ASIA PACIFIC PARTNERSHIP OF CLEAN DEVELOPMENT & CLIMATE

Industry Perspectives- an overview

ON

M.J.ChaddhaM.J.ChaddhaJawaharlal Nehru Aluminium Research Development and Design Centre

Total Red Mud Generation for 2008-09 (‘000 tons) 4465

Red Mud Generation in Indian Alumina Plants

0

500

1000

1500

2000

2500

Nalco Hindalco Balco +Malco

Vedanta

Red

Mud

in '0

00 to

ns

366412

1654

2033

RED MUD GENERATION IN INDIA – Present & Projections

Company (i)Present generation (Lakhs Ton/Annum)

Company (ii) Addl.Gen. by 2010 (Lakhs Ton/Annum)

NALCO 20.47 NALCO 6.50

HINDALCO 16.07 HINDALCO 4.55

BALCO 2.97 VEDANTA 18.20

MALCO 0.95 UTKAL 19.50

TOTAL 40.46 RAYKAL 18.20

ADITYA 18.20

JSW 18.20

TOTAL 96.85

Grand Total -(i) + (ii) 137.31

Present and Future generation of Red Mud in India

18-20 Al2O3 18-20

50-55 Fe2O3 35-37

4-5 TiO2 18-20

5-6 SiO2 7-9

4.5-6 Na2O 5-6

0.1-0.6 CaO 1-2

11-12 LOI 10-12

Hig

h Fe

& L

ow T

i

Low

Fe

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igh

Ti

East Coast Bauxite Central India Bauxite

Indian Red Mud - Characterisation

Disposal Practices

Indian Alumina Industry Overview

S.No Name of Industry Disposal Practice

1 NALCO, Damanjodi Wet Disposal

2 HINDALCO IndustriesRenukootBelgaumMuri

Dry DisposalDry DisposalWet Disposal

3 VedantaBhavanipatnam

Wet Disposal

4 Sterlite Industries, (Previous BALCO) KorbaMALCO Mettur (Now Closed)

Wet DisposalWet Disposal

Red mud Ponds of NALCO Damanjodi

Red Mud Pond of BALCO

Current Pond in Use Abandoned Pond

Red Mud Pond of INDAL (Muri)

Current Pond in Use Abandoned Pond

Red Mud Pond of Hindalco (Renukoot)

Advantages/Disadvantages of Wet Disposal

Advantages: Lower capital cost ( If land is cheap)No cost towards thickening/filtration of slurryNo dust problem due to presence of liquorDisadvantages :Large area required for disposalEnvironmental hazards associated with caustic leachatecontaminating ground water and surface water High capital required during closing and Rehabilitation and difficulty in closing pondsHigh soda and alumina loss with adhering moisture with mud

Advantages/Disadvantages of Dry Red mud StackingAdvantages: Land requirement for storage is minimisedThe soluble soda and alumina losses are reducedDue to reduced hydraulic head ground water contamination is reduced.Surface water contamination can be reduced by reducing the catchment area and returning runoff water to plant.Disadvantages :Not ideally suitable for area with high precipitation(rainfall)Dust control requires sprinkling of dust suppressant.Requires additional filtration stage to reduce moisture.

Red Mud Utilisation- Difficulties• Soda content

– Leachable around 1-2 % – Bound Soda around 3-6 % in form of sodium aluminosilicate. – High amount of soda act as a preliminary barrier for its use as

a raw material for industrial application such as cement and clinker production, steel industry, constructional bricks, blocks etc

• Composition variability– Chemical and mineralogical composition of red mud generated

depend on the nature of bauxite and the processing parameters.

– Hence the utilisation of red mud cannot be uniform since it is constituent dependent

Utilisation of Red Mud for Various Application

The reuse of red mud for any application should have following criteria :Volume : The application should have high volume usagePerformance : It should be a low cost substitute for other material and its performance should be the same.Cost : It should be cost effective Risk : There should be no environmental risk associated with its use such as health and safety.

R & D for Reuse of red mud (NALCO Contribution)

NALCO has funded many projects on use of red mud for several applications :Development process for the manufacture of Artificial Ceramic Stone Chip, Constructional Bricks as Building Material and Stabilised Blocks for Protection Land Erosion by Sea Water. A Joint project between JNARDDC, MRCPL & NALCO) (AP-7 Sub-Project)Bench scale studies for development of Glass Ceramics(AP-7 Sub-Project)Development of light weight aggregates (AP-7 Sub-Project)

(NALCO Contribution)

Development of Red mud building block/brick, red mud aggregates, red mud plate and tile using an admixture of Red mud + Blast furnace slag + Fly ash with IIMT, Bhubaneswar. Development of Fibre Reinforced Red mud composite doors (R-Wood) by AMPRI, Bhopal Use of Red Mud as Soil Conditioner / Fertilizer by IMMT, Bhubaneswar.Use of Red Mud for Production of OPC by NCB , Ballabgarh. OPC which confirmed to ISI 33, 43 & 53 grade of OPC.

Reuse of Red Mud for Various Application(Stabilised Blocks /Hollow Bricks)

Stabilised Red Mud Blocks has been prepared by BHU ( Met. Dept. ) using HINDALCO Red Mud using an admixture of Red mud, Fly ash, lime grit, ordinary portland cement, blocks of high strength 60 kg/cm2

are produced after sun drying ( curing)

CBRI, Roorke has developed stabilized blocks whose strength lies between grade II / III bricks.

BHU ( Met. Dept. ) had prepared Low density / Hollow bricks andBlocks of Red Mud with low density 1.1-1.2 gm/cm3 . These Hollow /foamed bricks has varying crushing strength of 50-260 kg/cm2 .

CGCRI, Jadhavpur has also prepared hollow bricks using red mud and proprietary foaming agent.

Reuse of Red mud for various ApplicationRed Mud Bricks

BHU ( Met. Dept. ) has used an admixture of Red mud, Fly ash and additive with firing at 1000o C producing bricks with crushing strength of 130-160 kg/cm2 and 14 % water absorption capacity. CBRI, Roorke Developed red mud + clay and red mud + fly ash bricks of high strength comparing to grade I bricks.

CGCRI, Jadhavpur has developed red mud + clay and red mud + fly ash bricks of high strength comparing to grade I bricks

Tiles/Glass Ceramic Tiles

CGCRI, Jadhavpur has Produced Ceramic Tiles using red mud and Fly ash.

JNARDDC, Nagpur has produced Glass Ceramic Tiles (a Project sponsored by BMPTC) The Developed glass ceramic tiles are with different shades with glossy finish having and good scratch resistance and strength using admixture of red mud + Fly ash and additives.

Additives for CementBHU ( Met. Engg.) & BHU ( Civil Engg.) has used Red Mud as additive for Production of Cement and mortars ( Project Sponsored by HINDALCO) The crushing strength was found to be optimum at at-least 10 % red mud addition. The crushing strength and bond stress of the mortar has found to improve with 5-10 % red mud addition. The red mud used for above was neutralized by HCl before use.

MALCO red mud has been used by Orient Cements (2-4 %) and certain parameters of the cement showed improvement while using red mud.

Special Cement & Red Oxide Primer

BHU ( Civil.Engg) has developed a Special Cement ( Project Sponsored by HINDALCO) using an admixture of 35 % Red Mud, 15 % bauxite, 10 % gypsum and 4 % limestone at 1250o C and firing for 1.5 hours gave special cement with high strength.

CGCRI, & BALCO using BALCO red mud and lime stone at 1150-1200 oC has produced iron rich cement having strength of 200 kg/cm2.Red Oxide and Primer from Red MudCECRI Karaikudi has prepared an inhibitive and fire resistant primer was using an admixture of red mud, vermiculite and bariumpotassium chromate cashewnut shell liquor. The red mud used for above was calcined at 800-900 oC.

Recovery of TitaniumBALCO In-house R & D Lab has developed process of Two stage digestion followed by hydrolysis to obtain TiO2.BHU ( Met. Dept.) in the Lab studies (Project Sponsored by HINDALCO ) produced 2 grades 57 % TiO2 and 99.5 % TiO2from red mud using acid leaching route. Production of Ferro-Titanium BHU ( Met. Dept. ) a (Project Sponsored by HINDALCO ) findings are :Direct electric arc smelting or aluminothermic reduction route of red mud is not feasible.However Red Mud HCl leached residue with some mill waste produced ferro-titanium of 8-30 % with SiO2 as principal impurity.

SummaryRed mud wet disposal practice create hindrances in collection and transportation of red mud from existing ponds. Industry-academic institution has developed useful product but no pilot plant scale studies has been carried out. No marketing work has been carried out to determine markets for the developed product . Government support in the form of subsidies are not available to attract entrepreneurs for setting up industry for developing products from red mud.The process of developing products or recovery of valuable metals from red mud are technically feasible but not techno-economical.Hence NALCO along with JNARDDC and MRCPL are coming up with an idea of using Primary Aluminium Industry-R & D institute & Entrepreneur collaboration.

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