BlueScope Steel plant report_Final

2012
COMPOSED BY: AngelaChen
(z3189156)
UNSW - MATS5394 Pollution
Control in Industry
10/5/2012
PLANT REPORT FOCUS:
POLLUTION CONTROL

MATS5394 Pollution Control in Industry
Page | 1PLANT REPORT: BLUESCOPE STEEL AT PORT KEMBLA
Table of Contents
ABSTRACT........................................................................................................................... 1
PORT KEMBLA PLANT TRIP SUMMARY................................................................2
BASIC OXYGEN STEEL-MAKING (BOS)...................................................................3
OVERVIEW ............................................................................................................................... 3
POLLUTANTS............................................................................................................................ 4
HEALTH AND HAZARDS............................................................................................................. 4
EMISSION OVERVIEW AND NPI DATA........................................................................................ 5
CLEANING AND REDUCTION CONTROL METHODS...................................................................... 5
CASTINGPROCESS - OVERVIEW................................................................................6
POLLUTANTS............................................................................................................................ 6
DUST TREATMENTS AND CONTROL METHODS........................................................................... 7
ROLLING PROCESS - OVERVIEW..............................................................................8
POLLUTANTS............................................................................................................................ 8
MONITORING AND CONTROL METHODS................................................................................... 9
RECYCLING and REUSE PROCESSES.......................................................................10
OVERVIEW ..............................................................................................................................10
WATER AND ENERGY CONSUMPTIONS.....................................................................................11
MONITORING AND CONTROL METHODS..................................................................................12
INNOVATION AND EMERGING TECHNOLOGIES...............................................12
CONCLUSION.....................................................................................................................13
REFERENCES ....................................................................................................................15

ABSTRACT
The main types of plants involved in iron and steel industry are blast furnaces, steel
works and sintering plants, direct reduction plants, ferroalloy production, coking
plants, rolling, iron and steel foundry, and other technologies such as: argon -oxygen
decarburization, ladle metallurgy vacuum degassing1
. Due to large scale
manufacturing plant and high volume output, the iron and steel industry causes
significant effects on environmental media – air, water and soil.
Figure 1 - Night view of Port Kembla Steelwork Plant and smog emissions
This report will examine the dominant emissions generated from material handling;
wind-box exhausts, discharge end, and cold screen are particulate emissions. These
mainly consist of iron oxides, sulphur oxides, calcium oxides, hydrocarbons,
carbonaceous compounds, and chlorides1
. Emissions from the Blast Furnace are
generated from the top, in the casting stages, by drilling and plugging the taphole.
During the casting operations, iron-oxides, magnesium oxides and carbonaceous
compounds are generated. The most significant emissions from the Basic Oxygen
Process are emitted during the oxygen blowing period where iron oxides, mainly
heavy metals and fluorides are released into air. Furthermore, during the semi-
finished product preparation the pollution is produced from the pouring of the
molten steel into ingot moulds and when semifinished steel is scarfed.
Another section of the report will also investigate the control methods for polluting
emissions in the iron and steel industry. These monitoring and control methods
include various technology and devices such as: cyclone cleaners, dry or wet
electrostatic precipitators, scrubbers, bag house, hoods, furnace enclosures;
chemical, catalytic and biological methods.

PORT KEMBLA PLANT VISIT
This report is based on a plant visit to BlueScope Steel in Port Kembla, NSW. It is a
large scale steel and iron making industry that has the steel-making capacity of 5
million tonnes a year, on an area of 800 hectares and has up to 6000 employees2
.
The tour started at the Visitors Centre and all participants were fitted with safety
glasses, gloves, helmet, high visibility vest, and hearing protection with
communication devices2
. Then the tour entered through the BlueScope Steel
Northgate, went past buildings, gardens, also between the immense blast furnace,
massive stockpiles of coal and other raw materials. It was pointed out that the No.6
Blast Furnace recently had all their alignment done and is in full operation where it
was initially commissioned in 1996 at a cost of $460 Million2
.
It was evident on the tour that BlueScope Steelworks made significant efforts to
protect and sustain ecologically local flora and fauna. Continuous improvements in
the past two decades, 441000 trees, shrubs and ground cover were planted2
. Along
the drive, there were about 180 individual gardens, and designated resting areas for
employees, restricted areas for a rare colony of green and golden bell frogs where
their health is now subjected to ongoing monitoring by joint project with Southern
Cross University2
. Also a recent census showed that 39 species of birds live and or
visit the site. However, it was also noted that open dust sources include vehicle
traffic, raw material handling and wind erosion from storage piles all contribute to
the atmospheric pollutions.
Figure 2 - Blast Furnace and Emission stack at BlueScope Steelworks, Port Kembla

BASIC OXYGEN STEEL-MAKING (BOF)
The tour continued to the first visiting site which is the Basic Oxygen Steelmaking
Plant. This is one of the critical steps in making steel where iron is proportionally
mixed with small quantities of carbon and other additives. The group went up the
external staircase to the furnace floor to witness the 1600 degree Celsius process
that makes steel in this vessel. The raw materials include molten iron and scrap that
consists of 1/5 of the total volume is placed in the vessel, combined with heat and
oxygen blast to create and refine carbon in steel2
. At Port Kembla there are three
Basic Oxygen Steelmaking apparatus each with capacity of 5 mega-tonne per annum,
which can be seen from the following image (Figure 3)2
.
Figure 3 - BOS Vessel at BlueScope Steelworks
In Basic Oxygen Steelmaking Plant there are also two air separation units producing
gaseous oxygen and nitrogen along with liquid oxygen, nitrogen and argon. Typical
operational capacities are about 1,080 tonnes per day of gaseous oxygen and 220
tonnes per day of gaseous nitrogen2
. Due to such large volume of gaseous
substances being added to the steelmaking process each day, there is no doubt the
amount of air pollutant emitted into the atmosphere. Hence there are monitoring
systems and preventative techniques in place to reduce pollutants and health
hazards.

Figure 4 – General Process of Basic Oxygen Steelmaking flowchart – Specifying individual
operations and the input and output mass streams
Pollution Prevention in the BOF
Slag is a major component of the waste produced in BOFs. Due to its composition,
this slag, unlike that from the blast furnace, is best used as an additive in the
sintering process. Since metallic content is lower, hence is not a good raw material
for the construction industry3
.

Hot gases are also produced by the BOF. Furnaces are equipped with air pollution
control equipment that contains and cools the gas3
. The gas is quenched and cooled
using water and cleaned of suspended solids and metals. This process produces air
pollution control dust and water treatment plant sludge (Figure 5). For instance,
typical pollution control equipment like: Top Gas Recovery Turbine (TRT); Hot stoves
waste – Gas Heat Recovery Systems; using EFA (Entrained Flow Absorber) - Sintering
Off-gas treatment; also De-dusting and Air Pollution Control Systems (i.e. Stock-
house facilities) 4
.
Figure 5 - Recycled water used for cooling and de-dusting hot steel slabs
It is evident that in the iron and steel making industry, the manufacturing process
(which is clearly explained by the flowchart in Figure 4) does generate significant
amount of pollutants in the environment specifically in air, water and landfills2
. Thus,
Australia has a nationally pollution monitoring system known as NPI where the
general public can all access up to data emission data and be aware of hazardous
pollutants caused by particular industries. This report will also discuss specific
emission data in the next section and their effect on health. BlueScope Steelworks
have inputted tremendous efforts where they implemented many techniques to
reduce the pollutant effects and protect the environment.

BlueScope Steel is part of the “World-steel Climate Action Programme”: that is a
measurement and benchmarking of greenhouse gases. It is a crucial pathway
towards encouraging, developing and enacting company-specific and industry-wide
initiatives for reducing CO2 emissions6
. This is a scheme which recognises that a steel
producer has fulfilled its commitment to take part in the World-steel CO2 data
collection program. The data collection program is at the core of the steel industry's
global steel sectoral approach to climate change6
. Based on a common methodology
and agreed definitions and boundaries, the data collection programme enables
individual steel plants to compare themselves against both average and best
performance and to identify scope for improvement.
EMISSIONS & HEALTH HAZARDS
BlueScope Steelworks Emission Data obtained from NPI websites shows that the
major air pollutant emission is carbon monoxide (CO) totally of (1.55e8 kg = 155
tonnes per annum into air)5
. Hence, it is crucial to have awareness of the potential
hazards and health risks associated with CO.
Carbon monoxidegas is produced in substantial amounts by avariety of furnaces.It may also be
released during thepouring of moltenmetal.Inhaled carbon monoxideprevents the bloodfrom
carrying a normal supply of oxygen. Exposure to concentrations of 500 to 1000parts per million
(ppm) for approximately 30 minutes may precipitate headache, accelerated breathing, nausea,
dizziness andmental confusion6
.Thus apossible secondary effectof exposure isan increased
riskof accident andinjury to the worker.Exposure to higherconcentrations (approx.. 1000
ppm)may result in the appearance of symptoms after several minutes, or unconsciousness may
occur rapidlywithoutany warning symptoms5
.

Since Carbon Monoxide is a colourless and odourless substance so it has no warning
properties when inhaled or in contact3
. The only way to determine the concentration
of the gas is by regularly monitoring the foundry air. Automatic alarms are in place to
warn workers of the dangerous Co levels, provided they are correctly adjusted10
.
Exhaust ventilation is an effective controlling carbon monoxide emissions at the
source. For all potential exposed workers should be instructed in the dangers,
recognition and treatment of CO poisoning. The biological monitoring of carbon
monoxide via blood sampling or in exhaled air samples maybe a useful technique.
The samples should be taken at the end of the working shift6
.
Various metal fumes may be generated during founding processes, especially during melting and
pouring operations.Lead,magnesium, zinc, copper, aluminium, cadmium, antimony,tin and
beryllium fumes are commonly present in non-ferrous foundries. Iron oxide is the
major fume generated in iron and steel operations4
. ‘Metal fume fever’ mayresult from
exposure tothese contaminants. This isan acuteillness ofshort duration which commences
some hours after inhalation of the metallic fumes. The initial symptoms are flu-like:
nausea, headache,dry throat andcoughing, and muscular pains. Chills and sweatingmay occur
later.Recoveryis usual within24 hoursafter removalfrom exposure3-5
. The fumes of zinc and
copper are the most common causes of metal fume fever. The fumes and dust of cadmium,
beryllium, nickel andchromium, contained insome alloys,are verytoxic.
Figure 6 - Air emissions from Blast Furnace gas tower at BlueScope Steel, Port Kembla

VOC Sulfuric Acid
Sulfur Dioxide
PM2.5
PM10
Nitrogen Oxides
Lead&Compounds
HydrochloricAcid
Ammonia
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
158823 93394 7692026 98995 1697953 8177721 2577.06 309396 455079
NPI Data: Other Pollutant Substances emitted from Iron/Steel Industries
(Total Air and Water in Kilograms )

CONTINUOUS SLAB CASTING PROCESS
The plant trip continued after the molten metal is released from BOF, to the second
visiting site where it must be formed into its final shape and finished to prevent
corrosion. Traditionally, steel was poured into convenient shapes called ingots and
stored until further shaping was needed3
. Current practices favour continuous
casting methods, where the steel is poured directly into semi-finished shapes.
Continuous casting saves time by reducing the steps required to produce the desired
shape.
Figure 7 - Continuous casting and cutting of Steel slab as semi-finished product
Due to the excessive heat required to heat up for continuous casting and cutting
large energy expenditure are required. All BlueScope facilities harness as much
energy as is economically feasible from the gases generated by on-site activities:
gaseous by-products are cleaned, and then used to generate energy for the plant7-
9
. This not only utilises the by-products of the steelmaking process, but also
contributes to resource sustainability and greenhouse gas (GHG) emission reduction.
80% per cent of the energy required to power the coke ovens at Port Kembla
Steelworks is derived from gases produced in the blast furnace. The other 20% of the
energy required comes from gases recovered from the coke ovens themselves8
.

BlueScope Steel industry is also the leading the water recycling project,
commissioned in partnership with Sydney Water, now recycles wastewater from
across the Illawarra region and treats it for re-use at Port Kembla Steelworks. The
introduction of recycled water reduced the Steelworks' fresh water consumption and
has saved more than 21 billion litres of fresh water to date (2010)6
. At Port Kembla
Steelworks the great majority of water used is seawater (96 per cent), which
displaces the need to use fresh water for much of the site’s cooling requirements7
.

ROLLING / HOT STRIP MILL PROCESS
Primary wastes produced in the metal forming process include contact water, oil,
grease, and mill scale4-5
. All are collected in holding tanks. The scale settles out and is
removed. It can be reused in sintering plants or, if the metal content is sufficient,
may be sold as a raw material elsewhere8
.
The remaining liquid leaves the process as waste treatment plant sludge6-7
. As the
waste results in a small portion of pollution produced by steelmaking, pollution
prevention and process modification opportunities are not a top priority.

THE RECYCLING PROCESS
There are two methods of steel production: Blast Furnace-Basic Oxygen Steelmaking
(BF-BOS) and Electric Arc Furnace (EAF) production8
. The BF-BOS process uses virgin
material, including iron ore, coke and fluxes, as well as scrap steel. Scrap is added to
the BOS vessel to maintain thermal balance. All flat steel products (e.g. automobile
panels and roofing and fencing materials) and some long products (e.g. railway tracks)
made in Australia are produced through the BF-BOS route7
. EAF steel can be
produced from up to 100% recovered material. However, EAF production is limited
by the worldwide availability of scrap, and is therefore insufficient to meet market
needs8
.
BF-BOS recycled content proportions may also be limited by the availability of scrap;
however, there are also technical limitations. These factors result in the proportion
of recovered material in the steel produced in the BF-BOS process by BlueScope Steel
in Australia being, on average, 17–20%.7-8
The majority of this material is classed as
reutilised scrap, not pre-consumer or post-consumer recycled content. From a
sustainability point of view, the proportion of steel that is recovered for recycling at
the end of each use phase is more relevant than the recycled content in any one
product at a particular point in time10
.
Figure 8 - BlueScope Steel-works external conveyor to melting vessels, Port Kembla

INNOVATION & EMERGING TECHNOLOGY
BlueScope Steel has successfully developed high-strength steel products, so that the
same function is achieved using fewer raw materials. Roofing that was once
manufactured at 0.55 mm thick, is today made from high-strength COLORBOND®
steel 0.42 mm thick – a reduction of 24% without any sacrifice in performance8
.
Improvements have also been made in terms of the coatings that go on our steel. A
highly corrosion resistant aluminium/zinc (AZ) mixture is used to coat some products
that were once treated with zinc alone (traditional galvanised products). The AZ
coating is lighter (on a volume basis) than a pure zinc coating, the same coating
thickness can be achieved using less material. The standard 20 μm thick coating
requires approximately 45% less coating material when AZ is used compared to zinc
alone8
. This translates to a 75% reduction in the amount of zinc used per square
metre of coated steel. Further, the increased durability of the AZ coating means that
the final product lasts longer, which gives a lower environment footprint8
.
CONCLUSION
The iron and steel industry causes significant effects on environment media: for air
emissions of SO2, NOx, CO, H2S, PAH, Lead, Ni, As, Cd, Cr, Cu, Zn, Se, Hg, PM10, PM2.5
etc. For water pollutant emissions include: organic matter, oil, metals, suspended
solids, benzene, phenol, acids, sulphides, sulfates, ammonia, cyanides, thiocyanates,
thiosulfates, fluorides (scrubber effluent)15
. Last but not least, land pollutants of slag,
sludge, sulphur compounds, heavy metals, oils and grease, residues, salts.
This report discussed the aforementioned pollutants, their threatening effects on
health and preventative techniques to reduce and monitor various hazardous
emission levels. Examples were given by detailed observations and information
gained from plant trip around BlueScope Steelworks at Port Kembla, NSW and
literature values from NPI database. Typical polluting emissions generated in the iron
and steel industries are controlled by a variety of evacuation systems, devices and
methods16
. These include cyclone enclosures, dry or wet electrostatic precipitators
(EC), scrubbers, bag houses, hoods, vegetation planation, and furnace enclosures
implementations etc. In essence, with the new millennium there must be an
awareness to make improvements and developments of modern, sustainable iron
and steel technology within human activity in coexistence with environment on a
global-scale17-18
.

REFERENCES
1. NPI: Emission Estimation Technique Manual (NPI Gov. website database)
2. Lecture Handout– BlueScope Steelworks Briefings and Field Trip info
3. European Commission – (BAT): “Iron and Steel Production”, Industrial
Emission Directive EU: Integrated Pollution Prevention and Control
4. http://www.istc.illinois.edu/info/library_docs/manuals/primmetals/cha
pter2.htm
5. Pollution Prevention and Abatement Handbook - WORLD BANK GROUP:
Effective July 1998
6. http://www.sydneywater.com.au/Publications/Reports/AnnualReport/2
007/menu/performance/goal2/recycling.cfm
7. http://www.paulwurth.com/en/Our-Activities/Energy-
environment/Blast-Furnace-gas-cleaning-systems
8. http://annualreport2005.bluescopesteel.com/results/port-kembla-
steelworks.html
9. Chatterjee, Amit. "Recent Developments in Ironmaking and
Steelmaking." Iron and Steelmaking. 22:2 (1995), pp. 100-104.
10.Frukawa, Tsukasa. "5000 Daily Tons of Direct Iron-OreSmelting by
2000." New Steel. 10:11 (November, 1994), pp. 36-38.
11.McManus, George, ed. "Replacing Coke With Pulverized Coal." New Steel.
10:6 (June, 1994), pp. 40-42.
12.Ritt, Adam. "DRI comes to the Gulf Coast." New Steel. January, 1996, pp.
54-58.
13.Strohmeier, Gerolf, and John Bonestell. "Steelworks Residues and the
Waelz Kiln Treatment of Electric Arc FurnaceDust." Iron and Steel
Engineering. April, 1996, pp. 87-90.
14.U.S. Department of Commerce. 1992 Censusof Manufacturers —Blast
Furnaces, SteelWorksand Rolling and Finishing Mills. 1992.
15.USEPA. "Profileof the Iron and Steel Industry." EPA/310-R-95-010, U.S.
Environmental Protection Agency. Washington, D.C., September 1995.
16.Andres, A., et al. "Long-termBehavior of Toxic Metals in Stabilized Steel
Foundry Dust." Journalof HazardousWaste Materials. 40 (1995)
17.Berry, Brian. "Hoogovens Means Blast Furnaces —And Clean Air." New
Steel. December, 1994. pp. 26-30. McManus, G.J. "TheDirectApproach
to Making Iron." Iron Age. July, 1993. pp. 20-23.
18.Mohla, Prem. "New Ductile Iron Process Meets the Challenge of the
1990's Head On." Foundry Managementand Technology. 121:4(April,
1993), pp. 52-56.

BlueScope Steel plant report_Final

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (19)

Similar to BlueScope Steel plant report_Final

Similar to BlueScope Steel plant report_Final (20)

BlueScope Steel plant report_Final