solid waste management.

1. SOLID WASTE MANAGEMENT IN
PRIMARY STEELMAKING
Presented by-
Prince Kumar Maurya
193110030
Supervised by-
Prof. Somnath Basu

2. Steel industry Scenerio
 1808.6 MT(2018) Crude steel production
 928.3MT(2018)
 106.5MT(2018)
 104.3MT(2018)

3. The 4 R’s
Worldsteel.org
 Reduce
 Decreasing the amount of material, energy
and other resources used to create steel
and reduce the weight of steel product.
 Reuse
 Reuse is using an object or material again,
either for its original purpose or for a similar
purpose, without significantly altering the
physical form of the object or material.
 Remanufacture
 The process of restoring durable used steel
products to as-new
condition.
 Recycle
 Melting steel products at the end of their
useful life to create new steels. Recycling
alters the physical form of steel object so
that a new application can be created from
the recycled material.

4. Introduction
 Per ton of liquid steel needs about
 2.8 tonnes of raw materials,
 2.5 tonnes of water
 5 tonnes of air.
 The outcome from iron and steelmaking process is
 8 tons of moist dust laden gases
 0.5 ton of effluent water
 0.4 to 0.8 ton of solid waste
 Solid waste/tonne of crude steel
 450-550kg
 <200kg
(40-70)%
(100)%

5. Sources and Types of solid wastes
Feed
materials
Ore Fines
Sinter plant
Coke Oven
Plant
Iron Ore Fines
Dolomite Fines
LimestoneFines
Sinter plant Dust
Sludge
Quenching Tower
Sludge
Oven door cleaning
Waste bag filter
dust
Drain sludge
Refractory waste
Thermal
Power
Plant
Fly ash
Bottom ash
Transformer
oil sludge
Metallurgical
Plant
Ironmaking
Steelmaking
BF Slag
Flue dust
BF Sludge
GCP Sludge
BOF Sludge
BOF Slag
BOF Dust
Rolling
mill
Mill scale
Scrap
Oil sludge

6. Types of solid waste/by-product
 Process waste
 slag, dust, GCP sludge, scrap, refractories, scale, muck and debris, etc
 Sorting
 Non process waste
 rubber, card-board, electric wire, glass, etc.
 These waste materials are segregated at different locations in the plant and sold.
 Ferrous waste
 iron in the metallurgical slag, oxide iron skin of rolling steel, gray iron dust, etc
 Non-ferrous waste
 fly ash, quenched blast furnace slag, dry blast furnace slag, Bessemer steel slag,
electric furnace slag,waste refractory materials, and other industry waste.
Recycling

7. Cause and Solution
 Poor quality of raw materials
 High ash content coal increased coke increased slag in BF
increased fly ash in PP.
High alumina content of iron ore increases the coke rate volume in BF. High Si and S level
in HM increases the slag rate/tonne of crude steel.
Some Technological advancements-
(i) High BF temperature; High top pressure; Injection of prepared burden
to reduce the coke consumption rate as well as slag volume.
(ii) Continuous charging techniques for EAF
(iii) COREX iron making process

8. Blast furnace slag (silicates, aluminosilicates,
and calcium-alumina-silicates)
Types of BF slag
• Air cooled BF slag (90%)
• Expanded or foamed BF slag
• Pelletized BF slag, pellets
• Granulated BF slag
TATA steel
Researchgate, John Emery

9. Types of BF slag
 ACBFS
 Slow ambient cooling
 a crystalline structure, a hard, lump slag
 used as a conventional aggregate, granular base applications
 lower compacted unit weight of blast furnace slag
 Expanded or foamed BF slag
 controlled cooling with water, air and stream
 Cellular nature, lightweight expanded or foamed product
 Pelletized BF slag
 Water and air quenched in spinning drum
 pellets, rather than a solid mass
 beneficial for aggregate use, or more vitrified (glassy)
 Cementitious application
Granulated BF slag
Rapid water quenching, to a glassy state
Formation of sand size fragments
Crushed GGBFS has cementitious properties

10. STEEL SLAG
 List the intended outcomes for this training
session.
 Each objective should be concise, should
contain a verb, and should have a
measurable result.
 Tip: Click and scroll in the notes pane below
to see examples, or to add your own speaker
notes.
Slag production in modern integrated steel plant
Worldsteel.org

11. STEEL SLAG
Composition and physical properties
Chemical composition of steel slag from different furnaces (values sourced from Shi, 2004)
Components BOF(%) EAF (for carbon
steel)(%)
EAF (for alloy
stainless
steel)(%)
Ladle(%) Ordinary
cement
SiO2 8-20 9-20 24-32 2-35 22.0
Al2O3 1-6 2-9 3-7.5 5-35 5.5
FeO 10-35 15-30 1-6 0.1-15 3.0
CaO 30-55 35-60 39-45 30-60 64.2
MgO 5-15 5-15 8-15 1-10 1.5
MnO 2-8 3-8 0.4-2 0-5 -
TiO2 0.4-2 Not available Not available Not available -
S 0.06-0.15 0.08-0.2 0.1-0.3 0.1-1 2.0
P 0.2-2 0.01-0.25 0.01-0.07 0.1-0.4 -
Cr 0.1-0.5 0.1-1 0.1-20 0-0.5 -

12. Property
Specific gravity 3.1-3.5
Bulk density 1600-1760 kg/m^3
Aggregate crushing value 12-25
Aggregate impact value 18-24
Aggregate abrasion vaue 3-4
Water adsorption (% by mass) 0.2-2
Physical properties of steelmaking slag (values sourced from Lee, 1974).
STEEL SLAG
Composition and physical properties
Basicity =
CaO
SiO2
Basicitycement
= 2.92 BasicityBOF slag = 3.0
BasicityEAF slag = 3.27

13. STEEL SLAG
 BOF slag
 P content is much high to be used in iron and steel making process.
 After proper treatment, with high fluxing capacity, it is added to BF.
Leaching behavior of steelmaking slag
Comparison of slag lechate concentrations from blast furnace (BF), basic oxygen
steelmaking (BOS) and electric arc furnace (EAF) slag after leaching at pH 2.8 (values
sourced from Proctor et al., 2000).
Element Criterion BF BOS EAF
Arsenic 5 .0048 .0054 .001
Barium 100 1.2 .88 1.67
Cadmium 1 .0054 .01 .037
Chromium(VI) 5 .026 ND .018
Chromium
(Total)
5 .22 .04 1.0
Lead 5 ND .015 .063
Mercury 0.2 ND .0005 .00089
• Metals are more
susceptible to
leaching under
acidic conditions, it
is unlikely that
metals would leach
out under neutral
solution
• Means slag can
generally be
categorised as a
non-hazardous by-
product from the

14. Free lime volume instability
• Short and long-term hydration of lime and magnesium oxides.
• Moisture could esily cause volume expansion so outside applications are limited.
• Wet road surface can leads to fracture due to free lime expansion.
• BOS slag volume expansion up to 10% (Mikhail and Turcotte, 1995).
Free lime volume stabilization
• Carbothermic reduction
• Homogeneous powder of BOS slag + Carbon (5-8 wt%), alumina and silica
• Air oxidation
Air atmosphere
1673 K
5K/min
Furnace (1600°C for 1 hr)
Water quenching
Wustite Fe2O3
2CaO + xFe2O3 + (1-x)Al2O3 Ca2(FexAl1-x)2O5
STEEL SLAG

15. Utilization of waste
 BF slag can be used as raw material to manufacture-
 Cement
 Road base
 Railroad ballast
 Lightweight concrete block
 Glass and artificial rock
 High performance concrete admixtures
• .Utilisation
• Slag Atomisation
• New technology of atomising molten slag
• Molten slag (1300-1350°C) Precious slag ball-PS balls (0.1-4.5mm)
• Process consists of a high speed air blowing system with catalyst and water
exposed to the stream of falling molten slag.
• PS ball structure is typically a spinel structure.
• PS balls are dumped into ground.
• Rail Ballast
• It is hard, dense and has high attrition and abrasion value.

16. Utilization of waste
• Land applications
• Concrete
• The addition of BF slag as aggregate to cement matched the strength of sand
with natural sand.
• Adding BOS slag with BF slag incresed the mechanical strength to 25% in 28
days and decreased it by 5% after 91 days, means volume instability not appear
as a problem.
• Brick manufacturing
• SMS slag fines mixed with fly ash used for brick manufacture.
• Soil conditioners
• BOS slag has good use as aliming material when spread over acidic soils to help
raise the pH to a more neutral level.
• Phosphrous in the slag acts as nutrient to the soil.
• Waste water treatment
• Steel slag contains oxide of aluminium and iron combined with calcium base
which reacts to neutralise pH of the waste water.

17. Summary
 Due to high ash content of Indian coals, slag generation is high in BF and its disposal lead to
environmental problem.
 P content in BOF slag cannot be removed by any physical beneficiation technique.
 For sustainable growth of steel industry, we must adopt the methods and technologies for
100% recycling and reuse of product.
 The enormous support by R&D is required in this field.

18. References
 Worldsteel.org
 Utilization of solid waste from steel melting shop, MECON Limited
 International Seminar on Waste Management in Iron and Steel Industry jointly organized by
SAIL and IIPE, 9-10 May’ 2008, pp 1-192
 Das. S. K Kumar Sanay and Ramachandrarao P, (2000), “Exploitation of iron ore tailing for the
development of ceramic tiles”, Wastemanagement, 20, pp. 725-729
 Lucy V. Fisher, Andrew R. Barron, "The recycling and reuse of steelmaking slags", Resources,
Conservation & Recycling 146 (2019) 244-255.
 P.V. Viswanathan and T.K. Gangadharan, "Environmental and waste management in iron and
steel industry", NML, Jamshedpur, pp. 199-207.
 Adhikarla Baba Srinivas, Santosh Kumar Sar, Shweta Singh, Santosh Yadav, "Solid waste
management from steel melting shop", Journal of Applied and Advanced Research 2017, 2(1):
43-55.
 Wenceslao Jaimes and Samane Maroufi, "Sustainability in Steelmaking".