IREL Turn-around of Orissa Sand Complex

The birth of Indian Rare Earths Ltd (IREL) is closely linked with the emergence of the Atomic Energy Commission in India. It was incorporated on 18th August, 1950 as a private limited Company and its activity started with the commissioning and operation of a Rare Earth Plant at Alwaye, Kerala, for the processing of monazite mineral to thorium concentrate, rare earth chloride and trisodium phosphate. Subsequently, IREL became a full-fledged Central Govt. Undertaking under the administrative control of Department of Atomic Energy and took over the beach sand mineral industries of the country in 1965. It started operating two mining and mineral separation plants one at Chavara, Kerala,. and the other at Manavalakurichi, Tamil Nadu, to exploit its beach sand containing heavy minerals. The activities of these two plants essentially involved dry mining of the black sands from the beaches and its separation to individual minerals like ilmenite, rutile, zircon, monazite, sillimanite and garnet taking advantage of the differences in properties like specific gravity, magnetic susceptibility, electrical conductivity and surface characteristics. Besides chemical processing of monazite at Alwaye plant, only other value addition activity undertaken that time was dry grinding of the zircon concentrate to zirflour for its application as an opacifier in ceramic industry. In the next ten years or so, Company's sales turnover improved from mere 1 core to about 5 core making reasonable profit every year. Besides rare earth chloride, the major mineral-ilmenite, particularly that from Chavara (-60% TiO2) was regularly exported as it was in great demand as a feed stock for the production of TiO 2 pigment.
During 1973-74, a decision was taken to exploit the 250 million tonnes of raw sand deposit with 20-25% heavy minerals of South Orissa Coast.Although heavy mineral contents in Orissa sand are lower than those of west coast deposits (40 to 60%), it was thought to be compensated by its large volume and other favourable factors like the area being sparsely populated and availability of port, railway and highway in the vicinity. Accordingly project activity was initiated to set up an integrated mining, mineral separation and value addition facility called Orissa Sand Complex (OSCOM) at Chatrapur-an industrially backward area about 150 km away from Bhubaneswar with following name plate capacity of mineral production:

Ilmenite	220,000 tons
Rutile	10,000 tons
Zircon	2,000 tons
Sillimanite	30,000 tons
Monazite	4,000 tons

The scope of the project also included setting up of a chemical plant for the conversion of the entire amount of ilmenite to 100,000 ton of synthetic rutile-a much sought after value added feedstock for the production of pigment.
The project was in fact quite ambitious as it envisaged dredge and wet concentration- a mining technique to be adopted by IREL for the first time and conversion of entire amount of low grade(50% TiO2) ilmenite to 92% grade synthetic rutile (SR) based on the Benelite process technology (ref Fig.1A) involving reduction roasting of ilmenite followed by it high pressure-high temperature leaching with concentrated hydrochloric acid and its regeneration from the spent acid. It took almost ten years to set up the facility at an escalated cost of Rs. 135.34 crores entirely funded by Govt. of India at a debt-equity ratio of 1:1. It was expected that with OSCOM reaching name plate capacity, the sales turnover as well as foreign exchange earning of the company would be doubled. Eventually OSCOM became operational from 1.10.1986 but the projected returns in term of sales turn over and profit were never realised.
PROBLEMS OF OSCOM
The complex as mentioned earlier, essentially comprises of two production lines. The first includes Dredge and Wet Concentrator(DWC) and Mineral Separation Plant(MSP) for the production of individual minerals. The second line consists of Synthetic Rutile Plant (SRP) and Acid Regeneration Plant (ARP) for conversion of ilmenite to SR. Most of the unit operations of SRP and ARP are based on processes/technologies, which are attempted in the country for the first time. Also, while procuring plant and equipment for the project, IRE had utilised indigenous sources and technologies to the maximum extent possible and import was limited to items not manufactured indigenously. In view of above, problems encountered at OSCOM are not only unique in nature but also large in magnitude especially in view of the fact that the basic technology has been obtained from different agencies and an attempt has been made to unit them together.Repeated failures of various equipment like roaster, calciner, digesters, filters, hardware(valves/pipelines) and structurals due to severe high temperature and corrosive atmosphere resulted in frequent shutdown of the plant, extremely poor yield of SR, and mounting variable cost of production. In addition, it should be noted that OSCOM project was conceived in the wake of increasing world demand of SR as feed stock for titanium pigment industry. However, when OSCOM finally became operational and its new plants were struggling to overcome various problems the international market for feed stock and pigments entered one of its worst recessions ever. Moreover,the costs of major inputs like power, fuel oil,acid and coal increased substantially - far above the assumed figures. As a result, OSCOM during its first 10 years operations could register ilmenite production in the range of 14 to 47% of name plate capacity.Similarly, capacity utilisation of SRP was only in the range of 1 to 8% with frequent closure of the plant. The SR yield under best of the conditions operated was only 60% resulting in extremely high cost of production and consequent loss during its sale.
In between there were many efforts to address various individual problems mentioned as well as total revamping of entire SRP but without much success. As far as mining and mineral separation activity is concerned, a collaborator was found in M/s QIT-Ferro-et Titanic Inc,Canada,who was ready to form a Joint Venture Company(JVC) and provide all the inputs necessary for increased production and assured markets for Orissa grade ilmenite for making of titania slag. However, after trials and test work, QIT opted out of JVC on consideration of Orissa ilmenite being unsuitable for the slag process, IRE, however, continued its efforts and could gradually raise its mineral production and quality.
RECENT DEVELOPMENTS
In the last five years or so, there have been marked improvements in the performance of OSCOM particularly with respect to its mining and mineral separation activities. The
mineral production figures are presented below:
It can be seen that production of all minerals has improved significantly over the years. Special mention should be made of ilmenite for which more than 80% of the name plate capacity has already been achieved. Garnet is yet another mineral present in the Orissa sand in large concentration which could be recovered to almost 18000 ton by introducing additional circuit developed in-house Such improvements have been possible by (i) replacing the old trommel by a superior one (ii)increasing the length of the cutter, (iii) replacing the corroded structures (iv) improving the instrumentation and control system (v) replacing the old spirals with better designed one and (vi) introducing better mining plan. in the Mineral Separation Plant, debottlenecking, changes and fine tuning of the unit operations, optimisation of their performance and location have all paid rich dividends.IRE is presently selling about 1,45,000 ton of OSCOM ilmenite in the export market as a feed stock for the production of slag anatase grade pigment.
As far as SR production was concerned,a decision was taken in 1997 to stop commercial

MINERAL PRODUCTION AT OSCOM IN THE LAST FIVE YEARS, TONS

MINERAL	1994-95	1995-96	1996-97	1997-98	1998-99
Iimenite	73521	102714	91023	118190	177341
Rutile	2802	3697	3099	4515	5654
Zircon	1176	1503	1639	2383	2848
Sillimanite	1221	2026	2638	2951	4665
Garnet	938	2062	2269	4259	17920

operation as it was no way profitable in the way it was being run. Instead efforts were initiated to address the various defects of the reduction roaster so that oxidation of the reduced material coming out of the hot zone did not take place and overall reduction
improves much beyond 40%. At the same time detailed laboratory scale investigation was initiated to modify the leaching flowsheet with an aim of simplifying the operation and improving the SR yield beyond 90% so that the variable cost of production comes down significantly. It was a matter of satisfaction that after suitable modification, the roaster could achieve a reduction efficiency of more than 70%. More importantly, according to the new modified leaching process(ref Fig.1B), it was found possible to achieve SR yield and grade both of the order of 93% by a simple single stage leaching of the reduced material with 20% HCI in the presence of certain additives.Such results of laboratory scale experiments were reconfirmed by three series of plant scale trial (more than 50 batches) wherein the variable cost of production could be brought down by almost 50%. It is now contemplated to put 6 out of the original 16 digesters in operation for one month continuously. Once the commercial aspect of the modified process is well established by the proposed month long trial, investment decision will be taken to restart the commercial operation of the revamped section of SRP and ARP with at least six digesters each producing about 9T of SR per day.
JOINT VENTURE ACTIVITIES
In parallel to above mentioned in-house efforts towards restarting SR production on a limited scale, IRE is very actively pursuing tow joint venture efforts one with AUSTPAC of Australia and the other with Saraf Agencies Ltd, Calcutta, and Ishihara Sangyo Kaisha Ltd (ISK), Japan, for setting up of a demonstration and a commercial scale respectively. The JVC with AUSTPAC contemplates to set up at OSCOM premises a 10,000 tpa SR plant based on a patented process involving fluidised bed oxidation-reduction roasting followed by fluidised bed leaching with 20% HCI at atmospheric pressure. Such a process is expected to yield high grade (96% TiO2) SR from any low grade ilmenite with excellent TiO2 recovery figures. Once this technology is well established through the proposed Demonstration Plant, it would be applicable for processing other low grade ilmenites of the country.
The other JVC proposes to set up a 100,000 tpa SR plant again at OSCOM premises based on Lurgi-Becher technology. The suitability of Lurgi-Becher process for the conversion of low grade Orissa ilmenite (~50% TiO2) to 92% grade SR has already been established by LURGI, Germany.
Once these two plants become operational to its full name plate capacities, OSCOM has to supply as much as 2,40,000 TPA of ilmenite to the proposed Joint Venture Companies. All the SR produced from the bigger plant will be bought by ISK for their Singapore Pigment Plant.
To sum up it can be said that OSCOM is indeed in the process of turning around and appear to have better days ahead-already registering more than 5 crore gross margin in the year 1997-98 with its mineral production rapidly increasing to name plate capacities. In fact IRE has plan to take ilmenite production at OSCOM well beyond its present name plate capacity, targetting a figure of 4,50,000 tpa to meet the demand of domestic and international market during the X th Plan period. OSCOM will also have access of three different technologies for the production of value added material like SR.As per the IREL Corporate plan, OSCOM with its present sales turnover of about 51 crores is expected to emerge as a profit making unit. Such transition of OSCOM form a loss making unit of IREL to a profitable one will be no doubt hastened up once its financial restructuring proposal to take care of its outstanding loan and accumulated interest is favourably considered by the Government.