gas treatment plant at the oxygen converter shop. The total cost of the project will be about RUB 2.5 billion. The project is due to be completed by June 2022. Total dust emissions from the oxygen converter shop will be reduced by at least 500 tonnes per year after the project is implemented.
The reconstruction of the converter unit is not the only environmental project at MMK's oxygen converter shop. In the near future, the plant plans to start reconstruction of dust and gas collecting units and gas-discharge tracts of assembly units at the non-furnace steel processing unit of the oxygen converter shop. This will allow for more efficient capture, cooling, transportation and cleaning of the entire volume of gases generated during the operation of ladle furnace installations, electric arc steel heating units, steel finishing units and vacuum cleaners.
In addition, MMK management plans to build a new vacuum pump in the oxygen converter shop, which will allow for serial casting of evacuated autoclave metal at oxygen converter shop No. 4. Also, to reduce the cost of steel production and improve product quality, MMK is considering the possibility of introducing base purging converters at the oxygen-converter shop.