TENORM IN IRON AND
STEEL INDUSTRY
KHATER A., BAKR W.
King Saud University- Saudi Arabia
Nuclear and Radiological Regulatory
Authority- Egypt
Iron and steel industry
• It has been ranked as the largest industrial
source of environmental contamination.
• About 2-4 tones of various wastes per ton of
steel production.
22-04-2013
NORM 7, Beijing- china , 2013
2
World crude steel production reached 1,548 Mt for
2012, up by 1.2% compared to 2011. This is a record
for global crude steel production
3100 -6200 Mt wastes
NORM 7, Beijing- china , 2013
3
Iron and steel industry
• These wastes contain a considerable amount
of NORM and other contaminant ( such as
Pb, Cd and Zn)
•
NORM 7, Beijing- china , 2013
4
Iron and steel industry
Iron Ore
Coke
Scrap
Sinter
Pre-reduction
Pellets
Coal
Blast Furnace
O2
Hot metal (pig iron)
Scrap
Smelting
reduction
(Corex)
O2
O2
Electric arc
furnace
Hot
metal
Scrap
O2 converter
(Basic oxygen furnace)
Steel
NORM 7, Beijing- china , 2013
5
Iron and steel industry
NORM 7, Beijing- china , 2013
6
Sintering and pelletizing
• Input:
• Iron ore, dolomite, coke and recycled dust
• Temp. to 1400 oC in combustion zone
• Output:
• Iron ore sinters
• Dust
• Slug
NORM 7, Beijing- china , 2013
7
Blast Furnace (BF)
Inputs
:
sintered, pelletized and Iron
ore, limestone and coke
hot air (up to 1400oC)
Outputs:
Molten (pig) iron and wastes
(i.e. Slag, residue of BF
washing and dust)
NORM 7, Beijing- china , 2013
8
Blast Furnace (BF)
• 1.6 t ore + 0.7 t coke +
0.25 t limestone +3.6 t
of air (1600oC)
• 1 t of pig iron + ? t
wastes
The US steel industry produces 13–15 Mt of BFS annually, while in Europe 26.2
Mt of BFS is produced every year. Approximately, 300–350 kilograms of BFS is
generated for each ton of steel production.
NORM 7, Beijing- china , 2013
9
Smelting reduction (Corex)
NORM 7, Beijing- china , 2013
10
Basic oxygen furnace (BOF)
• Input:
• Molten (pig) iron
and scrap
• Output:
• Steel and wastes
(e.g., Slag and dust)
NORM 7, Beijing- china , 2013
11
Electric Arc Furnace
• Input:
• Scrap
• Output:
• Steel and wastes (e.g.,
slag, dust and scale
NORM 7, Beijing- china , 2013
12
Experimental
Work
NORM 7, Beijing- china , 2013
13
Sampling and samples preparation
Factory A: - Iron ore - Dust (sinter plant-SP & BF)
- Residue of ore washing (OW)
- Slag (sinter plant & BF & BOF)
Factory B:
- Dust (EAF)
- Slag (EAF)
Factory C:
- Dust (EAF)
- Scale (EAF)
- Slag (EAF & water
treatment-WT)
Factory D: - Iron ore
Raw materials:
- Limestone
- sludge
& Dolomite & Feldspar
Khater- NORM 7, Beijing- china , 2013
& coke
14
-Iron Ore (2)
• SP
• BF
• BOF
• EAF
• WT
- Scale (1)
NORM 7, Beijing- china , 2013
Residue (2)
Slag (5)
Dust (4)
• SP
• BF
• EAF
• OW
• BFW
- Sludge (1)
15
Analytical Techniques:
Gamma-ray spectrometer based on HPGe
detector; 238U, 226Ra, 210Pb & 228Ra & 40K
 Alpha particle spectrometer based on PIPS
detector; 210Po
Laser Fluorometer; U
ICP-MS (ALS- Chemex, Vancouver- Canada); U, Th,
K and other elements
NORM 7, Beijing- china , 2013
16
Gamma-ray spectrometer:
Coaxial Configuration :Relative Efficiency : 35%
Resolution :1.9 keV ( 1332.3 keV of 60Co)
Efficiency Calibration:
226Ra
Point source- KCl
Standard solution
N.F (K-40) = Wt *16.28/CR
R.E(Y)= A0+A1Y+A2Y2+…
N.F (Y)= R.E(K-40)*BR(k-40)* N.F(K-40)
R.E.(Y) *BR(Y)
Activity = N.F (Y)* CR/d
Radionuclide
 -Iines (keV)
Intensity%
U-238 (Th-234)
63.3
43.8
Pb-210
46.5
4.0
Ra-226 series
Pb-214
Bi-214
Bi-214
Bi-214
351.9
609.3
1120.3
1764.5
37.3
46.3
15.0
16.0
Th-232 series
Ac-228
Ac-228
Tl-208
338.4
911.1
583.0
12.0
29.0
30.9
K-40
1460.7
10.7
Radiochemical Separation of 210Po
Dried sample materials
Add yield tracer Po-209 and
Digestion with HNO3 acid and HF
Evaporate to dryness
Dissolve in 0.5M HCL
Heating to boiling and add 0.2gm
Ascorbic acid
Po deposition on the rotated
stainless steel disc
Alpha spectrometry
Set-up Diagram of Alpha Spectrometer
Energy and Efficiency Calibration : Am-141, Pu-239
and Cm-244
A(Po-210)= C(Po-210) * A(Po-209)
C(Po-209)*m(kg)
Sample Preparation for Laser Flourimetry Measurements
Radiochemical Separation of Uranium
Ashed Sample
5ml Conc. HNO3+5ml
40% HF
Evaporate to dryness and Repeat
5ml Conc. HNO3
Evaporate to dryness
5 ml 2 M HNO3
Evaporate to dryness
Evaporate to dryness
2ml 2M HNO3+10 ml Ca-EDTA and then
filtrate
Set-up Diagram of Laser Flourimetry
Calibration : Standard Solution of Uranyl Nitrate
C(U)ppm = RS
* Cstand* Vstan/Vsample
RS+St-RS
RESULTS &
DISCUSSION
NORM 7, Beijing- china , 2013
24
Iron ore samples
Bq/kg
 This
variation
is
because hematite occurs
in many different types
of host-rocks. It occurs
associated with vein
deposits (igneous, metamorphic, and sedimentary rocks) and as
product of the weathering of magnetite.
150
O-1
140
O-2
130
120
110
100
90
80
70
60
50
40
30
20
10
0
U-238
Ra-226
Pb-210
Po-210
Fe2O3 %
Therefore, NORM concentrations vary according to their geochemical
properties and their concentrations in source rock materials
NORM 7, Beijing- china , 2013
25
18
Ratio (O1/O2)
Also, the increase of Fe
16
content in the ore would
12
absorbed
uranium
(Ahmed et al., 2007).
Ratio (O1/O2)
increase the originally
14
10
8
6
4
2
0
U-238
Ra-226
Pb-210
Po-210
Fe2O3 %
On the other hand, an increase of silica content in the ore
indicates an increase in the amount of detrital quartz grains
and hence a possible increase in heavy radioactive detrital
(Ahmed et al., 2007).
NORM 7, Beijing- china , 2013
26
140
130
120
110
100
90
Fe2O3
U238T
U238L
40
30
20
10
0
Ore-1
Ore-2
The radioactivity of the ore depends on a balance between two complex factors:
[Gindy, 1962]
• Uranium originally absorbed in the hematite particles and other
microcrystalline matter ,
• Uranium fixed in some of the minute detrital heavy grains.
O-1
40
O-2
Bq/kg
30
20
10
0
Th-232
Ra-228
K-40
Fe2O3 %
E
NORM 7, Beijing- china , 2013
28
Factory (A)
U-238
Th-232 K-40 U-238-G Ra-226 Ra-228 Pb-210 Po-210
ORE
135
5
28
114
133
15
50
25
RES. F. WASHING
24
3
13
98
157
25
4238
5656
RED. OF ORE WASHING
109
6
34
57
87
6
186
200
BLAST FUR DUST
77
7
85
80
70
5
2340
470
SINTER DUST
60
5
110
57
70
8
19
65
SINTER SLAG
80
7
63
34
65
6
30
87
TRANSFORMER SLAG
35
4
22
43
46
7
14
BLAST FUR. SLAG
289
29
135
297
552
56
45
International topical conference on Po and
Radioactive Pb isotopes Ashraf Khater
Activity concentration of Po-210 and Pb-210 in B.F. dust
depends on their concentration in ore and their enrichment
during thermal process.
Their conc. In B.F. dust is high comparing to Ttotti (2004)
study (59 and 50 Bq/kg, respectively). While their concentration
is much lower comparing to Trotti et al., study, 42867 and 47243
Bq/kg , respectively.
NORM 7, Beijing- china , 2013
30
100%
18.6
90%
50.21
30.4
80%
60%
46.2
182.6
70%
133.3
96.7
64.25
4238.2
50%
2340
40%
87.2
30%
42.8
20%
114.4
57.4
43.2
10%
56.9
157
97.8
0%
Iron ore
Sinter dust
Sinter slag
Residue of ore
washing
U-238
Ra-226
70.1
79.6
Residue of furnace Blast furnace dust
washing
pb-210
The Distribution of the Activity Concentrations of the Selected Isotopes
Transformer slag
NORM 7, Beijing- china , 2013
SC
©
S1
S- (S
2 S- (B A)
3 F(
S- BO A)
4 F(E A
S- AF )
5
S- (W C)
6 T(E C
AF )
-B
)
-4
D
-3
D
-2
D
-1
D
-2
R
-1
-2
-1
R
O
O
RaEq
Radium Eq. Of different samples
600
500
200
100
0
32
U (L)
NORM 7, Beijing- china , 2013
©
300
S
C
S
-1
S (S
-2 S (B A)
-3 F
( S BO A)
-4 F
(E -A
S AF )
-5 S (W C)
-6 T
(E -C
A )
FB
)
-4
D
-3
D
-2
D
-1
D
-2
R
-1
-2
-1
R
O
O
U-238, Bq/kg
Effect of the processing on the leachability of U
U (T)
250
125
100
75
50
25
0
33
U-238 series disequilibrium
U-238 series
PO/Pb
Pb/Ra
Ra/U
ORE
0.5
0.4
1.2
9.2
RES. F. WASHING
RED. ORE WASHING
1.3
1.1
27.0
2.1
1.6
1.5
6.3
14.5
BF - DUST
SINTER - DUST
0.2
3.4
33.4
0.2
0.9
1.7
13.2
12.7
SINTER SLAG
BOF- SLAG
BF- SLAG
2.9
0.5
1.9
1.1
1.9
10.6
7.1
9.9
Activity Ratios
Ra6/Ra8
CONCENTRATION FACTOR
B.F.
WASH
ORE
WASH
Sint.
DUST
B.F
DUST
Sint.
SLG
B.F.
SLG
TRANS.
SLAG
U-238
-0.8
-0.2
-0.6
-0.4
-0.4
1.1
-0.7
Th-232
-0.4
0.2
0.0
0.4
0.2
4.5
-0.3
K-40
-0.6
0.2
2.9
2.0
1.2
3.8
-0.2
U-238, T
-0.1
-0.5
-0.5
-0.3
-0.7
1.6
-0.6
Ra-226
0.2
-0.3
-0.3
-0.5
-0.5
3.1
-0.7
Ra-228
0.7
-0.6
-0.5
-0.6
-0.6
2.8
-0.6
Pb-210
83.8
2.7
-0.6
45.8
-0.4
Po-210
225.2
7.0
1.6
17.8
2.5
0.8
-0.4
PO/Pb
1.7
1.2
5.8
-0.6
4.8
•Po relative solubility (washing Res.) - Valorization of Po in BF temp (1600 oc)
• in sintering process Po > ppb although Pb>po in the ore ???
Exposure pathways
External
Exposure
From the
plume
From
ground
Internal
Exposure
Inhalation
(contaminated
Foodstuffs)
Radiological Dose Assessment
In general, the total annual effective dose is
determined by means of the following equation:
Htotal = Hext + Hinh + Hing
where Hext, Hinh and Hing are the annual effective
doses (mSv/y)
NORM 7, Beijing- china , 2013
37
Scenarios for workers
Road construction
Outdoor storage
Transport (long distances)
(earthwork application)
External Inhalation Ingestion
External Inhalation Ingestion
External Inhalation Ingestion
NORM 7, Beijing- china , 2013
NASDK
Co
El-Ezz
Rebars Co.
El-Delta
for Steel
Co.
2.4
2.2
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Egptian
Iron&
Steel Co.
Annual Dose Rate ( Micro Sv)
The Average Annual Effective Dose of Operating Personnel Due to Gamma Radiation
( the Four Factories)
38
Other Toxic elements
NORM 7, Beijing- china , 2013
39
Toxic Elements in Iron and Steel industry
wastes
As
Cd
Cr
Cu
Hg
Ni
Pb
Zn
MAC
TAV
D
R
15-20
10-65
41-70
58-95
1-5
2-10
20-401
2-38
50-200 50-450
162-1120
66-187
60-150 60-500
134-3200
11-18
0.5-5
1.5-10
0.1-2.4
0.04-0.08
20-60
75-150
27-153
10-30
20-300 50-300 2020- >10000 129-3130
100-300 200-1500 > 10000 5720- >10000
NORM 7, Beijing- china , 2013
S
<2-52
2-6
95-2510
16-450
0.02-0.16
11-50
133-366
1275-6650
40
NORM 7, Beijing- china , 2013
41
CONCLUSIONS
NORM 7, Beijing- china , 2013
42
Conclusions
1
• Iron and steel industries produce a
huge amount of wastes
2
• TENORM is extremely high in some
wastes. Their radioecological impacts
should be investigate deeply to ensure
the safety aspects
3
• Toxic heavy element impacts should be
considered as associated risk with
TENORM
NORM 7, Beijing- china , 2013
43
“It is unlikely to pose any significant
adverse health impacts, according to the
cited national and international legislation
and guidance used for comparison” ( Ugur et
al., 2013).
It is nice >>>It is very good >>>>it s very scientific
Is it enough?
NORM 7, Beijing- china , 2013
44
Best radioecolgical Practice
Achieve safe
disposal and
recycle
Risks to
Worker or
Public &
environment
Wastes
Time
NORM 7, Beijing- china , 2013
45
Thank you for your attention!