Federacciai | 19 Ottobre 2020 | 0
BEST PRACTICETag: Best Practice
LIFE13 ENV/IT/001203 “SNOW-LIFE”
Slag NO Waste: Innovative system for 100% recycling of white slag and for ZERO WASTE electric steel Production
In 2013 more than 300 European steel plants produced about 172 million tons of steel and about 4,8 million tons of white slag, a special waste which ends up in dumps.
This project aims at:
- eliminating EAF slag waste;
- eliminating the negative environmental impact of slag waste disposal;
- reducing the use of natural resources and greenhouse gas emissions
…by demonstrating an innovative and environmental friendly solution for recycling white slag and exhausted refractories which, in combination with black slag recovery technologies, can lead to a zero-waste slag steel production cycle, suitable to be used by any electric steelwork.
For the treatment of black slag a previous Eco-innovation project (http://www.slagrec.eu/), led by ASO, has demonstrated a patented solution to transform this waste into a product that can be used as aggregate for construction.
The solution for the recovery of white slag, developed by MHT SpA, is the core of this project.
The black and white slag treating system, will be the solution for a zero slag waste steel production!
Project title: Slag NO Waste: Innovative system for 100% recycling of white slag and for ZERO WASTE electric steel Production
Project acronym: SNOW-LIFE
Project policy area: Waste and Natural Resources
Eng. Massimo SVANERA
ASO Siderurgica Spa (ITALY)
Material Handling Technology S.p.A (ITALY)
Federazione Imprese Siderurgiche Italiane (ITALY)
Provincia di Brescia (ITALY)
Duration: 01/06/2014 – 31/05/2018
Total project budget: 2,449,682 Euro
Total eligible project budget: 1,332,996 Euro
EU financial contribution requested: 666,497 Euro
Contract number: LIFE13 ENV/IT/001203
SNOW responds to the priority of natural resource saving and waste recycling. It improves the environmental performance of the ASO steelwork, by reducing the use of natural resources and CO2 emissions and avoiding steel production waste (slag) to be dumped.
White slag has a high content (40-45%) of free lime – CaO ; natural CaO is at the same used as an essential additive for steel production (black slag foaming additive). Presently, lime for steel production comes from natural limestone (CaCO3) which, is turned into lime by a very energy intensive process which releases 1250 kg of CO2 per each ton of produced lime (786 from CaCO3 dissociation and 554 from its calcination).
The project founds on an innovative system (applied for patent) which minimizing the environmental problem and also leads to remarkable savings in operational costs of steel plants. The system recovers free lime and magnesium oxide from white slag and exhausted refractories and reintroduces them into the same steelmaking process, substituting 30-40% of presently purchased additives.
Expected results (outputs and quantified achievements):
The SNOW system is an excellent outstanding example of innovation for the benefit of the environment, as white slag will be not more dumped, resulting tangible benefit to the territory.
The environmental problems posed by slag are of remarkable importance also for administrative
and political institutions whose objectives is not only the safeguard of the territory and its landscape, but also the promotion of companies and occupation in their area. For this reason the Province of Brescia, whose territory has the highest concentration of Italian steelworks as well as limestone pits and landfill dumps, has a key role in this project; the other institutional partner is Federacciai: both will contribute to results dissemination and to promote this innovative solution.
The expected project results are:
• an innovative demo plant on industrial scale for obtaining zero slag waste of the electric steelmaking process;
• technological validation and performance analysis of the SNOW system in the ASO steel plant;
• evaluation of the environmental benefits.
Environmental impacts by the project end:
• 4,500 tons of white slag (and exhausted refractory linings) “saved” from dumps and recycled through the SNOW system;
• achievement of a potential zero slag waste steel production in the ASO steelwork;
• reduction of potential dust and smell sources from ASO steelmaking;
• 3,600 tons of virgin lime substituted with the treated white slag with consequent reduction of natural resources (limestone) use in the ASO steel plant;
• industrial demonstration of the effectiveness of an innovative white slag recycling system for
European steelwork to become more eco-compatible;
• industrial demonstration of the fact that lime recycled from white slag is an equivalent alternative of virgin lime and that dololime recycled from exhausted refractory materials is an equivalent alternative of natural dolomite.
Can the project be considered to be a climate change adaptation project?
This project will allow a reduction of CO2 emission because steel industry will have to purchase a considerably lower quantity of lime. The lime comes from natural limestone (CaCO3) excavated from calcareous rocks through a process which liberates 1250 kg of CO2 per each ton of lime produced.
ASO, a small plant producing special steel, consumes 3600 tons of lime each year. With the SNOW technology the requirement of lime is considerably reduced, with a concurrent significant saving of CO2 emission.
ASO Siderurgica S.p.A.
Via Seriola 122 – I-25035 Ospitaletto, (Bs), Italy
Federazione Imprese Siderurgiche Italiane
Viale Sarca 336 – 20126 Milano (Italy)
Provincia di Brescia
Piazza Paolo VI 29- 25122 Brescia (Italy)
Dott. Ing. Massimo Svanera
ASO Siderurgica S.r.l.
Via Seriola 122
I-25035 Ospitaletto, (Bs), Italy
Direct phone.: +39 030 6841560
Fax: +39 030 6841012