b6.3 kline the future for flyash
TRANSCRIPT
John Kline – Kline Consulting
Charles Kline – Kline Consulting February 2014
The Future of Flyash
Globally there is not enough flyash
Locally there is too much flyash
CO2 reduction will increase the value of “clean” Flyash
Utilities that market flyash will need to consider their path forward carefully
Mercury
Carbon / sorbents
Trona / sodium bicarbonate
The use of flyash in concrete
Pros
Improve concrete
Reduce costs
Reduce carbon footprint
Cons
Reduce strength
Reduce air entraining
CO2 from Cement
Depending on how you count …
Global cement production accounts for
some 4 – 7% of anthropogenic CO2
emissions
Main levers to reduce CO2 emissions
Clinker Reformulation
Energy Efficiency
Biogenic Fuels
Clinker Substitution
The Cement Technology Roadmap (CSI+IEA) B
t o
f C
O2
Supplemental Cementing
Materials (SCMs)
Portland cement is made up primarily of
calcium silicates
These react with water
Other Produced and Natural Materials
also contain calcium and silica oxides
Blast furnace slag
Flyash
Pozzolans (Natural and Artificial)
78%
4%
18%
11%
41%
26%
16%
6%
Water
Sand
Gravel
Cement
Air
Clinker
Gypsum
SCMs
Cement In
Concrete
Clinker In
Cement
Limestone in
Clinker
80%
20%
Limestone
Other Raw
Materials
CaO
SiO2
Flyash
Flyash
How Cement Works (The Simplified Version)
CaO SiO2 H2O
Calcium Silicate Hydrate
Both the Calcium and Silica Oxides
need to be in a reactive form
Clinker Substitution
2006 data, CSI
0%
5%
10%
15%
20%
25%
30% 26% 26%
24% 22%
21% 20%
17% 16% 16%
Avera
ge A
dd
itio
n c
on
ten
t in
cem
en
t
Most Important Binder Materials
C-Ash
SiO2
CaO Al2O3
PC
Slag
SF
F-Ash
MK
L
LegendC-Ash – ASTM Type C FlyashF-Ash – ASTM Type F FlyashL – Lime (Limestone - CaCO3)MK – MetakaolinPC – Portland CementSF – Silica FumeSlag – Ground Blast Furnace
PozzolanicReactions
Hydraulic Reactions
SlowerLater Strength
FasterEarly Strength
Keys to SCM Use
Chemistry and purity of the SCM
Reactivity of the SCM
Calcium in CaO form
Amorphous silica
Small particles (high surface to weight)
Availability of the SCM
Local specifications and norms
Most locations opening up to more SCMs
Iron and Steel Producing Countries
<
Where the Slag is
Where the Pozzolans Are
Coal Consumption
All Uses by Country
Where the Fly Ash is
0%
20%
40%
60%
80%
100%
120%
140%
160%
180%
200%
-
500
1,000
1,500
2,000
2,500
3,000
3,500
China Europe US India Russia Rest of World
Mill
ion
Me
tric
To
ns
Cement
Coal
Coal Ash
Saturation
Normal SaturationWorld Average 27%
Coal Ash to Cement Balance
Assumes 12% Ash
23%
4%
6%
4%
4%3%
56%
Use of Fly Ash in US
Concrete / Grout
Blends / Clinker Feed
Structural Fill
Mining Applications
Waste Stabilization
All Other Uses
Discarded
ACAA 2012 Data
Potential to Increase Flyash
Today Potential
Clinker 2780 77.2% 2780 68.6%
Gypsum 120 3.3% 120 3.0%
Flyash 250 6.9% 500 12.3%
Slag 150 4.2% 200 4.9%
Pozzolan 150 4.2% 300 7.4%
0 0.0% 0 0.0%
Limestone 150 4.2% 150 3.7%
Total Binder 3600 100.0% 4050 100.0%
$-
$2.00
$4.00
$6.00
$8.00
$10.00
$12.00
$14.00
$16.00
$18.00
$20.00
CO SC NC
MI
WY
MI
MD
OH
NE
MS
MI
OH FL FL TN IA LA WY
NE
LA WV
NV
MO TX LA WV
OH FL
MO
ND IN TX AL
TX CO IA
NM NH TX IA IA MI
WI
SC KS
PA
WI
OK
Fly Ash Revenue
Mean - $6.60
Data from EIA
Impact of Additives on Use
Material Raw
Materials
Cement Concrete
Lime Good Limited Limited
Limestone Good Limited Limited
CaBr2 OK OK OK
Mercury Very Limited OK OK
Activated Carbon Good Very Limited Very Limited
Trona Limited Very Limited Very Limited
Sodium Bicarbonate Limited Very Limited Very Limited
The Future of Flyash in Concrete
There is a need in most of the world
Flyash value will increase with CO2 constraints
Substitutes may be limited
Finite amount of slag available
Natural pozzolans not available globally
Artificial pozzolans require processing
Cost of disposal is increasing
Careful planning is therefore required