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COMMERCIAL PRODUCTION OF TITANIUM SPONGE IN INDIA

Defence Metallurgical Research LaboratoryHyderabad

ITA TITANIUM 2012 Conference 10 October 2012, Atlanta, Georgia, USA

Chaganti RVS Nageshand 

GVS Brahmendra Kumar

DMRL

Titanium minerals in India

India possess large reserves of ilmenite located all along the southern peninsular coasts

THE INDIAN TITANIUM SCENE

TITANIUMMINERAL WEALTH

ILMENITE:520 million tons

RUTILE: 20 million tons

ILMENITEIREL: 600000 tpyKMML: 200000 tpy †TOTAL: 800000 tpy

RUTILEIREL: 19,000 tpyKMML: 22,000 tpyTOTAL: 41,000 tpy

SYNTHETIC RUTILEIREL: 100000 tpyDCW: 50000 tpyKMML: 100000 tpy †CMML: 50000 tpy

TITANIUM DIOXIDE PIGMENT

KMML: 50000 tpy†TTPL: 25000 tpy‡

Kolmac: 4000 tpyKilburn: 4,000 tpy

TITANIUM ALLOY R&DDMRL, VSSC, BARC,

BHU, NCML, IISC, NAL, IIT (M)

INGOT MELTING & MILL PRODUCTS

MIDHANI: 150-200 tpy

TITANIUM FABRICATIONTEAM, TITAN, TITANOR,

EXOFAB, ZIRCOTAN, L&T,

ALFA-LAVAL, BHPV

TITANIUM SPONGEKMML

DMRL BRIDGED THE TECHNOLOGY GAP FOR PRODUCTION OF TITANIUM SPONGE – THE TECHNOLOGY IS TRANSFERRED TO

KMML

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Limited  Titanium Usage in INDIA‐Reasons

• Aerospace industry yet to pickup• Cost considerations for initial investment• Lack of appreciation of long term benefits titaniumapplications

• Technology gaps/infrastructural limitations intitanium production to fabrication of finishedcomponents

• Sharp fluctuations in prices and uncertaininternational supplies

DMRL

3000 -3750 kg

Mg Reduction – Vacuum Distillation in CombinedProcess Unit – Technology improvements anddemonstration

DMRL2000 onwards

Stages of Technology Development for Ti Sponge Production

Batch SizeProcessInstituteYear

1 kgMg Reduction – Vacuum DistillationBARC 1967

15 kgMg Reduction – Vacuum DistillationBARC 1972

5 kgMg Reduction – LeachingBARC 1973

100 kgMg Reduction – Vacuum DistillationNFC1975

60 kgNa Reduction – Leaching (Single Stage)NFC1976

120 kgNa Reduction – Leaching (Two Stage)NFC1978

5 kgFused Salt Electrolysis – LeachingBARC 1979

2000 kgMg Reduction – Vacuum DistillationDMRL1985

3500 kgMg Reduction – Vacuum Distillation in Combined ProcessUnit – Trial Runs

DMRL1994

DMRL – Defence Metallurgical Research LaboratoryNFC – Nuclear Fuel ComplexBARC – Babha Atomic Research Centre

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Technology development at DMRL

1.Development of technology in 2000 kg batches by conventional Kroll process

‐Experimentation over 25 batch operations ‐In depth study of reduction & vacuum distillation processes 

involving (i) thermodynamic analysis of phase equilibria in Mg‐Ti‐Cl system, (ii) heat conduction modelling (iii) standardization of operating conditions

2.Development of technology in 3000‐3500 kg batches by Combined   process

‐Design & development of equipment ‐Experimentation over number of batch operations‐Standardization of operating conditions of sponge production, 

grading and quality evaluation3. Technology demonstration & TOT to KMML, Kerala

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Technology development in 2000 kg batches‐Facilities created for TiCl4 purification, Reduction, Vacuum distillation and Sponge handling & crushing 

Reduction:TiCl4 feed rate, excess magnesium, reactiontemperature control, MgCl2tapping were studied extensivelyVacuum distillation:Heating rate, vacuum, temperature, soakingTime, equipment performance etc studiedSponge Handling:Sponge behavior during size reduction, Requirement of equipment & tooling etc

•23 batch operations conducted•Expertise gained on technology implications  in the large scale production of titanium sponge• The product purity has not been satisfactory

Major technological problems:•Interruptions in Reduction process due to bridging,Choking of nozzles , MgCl2 tapping valve malfunctioning•Incomplete distillation due to forced termination of VD process owing to clogging of lines•Difficulties in cake ejection & fire hazards in cutting & crushing

Computation of Phase Equilibria in the Mg-Ti-Cl System

-Stable phases in the temp range, 1000-1400K:Mg(l), Mg(g), TiCl4(g), TiCl3(g), TiCl2(s), TiCl2(l), MgCl2(l), and Ti(s)

-Equilibrium compositions computed using ASTRA software for different initial concentrations of TiCl4 & Mg representedby 12:1, 8:1. 4:1 and 2:1

Findings:‐At low magnesium concentrations, above 1000C,TiCl3 is stable phase and below 1000C, TiCl2 is stableAlong with MgCl2‐At higher magnesium concentrations at alltemperatures above 700C, Ti & MgCl2 arestable phases

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A simple thermal model for temperatures prediction in Kroll reactor

• FEM based unsteady state heat conduction model developed and validated with experimental results 

• Heat conduction in the liquid magnesium, forced convection on the reactor wall, initial Mg tempertureof 800C

• Magnesium temperatures determined as a function of TiCl4 feed rate

• Based on the model, magnesium surface temperatures could be calculated for any feed rate in large scale Kroll reactors

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Salient features of Combined Process Technology (3‐3.5 ton)

• Improved TiCl4 distillation procedures –removal of titanium oxy‐chloride

• Single furnace station for reduction & vacuum distillation (reduced overall cycle time & energy efficient, highest materials utilization) 

• ‘Valve less’ top transfer system for MgCl2 tapping• Process control & automation through PLC (Data logging & foolproof and safe process operations)

• Specially designed pipeline heaters (heating coils embedded in ceramic fiber modules) 

• Custom built and tailor made equipment & tooling for sponge cake ejection and cutting & crushing

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TiCl4+2Mg          Ti+2MgCl2+heat

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Typical operating conditions‐ Reduction

‐Excess magnesium (≈60%)‐TiCl4 addition200‐230 kg/h up to 60% addition and 

160‐180 kg/h for the rest

‐Temperature control450‐600C in the vapor phase zone790‐820C in the reaction zone830‐840C in the bottom zones

‐MgCl2 TappingFirst tap at 2T of TiCl4 addition,  subsequently after

each addition    of 1T of TiCl4 

Table-. Typical operating conditions of titanium sponge production

TiCl4 purification:Column-1(a)Top temperature(b)Bottom temperature(c)TiCl4 feed rate

Column-2(a)Temperature(b)Feed rate

138oC139oC157 kg/h139oC150 kg/h

Reduction:I)Excess magnesiumII)Reactor pressure:III)TiCl4 feed rate:IV)Temperature at Reaction zonesV)Process time (including heating and cooling)

60%0.5 - 3.5 psig180 - 220 kg/h800 - 810oC200 h

Vacuum distillation:I)Vacuum levelII)TemperatureIII)High temperature soakIV)Total cycle time

30 x 10-3 torr975 - 1000oC64 h240 h

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Process ParameterSensing Element

Mode of Control

RangeFinal Control

Element

Retort pressure DP Transmitter On/Off 0.5 - 3.5 psiPneumatically

actuatedSS angle valve

Tapping pipe back pressure DP Transmitter On/OffRetort

pressure+ 1.0 psig

Solenoid valve

Furnace temperature control(during reduction process)

ThermocoupleOn/Off

(Delta/Star) 820 / 830oC Contactor

TiCl4 flow rateCoriolis

Mass flow meterManual 190 – 210

kg/HrBellows seal

Flow control valve

Reaction zone temperature Thermocouple PID

(i ) 810 -820oC

(ii) 690 -700oC

(iii) 490 -500oC

Air dampers (Butterfly valves)

Cold air flow rate Pitot tube On/Off 0 – 6000 m3/hr Centrifugal air blower

TiCl4 feed tank pressure GP Transmitter On/Off 0.7 - 0.8 kg/cm2

Pneumatically actuated

SS angle valveFurnace temperature control (during vacuum distillation)

ThermocoupleOn/Off

(Delta/Star) 980 / 990oC Contactor

Pipeline heater temperatures Thermocouple On/Off 850 – 8750C Contactor

Parameters Measured/Controlled

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DMRL

Typical analysis of impurities  in titanium sponge of individual  fractions (in ppm)

Fraction

O N C Fe Ni Hardness(BHN)

A 292 40 111 100 <50 77

B 336 50 136 330 <50 80

C 550 80 132 120 <50 92

D 650 100 140 550 100 120

E 925 150 145 1250 125 145

F 1200 180 148 1550 145 165

Weights of individual fractions in a typical sponge cake

Fraction Weight, kg % of total weight of cake

Yield of aeronautical grade purity (%)

A 880 29.4 ≈ 70

B 731 24.4

C 177 6.0

D 544 18.1

E 487 16.2

F 181 6.0DMRL

Typical analysis of Core fractions of  sponge  produced in five experimental  batches

Element Batch No.

TP005 TP006 TP007 TP008 TP010

Content, ppm

Oxygen 290 350 300 350 400

Nitrogen 40 20 24 <50 <50

Carbon 110 140 110 135 115

Iron 100 400 100 84 119

Chromium 110 380 50 127 31

Nickel 50 50 50 <50 <50

Magnesium

60 130 80 70 60

Chlorine 110 240 100 160 100

Ti (bydiff.)

99.9% 99.9% 99.9% >99.9% >99.9%

Hardness,BHN

77 94 74 74 76

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Analyses (wt.%) of lots prepared from sponge produced‐Comparisonwith other standards

Element

Midhani

P.O. Spec.

CISTG-90

ASTMMD-120

SHOWA

S-90

DMRL Lot

1L001/

2K

DMRL Lot 2

L002/2K

DMRL Lot 3

L003/2K

Fe 0.050 0.060 0.120 0.030 0.018 0.018 0.050

C 0.015 0.030 0.020 0.020 0.006 0.013 0.010

O 0.040 0.040 0.100 0.060 0.033 0.037 0.045

N 0.015 0.020 0.015 0.010 0.003 0.006 0.005

Mg 0.080 0.080 0.080 0.045 0.004 - -

Chloride

0.100 0.080 0.120 0.080 0.005 - -

Ni 0.050 NS NS NS <0.005 <0.005 <0.005

Cr NS NS NS NS 0.009 0.012 0.013

H NS NS 0.01 0.002 0.0019 - -

Ti(By

diff.)

99.6 99.6 99.6 99.8 >99.9 >99.9 >99.9

Hardness

(BHN)

100 80-90 120 90 81.5 84 82

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Purification - Distillation Column 1 Purification - Stripping Column

DMRLSponge production facility

500T Ejection Press During Ejection of sponge cake & after ejection of cakeDMRL

Titanium sponge processing at DMRL

DMRL

SAMPLE Fe Ni Fe+3Ni BHNR015/DS7 38 12.45 75.35 77.8R015/DS9 49 15.86 96.58 83.26R015/DS10 36 11.75 71.25 71.27T015/AS2 12.3 11.27 46.11 93.6T015/AS3 11.75 12.00 47.75 71.27T015/AS4 20.75 11.60 55.55 76.09T015/BS1 14.90 8.13 39.29 79.56T015/BS2 21.05 7.04 42.17 87.2T015/BS4 23.10 7.10 44.4 85.19RO16/DS2 79 11 112 91.4R016/DS3 NA NA NA 89.26

Typical analysis of low Fe‐Ni batches

* R-Random Sample, T- Blended Sample DMRL

Transfer of technology – Setting up of country’s first commercial titanium sponge plant

• Plant location at KMML, Kerala• Funding by VSSC, ISRO, Dept. of space• Complete basic engineering and assistance in detailed engineering by DMRL

• Project consultancy by KITCO• Technology demonstration and training to KMML personnel  by DMRL

• Private industry participation (L& T, Welmech, Ecoman, Bemco, Hyfab etc)

• Plant commissioned in Feb 2011

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KMML 500 TPY Titanium Sponge Plant at Kollam, Kerala

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Future trends

• Increased usage of titanium in a wide range of industries

• Initiatives for expansion of facilities • Increased private industry participation in titanium industry/buisiness

• Increased non‐aerospace market

DMRL

Thank you all

DMRL