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Research & Development
Agglomeration of Ferromanganese alloy Fines to Use in LD Steel Making Process
Authors
Veerendra Singh, Prabhash Gokarn,
Ashutosh Kumar, B D Nanda, and Amitabh Bhattcharjee
Tata Steel Ltd., Jamshedpur - 831001, Jharkhand, India.
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Presentation outline
1. Introduction
2. Objective
3. Experimental Studies 3.1. Characterization Studies
3.2. Agglomeration Studies
3.3. Lab Trials
4. Plant Trials & Commercialization
5. Conclusion
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Mn alloys are added as deoxidizing agents and additives to increase strength, elasticity and abrasion resistance of steel.
Mn ferroalloys are made by carbo-thermic reduction of manganese ores, cast into pans and crushed into 10mm to 60mm size lumps.
Mn is added in the form of lumps of high carbon FeMn, SiMn and Mn metal.
The fines generated during sizing can not be used directly in LD, so these are sold at lower price ( <Rs 12-15k than lumps) to foundries.
• Low Mn Recovery• Handing losses• Low grade
An efficient agglomeration process can make them
suitable for steel making process.
Lumps (10-80mm) ( Mn : >70, C : 6-8)
Fines & Chips (0-3,3-10mm) ( Mn : 65-70, C : 6-
8)
FeMn Cake
FeMn Casting
Introduction
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
To produce a suitable Agglomerate to use in steelmaking in a cost effective way.
AgglomerateLadle
Size : <3mm Size : 20-30mm
FeMn Fines
It should not add any unwanted ingredient (P,S etc in steel)
High Cold Compressive Strength to avoid fine generation during handling.
High Hot Compressive Strength to avoid disintegration at high temperature.
Agglomeration process should be economical.
Objective
Challenges
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
(a) Chemical analysis of FeMn Lumps & Fines
Element FeMn Lumps (>10mm)
FeMn Fines (0-3mm)
Mn >70 >67Si 1.5 1.4-2P 0.30 0.25C 6-8 6-8
(b) Size analysis of fines (C) SEM analysis of FeMn Lumps & Fines
Experimental Studies : Characterization of Fines
0.0 0.5 1.0 1.5 2.0 2.5 3.0
0
20
40
60
80
100
Comm.Pass
%, P
asse
d
Particle Size (mm)
FeMn Fines
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
(a) Binder Selection : Metallic fines shows significantly different behavior than the ore fines
hence binder selection is most critical task.
Molasses +Lime
Cement
Lignosulphate
Coal tar
Sodium Silicate
Resins
Phenol-formaldehyde Resin
Acrylic Resin
Experimental Studies : Agglomeration Process
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
(b) Process parameter (Compaction load, dosage & curing conditions) optimization
Experimental Studies : Agglomeration Process
Binder % Load (ton) Curing ConditionSodium Silicate 5, 7.5 & 10 1 & 5 100 C, 1 hourSodium Silicate+ Bentonite 5+2, 7.5+2 & 10+2 1 100 C, 1 hourAcrylic Resin 5, 8 & 10 1 & 3 100 C, 1 hourPhenol formaldehyde Resin 3,4, 5, 8 & 10 1 & 5 100 & 150 C, 1 hour
Sample Preparation
(0-3mm) FeMn fine)
Mixing
Pressing(1-5ton)
Curing (100° C, 60 minutes)
Compressive strength Test
Binder
Process Methodology for Binder Selection Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
• Phenol-formaldehyde resin (resole resin) properties are as follow
PH(1 % Soln.) : 7.15 Specific Gravity :1.18 Solid Content : 70.65 % Viscosity at 25deg. C: 200 cps. Min Carbon : 35 %
• Phenol-formaldehyde resins are commonly used in coating, foundry, composites, molding, refractory and adhesive for woods.
Addition Condensation Curing
Experimental Studies : Binding Mechanism
(a) Mn Ore Particle (b) FeMn Particle
• Various kinds of forces act on particles in agglomeration process. (1) Intermolecular forces :Vander Waals, Hydrogen bonding, Electrostatic and (2) Others: Capillary force, Solid bridges, Mechanical Interlocking .
• The alloy particles are smooth with low
wettability and do not have crakes for binder absorption like ore particles.
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Experimental Studies : Agglomeration Process
© Agglomerate Quality
Properties BriquetteSize & Shape 30-20mmApparent Density 5200 kg/m3Compressive Strength 55MpaTensile Strength 15MpaTumbler Index (Wt 15kg, rpm 200@25) 95% (>6.3mm)Abrasion Index (Wt: 15kg, rpm 200@25) 3%( <0.5mm)Shatter Index (10 kg, 4 drops, Height : 2m) 98%(<5mm) (i) FeMn lump (ii) FeMn Briquette
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Agglomeration Process Flow Sheet
Lab Trials (5Kg)
Small Scale Pant Trials (500Kg)
Large Scale Plant Trials (10ton)
Shikher trials
Recovery Operational Performance Cost benefit analysis
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Steel Scrap (20kg)Slag
Metal
FeMn agglomerate(5 kg)
Tempt. : 1650o C (Mn: 0.15, C : 0.2,P : 0.011) (Mn: 66.33, C : 7, P : 0.25)
FeMn Lumps FeMn Fines FeMn Briquettes
Metal (kg)
Mn (%)
Reco. (%)
Lump 24.9 12.7 90.87
Briq. 24.7 12.7 90.73
Fine 24.5 11.1 81.09
1. It is safe to add the agglomerate
2. The Mixing of fines is very difficult and very faster for briquettes
3. Mn recovery was lowest (81 %) for fines and similar for briquettes and lumps.
Lab Trials
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Metal Analysis
Slag Analysis
(a) Briquette addition not increases level of P,S
and Nitrogen in the steel.
(b) Manganese and carbon pickup in steel was
similar for lumps and briquettes.
(c) Briquettes contain lower Mn content than
the lumps but recovery was slightly better
(~3%) for briquettes (t-test -p value:0.13).
(d) NO other operational problem was faced
during the trial.
Plant Trials
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Commercialization
(a) Vendor Development (250tpm)
(b) Addition in vesse
l
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
(i) Tangible : Profit = Cost Difference in lumps and fine - Briquetting cost = Rs 12-15,000 - Rs 5-7000 = Rs 7000/ton ( for Tata Steel : 2-3 Crore/annum)
(ii) Non-tangible Benefits Environment friendly recycling process Effective utilization of resources There is also potential to use low price fines of other Ferro-alloys(SiMn, FeCr
etc.) by adapting the similar practice
Conclusion
(a) A suitable agglomerate for Steel making can be produced from High Carbon ferromanganese alloys fines using the Phenolic resin as a binder.
(b) The developed agglomerate shown good physical properties and did not add any unwanted ingrinednt in the steel.
(c) Benefits :
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development
Contents
LD#1Mr. Debashish Das
Mr. H BillmoriyaMr. Alok Das Gupta
Ferro Alloys & Minerals Division Mr. Rajeev SinghalMr. L S Devikera
Mr. S Tanwer
ACKNOWLEDGEMENT
R & D and SSDr. D Bhattacharjee
Dr. Vilas Tathavadkar Dr. P K BanerjeeDr. D. Srinivas
Dr. Sandip BhattacharyyaProf. A K Laheri
Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals
Research & Development Presented at the 50th National Metallurgists’ Day ATM of the Indian Institute of Metals