Steelmaking PlantsBig River Steel
The DC electric arc furnace is designed for a nominal heat weight of 150 tons and a power rating of 160 megawatts. It features the SMS group-patented pin-type bottom electrode. The EAF produces heats at a rate of almost 220 tons per hour. A 150-ton twin-station ladle furnace offers the flexibility to treat two heats simultaneously. This proven steelmaking technology ensures that only the highest-quality steel reaches the CSP? thin slab caster.
The gas cleaning plant efficiently and effectively captures and cleans the dust-laden gases emitted by the production units. To comply with the strict environmental protection and work safety regulations at the Osceola location, the company must reliably prevent fugitive emissions. That requires extensive capturing of the strongly varying gas volumes in all operating phases of the steelworks.
When the first vacuum treatment has been finished and the ladle transfer car is moving the first ladle either to the ladletreatment station or to the take-over position, the second ladle can already be lowered by the shop crane onto the second ladle transfer car and taken to the RH treatment position. Vacuum is generated by a steam ejector vacuum pump. A steam boiler system supplies the required amount of steam to the six ejectors. A TOP lance system is installed to blow oxygen for forced decarburization or chemical heating during vacuum treatment, or to burn gas with oxygen to keep the vessel refractory material at operating temperature during non-vacuum treatment.
A special feature of this RH unit is the vacuum alloy addition system, which consists of a vacuum lock system and three vacuum scale hoppers. This arrangement allows electrical steel grades with Si-contents of up to three percent to be produced in less than 50 minutes cycle time.
The measuring and control equipment takes care of monitoring, controlling and regulating all process sequences. There is not only a basic automation system but also a process computer. This provides heat and process related information, collects data for a heat report, tracks and monitors the physical-chemical state of the heat, and finally determines set point data for the types and amounts of additions as well as for the duration of time-dependent treatment steps.