No Slide Title

Report
Industry Quality Review
September 2008
NACE Central Area Conference
Magnesium Anode
Electrochemical Properties
-1.75V Open Circuit Voltage
High Potential
-1.55V Open Circuit Voltage
Standard Alloy
1000 Amp-hrs/pound
-
Theoretical
500 Amp-hrs/pound
-
Nominal
50% current efficiency
-
Nominal
Quality & Performance Factors
Alloy Chemistry
Potential (voltage)
Current efficiency
Alloy Chemistry
ASTM B843 defines alloy requirements
>98.5% magnesium
Typically, 100% testing of every heat
Chemistry alone does not identify quality
Open Circuit Potential
Hi-potential magnesium
-1.75V to -1.77V
Standard alloy
-1.50V to -1.55V
Open circuit potential is controlled by chemistry and
casting process
Current Efficiency
% of energy within the alloy that is available
as cathodic protection current
Measured in Amp-Hr/pound
Nominal 50% efficiency for both H-1 and high
potential alloys
Determines life of anode
ASTM G97 test (Destructive test, 14 days, $1000 cost
Anode Life
Life (yrs) = 0.116 x Wt (lbs) x Efficiency x 0.85 (Utiliz. Factor)
Anode Current (amperes)
Value Analysis*
Efficiency
Life (Years)
Annual Cost
50%
16.76
$14.92
40%
13.41
$18.64
30%
10.05
$24.87
20%
6.70
$37.31
*17# anode at 50 mA, Assumes total installed cost of $250
Mag Anode Industry History
Alloy and market development by Dow
Foreign sources (China, Russia, Mexico) entered
market in late 90’s
Initial quality problems with foreign anodes
Foreign quality problems resolved by 1999
US suppliers not competitive with foreign sources
China/Mexico dominant suppliers to US market by 2002
60
Quality
Development
of Foreign
Sources
56
52
48
44
40
36
Early 98
32
Late 98
1999
28
1.65
1.80
1.70
1.75
1.85
OPEN CIRCUIT POTENTIAL IN (-) VOLTS (vs CuCuSO4)
60
56
%CURRENT EFFICIENCY
2002/
2003
Quality
Results
52
48
44
40
36
32
28
1.65
1.75
1.80
1.85
1.70
OPEN CIRCUIT POTENTIAL IN (-) VOLTS (vs CuCuSO4)
2003 Industry Sampling
5 high potential anodes obtained on open
market in mid-2003
Tested according to ASTM G97 standard by
third-party laboratory
Results confirmed widespread quality
problems in industry
2003 Industry Sample Results
Sample
OCP vs
CuCuSO4
Current
Efficiency
Life*
(yrs)
Annual
Cost**
A
-1.75v
49.3%
16.53
$15.12
B
-1.72v
41.6%
13.95
$13.98
C
-1.63v
12.1%
4.06
$61.58
D
-1.63V
11.0%
3.69
$67.75
E
-1.61v
4.8%
1.61
$155.28
*17# anode at 50 mA, **Assumes total installed cost of $250
Quality Concern Validation
Anode quality presentation by T. May (MESA) in
Oct 2003 w/publication in MP in Jan 2004
Anode quality presentation by B. Gummow
(CORRENG) in Feb 2004 at Northern Area
Conference
Anode quality presentation by M. Yunovich
(CCTechnologies) in Mar 2004 at Corrosion 2004
2003 Industry Assessment
Quality concerns apparent in late 2002/2003
Producers capable, but not providing quality
Diminished user quality control programs
Impact of low quality magnesium not well
understood
2005 Industry Sample Results
Sample
OCP vs
CuCuSO4
Current
Efficiency
Life*
(yrs)
Annual
Cost**
A
-1.81
57%
19.11
$13.08
B
-1.79
56%
18.77
$13.32
C
-1.79
55%
18.44
$13.56
D
-1.79
55%
18.44
$13.56
E
-1.68
29%
9.72
$25.72
F
-1.59
16%
5.36
$46.64
*17# anode at 50 mA, **Assumes total installed cost of $250
2005 Industry Assessment
Quality of cast anodes is generally improved
Extruded magnesium anodes are quality
alternative
No significant changes in end-user QA
programs
Still some scrap out there
2007 Industry Sample Results
Sample
OCP vs
CuCuSO4
Current
Efficiency
Life*
(yrs)
Annual
Cost**
A
-1.77
61%
20.45
12.22
B
-1.77
55%
18.44
13.56
C
-1.77
54%
18.1
13.81
D
-1.75
46%
15.42
16.21
E
-1.65
29%
9.72
25.72
F
-1.60
26%
8.72
28.67
G
-1.67
24%
8.05
31.06
H
-1.60
10%
3.35
74.63
*17# anode at 50 mA, **Assumes total installed cost of $250
2007 Industry Assessment
Industry sampling validates continuing
quality concerns
No significant changes in end-user QA
programs
Recent supply instability and price volatility
likely to increase quality concerns
End-User Impact
OCP vs
CuCuSO4
Average
of 2007
tests
Industry
Standard
Current
Efficiency
Life*
(yrs)
Annual
Cost**
-1.70V
38%
12.74
$19.62
-1.75V
50%
16.76
$14.92
+$4.70
*17# anode at 50 mA, **Assumes total installed cost of $250
Conclusions
Anode quality continues to be major industry
concern
Economic impact to industry estimated at
>$2MM per year
End-users and resellers largely unaware or
unconcerned of impact of quality
Instability of magnesium market makes
overall quality improvement unlikely
Industry Quality Review
September 2008
John Cole – MESA Products, Inc.

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