Reduced carbon footprint thanks to changed use of lime
Thanks to the use of a more energy-efficient lime in our steel mill in Sandviken, Sandvik has achieved an indirect reduction of 5,800 tonnes CO2 emissions per year.
“We are continuously evaluating the raw materials we purchase, both from an environmental and cost perspective. We want to work with suppliers who take responsibility for the environment, for their employees and for their products", says Michail Ternovski, Purchaser Direct Material at Sandvik Materials Technology.
In 2018, a project was started to investigate whether a more energy-efficient lime could be used in the electric arc furnace for cleaning the steel baths. Slag analyses and sharp trials were carried out with soft burned shaft kiln lime instead of hard burned rotary kiln lime, which was currently used. The project landed well and since just over a year ago, soft burned shaft kiln lime is fully used in the arc furnace – a lime grade that has significantly lower energy consumption in production. In addition, the slag is mined and processed much closer to Sandviken, which means reduced transportation.
“The success of this initiative is thanks to the will and drive of our employees at the Raw Material Yard, the Steel Mill, and Research & Development to challenge existing processes”, says Michail Ternovski.
About the use of lime in steel production
In the processes at the Steel Mill in Sandviken, lime is used as a slag former in the arc furnace (EAF), and the AOD* converter. The function of the slag in the process is to protect the refractory in the vessel and clean the steel bath by attracting undesirable contaminants and oxides.