Coking coal quality
evaluation and price
mechanism: changing the
approach
Shanghai April 2017
1
What we have today
Premium low-vol
CSR
HCC 64
Semi-hard
Semi-soft
As a result, coking coals with absolutely different parameters are classified
into one group and priced the same.
CSR
VM ad,
%
TM ar,
%
A ad,
%
S ad,
%
P ad,
%
Vitrinite,
%
Fluidity,
ddpm
Y,
mm
Coal A
45
24
12
8
0.43
0.05
54
300
Coal B
44
17.50
8.00
10.50
0.25
0.022
88
10
12
Coal C
30
34.50
9.80
8.30
0.85
0.052
86
10000
20
2
Inaglinsky Coking Coal vs Premium Lowvol
VM ad,
%
TM ar,
%
A ad,
%
S ad,
%
P ad,
%
Vitrinite,
%
Fluidity,
ddpm
Premium
Low vol
21.50
9.70
10.50
0.50
0.045
65
500
Inaglinsky
27.60
9.50
10.00
0.40
0.002
98
6000
G index
Y,
mm
96
28
It is important to evaluate ALL the parameters and their
influence on the quality of the blend
quality of
metcoke
quality of pig iron/steel, cost of production
3
Main parameters and their role in the
blend
Vitrinite – component which becomes plastic during caking process and acts as a liquid binder
component. As a result, high vitrinite coals can compensate less plastic and less expensive
carbon sources (e.g. low-caking coals, coke breeze)
Premium low-vol,
%
Inaglinsky,
%
65
98
COST SAVING without quality
degradation
Fluidity by Gieseler - high fluidity coals act as a liquid binder component in the blend and allow
to blend in a bigger proportion of lower quality=cheaper coals
Premium low-vol,
ddpm
500
Inaglinsky,
ddpm
6000
COST SAVING without quality
degradation
4
Main parametres and their role in the
blend
Sulphur – high sulphur in coke requires a bigger amount of lime in the blast furnace increases
the amount of of slag and the amount of coke required per 1mt of pig iron
Deteriorates the performance of the blast furnace
Low sulphur coals allow to blend in more cheaper high sulphur coals
Premium low-vol,
%
Inaglinsky,
%
0.50
0.35
0.50
0.35
COST SAVING without quality deterioration
Phosphorous – high phosphorous deteriorates the quality of pig iron/steel as it becomes more
brittle. Low Phosphorous coals allow to blend in more cheaper high phosphorous coals
Premium low-vol,
%
Inaglinsky,
%
0.045
0.002
COST SAVING without quality
deterioration
5
Main parameters and their role in the blend
Cold/mechanical strength – shows
the ability of coke to avoid yield loss
before charging, dust formation and
poor bed permeability in the BF.
Adding 7-10% of Inaglinsky in the
blend improves coke breakage M25
by 2-4% and abrasion index M10
by1%.
6
Conclusion
Each coking coal should be thoroughly evaluated taking into consideration all its quality
characteristics.
It is possible to reduce expenses for coke and steel production without loss of quality by
adding coals into the blend which due to their unique quality properties allow to use a
bigger proportion of cheaper lower quality coals.
Adding 5-10% of Inaglinsky coal into the blend allows:
• Reduce amount of high quality expensive coals in the blend
• Decrease the usage of metcoke in the blast furnace by 3-19 kg per 1 mt of pig iron
• Decrease pig iron production costs by 5-7%
• Receive good quality pig iron with low Sulphur and low Phosphorous
7
8
9