Breakthrough Process Improvement case study submitted by Emirates Aluminium during 3rd Continual Improvement & Innovation Symposium organized by Dubai Quality Group's Continual Improvement Subgroup to celebrate World Quality Day 2011.

1. 1

2. Introduction
 Emirates Aluminium Company (EMAL) is a strategic joint venture between
aluminium producer Dubai Aluminium Company (DUBAL) and Mubadala
Development Company (MUBADALA).
 The company’s facility at Al Taweelah, halfway between Abu Dhabi and Dubai,
 EMAL’s present work force is 2500 employees on rolls.
 EMAL will be largest single site Aluminium smelter complex at the end of phase-
2 with a capacity of 1.3 Million Ton of aluminium per year
 EMAL produces a wide range of high grade semi finished aluminium products,
like low profile sow , high profile sow, standard ingots, billets, sheet ingots etc.
Supplying to worldwide customers.
2

3. Aluminium Smelting
Process
Power DC Power
Plant
Molten Aluminium
Port Alumina
3

4. Project Charter
Anode effect frequency was increasing drastically during and
A after breakdown in Gas treatment center/ Pot feed system.
Which was creating disturbances in Reduction pots.
Problem Huge number of people were involved in quenching the
faced by B anode effects and stabilizing the pots.
EMAL
C Heavy PFC generation during anode effects, not safe for
employees and environment.
4

5. Project Charter
1.The Goal Statement.
To reduce the impact of Pot feed system and Gas treatment center stoppage
during breakdown and power outage on Reduction Pot performance by
improving Alumina quality supplied to pots
2.The teams involved:
Teams Roles
Process Control Controlling and monitoring
Operation ( Pot feed system & Pot line) Operating the system
Maintenance Maintaining the system
5

6. Project Charter
3.Stakeholders model:
• Supplying • Manufacturing
Alumina to Pot Aluminium from
lines Alumina
Pot feed
Pot lines
system
Operations
operations
Process
Maintenance
Control
• Controlling and • Maintaining the
monitoring the equipment's in
process and good working
equipment's condition
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7. Project Charter
4.The Project Timelines
Problem Plant wide Controls
Selection of
Identificatio Trials implementat and
solution
n ion monitoring
Oct - 2010 Dec - 2011 Jan-March 2011 April-June 2011 June-July 2011
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8. Measure
Line-2 Sec -4 Line-2 Sec -8
2B045 2A144
60.0 60.0
50.0 50.0
Feeder 1 Feeder 3
Feeder 2 Feeder 4
40.0 40.0
-325 %
-325 %
30.0 30.0
20.0 20.0
10.0 10.0
0.0 0.0
10/13/201 10/13/201 10/13/201 10/13/201 10/14/201 10/14/201 10/14/201 10/14/201
10/13/2010 10/13/2010 10/13/2010 10/13/2010 10/14/2010 10/14/2010 10/14/2010 10/14/2010
0 4:48 0 9:36 0 14:24 0 19:12 0 0:00 0 4:48 0 9:36 0 14:24
4:48 9:36 14:24 19:12 0:00 4:48 9:36 14:24
Time Time
2B039
60.0
50.0
Feeder 2 Feeder 4
40.0
-325 %
30.0
20.0
10.0
0.0
10/13/2010 10/13/2010 10/13/2010 10/13/2010 10/14/2010 10/14/2010 10/14/2010 10/14/2010
4:48 9:36 14:24 19:12 0:00 4:48 9:36 14:24
Time
During pot feed system stoppage Fines content increases in Alumina
8

9. Measure
Line-2 Sec -4 Line-2 Sec -8
• During and after Pot feed system stoppage anode effect frequency increases
drastically .
• This indicates whenever Fine contents increases in alumina it creates
anode effects and disturbs the pot performance.
9

10. Analyze
A.Problem Statement
• Avoid disturbance in reduction pots by reducing the
Anode effects frequency in reduction pots from 0.4
AE/Day to less than 0.15 AE/Day during and after
breakdown or stoppage of pot feed system and GTC.
• Reduce the fines content in Secondary alumina from 40
% to less than 20% by avoiding segregation of alumina
inside Secondary alumina silo, transport air slides, and
reduction pots.
10

11. Analyze
B. Validation of the Root cause
•During silo and pot hopper filling fine
Alumina entering
to Pot hopper/ Silo alumina gets segregated and
accumulates along the wall of pot
Finest particles hopper and alumina silo. This is due to
settles out and
accumulates here
the static, near to full level operation of
the silo and hopper. These areas may
have become inactive by the cohesive
nature of reacted alumina when left
static over long periods of time.
•During any breakdown in GTC or Pot
feed system these fine material starts
entering in to the pot and causes anode
effects which affects pot performance.
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12. Improve
A. Solution Criteria:
The solution should allow the alumina silo to vary between 40-
80% level
The solution should allow the pot to vary 75-100% level
B. Solution evaluation:
Trial conducted for one pot for evaluating purpose by stopping
alumina filling manually after every 6Hrs duration .During trial no
change in quality of alumina observed.
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13. Improve
C. Solution Selection Process
Reacted Alumina Silo
Automatic Pot Rotary Feeder Cyclic
Hopper Exercising Stopping Interval
and Alumina Silo Through PLC Logic
Feed Modifications Modification
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14. Improve
C. Solution Selection Process
Ranking
Engineering In-House
Sr.No Criteria Solution Solution
1 Easy implementation 1 5
2 Cost involved 1 5
3 Time to implement 2 4
4 Maintenance and control 1 4
5 The results 5 4
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15. Implementation
85%
83%
Silo Level Trend

16. Implementation
X
85%
35%
Y
Reacted Alumina Silo Level Trend

17. Implementation
X
85%
35%
Y
Reacted Alumina Silo Level Trend

18. Implementation
Reacted alumina rotary feeder is being operated with a continuous 6-hour
cyclic stopping interval.
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19. Results of Trial Action Plan
Check Do
Comparison of % fines in the hopper after stoppage of pot feeding system
After Potfeed system stopage for 6 Hrs After Potfeed system stopage for 6 Hrs
(During Trial ) (During normal operations)
Pot No % Fines Pot No % Fines
2A105 9.9 2A142 39.1
2A094 11.8 2A144 53.4
2A117 10.9 2A146 49.5
2A128 11.4 2A189 18.6
2A136 12.8 2B01 53.4
2A146 13.9 2B039 49.3
2A152 13.4 2B045 38.5
2A164 12 2A142 40.7
2A172 12 2A144 44.1
2A189 12.2 2A146 39
Average 12 2A189 20.2
2B01 35.1
2B039 49.2
2B045 48.6
Average 41.3
Stoppage of GTC or Pot feed system in normal situation % fines in pot alumina
increases, where as % fines in pot alumina remains unchanged where reacted
alumina rotary feeder cyclic stopping interval has been implemented.
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20. Results of Project Action Plan
Check Do
On 23rd April during GTC
breakdown Sec-3, & Sec-4
are not affected as much as
normal sections
AE-frequency in normal sections was 0.365 AE/Pd whereas in Sec-3 & Sec-4 AE-
frequency was 0.167 AE/Pd where reacted alumina rotary feeder cyclic stopping interval
has been implemented. This indicates the change in the quality of alumina.
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21. Results of Project Action Plan
Check Do
On 23rd April during GTC breakdown
Sec-3, & Sec-4 are not affected as
much as normal sections
The underfeed duration went down in the normal sections where as it was normal in
Sec-3 & Sec-4 where reacted alumina rotary feeder cyclic stopping interval has been
implemented. This indicates the change in the quality of alumina.
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22. Control Action Plan
Check Do
Alumina Silo level
Rotary
Feeders
Operation
System is controlled by SCADA, and continuously monitored by
operations and Process control 22

23. Benefits of Projects Action Plan
Check Do
• In-House Control Modification
• Engineering Solution
• For Automatic Pot hopper Exercise • Project covered both engineering
= $27,810 x 8 sections x 2 Lines proposal to a single cost-effective and
cost avoidance solution.
= $444,960
• Regular man-hours was used in
• For Reacted Alumina 700t Silo developing the PLC logic modification
Modifications and monitoring the system.
= $800,618.47 • Control flexibility was incorporated to
• Total Proposed Project Cost enhance mass-balance of the
upstream and downstream process.
= $444,960 + $800,618.47
=$1,245,578.47 or
= AED 4,575,321.07
Total Cost Avoidance: AED 4,575,321.07
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24. Results achieved Action Plan
Check Do
Supply of good quality Alumina to
Potlines will improve Pot performance
Improved work environment in the
Pot lines as emissions reduced
(Environment Protection)
Problem of AE frequency Eliminated / Avoided
Segregation of reduced during costly engineering
Alumina is GTC/Pot feed solutions for the
eliminated. stoppage Alumina segregation
problem.
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25. Project Closure Action Plan
Check Do
Team Recognition:
Team was recognized by EMAL management by selecting best
improvement project in June-2011, and team is nominated for
2011 Annual FALAH award.
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26. Action Plan
Check Do
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