24-01-2014 3065 Views

BMZ finished the reconstruction of the important facilities of steel melting production complex.

The reconstruction of two important facilities of steel melting complex was finished in Byelorussian Steel Works. Electrical-arc furnace №1 and powder-gas catching aggregate №1 were activated after long period of “silence”, now they are renewed. Its reconstruction will permit to increase a steel production capacity, making melting process more economical and ecological. The solemn putting into operation of these facilities after reconstruction took place the 17.01.2014.

The reconstruction of Electrical-arc furnace №1 and powder-gas catching aggregate №1 is an integral part of BMZ development program till 2015, the main target of which is to reach 3 million tons of steel per year and complete usage of continuous cast billet with its full processing with high added value instead of its sale.

It is worth mentioning that three electrical-arc furnaces operate at BMZ. The modernizations of EAF-2 and EAF-3 that took place before permitted to increase its productivity till 1 million tons per year. Now, thanks to reconstruction, during which the oxygen technologies were inserted and hydraulic furnace system was modernized, EAF-1 can also achieve the similar level. The fulfilled actions, in addition to increase the capacity of facility, will permit to decrease specific consumption of electricity, electrodes, to make shorter time of melting, to improve ergonomic index of steel melting process. Taking into consideration the complex usage of oxygen technologies and fresh-burned lime, decreasing of harmful impurities content, it will be possible to increase the quality of melted steel. As for economy, an oxygen technologies introduction will permit the energy efficiency improvement of steel on 8,5 %. At the same time, a specific economy of electricity on 1 ton of melted steel will be 5,25 USD dollars/t or 4, 987 million USD dollars per year.

The modernization of EAF control is the important reconstruction result, that also could increase a furnace capacity. The change of physically old-fashioned automation system will permit to decrease production cost of liquid steel on EAF-1. A number of advantages that has new equipment will promote this. First, the increasing for long period of time (10 and more years) the reliability of control system will decrease production losses, linked with equipment failures. Second, visualization will be implemented thanks to the usage of industrial computers and so called man-machine interface in the main new control methods and technological process. Third, a new possibilities of additional functions control are opened and they are linked with technology perfection as for decreasing of products cost. Not the least of the factors is the circumstance that a new control system of EAF-1, implemented gas-oxygen technologies, hydraulics and a new system of transformer protection was not possible without the installation of a new control system basing on Simatic S7.

The current modernization became the 3-rd for EAF-1, the history of BMZ began in fact from the commissioning of this facility. The initial annual capacity of the furnace was 10 731 tons, but very soon it could overcome a border of 1 million tons. The general costs for its reconstruction was more than 23 million of USD dollars.

As it was mentioned before, the reconstruction powder-gas catching aggregate №1 is one more inseparable from EAF facility, job here was started well in advance of furnace stopping itself. The contract with the company “Water Group” (Finland) was concluded to make a reconstruction, this company has a long-term experience as for escapes decreasing in atmosphere. Its projects are introduced in huge metallurgical plants of Russia, Ukraine and Finland. The finish specialists proposed the advanced technologies the analogs of which had only two European metallurgical plants in Poland and Germany on the moment of the contract conclusion.

The carried PGC modernization will permit to improve the ecological situation and cleaning economy. The additional utilization of outgoing gases heat will permit BMZ seriously reduce the natural gas burning volumes. So, before the gas pipe of EAF -1 was partly cooled by water. Heat was sent to boiler house and was used for heating factory mills and administration buildings. The reconstruction permitted to improve the current process. In particular, surrender of water for behalf of cooling steam evaporation system with higher performance supposes the generation till 21 tons of steam per hour with the temperature till 210 degrees and with pressure 16 bar. The generated heat can be used not only for heating but also for technological purposes it means for degassers operation. It was necessary to burn some fuel at the beginning of year to get the rigtht quantity of steam for its operation.

The considerable increasing of general filtration area will become one of the determinative factors of ecological situation improvement. Bag collectors foreseen by the technology assure the cleaning of industrial gases on 99.5%, in addition, that quantity of taken from operating furnace gases, will increase on 80%. Besides, a chamber of carbon monoxide afterburning, functioning simultaneously as a dust precipitation chamber will be installed. “Under roof umbrella” is also installed for escapes localization during furnace and cast tempering, it was reconstructed the existing cooling bed, were carried other actions, that will make the production more clean and economical.

It is very important to underline the proportion of fulfilled job as for EAF-1 and PGA-1. For example, only the reconstruction of powder-gas aggregate supposes the assembly of more than 1 200 tons of metal constructions. And that is why it is worth to take into consideration the fact that active jobs were carried out on one more construction unit – on continuous casting machine № 2 (CCM -2).

More than 15 subcontractors from the different cities of the republic took part in the reconstruction. More than 400 persons were involved in the construction and assembly round-the-clock.

Steel grade ApX with bore was melt during the solemn ceremony. After melting it was sent to the rolling mill 150 where it will be processed till 9 mm diameter and send to wire-mill-3 for production of cold-drawn rebars of 8 mm diameter for existing orders to Germany, Finland, Sweden.