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.com
Volume 6, Issue 4 (Suppl)
J Material Sci Eng, an open access journal
ISSN: 2169-0022
Materials Congress 2017
June 12-14, 2017
June 12-14, 2017 Rome, Italy
Materials Science and Engineering
9
th
World Congress on
J Material Sci Eng 2017, 6:4(Suppl)
DOI: 10.4172/2169-0022-C1-068
EAFlong term industrial trials of utilization of char frombiomass andwaste residues as fossil coal substitute
Teresa Beone, Filippo Cirilli
and
Antonello Di Donato
Centro Sviluppo Materiali, Italy
B
iomass is a renewable resource having a steady and abundant supply, especially those biomass resources that are by-products
of agricultural and industrial activity. Its use is by supplying neutral carbon, can displace fossil fuels, and help reduce GHG
emissions while closing the carbon cycle loop. Every year End of life vehicles (ELVs) generate about 8 M tons of waste of which the
ferrous fraction represents about 70-75%, nonferrous metals about 5%. The remaining 20-25%, the ASR, contains rubber, ferrous
and non-ferrous metals, textile, fiber material, wood, glass and a relevant fraction (~40% wt) of polymers with high calorific value
(~25 MJ/kg). With a start date of January 1st 2015, the EU directive 2000/53/EC establishes the reuse and recovery of a minimum
of 95% ELV total weight. Therefore different ASR management options, such as further material and energy recovery, must replace
the landfilling. Steel produced starting from scrap, already needs less energy with beneficial effects on environment and economy
that are greater as increases the share of fossil fuels in total energy feeding. The replacement, in EAF practice, of fossil fuels with char
and syngas obtained from biomass, waste residues (i.e. plastics, automotive shredder residue (ASR), petrochemical sludge, etc.) can
further improve the environmental performance and the attractiveness of the EAF based route, eventually increasing the amount
of chemical energy respect electrical one, with beneficial effects on environment, economy and flexibility of the EAF process. The
feasibility of biochar as fossil coal substitute as charge material in EAF has already been proved in two previous European projects
(GREENEAF and GREENEAF2) were an intensive industrial utilization of biochar was foreseen. A test sequence of six consecutive
heats was carried out replacing standard anthracite with biochar. The results of the industrial tests indicate that utilization of char
as charge material can be done, but operating practice, environmental evaluation of off-gas emissions, for these new applications
needs to be optimized with long term experimentation. The results of industrial long term trials confirmed the feasibility of the use
of biochar as charge material, without significant modification in steel and slag analysis. This paper describer the industrial long term
trials with biochar in EAF, with the final target to replace fossil coal and new laboratory trials with plastic, ASR and petrochemical
sludge.
t.beone@c-s-m.itEffect of surface treatment on oxidation behavior of Ni-base superalloys
Wojciech J Nowak, Bartek Wierzba, Paweł Pędrak
and
Jan Sieniawski
Rzeszow University of Technology, Poland
T
he materials used at high temperature, like in gas turbines or jet engines, need to fulfill a number of requirements, e.g. high creep
strength and oxidation resistance at a wide range of operating temperatures, environments and loading condition as well as a
suitable ductility at low temperature. Such properties are obtained in Ni-base superalloys, due to their microstructure consisting of
thermodynamically stable γ-Ni matrix with combination of strengthening γ’-Ni
3
Al phase. However, when one exposes the alloys at
high temperature, an oxidation process occurs and thematerial starts to forman oxide scale.The Ni-Cr-Al based alloys can be classified
into the three groups of materials in term of formed oxide scales: NiO-forming, chromia layer forming and an alumina forms alloys.
Formation of protective oxides like Al
2
O
3
or Cr
2
O
3
substantially increase the lifetime of the component exposed at high temperature.
To provide a resistance against oxidation a protective coatings such as MCrAlY (where M is mainly Ni or Co) or β-NiAl which are
an alumina forming materials are applied. However, coatings production is time consuming, results in additional component costs,
and can negatively affect alloy mechanical properties, such as fatigue strength. Therefore, another method to force material to form a
protective oxide scale is proposed in the present study. Namely, a different surface preparation of Ni-base superalloys, like grinding,
polishing, sand blasting, etc., on oxide scale formation during exposure at high temperature in Ar-O
2
atmosphere will be presented. It
was found that material ground material formed less non-protective NiO compared to polished one (Figure 1). The effect of surface
treatment on oxidation kinetics and oxide scale formation will be described as well.
w.nowak@prz.edu.pl