Lime injection is a well-established practice, used by most of the modern electric arc furnaces (EAFs). Lime injection technology provides a closed circuit environment. Its advantages include a better and safer working environment; process controls that help to maintain a consistent foaminess and result in direct savings on lime; plus significant benefits from metallic yield, energy and electrode consumption, as well as refractory savings. The coherent jet of lime injection, which is shrouded with oxygen, helps to direct the lime into the slag metal interface. This minimizes the chance of any lime particles being lost to de-dusting systems.

Carmeuse is a global leader and expert in providing lime products and solutions that are customized for individual application needs in the steel industry. We are uniquely positioned, thanks to a strong reference list and an operational lime injection pilot system. This system is capable of testing and comparing current or potential lime injection materials in multiple configurations, thus mimicking current or potential lime injection systems in an EAF. 

Our technical engineers and experienced technicians are available for on-site diagnosis of current problem areas. They can also make recommendations for solutions, provide technical and operational training, and help with system implementation and start-up. Moreover, our trained team can assist in the examination, maintenance and refurbishment of existing lime injection equipment.
 

CHALLENGE 

Improving safety and working environment for the workforce in any steel manufacturing site is of paramount importance along with optimizing cost and delivering world-class performance to the stakeholders.  Given the complexity of the steel making process, every step change is a way forward to achieve desired results. 

Foamy slag and its benefits are not alien to steel makers. Foamy slag increases thermal efficiency, decreases melting times and reduces energy, electrodes, and refractory consumption. To make a good foamy slag, a right balance of all slag components at the correct temperature is required. In an electric arc furnace, it is a challenge to maintain or improve the slag foaming intensity, preserving the liquid steel quality and keeping emissions at a low level.

Lime injection through side wall is designed to control the timings and flow to feed lime and help in achieving foamy slag. Lime addition, using conventional routes of scrap charging buckets or conveyors etc., does not help in balancing the components at the right time and right temperature. 

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SOLUTION

Lime Injection is a well-established practice, used by most of the modern EAF’s. Lime injection technology provides a closed circuit environment helping in providing better and safer working environment; process controls helping consistent foaminess; and bring direct savings on lime (10%) and indirect savings on consumables. 

The coherent jet of lime injection, shrouded with oxygen, helps lime directed into the slag metal interface minimizing the chance of any lime particles being lost to de-dusting systems. This jet enables near to 100% utilization of lime injection, compared to about 80% with traditional addition through buckets or conveyors using 5th hole. Modern lime injection systems are able to inject material within a controlled period, hence injecting lime only when needed enabling slag foaminess during the last part of liquid steel superheat phase when the foamed slag tends to lose such status. These controls enable further saving of lime or dolime also helping to reduce the slag volumes and dust burden on de-dusting systems.

Lime injection brings significant cost benefits from reduction in lime consumption to process benefits (having consistency in foaminess) including but not limited to improving metallic yield, reduced melting power, reduced electrode consumption, and refractory savings. 

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EXPERTISE

Carmeuse is a global leader and expert in providing the lime products and solutions customized to individual application needs in the steel industry. Carmeuse is uniquely positioned having a strong reference list and an operational lime injection pilot system capable of testing and comparing current or potential lime injection materials in multiple configurations to mimic current or potential lime injection systems in EAF.

Technical engineers as well as experienced technicians are available for onsite diagnosis of current problem areas, recommendations for solutions and help with system implementation and startup.  Our trained team is capable of assisting in the examination, maintenance and refurbishment of existing lime injection equipment.
 

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Carmeuse is in good partnership with leading lime injection technology provided to deliver our customers a reliable injection system and products ensuring desired flow rates with full controls supported by slag models. Carmeuse is willing to support investment in lime injection setting up long working partnership with customers.

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