Title

DEVELOPMENT OF IRONMAKING TECHNOLOGY AT RAUTARUUKKI STEEL, FINLAND

DEVELOPMENT OF IRONMAKING TECHNOLOGY AT RAUTARUUKKI STEEL, FINLAND

Authorship

KALLIO, SAKARI

KALLIO, SAKARI

I am this author

DOI

10.5151/2594-357x-29Red-01-16

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Abstract

RAUTARUUKKI is a Finnish steel company with an annual production of 3.8 million tons. Its main products are hot rolled steel works with two blast furnaces. The cost efficiency of the Rautaruukki Steel Works is very much dependent on the overall cost of hot metal, coke oven gases are a significant part of the total plant production costs, so minimizing energy consumption for both steel and commercial aspects have to be considered. Low energy consumption, together with high productivity and stable blast furnace operation, has been achieved at Rautaruukki Steel due to efficient use of computer technology in the process control and the improvements in raw materials and coke quality as well as in production technology. Today the blast furnace operation at Rautaruukki belongs to the most efficient in the world. The increased iron Fe-content in 61-62% by decreasing the sinter SiO₂-content has been possible as a result of continuous improvement in sintermaking and raw material quality development. Sinter plant operation systems effectively applied resulting improved sinter quality and production costs. The two blast furnaces were rebuilt in 1995 and 1996. The furnace cooling system and refractory wear were totally renewed in order to meet the future production demands. By adopting 100% coke charging, furnace volume was also to be increased. The number of tuyeres was increased to 28 and 30 respectively. The main goal was to increase blast furnace productivity above 2.0 t/m³/d while reducing fuel rate. The automation level of blast furnaces were remarkably increased to enable better furnace condition monitoring as well as cost efficient and highly productive operation. The blast furnace operation systems were modified and improved to develop a stable and flexible control system in decision-making. The blast furnace operation system is designed to support the decision-making in medium and long-term process control. It is one of the control system combining reports, special displays, trends and mathematical models describing the in-furnace phenomena. The information processing of blast furnace operation phenomena is grouped such that little time is needed to find out the current state of the process. Due to complexity of the blast furnace process, neural networks system and expert system to guide and diagnose the short and medium-term blast furnace operation have developed. The improvements in ironmaking technology and operation efficiency have resulted in reducing material consumption (440 kg/tHM) and high productivity (3.1 t/m³/d) at Rautaruukki Steel blast furnace.

RAUTARUUKKI is a Finnish steel company with an annual production of 3.8 million tons. Its main products are hot rolled steel works with two blast furnaces. The cost efficiency of the Rautaruukki Steel Works is very much dependent on the overall cost of hot metal, coke oven gases are a significant part of the total plant production costs, so minimizing energy consumption for both steel and commercial aspects have to be considered. Low energy consumption, together with high productivity and stable blast furnace operation, has been achieved at Rautaruukki Steel due to efficient use of computer technology in the process control and the improvements in raw materials and coke quality as well as in production technology. Today the blast furnace operation at Rautaruukki belongs to the most efficient in the world. The increased iron Fe-content in 61-62% by decreasing the sinter SiO₂-content has been possible as a result of continuous improvement in sintermaking and raw material quality development. Sinter plant operation systems effectively applied resulting improved sinter quality and production costs. The two blast furnaces were rebuilt in 1995 and 1996. The furnace cooling system and refractory wear were totally renewed in order to meet the future production demands. By adopting 100% coke charging, furnace volume was also to be increased. The number of tuyeres was increased to 28 and 30 respectively. The main goal was to increase blast furnace productivity above 2.0 t/m³/d while reducing fuel rate. The automation level of blast furnaces were remarkably increased to enable better furnace condition monitoring as well as cost efficient and highly productive operation. The blast furnace operation systems were modified and improved to develop a stable and flexible control system in decision-making. The blast furnace operation system is designed to support the decision-making in medium and long-term process control. It is one of the control system combining reports, special displays, trends and mathematical models describing the in-furnace phenomena. The information processing of blast furnace operation phenomena is grouped such that little time is needed to find out the current state of the process. Due to complexity of the blast furnace process, neural networks system and expert system to guide and diagnose the short and medium-term blast furnace operation have developed. The improvements in ironmaking technology and operation efficiency have resulted in reducing material consumption (440 kg/tHM) and high productivity (3.1 t/m³/d) at Rautaruukki Steel blast furnace.

Keywords

ironmaking, blast furnace, process control, energy efficiency, productivity

ironmaking, blast furnace, process control, energy efficiency, productivity