[ Sustainability ] used to make high-alloy components in aerospace , medicine and other industries , is less energy-consuming and wastes less material than subtractive manufacturing . The materials invented specifically for 3D printing have properties that cut CO 2 emissions . For instance , Sandia National Laboratories has just announced a new 3D-printed superalloy that is stronger at 800 ° C than others currently used in turbine parts . This translates into lower emissions for every watt of power output . Outokumpu entered the 3D-printing business a year ago by starting to produce low-carbon content metal powder at the company ’ s mill in Krefeld , Germany . The metal powder production further strengthens the circular economy by using steel scrap from local production .
[ Sustainability ] used to make high-alloy components in aerospace , medicine and other industries , is less energy-consuming and wastes less material than subtractive manufacturing . The materials invented specifically for 3D printing have properties that cut CO 2 emissions . For instance , Sandia National Laboratories has just announced a new 3D-printed superalloy that is stronger at 800 ° C than others currently used in turbine parts . This translates into lower emissions for every watt of power output . Outokumpu entered the 3D-printing business a year ago by starting to produce low-carbon content metal powder at the company ’ s mill in Krefeld , Germany . The metal powder production further strengthens the circular economy by using steel scrap from local production .
Recycling Stainless steel , like carbon steel , is 100 % recyclable – except here too stainless has an advantage , as it rusts less quickly if at all ! ( However , with certain specialty CRAs such as heat-resistant nickel alloys , 100 % recyclability cannot be achieved .) The most important alloying elements – chromium , molybdenum , aluminium , copper , nickel and titanium – are also recyclable . However , “ at a global level almost 50 % of the materials to produce stainless steel are scrap materials ( stainless steels and carbon steel scrap )” ( World Stainless Association CO 2 Emissions Report ). By contrast , Outokumpu uses 95 % recycled material ( nickel content excluded ) and is aiming to go even further . It has also started to recycle the waste – unused slag , tailing sand from mining operations , as well as sludge , dust and scales from production . The metals from these waste streams are extracted and can be re-used in stainless-steel production . The waste can also be recycled in road construction , refractory and concrete production , as well as water treatment . Other stainlesssteel producers boosting their recycling operations include BUTTING ( which is working with Cronimet Envirotec to recycle materials , waste and cutting residue ) and Stalatube , which guarantees that a minimum 75 % of stainless-steel raw materials are recycled . This uptick in recycling activity is driving sales of EAFs , in which electricity replaces fossil fuels ( see below ). Carbon capture and storage ( CCS ) is another way of dealing with CO 2 . The steel industry has been using it for several years , and several new projects
are in the offing . In the stainless-steel industry , Outokumpu is leading the way by exploring with QPower the potential of carbon capture utilization ( CCU ) to re-use the company ’ s emissions as raw materials to make new products such as e-fuels .
Decarbonization Three promising paths towards decarbonization are electrification , biocoke and ( possibly ) the use of hydrogen as a reductant .
Electrification Both carbon-steel and stainless-steel mills are switching from coke-fuelled blast furnaces to EAFs , which produce lower CO 2 emissions than blast furnaces . They are not new , having originated in the 19th century . They are the preferred type of furnace in mini-mills , but integrated mills are turning to them as they can smelt scrap consuming less energy than traditional blast furnaces . They are also more efficient , as they can be switched on and off to accommodate fluctuations in demand . Naturally , the CO 2 reduction will be greater if the electricity is renewably resourced : it is no coincidence that green-steel projects are largely concentrated in countries where most electricity comes from fossil-free sources such as renewables and nuclear . Outokumpu , being the only producer in the world to mine its own chromite , is well placed to refine it into ferrochrome in a more sustainable manner , using low-carbon electricity there as well as with its operations locally . The ore is crushed , then , using centrifugal
Electric Arc Furnace operating at Outokumpu ’ s mill in Calvert , USA .
forces , is concentrated into chromite . The concentrate is injected into a more efficient type of EAF , the submerged arc furnace ( SAF ). Into this melt , carbon is added solely as a reductant , not as a heat source , along with other materials . One of the waste products of this process is carbon monoxide , which is either sold ( for instance , to chemical plants ) or reused as fuels to fire up the furnaces . Some carbon-steel mills are building their own renewable power plants , including US producer EVRAZ , Panatère in Switzerland and SSAB in Italy . Among stainless-steel producers , Outukumpu is partnering with Fortum to explore the use of Small Modular Reactors ( SMR ) in Finland , while Aperam is exploring how to use hydro-electricity , photovoltaics ,
Ferrochrome , the fundamental ingredient of stainless steel . By FocalPoint - Own work , CC BY-SA 4.0 , https :// commons . wikimedia . org / w / index . php ? curid = 3150871
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