REVaMP: Retrofitting Equipment for Efficient Use of Variable Feedstock in Metal Making Processes

In the Euro­pean pro­cess indus­tries lar­ge amounts of ener­gy and resour­ces are used to pro­du­ce mil­li­ons of ton­nes of mate­ri­als each year. Espe­ci­al­ly in metal making pro­ces­ses, metal­lic scraps from end of life goods are recy­cled and used as secon­da­ry raw mate­ri­als in the pro­ces­ses. Usa­ge of scrap is both eco­lo­gi­cal­ly and com­mer­ci­al­ly bene­fi­ci­al, sin­ce it redu­ces the deple­ti­on of natu­ral resour­ces like vir­gin ores and avo­ids land­fills with was­te mate­ri­al. Today even more important is that the ener­gy con­sump­ti­on and the CO₂ emis­si­ons of the reduc­tion pro­ces­ses of metal ores can be redu­ced or even total­ly avo­ided when using recy­cled mate­ri­als as feedstock. Howe­ver, using incre­asing amounts of scrap in the feedstock bears chal­lenges, sin­ce the che­mi­cal com­po­si­ti­on of the scrap can vary signi­fi­cant­ly by regi­on, by time and even from pie­ce to piece.

Inter­ac­tion of the dif­fe­rent retro­fit solu­ti­ons for the use cases in REVaMP.

On the one hand, the amount of valuable ele­ments in the scrap which are used for alloy­ing of the metal, increa­ses the pri­ce of the scrap and needs to be quan­ti­fied. On the other hand, the amount of tramp ele­ments which can­not be remo­ved from the melt any­mo­re needs to be mini­mi­sed. Ste­ri­les, i.e. non-metal­lic mate­ri­als like soil, sand and wood, which can be pre­sent in the scrap mate­ri­al, decrease the mate­ri­al yield as well as the ener­gy effi­ci­en­cy of the mel­ting pro­cess. Also the scrap needs to be free from water which can cau­se explo­si­ons during metal pro­duc­tion, and from pla­s­tics, which can dete­rio­ra­te the off-gas emis­si­ons, e.g. in terms of dioxins. Last but not least, it needs to be assu­red, that explo­si­ves and radio­ac­ti­ve sources included in the scrap mate­ri­als are not trans­fer­red to the pro­duc­tion cycle.

Fur­ther­mo­re, ener­gy con­sump­ti­on is of cen­tral con­cern for the metal making indus­try. Alt­hough mel­ting and refi­ning of recy­cled metal scrap requi­res much lower ener­gy inputs than nee­ded to pro­du­ce pri­ma­ry metals from vir­gin mine­ral ores, elec­tri­cal ener­gy and fuels con­sump­ti­on still account for the major share (30% to 60%) of metal making costs.

The­r­e­fo­re, exis­ting metal pro­duc­tion plants need to be retro­fit­ted with appro­pria­te sen­sors for scrap ana­ly­sis and fur­nace ope­ra­ti­on, to cope with the vary­ing con­di­ti­ons of the feedstock regar­ding mate­ri­als and ener­gy. Fur­ther­mo­re, the sel­ec­tion of the opti­mal feedstock in terms of mate­ri­al and ener­gy effi­ci­en­cy has to be impro­ved by appli­ca­ti­on of appro­pria­te pro­cess con­trol and decis­i­on sup­port tools. Also solid scrap pre­hea­ting sys­tems can increase the ener­gy effi­ci­en­cy of the mel­ting pro­ces­ses. To moni­tor and con­trol the pro­cess beha­viour in an opti­mal way, model-based soft­ware tools have to be deve­lo­ped and applied.

Over­view of the pro­ject part­ners invol­ved in REVaMP

The main objec­ti­ve of the REVaMP pro­ject is to deve­lop, adapt and app­ly novel retro­fit­ting tech­no­lo­gies to cope with the incre­asing varia­bi­li­ty and to ensu­re an effi­ci­ent use of the feedstock in terms of mate­ri­als and ener­gy. This will be exem­pla­ri­ly demons­tra­ted within three dif­fe­rent use cases from the metal making indus­try. Due to the indus­tri­al rele­van­ce, the use cases were cho­sen from elec­tric and oxy­gen steel­ma­king, alu­mi­ni­um refi­ning and lead recy­cling. The per­for­mance of the dif­fe­rent tech­no­lo­gies will be asses­sed, and the bene­fits will be quantified.

The REVaMP pro­ject will deve­lop and test retro­fit solu­ti­ons for the Euro­pean pro­cess indus­try, espe­ci­al­ly for the very resour­ce and ener­gy inten­si­ve metal pro­duc­tion. With advan­ced pro­cess-spe­ci­fic tools for (secon­da­ry) raw mate­ri­al cha­rac­te­riza­ti­on, ener­gy effi­ci­en­cy impro­ve­ment, and pro­cess moni­to­ring and con­trol, ener­gy and raw mate­ri­al effi­ci­en­cy will be signi­fi­cant­ly impro­ved. This is demons­tra­ted below by a detail­ed assess­ment of the expec­ted impact on the dif­fe­rent use cases of steel, alu­mi­num and lead pro­duc­tion. The assess­ments are based on the pro­duc­tion plants invol­ved and are then sca­led up as far as pos­si­ble to all plants of the part­ners con­cer­ned and final­ly on a Euro­pean level accor­ding to the total pro­duc­tion capa­ci­ty in Europe.

As a part­ner in the REVaMP pro­ject, the Insti­tu­te for Indus­tri­al Fur­naces and Heat Engi­nee­ring is lea­ding the work packa­ge “Eva­lua­ti­on of Retro­fit Solu­ti­ons on an Indus­tri­al Sca­le”. Within this frame­work, exten­si­ve mate­ri­al flow ana­ly­ses (MFA) and life cycle assess­ments (LCA) are car­ri­ed out and coor­di­na­ted. In clo­se coope­ra­ti­on with the part­ners SIDENOR, GRUPAL and EXIDE, the IOB will deve­lop three mate­ri­al flow ana­ly­ses as well as three life cycle assess­ments for dif­fe­rent pro­duc­tion sce­na­ri­os of steel, alu­mi­num and lead pro­duc­tion. Final­ly, an eva­lua­ti­on of the deve­lo­ped and imple­men­ted retro­fit solu­ti­ons will be car­ri­ed out with regard to tech­ni­cal, eco­lo­gi­cal and eco­no­mic aspects as well as their cross-sec­tor transferability.