pyrometallurgy: recent progress and issues to address
TRANSCRIPT
Content
• Common challenges for the pyrometallurgical industry
• Recent developments – examples from different industries and
processes
• New technologies
• Research for reduction of CO2 emission in BF ironmaking
• Recycling issues and methods
• Gasification in metal bath
• Examples on changing raw materials
• Summary
Common challenges for the pyrometallurgical
industry
• Reduced environmental impact in terms of
• Lower emissions to air and water
• Reduced greenhouse gas emission including carbon footprint
• Reduced emission of dust, metals etc.
• Taking care of residual materials produced - recycling instead of landfilling
• Improved material and energy efficiency in the process for reduced requirements
of virgin raw materials
• Changed raw material situation
• Reduced availability or increased costs for high quality raw materials
• Lower contents of desired components and larger content of impurities
• Changed physical properties as e.g. fine particulate ores
• Sustained high quality or new improved one for products in spite of
changed conditions
New and developed technologies
How can these challenges be coped with-a few
examples
• Development of new technologies
• Reduction of CO2 emission in steelmaking
• Recycling technologies
• Liquid steel gasification-production of fuel
• Changed raw material situation
New technologies - some selected demonstration
plants
MIP/PCIG
STRIPCASTING
CONTOP
HYMELT
LKAB EBF
ROTOVERT
WORCRA
ELRED
KALDO
INRED
Italy
Australia
Jp/G/Sw
G/EU/Sw
VAI - AUS
USA
C
H e-
BF-BOF
Midrex/HYL-EAF
”Wiberg”-EAF
ULCORED-EAF
HDRI-EAF
2015: 1800 kgCO2/ton
2025: 900kg
CO2/ton
2050:
<100kgCO2/ton
New technologies for reduced CO2 emission in
steelmaking, CO2-triangle
El-based gasification and heating
O2-based gasification and heating
Air based gasification and heating
El-based H2-prod and heating
750
BC - El-based smelt reduction
But local prerequisites may limit
possibility to select technology
Low CO2 ironmaking
ULCOS (EU and RFCS)
• Top Gas Recycling
• Advanced DRI
• Hisarna
• Electrolysis
• CCS
Course 50 (Japan)
- Use of H2
- CCS
ULCOS NBF and ULCOS TGRBF
Versions of top gas recycling BF
Ref. Jan van der Stel et al., Developments of the ULCOS Low CO2 Blast Furnace Process, at
the LKAB Experimental BF in Luleå, Metec, Düsseldorf, 27 June – 1 July 2011
Basis for recycling and pyrometallurgical
processing
A: CaO, SiO2, Al2O3, MgO
B: NiO, FeO, MnO, V2O5, Cr2O3, P2O5,Cu, Co, Mo
C: ZnO, PbO, Na, K, Cl, Cd, Hg
D: C-H-O, plastics/textile/fluff
In Plant By-product Melting
Additives Reductants Slag formers Power
Steelmaking wastes (incl. slags) from carbon and stainless steel production Power plant ash, V rich EAF dust Millscale Blast furnace dust/sludge BOF dust/sludge Incinerator ash Lean bauxite Scrap residue Pickling sludge Fayalite slag from cupper smelter
Zn-enriched fumes (Zn, Pb, alkali)
32000
29000
27000
25000
23000
21000
17000
14000
12000
10000
7900
5800
3600
1500
Temperature (K)
Slag and metal fraction
ZEWA(00-2004) ZEWA process
CRM – VAI -etc
2009
V recovery from Finnish and Swedish BOF slag
balance at SSAB EMEA
Testing in 3 MW DC furnace
• Metal FeV
• Pure slag with low V content that
can be granulated and used in
cement
Third International Slag Valorisation Symposium │
Pickling sludge to substitute fluorspar
Third International Slag Valorisation Symposium │ Ye, Lindvall, Magnusson
EAF dust
(~3% Cl, 0.4% F)
Coke
breeze
Slag
former
Metal Slag
Power
ZnO fume
(>75%ZnO, 6%Pb, 1%Fe and ~6% Cl)
Leaching by water
Leached ZnO fume for electrolytic
Zn-production
(50-100 ppm Cl, F)
Three major projects for Zn recovery
High ZnO dust for extern use
Conventional
filter
High ZnO dust /very low F, Cl
EAF dust with ZnO (contains Cl, F)
High ZnFe2O4 EAF dust for injection
DC-furnace with
hollow electrode
(1992-1996)
By-pass filter
(REZIN) (2003-
2006)
Scrap cleaning and pre-heating (Protect) (2009-2013)
1. Combustion of fluff = heat + HCl(g)
2. Zn (coated on scrap)+2HCl (g) = ZnCl2
Gasification of coal by injection into molten
iron bath P-CIG and MPI
General characteristics • CO and H2
• Hot metal bath absorbs impurities, ash forms a molten slag
• Commercialization planned but not realized
• P-CIG – Pressurized Coal Iron Gasification (1984-85) • Nippon Steel, Interproject Service AB
• Full-scale plant designed
• MIP- Molten iron pure gas (1985-1986)
• Sumitomo Metals, KHD
P-CIG
HYMELT – Gasification of coal by injection into
molten iron bath (2003)
EnviROES, DOE (US)
•Production of ultra clean fuels
•Two gasification steps
• O2 blowing CO
• Coal injection H2 and
carburization of HM
• Plan to build 1.1 m in diameter
commercial plant (250-300
t/day) in Ashland, Kentucky
Some aspects on raw materials quality
– e.g. ring structured hematite makes liberation
problematic
Changing quality of ores , e.g. Cu-ores
• Changing quality of
ores e.g. cupper ore
• Higher Fe, S
• Lower Cu
• Higher impurities as
e.g. As, Sb
• Pre-treatment
methods are
important e.g. in fluid
bed
New raw materials or waste can be investigated for calcination, drying,
reduction, roasting, gasification, catalytic combustion before used on
industrial scale
Recycling of electronic scrap at Boliden Rönnskär • E-kaldo a further development of kaldo process
• capacity of 120 000 tonnes per year
• metal recovery into black cupper containing also
precious metals
• plastic becomes energy rich gases and is used for
electricity production and district heating
• Changing composition of e-scrap
• lower content of Cu and precious metals
• higher content plastic and of impurities as e.g. Cd,
Source; http://www.boliden.com/
Summary
Principle
Tools
Imagination
Innovation
Thank you for your
attention