Yin R. Metallurgical Process Engineering
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XXX
List
of
Figures
Fig. 9.6
Fig. 9.7
Fig. 9.8
Fig. 9.9
Fig. 9.10
Fig. 9.11
Fig. 9.12
Fig. 9.13
Fig. 9.14
Fig. 9.15
Material and energy input and output
of
the blast furnace
Material and energy input and output
of
BOF steelmaking
The temperature- time track
of
mass flow in BF
-BOF
process
Diagram of material, energy and environmental burden in
BF-BOF-thin
slab casting-rolling process (Enterprises
without their own power plant)
The temperature- time track
of
matter flow in EAF
-thin
slab
casting-rolling process
Diagram
of
material, energy and environmental burden in
EAF- thin slab casting-rolling process
Injecting waste plastics into
SF
(recycled plastic containers
and package materials can be injected into
SF)
The development philosophy
of
environmental friendly and
suburb type steel plants
The role
of
a steel plant in eco-industrial zone
Eco-industrial chains and circular economy
309
310
311
312
312
313
315
320
321
321
List
of
Tables
Table 1.1
Percentages
of
steel consumption by China's relevant
manufacturing industries from 2001 to 2006 ( Unit:%)
7
Table 1.2 Changes in regional steel production from 1950 to 2006 in
mainland China
9
Table 1.3 China's GDP in recent years and contributions to the GDP by
the primary,secondary and tertiary industries
11
Table 1.4 Total output and ratio
of
EAF steel in China since 1990 13
Table 1.5 China's outputs and imports of iron,manganese and chromium
ores from 1990 to 2006 13
Table 1.6
China's scrap imports from 1991 to 2006 ( Unit: Mt)
14
Table 1.7 Effects of increasing continuous casting ratios on the use
of
China's open hearths 17
Table 1.8 The effect of slag splashing technology on BOF campaigns
in China 19
Table 1.9
Changes in techno-economic indexes of the Chinese steel
industry since 1990s (Yin, 2008) 20
Table 2.1 Processes at different levels and their ranges of space-time
scale (Lerou, 1996) 29
Table 3.1 Trend of integrated fundamental researches 66
Table 3.2 Analysis
of
level relationships in term
of
science of steel
manufacturing process
69
Table 4.1 Function analysis of the procedures in steelmaking process
107
Table 6.1 The important factors in metallurgical process 156
Table 6.2 The continuation degree of some steel manufacturing
processes 166
Table 6.3
Processing time,temperature in
BF-B
OF- ingot teeming-
hot charging- hot rolling process 167
Table 6.4
Process time, temperature in blast fumace- hot metal
pretreatment- converter- secondary metallurgy- continuous
casting - cold charging- hot rolling process
167
Table 6.5 Processing time,temperature in blast fumace- hot metal
xxxn
List
of
Tables
pretreatment- converter - secondary metallurgy-
continuous casti
ng-
hot chargi
ng-
hot rolling process 168
Table 6.6 Processing time,temperature inblast furna
ce-
pretreatment
of hot metal- converter - secondary metallurgy - thin slab
casting - rolling process 169
Table 7.1
The calculated inventory capacity,actual inventory capacity,
and loop capacity index between slab caste
r-
hot rolling
mill 197
Table 8.1 Cost to remove 1kg sulfur by different procedures 222
Table 8.2 Evolution
of
refining function
of
secondary metallurgy 225
Table 8.3 Comparison
of
influences on energy consumption by
different steelmaking-rolling processes 227
Table 8.4 Function distribution and composition
of
iron and steel
smelting procedures 230
Table 8.5 Distribution and composition
of
functions
of
solidification
and rolling procedures 230
Table 8.6 Process time comparison between different steelmaking-
rolling processes 232
Table 8.7
Evolution chronicle
of
rolling speed
of
high-speed wire mill
256
Table 8.8 Theoretical limit
of
contents
of
impurities in steel 264
Table 8.9 Transporting devices in 3 typical EAF steelmaking workshops 269
Table 8.10 Changes
ofBF
utilization coefficient and grades
of
ores
burden in China during 1990 - 2006 271
Table 8.11 Composition
of
ores burden for some European BFs 271
Table 8.12 Burden design and slag ratio
of
some European BFs 272
Table 8.13 Comparison
of
coke key figures 274
Table 8.14 Proportion
of
hearth active zone and smelting intensilg
275
Table 8.15 Calculation
of
intensified smelting
of
BFs with different
volumes 276
Table 8.16 Expected annual production
of
BFs with different volumes
after smelting intensifying 277
Table 8.17 Comparisons
of
volume utilization coefficient 'lv, furnace
hearth area utilization coefficient
'lh, smelting intensity Is.
combustion intensity Ieand VIA
of
BFs with different
volumes 278
Table 9.1
Comparison between the eco-type factory and the traditional
factory
308
Table 9.2 Energy and CO
2
emission comparsion
of
cement produced
by BF slag and by limestone 314
Chapter 1
Steel-the
"Material of
Choice"
No substantial changes will take place in the position
of
steel as the important structural
and functional material because
of
its abundant resources, comparatively low cost, excel-
lent material characteristics, and ease
of
processing and recycling. Steel is still the "mate-
rial
of
choice" and it is the recycling material. It is an important basic material in the
processes
of
social civilization and economic development.
The Chinese steel industry has been rising since the 1990s. The development, integra-
tion and popularization
of
six key/common technologies
-co
ntinuous casting, PCI tech-
nology, BF(Bla
st
f
urna
ce) campaign elongation technology, continuous rolling, BOF
(Basic oxygen furnace) slag splashing technology,
and
energy conservatio n- have pro-
moted the optimization
of
the Chinese steel industry s production processes, energy-saving
and emission reduction and improved its production efficiency, and put an importantfou n-
dation for fu rther rapid developement
of
the Chinese steel industry.
Steel and other metallic materials developed vigorously in the 20
th
century and
have become an important material basis for the constant advances of the global
economy and social civilization. Steel has been produced on an industrial scale
since the invention
of
the Bessemer converter in 1856. Since then, the world
crude steel output has undergone constant albeit frequently fluctuating develop-
ment amid such major events such as economic booms and crises, world wars and
oil crises, and with the development and application
of
oxygen converter steel-
making, continuous casting, large blast furnaces, continuous rolling and the use
of
information techniques. The advance in steel output in the world since 1870 is
shown in Fig. 1.1. World steel output surpassed 1.2395 billion tons in 2006. Peo-
ple's cognition of the socio-economic value
of
steel has variously been consistent,
divergent, or blurred and ambiguous in different periods
of
time and different
countries/regions. In sum, it remains a matter that deserves concern and discus-
sion.
R. Yin, Metallurgical Process Engineering
© Metallurgical Industry Press, Beijing and Springer-Verlag Berlin Heidelberg 2011
2 Metallurgical Process Engineering
1.2395 billion tons in 2006
Emergence of Thin-slab
casting technology
1974 1984 1994 2004
1969 1979 1989 1999 2006
Emergence
of
1301'
and CC
World War II
Economic crisis
World War I
1870 1904 1914
1895 1909 1919
1400
1200
'"
"
,9
1000
"
~
~
800
:::l
B-
600
:::l
0
"
"
400
Vi
200
Year
Fig.
1.1
Trend in world steel output since 1870
1.1
The Position
of
Steel among Diverse Materials
No major change has taken place in the position
of
steel as an important structural
and functional material, yet this is still a matter that calls for discussion and
analysis.
A fairly systematic survey is conducted in the article by Czichos Horst (1994)
on the requirements and criteria for the evaluation
of
materials. Fig.l.2 provides
an authoritative analysis
of
the evaluation criteria in industrial circles for the per-
formance
of
materials, and shows that such qualities as strength, deformation,
21.6
20.1
16.3
9.4
8.9
7.3
7.0
4.4
,p 2.1
0 2.1
~08
- -
Biological characteristics
o ' .0 10.0 15.0 20.0
1).0
Fig. 1.2 Evaluation
of
the characteristics
of
materials vital to industry (Total points: 100)
Erccp
Elasticity
Density
Fatigue resistance
Heat characteristic
Corrosion resistance
Abrasion resistance
Strength, deformation. fracture
Overall performancc
Magnetic and optical performances
Chapter 1 Steel
-the
"Material
of
Choice" 3
fracture, thermo-properties, and integrate properties are still the main require-
ments for various kinds
of
materials. All engineering materials in terms
of
their
strength, toughness and strength values at different temperatures were compared
in the article by J. R. Davis (1995).
It is evident that, at least in terms
of
current
knowledge and existing technical conditions, steel possesses advantages in all the
relevant aspects.
Evaluation indexes for materials and industrial techniques that will be used in
the future have been put forward (Fig. 1.3, Horst, 1994).
It
is evident that the
principal indexes for evaluation are such factors as low price, ease
of
recovery,
environmental friendliness, and low consumption
of
energy and materials. Steel
materials show comparative advantages in terms
of
all the factors evaluated.
t
I
I
~
'
C:::J
'
:::::J
0
Replaceable
o 10 20 30
-1
0
Fig.1.3 Future requirements in terms of materials and industrial technology
Availability
Acceptability
Automation
~ n
e
r
gy
and material economy
Environmental protection
l.ow cos
Labor protection
Changes in the prices
of
various mass produced materials, such as steel, alumi-
num, plastics, and cement from 1974 to 1994 (Ruprecht, 1995), are shown in Fig.
1.4. The price
of
steel has fluctuated within a range
of
approximately 15%,
whereas the prices
of
cement and plastics have risen significantly in the same
period and the price
of
aluminum has fluctuated sharply and risen more than the
price
of
steel.
Cement
Year
Fig. 1.4 Prices
of
various materials since 1974 (Price indices for 1974 = 100)
4 Metallurgical
Process
Engineering
Changes in the relative prices
of
steel and its downstream processed products
are shown in Fig. 1.5 (Schulz, 1993). In the 20 years after the oil crisis, the prices
of
household appliances, automobiles, and machinery made
of
steel have in-
creased at a rate significantly higher than the price
of
steel materials.
1997
Steel
19931989
1981
1977 1985
Year
Fig. 1.5
Changes
inthe
prices
of
steel
andits
downstream
processed
products
220
Engine
200
Equipment
180
'"
Civilian
u
160
'5
Commodity
.=
" 140
o
d:
120
(Price
indices
for1974 = 100)
The effects
of
materials recycling on energy savings and the environment are
also important evaluation criteria (Fig. 1.6, Schulz, 1993).
It
shows the recycling
rate
of
such principal materials as steel, glass, paper, aluminum, and plastics. The
recycling rate
of
steel is significantly higher than that
of
other materials. Global
output
of
steel scrap has fluctuated in the range
of
approximately 350 million tons
per year in the last 30 years and reached 469 million tons in 2006. Compared to
extracting iron from iron ore, the use
of
scrap steel as a recycled resource is
of
significant importance for saving natural mineral resources and energy, with en-
ergy
saving
approximately
36%
(Yin and Cai, 1999). World
crude
steel
Steel/iron
Glass
Paper
Aluminium
Plastic
155
145
133
127
110
10 20 30
40
50 60
Recycling rate/%
Fig. 1.6
Recycling
rate
('Yo)
of
various
materials
Chapter 1 Steel
-the
"Material
of
Choice" 5
output was 1.2395 billion tons in 2006.
Of
the corresponding consumption
of
fer-
rous element resources, steel scrap accounted for about 33.5% (469 million tons),
pig iron about 63% (881 million tons), and DRI/HBI about 3.5% (49.46 million
tons) (IISI, 2007) in 2006.
In sum, steel is still irreplaceable for the world's primary basic industries and
infrastructure and even daily consumption due to its excellent overall properties.
The competitiveness
of
steel in terms
of
price is also quite obvious. The cost per
unit strength
of
steel compared with those
of
various structural materials is only
1/4 to
1/5 that
of
aluminium, ceramics, and carbon materials.
Also, iron ore deposits for the manufacture
of
steel are available in large quan-
tities and easy to exploit, and steel products are easy to process and recycle. Thus
steel will remain as the principal basic material worldwide in the foreseeable
fu-
ture, and will continue to play an active role in the world's social civilization and
economic development, especially in China where the national economy is grow-
ing at a rapid pace.
In the 21
51
century, the international steel industry has been paying close atten-
tion to the position and role
of
steel materials and has expressed many views
of
an
evaluating nature.
It
appears that the opinions
of
all countries are unanimous in
these aspects. A typical opinion is that
of
the AISI (Kavanagh, Carson, Dasgupta,
et ai, 1998), which maintains that steel will continue to be the "material
of
choice".
In China, where the economy is in a period
of
rapid growth, steel consumption
is swiftly increasing in the wake
of
the country's rapidly developing national
economy and social civilization, the apparent consumption
of
steel reaching 411.6
million tons in 2007. Relevant studies hold that petroleum, steel, aluminum, and
copper are strategic materials for this country and should be given a high degree
of
attention.
1.2
Steel-
An Important Basic Material in the Process
of
In-
dustrialization
Industrialization is an indispensable stage in China's efforts to become a modem
country. China is currently in the course
of
industrialization, or, more accurately,
in the middle period
of
industrialization. Practice has prove that in this middle
period
of
industrialization, increases in gross domestic production (GDP) hinge
mainly on the growth
of
the secondary industries (i.e. the manufacturing and con-
struction industries). China's GDP, which was 1854.8 billion yuan (RMB) in 1990,
amounted to 24661.9 billion yuan (RMB) in 2007. In this period, significant
changes have taken place in China's industrial structure. The proportion
of
the
national economy's secondary industries has increased considerably (from 41.6%
in 1990 to 49.2% in 2007), while that
of
the primary industries (agriculture, for-
6 Metallurgical Process Engineering
estry, animal husbandry, and fishery) decreased significantly (from 27.1% in 1990
to 11.7% in 2007). The tertiary industries also grew significantly in terms
of
total
output but increased only slightly in terms
of
their proportion in the industrial
structure (from 31.3% in 1990 to 39.1% in 2007). The evolution
of
China's indus-
trial structure from 1970 to 2006 is shown in Fig. 1.7 (Yin, 2008).
1994 1998 2002 2006
1996 2000 2004
1986 1990
1988 1992
Yea
r
1982
1980 1984
-.-
Primary
indu
stries
-It-
Secondary
indu
stries
-...-Tertia ry
indu
stries
O
L-
-'-----
-"----
----'--
_
-'--------'---
-----'_
---'--------'-
_
-"----
----'--
_
-'--------'---
-----'_
---'---
-----'_
---'--------'-
_
-'------'
1970 1974 1978
1972 1976
60
~
~
'"
u
'"
~
-;;
.
~
'"
"0
.s
10
Fig. 1.7 Evolution of China's industrial structure from 1970 to 2006 (Yin, 2008)
Statistics compiled in past years show a close relation between China's con-
sumption
of
steel products and its GOP and especially with developments in its
secondary industries and fixed assets investments.
China's steel consumption has increased with increases in its GOP. For exam-
ple, when calculated according to comparable prices, the average yearly increase
in China's GOP was 9.75% in the period from 1986 to 2002, while that
of
steel
consumption was 9.3%.
Of
course, there have been some differences in steel con-
sumption and GOP growth trends in different phases
of
China's economic devel-
opment, and abnormal situations have also occurred in certain years.
There was a significant correlation
of
steel products consumption with the con-
struction and secondary industries in the 1980 to 2002 period. The average annual
increase in output
of
the construction industry was 17.8% and that
of
the secon-
dary industries as a whole was 21.67%, while that
of
steel products consumption
in the same period was 17.6%.
The relationship
of
steel products consumption with the amount
of
fixed assets
investment was even more evident. From 1981 to 2002, steel products consump-
tion increased synchronously with increases in fixed assets investment. In general,
of
course, steel products consumption increases at a slightly lower rate than fixed
assets investments, depending in the main on the structure
of
fixed assets invest-
ments in different years. Steel products consumption may increase at a higher rate
than fixed assets investments when the latter are focused on infrastructure and
real estate projects. In China, fixed assets investments increased at a yearly rate
of
Chapter 1 Steel
-the
"Material
of
Choice" 7
25.5% between 1981 and 2002 while related steel consumption rose at a yearly
rate of 20.6% in the same period.
The structure of China's steel products consumption still bears certain charac-
teristics
of
a developing country as it is concentrated primarily on users in the
construction, machinery, light manufacturing, automobile, shipbuilding and ship-
ping container industries (Table 1.1) .
Table 1.1 Percentages
of
steel consu mption by China's relevant manufacturing
industries from 2001 to 2006 (Un it:
%)
Year
Construction
Machinery
Light Ship Shipping
Automotive
(building) manufacturing building
containers
2001 59.02 15.63 12.65 1.29 1.06 4.12
2002 55.00 15.03 10.36
l.l
5 0.92 3.76
2003 52.35 15.53 9.11 1.08 1.38 3.97
2004 55.19 16.28 9.12 1.32 1.31 4.69
2005 52.37 15.88 8.18 1.33 1.36 4.78
2006 53.12 15.54 7.55 1.56 1.25 4.82
From the perspectives
of
either the global economy and social development or
of China's modernization process, steel will, in the foreseeable future, remain as a
highly important basic material in the world, not only as an important construc-
tion material but also as the world's most-used functional material (such as
stainless and electrical steel). Consumption
of
stainless steel has risen rapidly in
the world since the 1980s, with the world's output
of
stainless steel almost tripling
(Fig. 1.8) in the past thirty years and reaching approximately 28.4 million tons in
2006. World stainless steel output grew at an annual rate
of
5.8% over the fifty or
more years from 1950 to 2001, close to that crude steel.
300
250
V>
200
t:
8
t:
.s
150
~
·c
100
~
50
284
246 243
213
195 189
200
170 168 179
156156
1321 281281281281271 38
102
102106116
~
LL98::-'-4ll-.LILL9c:'-86L.L.l
c:'-
1
9L.,8'-=8LL.L
-'-1
9L.,9'-'0c:'-c:'-
-'-1
9'-=9'-'2-'--'-
.LJ
I
9
LJ9
U4-'--'-.LJ
I
9L...J
9
U
6
-'--'-.LJ
I
9L...J
9
U
8
-'--'--:-'20LJOUO-'--'--:-'20LJOL...J2-'--'--':-'20L...J0
::-'-
4.L.L2=-'0,.-J-J06
1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005
Year
Fig. 1.8 Development of world stainless steel output from 1984 to 2006 (China Steel Yearbook)