Team Hindalco Welcomes You All Hindalco Industries Limited, - - PowerPoint PPT Presentation

Team Hindalco Welcomes You All

Hindalco Industries Limited, Renukoot

Team Introduction

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Vibhav Upadhyay Anuj Verma Vivek Agrawal

Aspect of Energy Saving

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Ensuring Energy Security.

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Climate Change Concerns.

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Statutory requirement like PAT , RPO etc.

Methodology

 By Enhancing Energy Efficiency.  By Energy Conservation

Hindalco Industries Limited, Renukoot

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To Reduce Pot Voltage at Renukut Smelter to Enhance Energy Efficiency

16 Nov 2016

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Project Theme

INDEX

Hindalco Renukoot – Profile & Process introduction Background of the Project Concept of the Project Root cause Analysis and Approach adopted Project Savings & Economics Challenges faced in implementation Measurement and Verification

Hindalco Industries Limited, Renukoot

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Hindalco, the flagship company of the Aditya Birla Group and industry leader in aluminium and copper has consolidated turnover of US$17 billion & having footprint in 13 countries outside India. It is fully integrated plant. Hindalco Renukoot: Profile

Hindalco Industries Limited, Renukoot

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Finish Product Aluminium

Hindalco Renukoot : Fully Integrated Operations

Alumina

Bauxite Captive Power

THROUGH

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Typical Cost of Aluminium Production

Smelter Power 40%

Store, potlini ng, misc. 4% AlF3 1% Depriciation 1% Net carbon 15% Alumina 35% wages 5%

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Renukut Smelter

• Renukut smelter has 11 pot lines and 2138 Electrolytic cells

(pots). Annual Aluminum Production is 409 KT.

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Process Description

ALUMINA HOPPER

ANODE (+) ANODE (+)

MOLTEN CRYOLITE BATH

MOLTEN ALUMINIUM

CATHODE BLOCK (-) POINT FEEDERS SiC BRICKS DIATHERM 23 INSULATION BRICKS CATHODE BUS BAR COLLECTOR BAR POT COVERS ALUMINA INSULATION FROZEN BATH CRUST TOE PLATE MONOLITHIC PASTE LINING DENSE FIRE BRICKS

2 AI2O3 + 3 C 4 AI + 3 CO2

ANODE RING BUS CALCIUM SILICATE INSULATION MOLTEN METAL

According to Faraday’s Law: Production = 8.052* Amperage*Current Efficiency

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Project background

• Power Consumption

298 /   CE V kg kWh

4.420 4.440 4.460 4.480 4.500 4.520 4.540

Pot voltage, V

This project was taken to reduce pot voltage by 80 mv

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Problem Diagnosis

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Project Scoping

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Approach

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Project Methodology: Statistical analysis of process parameter

• Stability Test ( Run Chart)
• Process Capability
• Gage R & R Study
• Micro mapping & Process Mapping
• Regression Analysis

Cause and effect analysis

Macro Map

Pot Lining

• New pot shell
• Refractory lining

Pot baking

• Pot taken

in circuit Pot Loading

• Pot taken in
• peration

Alumina Feeding

• Installation of point

feeders and Micro Processor control Metal Tapping

• Metal tap out in

cruce Crust breaking

• Crust breaking
• Bath melting

Bath maintenance

• Solid bath addition

Anode changing

• Spent anode removal

Dust skimming

• New anode set
• Anode covering

Sampling

• Bath ratio, temperature
• Bath Level

measurement

• DC Power from Rectifier
• Anodes from carbon

plant

• Corrections
• Bath ratio balance

by adding AlF3 or Soda ash

• Bath maintenance
• Primary alumina from Alumina

plant

• Secondary alumina through DSS

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Fish Bone Diagram

Team did round of brainstorming sessions to identify all potential causes using fishbone diagram. Total 18 X’s identified which further reduced to 10 using C&I matrix 16

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• ACD
• Cathode Voltage drop
• Pot age
• Noise
• Alumina concentration
• Metal level
• Anode effect
• Bath Chemistry
• Clamp drop
• Diamond drop

Critical parameters

Regression Analysis

Correlation & regression analysis carried out to find out most critical parameters

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Regression Analysis

• Series of DOE were carried out to find out the way to reach

at optimum pot voltage without affecting other critical parameters.

• A Solution Selection Matrix prepared to prioritize the

solution and different DOE (Design of Experiments)

• conducted. Finally an action plan made to reduce pot voltage.

.

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Pot age ,ACD ,Noise ,CVD, Bath Chemistry

Problem Remedy

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Voltage Reduction Plan

Problem Remedy

Noise

• 1. Noise limit for voltage reduction –Avg. noise value 0.002V/pot
• 2. Voltage will be reduced @ 0.01V/pot only

Age

• 1. Minimum voltage of 4.27 V with life 90 to <3000days.
• 2. High life (>3000 days) voltage 4.36 V(min)
• 3. New pot maintained upto 4.320 V/pot by 90 days of life.

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Problem Remedy

CVD

• 1. Voltage of pots with high CVD is 4.35 (min)

Bath Chemistry 1. Bath Ratio target increased from 1.130 to 1.160 due to higher CaF2 content in bath 2. Maximum 0.06 V reduction in one week

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ACD

• 1. No voltage reduction if pot is under high noise, low bath level,

metal left in the pot, and less current anodes

Control Plan

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Monitoring parameters

• Metal Left
• High bath temperature Pots.
• High Bath Ratio Pots.
• Low Bath Level Pots.
• Anode Effect frequency.
• High search time ( higher Alumina content in bath) pots.
• Avg. Noise of the lines and No. of noisy pots.
• No. of pot failure

Monitoring of all these parameters and strategy change in between whenever deviations found.

Control plan for Improvement

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• Formation of Standard Operating Practices.
• Extended trial in all pot lines before implementation
• Implemented in all pot lines
• An exhaustive monitoring system developed
• Any deviations were planned to be rectified within 8 hrs

Replication

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Results

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Tangible Results

July'15 Aug'15 Sep'15 Oct'15 Nov'15 Dec'15 Jan'201 6 Feb'16 Mar'16 Pot voltage 4.515 4.513 4.479 4.470 4.453 4.448 4.450 4.444 4.442 Volts/pot

Pot voltage

Strict follow up of action plan led to reduction in pot voltage

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Tangible Results

4.400 4.420 4.440 4.460 4.480 4.500 4.520 4.540 July'15 Aug'15 Sep'15 Oct'15 Nov'15 Dec'15 Jan'2016 Feb'16 Mar'16 Volts/pot

Pot voltage

• Improvement in CTQ

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Tangible Results

13800 13850 13900 13950 14000 14050 14100 14150 14200 14250 14300 July'15 Aug'15 Sep'15 Oct'15 Nov'15 Dec'15 Jan'2016 Feb'16 Mar'16

Power, kWh/T

• Improvement in Power consumption

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Tangible Results

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Power consumption reduced by 284 kWh/ T

• Enhance in process consistency also improved

metal purity

• Lowest Iron content and Silicon content in

aluminium.

• Increased Internal customer satisfaction

Intangible Results

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Thank You

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