Tuesday, September 4, 2012

Indian rare earths: genesis and growth -- TR Mukherjee, IREL

Indian Rare Earths – Its Genesis and Growth
T. K. Mukherjee
Chairman & Managing Director,
Indian Rare Earths Ltd., Mumbai

 

 

India has large reserves of beach sand minerals such as ilmenite, rutile, zircon, monazite, sillimanite and garnet the first four being categorized as prescribed substance for use in production of atomic energy and related R&D activities. These reserves are mostly located in the coastal stretches of peninsular India with the exception of few inland placer deposits. According to the Beach Sand and Off Shore Investigation Group in the Atomic Minerals Directorate for Explorations and Research who has so far surveyed 2088 kms against the target of 6000 kms of coastal tract, the ilmenite reserve is estimated as high as 278 million tons (highest in the world), along with 13 million tons of rutile, 18 million tons of zircon, 7 million tons of monazite, 86 million tons of garnet and 84 million tons of sillimanite (Table-1). These resources occur as beach washing deposits between the high and low tide lines along the beach and also as inland extension of placer sands.

 


T. K. Mukherjee, CMD Indian Rare Earths Ltd.

 

The discovery process for this huge Indian deposit was accidentally initiated in the year 1908 when Herr Schomberg, a German chemist identified the presence of monazite in the sand remnants of contaminants of coir imported from Kerala. Encouraged by the great demand in those days for thorium oxide in gas mantle, Schomberg established the first plant at Manavalakurichi (MK) in 1910 for separation of monazite and later another plant at Chavara. Subsequent to the arrest of Schomberg on charges of being a German spy during the first world war, both his plants at Manavalakurichi and Chavara were closed down. The London Cosmopolitan Mineral Company established in the year 1914 in London took over these plants and continued operations. In 1920, Hopkins and Williams (H&W), yet another London based English Company started operation at MK and Chavara.

 

The first export of ilmenite from Chavara took place in the year 1922 and the Indian ilmenite maintained a virtual monopoly in the world market as basic raw material for titania pigment (white) till 1940 when four plants belonging to Travancore Minerals Ltd. (TMC), Hopkins & William Travancore Ltd. (H&W) and Fx Pereira & Sons (FXP) together exported as high as three hundred thousand tons of ilmenite from Chavara. From a position of such a virtual monopoly in 1940, the demand of Chavara ilmenite however, dwindled in subsequent two decades due to variety of reasons like demand for better quality, labour unrest, difficulty in shipping, etc. Meanwhile the unbridled export of monazite continued till 1947 when the Govt. of India realised the strategic importance of the mineral and placed an embargo on its export. Around this time, to be precise on August 18, 1950, Indian Rare Earths Ltd. (IREL) was incorporated as a private limited Company under the Indian Companies Act, 1913, jointly owned by the Government of India and the then Government of Travancore-Cochin.

 

The immediate objective of the new company was to setup a chemical plant for processing of monazite for the recovery of thorium and uranium values in the form of concentrate and separate all the rare earths as mixed Rare Earths (RE) chloride. Accordingly in 1952, IREL setup a Rare Earth Plant at Alwaye, Cochin with an initial capacity of processing 1500 tpa of monazite based on the technology provided by the Societe des Products Chemiques des Terres Rares (now Rhodia Inc). The Company was also entrusted with the responsibility for setting up a Thorium Plant at Trombay to convert a part of the thorium concentrate to pure thorium nitrate for its application in the area of gas mantle making. From 1955 to 1998, IREL operated this plant on behalf of the Department of Atomic Energy (DAE) and supplied thorium nitrate to gas mantle industries and nuclear grade thorium oxide for research and development work related to utilization of thorium in the Indian nuclear energy programme. Only recently the plant has been closed as it has outlived its life.

 

TABLE-1: Statewise Reserves of Ilmenite and other associated Heavy Minerals

 

ZoneStateAv. Total Heavy Mineral (%)Reserves in Million Tonnes
   IlmeniteRutileZirconMonaziteGarnetSillimanite
EasternOrissa & Andhra Pradesh10-351113.984.932.6463.9151.25
Tamil NaduTamil Nadu7-39874.467.631.3421.5218.78
KeralaKerala7-64754.855.221.130.9712.09
OthersMaharashtra, Bihar & Bengal-50.200.471.44-1.74
 TOTAL 27813.4918.256.5586.4083.86

 

Going back to early days of the Indian beach sand operation which is presently the main activity of IREL, it is worthwhile to mention that out of the four plants those of TMC and H&W were closed down between 1960 and 1963. The only unit that remained functional was FXP owned by Kerala Government. The unit was later amalgamated with the Kerala Minerals & Metals Ltd. (KMML). Meanwhile in 1963, shares of the State of Travancore-Cochin were handed over to the Govt. of India and IREL became a full fledged Central Government Undertaking under DAE to initiate its mining and mineral separation activities.

 

Between 1965 and 1967, IREL took over all the plants of TMC and H&W and started operating one unit at Chavara, Kerala after suitable refurbishing and the other at Manavalakurichi (MK), Tamil Nadu presently known as Mineral Divisions, Chavara and MK respectively for the production of six heavy minerals like ilmenite, rutile, zircon, monazite, sillimanite and garnet.

 

The Chavara plant is based on the mineral deposit of 23 km long stretch of land in the belt of Neendakara and Kayamkulam which is well known as the richest and the single largest ilmenite deposit in the country. The MK plant, situated 25 km north of Kanyakumari, exploits minerals from 8 km. stretch between Kadiapatnam and Colachel in the Midlam area.

 

The commercial activities of IREL at Chavara and MK during the early days essentially involved dry mining of the beach washings followed by its pre-concentration with respect to its heavy minerals by wet gravity separation equipment i.e. spirals. The concentrate containing around 90 to 95% heavy minerals is dried and subjected to a series of mineral separation process to isolate the constituent minerals from the concentrate taking advantage of their differences in specific gravity, electrical and magnetic properties. According to simplified basic scheme practiced at MK and Chavara plants, the dried concentrate is first subjected to high tension operation where the ilmenite and rutile report as conducting fraction and the other minerals as non-conducting. The primary conductings are then subjected to low intensity magnetic separation from which ilmenite and rutile concentrates are produced. The ilmenite concentrate is further purified with respect to associated minerals utilising high tension and magnetic separators. Rutile concentrate is similarly treated to finished grade product. The primary non-conducting fraction is separately treated by high intensity magnetic operation to generate monazite/garnet concentrate and zircon/sillimanite/quartz concentrate. The monazite/garnet concentrate is once again processed in a combination of low and high intensity magnetic separators as well as air tables to produce clean monazite and garnet rich concentrate. The garnet rich concentrate is next processed through high tension seperators, high intensity magnetic separators and sizing equipment to produce clean garnet. The zircon/sillimanite concentrate on the other hand is treated in a separate circuit consisting of air tables, spirals, wet tables as well as high tension and magnetic separators to produce clean zircon.

 


Total Sales & Exports by IREL

 

During 1965 to 86, the Company gradually raised its production capacities with respect to its various products such as ilmenite, rutile, zircon, monazite and rare earth chloride to the level of 170000, 5800, 11000, 4000 and 4400 tons respectively. In addition to meeting the indigenous demand for these minerals the company established itself as a dependable supplier of heavy minerals in the international market.

 

During this period, IREL also got into value addition activities like grinding zircon to zirflour and Zr based chemicals and separation of mixed RE chloride to individual RE salts through ion exchange and solvent extraction techniques. Rare Earths Division (RED) introduced a number of value added materials in its product list like various grades of cerium oxide, light, medium and heavy rare earth chloride and samarium oxide.

 

With the growing experience in the management of mineral sands industry as described above, IREL decided to setup a major expansion project known as Orissa Sands Complex (OSCOM) with capital outlay of Rs 135 crore, to exploit the large beach sand deposits of Orissa Sea Coasts. The Complex was put into operation from 1986 onwards. According to the name plate capacities, OSCOM was planned to produce 2,20,000 tons of ilmenite and associated minerals. Since the ilmenite was lower in grade with respect to its TiO2 content, OSCOM was also incorporated with two chemical units namely Synthetic Rutile Plant (SRP) and Acid Regeneration Plant (ARP) to convert the entire amount of ilmenite to 100,000 tons of 92% grade synthetic rutile based on the Benelite cyclic process. The process in brief consisted of reduction roasting of the raw ilmenite with coal at temperatures in the range of 850 to 950oC followed by leaching with 20% HCl at about 140oC and 3 atmospheric pressure to preferentially remove iron oxide.

 

The leach liquor containing the dissolved iron value is treated at ARP to generate HCl for its recycle to SRP. Unfortunately these two plants, SRP in particular never functioned properly as the various hardwares could not withstand the highly corrosive conditions resulting in frequent failure. Consequently the plant could not reach even 10% of its name plate capacity. Failure of SRP to add value to ilmenite had downward cascading effect on the motivating force to achieve higher production in the dredge and mineral separation plant. As a consequence, OSCOM operation, instead of boosting production and elevating the profit margin of the company became a source of significant loss. Consequently IREL could neither service the government loan nor the interest and had to apply for moratorium every year. Finally in 1997, commercial operation of SRP was altogether stopped with an intention of arresting the loss and modifying the existing process so that the low TiO2 recovery of 60% which was responsible for high variable cost of production could be improved. Simultaneously all out effort was made to enhance mineral production activities as OSCOM ilmenite became well accepted the worldover as raw material for the production of titania slag and pig iron as well as sulphate grade (anatase) pigment.

 

As mineral production at OSCOM has picked up significantly in recent years, it is expected that by year 2000-01, 90% of its name plate capacity will be easily achieved. While value addition activities of IREL with respect to its major mineral product ilmenite has not so far met with much success slow but steady advance is being made on value addition on rare earths in the form of wide range of pure salts of individual rare earths. Over the years the plant of RED has been equipped with various facilities including large chain of mixer-settler units which are so essential for large scale separation of chemically similar rare earths by solvent extraction. Setting up of plants such as HERO (Heavy Rare Earth Oxide) and PRYNCE (Praseodymium, Yttrium, Neodymium and Cerium) which fractionate the composite rare earth chloride into light, medium and heavy rare earth bearing salts as well as produce pure salts of Nd, Pr and La are typical examples of IREL’s effort to add value to its products.

 


A Dredge and Wet Concentrator (DWC) in operation at OSCOM

 

The brief account given indicates how IREL by late nineties have successfully emerged as a reliable producer and supplier of heavy minerals and rare earth chemicals in the national and international market. The disturbing trend in the last decade on the other hand, has been the stagnancy of production of ilmenite and associated minerals. IREL is indeed concerned about this scenario as well as about the upcoming challenge to be faced as it has lost its protection with the opening up of the beach sand minerals industry to all wholly owned Indian companies according to the Government of India’s new policy on exploitation of beach sand minerals notified during October 1998.

 

Export Awards Bagged by IREL during the last 5 years:

  1. CAPEXIL special Export Awards (Proc.Minerals Group) 1995-96, 1996-97, 1997-98, 1998-99, 1999-2000.
  2. Orissa State Export Award 1995-96, 1996-97, 1997-98.
  3. CAPEXIL special Export Awards (Paint & Raw Material Group) 1995-96.

The performance of the company during 1999-00 has been fortunately outstanding with ilmenite production (Table-2), sales turn over foreign exchange earned and profit before tax all touching record figures. The company has therefore made a confident entry to the new millennium with the OSCOM unit poised to make profit for the first time and RED capturing back its market share of rare earth products. The company is also actively pursuing with Government of India for getting its financial restructuring proposal approved. Such an approval would go a long way in improving the balance sheet of the company significantly and executing its expansion plan with respect to its three mineral divisions. Simultaneously IREL is also pursuing a number of joint venture proposals with both Indian and foreign companies to exploit new deposits and adding value to ilmenite.

 

TABLE-2: Major Production Data of IREL during 1999-2000 (Qty. in ton)

 

PRODUCTCHAVARAMKOSCOMREDTOTAL
Ilmenite12618376354175008-377545
Monazite-1654--1654
Zircon1362047653154-21539
Rutile894326165442-17001
Sillimanite9595-4873-14468
Zirflor4920---4920
Brown Ilmenite745---745
Garnet-913611433-20569
Zir. Chemicals-159--159
R.E.Chloride---25802580
TSP---25802580
R.E.Fluoride---114114
Cerium Oxide---8181
Ce Hydrate--6666-
Nd-Oxide---99
Did. Carbonate---4646

 

Mineral Sand Industry – Present scenario & future options
S. Sivasubramanian
Director (Technical),
Indian Rare Earths Ltd., Mumbai

 

 

The Status:

 

The current world production capacity of ilmenite and other titanium feed-stocks for production of titanium oxide pigment, titanium metal, welding electrodes, etc. is around 70 lakh million tons per annum (tpa). Approximately half of this is from beach sands and the balance from ilmenite rocks mostly found in Canada and Norway. In view of the limited supply of natural rutile its share of consumption in pigment production is rather small and 55% of its total availability of about 5 lakh tpa is used in the non-pigment applications pre-dominantly in the production of welding rod and titanium metal. The present production capacity of pigment in the world is just above 40 lakh tpa. North America is the largest producer with 37% of the global capacity. Europe with 32% capacity is the second largest producer and Asia-Pacific region with 21% capacity is the third. The balance 10% is distributed among the rest of the world.

 

In India, the installed production capacity for ilmenite is 4.75 lakh tpa and the production of ilmenite and rutile during 1997-98 was over 3 lakh and 13,000 tons respectively. There are four synthetic rutile plants in the country belonging to Indian Rare Earths Ltd., Kerala Minerals & Metals Ltd., DCW Ltd. and Cochin Minerals & Rutiles Ltd., all of which operate on the Benelite/Wachang process. The total synthetic rutile production during 1999-00 was about 60,000 tons, more than half of which was exported. There are four pigment producing plants in the country, three based on sulphate process and one based on chloride process with a total production of about 30,000 tons in 1999-00.

 

Mineral Reserves:

 

The occurrence of the mineral deposits in India can be broadly divided into four zones viz.

  1. Eastern Zone: Covering States of Orissa and Andhra Pradesh.
  2. Tamil Nadu Zone.
  3. Kerala Zone and
  4. Others: Covering small deposits also occurring in the coastal Maharashtra and inland placers in Bihar and West Bengal.

The Heavy mineral content in Indian deposits by and large ranges between 10-50%. Within this, the ilmenite content (which is the dominant constituent) varies from zone to zone.

 

Optimal Exploitation of Heavy Mineral Resources:

 

Although Indian reserves are largest in the world exploitation of a substantial part of this resource is economically unviable at present. Examining the exploitation level in other countries having similar resources, it is observed that Production to Reserve Ratio (PRR) in our country is 0.001 which is relatively very low. This indicates that our large reserves are not being exploited at an optimum level. At this rate the reserves are likely to remain unexploited for a very long period.

 

Policy on Exploitation of Beach Sand Minerals:

 

Considering the low exploitation ratio of the reserves, the need for faster economic development, the demand for these minerals and their value added products in the domestic as well as international market, high capital requirement for greenfield project, etc. The Government of India promulgated a policy on October 6, 1998 allowing private sector participation including foreign direct investment in the beach sand mineral industry. The policy aims at maximization of value addition to the raw materials within the country, upgradation of existing proven technologies, attracting funds and new technology, bringing regional balance and regulating the rate of exploitation.

 


PRYNCE drying and calcination system

 

Future Plans of IREL:

 

In the light of this policy and to cope with the changing scenario, IREL is adopting a two pronged strategy viz.

  1. Consolidation & expansion of existing operation and
  2. Joint venture for value addition and new production facilities.

Expansion of existing capacity:

 

IREL has initiated action to nearly double its existing capacity for production of ilmenite and associated minerals. The intention is to reach a production level of 8 lakh tons of ilmenite by the year 2005, so that IREL could be a sizable supplier in the market.

 

Joint venture proposals:

 

In respect of joint venture, IREL has made following arrangements:

  1. A joint venture agreement has been executed with Austpac Resources NL, Australia, subject to approval of the Government of India, for setting up a 10,000 tpa Synthetic Rutile Plant at Orissa using the OSCOM ilmenite. This will be based on the proprietory process developed by Austpac. Consequent on the success of this demonstration plant, IREL is proposing to enter into MOU involving Austpac Resources and Ticor Ltd., Australia for setting up further 100,000 tpa SR plant at Orissa using the OSCOM ilmenite and/or green field project involving mining, mineral separation and value addition to ilmenite.
  2. An MOU was executed with Saraf Agencies Ltd., Calcutta, to setup a 100,000 tpy SR plant using the SLRN Lurgi/Becher process in which Ishihara Sangyo Kaisha, Japan, will also be a partner. Subject to an investment decision and approval of the Government of India, a joint venture agreement would be finalized for proceeding with the project.
  3. An MOU was executed with Andhra Pradesh Mineral Development Corporation, Hyderabad and National Mineral Development Corporation, Hyderabad for exploiting the beach sand deposits of Bhimilipatnam in Andhra Pradesh near Vizag. The project envisages setting up mining & mineral separation plant for 100,000 tpa ilmenite and associated minerals and a value addition plant for ilmenite.
  4. An MOU has been entered into with WSIL Mineral Sands India Pvt. Ltd. for exploiting the Kudiraimozhi teri deposit in Chidambaranar District of Tamil Nadu. The project involves foreign direct investment by Ausind Sands Ltd., Mauritius, a subsidiary of Mineral Deposits Ltd., Australia.
  5. An agreement has been entered into to get technical assistance from Showa Denko K.K., Japan, for setting up Neodymium metal production facility at Rare Earth Division.

Conclusion:

 

IREL is fully seized of the changing environment and is geared up to consolidate and retain its predominant position in the mineral sands industry.

 

Production of Neodymium at PRYNCE Plant
V. R. Nair
General Manager (Production and R&D)
Rare EarthsDivision, IREL, Udyogamandal, Kerala

 

 

For nearly four decades the Rare Earths Division (RED) of the Indian Rare Earths Limited (IRE) has been in the forefront producing and supplying world class rare earth materials to the indigenous as well as international market. Located at Udyogamandal near Kochi in Kerala amidst picturesque surroundings this ISO 9002 company boasts of a wide range of products matching the quality of materials required by the international markets. The Division is committed to process rare earth materials and supply rare earth compounds and by products of consistent quality striving to maximise customer satisfaction. To meet the challenges of a competitive market, RED continously reviews its product mix and plans its market and production strategies accordingly.

 

 

India is blessed with large resources of rare earths. The rare earth reserves of India is estimated to be 2.7 million tons. (Fig.1)

 

As was customary (upto 1970) with most of the rare earth mineral processing industries in the world which were much older than ours, RED too engaged itself more or less exclusively in the production and marketing of mixed rare earths chloride from monazite. IRE continued with this activity with only minor deviation till nearly the end of 1980’s. The high technology applications of individual rare earth compounds and metals changed the face of rare earth industry after 1970. Recognising the potential market earnings of individual rare earths, leading rare earth producers like Rhodia (France), Molycorp (USA), etc., went into massive and rapid diversification projects and reaped sizable benefits. Peoples Republic of China, taking advantage of its enormous mineral resources stepped up production to such an extent that today they virtually control the world market.

 

After the entry of China in the international market for rare earths, RED which was mainly dependent on the international market found it rather challenging to export its products. Diversification of rare earth products was started in RED quite early to produce small quantities of cerium oxide for glass polishing, rare earths fluoride for cinema arc carbons, etc., which were all low technology low value items. Realization of the changes in the rare earth scenario started in the late 1980’s and RED commissioned a plant in 1990 to produce samarium oxide (>95%) used for the manufacture of samarium-cobalt permanent magnets by solvent extraction process. The technology was completely indigenous developed by RED with the assistance from Uranium Extraction Division of Bhabha Atomic Research Centre (BARC). This plant worked successfully producing sizable quantities of pure samarium oxide. Meanwhile the market potential for neodymium for the manufacture of permanent magnets was realized. The discovery of the outstanding properties of Nd-Fe-B alloys is considered as an exciting technological and commercial development in the history of rare earth materials.

 

World production of rare earth magnets in 1994 was estimated at US $ 1.16 billion and is expected to grow to US$ 5.4 billion by 2004. With the world wide development of tremendous interest in the Nd-Fe-B permanent magnets IRE decided to establish a facility at RED called PRYNCE (Praseodymium-Yttrium-Neodymium-Cerium) to produce 135 tons per annum of neodymium oxide (>95% pure) suitable for manufacture of Nd-Fe-B magnets.

 

Table-1: Energy products of magnetic materials

 

MaterialFerriteAlnico 5Alnico 9SmCo5Sm2Co17Nd2Fe14B
Energy Product344484176208350
(kJ/m3)      

 

Neodymium-iron-boron permanent magnets with their high energy product can help to miniaturise several magnetic devices to hitherto unbelievable small sizes. Advantages of these magnets are high efficiency, high torque and high power in a compact size, with low noise, low temperature rise, improved dynamic response, etc. These magnets find applications in brushless DC motors, stepper motors, DC liner motors, synchronous DC motors, magnetic separators, magnetic resonance imaging (MRI), microwave devices, relays & switches, impact printers, audio transducers (telephone, microphone, speaker), actuators, computer disk drives, CD players, videorecorders & camcoders, solar powered vehicles, medical devices, aerospace, high speed turbines, low speed direct drive wind generators, etc. The industrial and commercial applications of NdFeB magnets are wider than just electric motors. A breakdown of the use of these magnets is shown in Fig. 2.

 

 

Process Description:

 

The process for the preparation of neodymium oxide is based on solvent extraction with a reagent called PC88A and the technology used is completely indigenous developed by the joint efforts of BARC and RED. The counter current solvent extraction process is carried out in mixer settler units made of FRP. The process involves 18 stages of extraction, 24 stages of scrubbing, 6 stages of stripping for neodymium and 6 stages of stripping for samarium.

 

The aqueous feed solution for this process containing Nd, Pr, Ce and La is obtained after the recovery of samarium and heavier rare earths from the composite chloride solution. In the latter half of 1990's, magnet manufacturers observed that for obtaining high quality Nd-Fe-B magnets, neodymium oxide of purity >99% is needed. Subsequently the demand for 95% neodymium oxide dropped and RED had to modify the solvent extraction process to produce >99% pure neodymium oxide by increasing the number of scrubbing stages from 24 to 60.

 

Erection and Commissioning:

 

The plant was commissioned in December 98 and was inaugurated by the then Chairman, Atomic Energy Commission (AEC), Dr. R. Chidambaram to initiate production of 95% pure neodymium oxide. The scope of the plant was subsequently revised to produce 99% pure oxide as mentioned above and after establishing the process parameters trial runs were commenced in September 1999. RED has till date produced about 75 tons of neodymium oxide suitable for neodymium magnet production.

 

Conclusion:

 

The commissioning of the PRYNCE Plant has given IRE confidence to design and supply new value added rare earth products to its customers. It will also help the Company to face new challenges in the fast changing rare earth markets and ensure that RED remain as a reliable supplier of value added rare earth products.

 

Research and Development Activities of IREL
S. Suresh Kumar, C. M. Mani, N. R. Nair and T. K. Mukherjee
Indian Rare Earths Ltd.

 

 

For any industrial unit engaged in the commercial scale production of minerals and its further processing for value addition, research and development is considered as a very important activity and IREL is no exception. Among the three dedicated laboratories which cater to the various needs of IREL, the first is located at Kollam, Kerala and known as Mineral Research Development Centre (MRDC), the second at Orissa Sands Mining Complex (OSCOM), Chatrapur, Orissa and the third and the oldest one at Rare Earths Division (RED), Alwaye, Kerala. The laboratories at MRDC and RED are engaged in R&D activities related to mineral beneficiation in general and value addition to radioactive mineral like monazite by separating its thorium and rare earths components respectively The laboratory at OSCOM addresses both mineral separation and value addition to remaining non-radioactive minerals through chemical routes.

 


Mixer-Settler of Indian Rare Earths

 

Mineral Research & Development Centre:

 

Beach sand mineral deposits earlier mined by IRE were of high grade, simple mineralogy and of close grain size range. This mostly required conventional physical processing techniques only to meet the purity and recovery targets. But the non-availability of high-grade ores necessitated exploiting leaner deposits. The new deposits identified for mining have complex mineralogy, lower feed grades and wide grain size ranges. The mining and processing of these require improved processing techniques. Based on the market demand, new physical and chemical techniques are required in addition to the conventional processing methods to obtain graded products. Energy efficient, environment friendly and cost effective processing plants with automated process control techniques are the requisites of tomorrow. In such highly competitive heavy mineral market, adaptation of new technologies was found essential for keeping the company in the fore front. This led to the setting up of Mineral Research and Development Centre (MRDC) at Kollam, Kerala in 1990. Over the years, this laboratory has been equipped with whole range of ore beneficiation and separation equipment to achieve following objectives:-

  1. Detailed mineral characterization studies for increasing the efficiency of separation in unit operations and suggesting required instrumentation for control of process parameters.
  2. Develop intelligent systems for simulating plant operations for improving the plant efficiency.
  3. Develop suitable technology for improving the mining and material transportation at the operating plants.
  4. Suggest modification/alternative techniques to improve the efficiency of existing circuits.
  5. Conduct energy audit for optimizing the energy consumption.
  6. Identify the low level impurities in the mineral products for specific end users.
  7. Study and develop new physical separation techniques for exploiting leaner deposits.
  8. Develop new value added mineral products.
  9. Identification of mineral specification for customers and develop techniques to obtain classified or graded mineral products.

Some of the major works undertaken at MRDC since its inception are:-

  1. Detailed investigations in developing a flowsheet for the beach sand deposit of Bhimlipatanam (Andhra Pradesh) to concentrate the heavy mineral content and recover the individual minerals.
  2. Studies to recover ilmenite from sediments of Kalbadevi bay for Geological Survey of India (GSI) west coast division.
  3. Studies on Floatex density separator with the nonconducting nonmagnetic fraction to check the feasibility of separating fine sillimanite with the objective of eliminating air table from the present OSCOM zircon circuit and recover sillimanite from OSCOM CUP tailings.
  4. Studies conducted to recover the garnet and sillimanite lost in OSCOM CUP tailings.
  5. Studies conducted to develop a flowsheet to recover monazite from air table feed at Manavalakurichi (MK) using column flotation.
  6. Studies conducted to develop a flowsheet for beneficiating the feed stock (silica sand) of M/s. Excel Glasses Ltd., Alleppey and carry out engineering design and commissioning of the plant.
  7. Studies on beneficiation of Silica sand of M/s. Hindusthan National Glass and Industries Ltd. (HNGIL), Bahadurgarh, Haryana.
  8. Develop a flowsheet including metallurgical design, equipment specification and conceptual design of a plant with 90,000 tpa capacity.

R&D Laboratory, OSCOM:

 

To have dedicated quality control cum applied research lab which can address the different process problems and help in devising value addition processes the lab was progressively equipped with facilities for value addition to minerals and to carry out analytical and basic studies in the related fields. This inhouse laboratory of OSCOM is not only meant for routine analysis as required by the various plants of OSCOM but also for carrying out R&D work on value addition on various minerals.

 

Various R&D studies have been conducted by this laboratory to improve the metallurgical performance of mining and mineral separation plants. As a result throughput of the plants has increased and the grade and recovery of heavy minerals in concentrate has been enhanced. The two most outstanding contributions of this laboratory in the areas of value addition are development of new process flowsheets for the preparation of synthetic rutile from OSCOM ilmenite and zirconia from zircon.

 


Pilot-plant for producing Stabilized Zirconia with process technology developed in-house

 

Value addition on Ilmenite:

 

In 1986, world’s largest synthetic rutile plant was commissioned at OSCOM with an installed capacity of one lakh tons of Synthetic Rutile (SR) based on cyclic process developed by Benelite Corporation of America (BCA). The project faced various problems which finally resulted in the stoppage of production in 1991. The plant was restarted at low capacity after short maintenance programme but due to frequent failures of leaching system and connected equipment the desired output was not achieved. Commercial production of SR was therefore discontinued from May, 1997 onwards.

 

An extensive R&D study was initiated to modify the process so that it becomes simple to operate with existing equipment and most importantly with higher yield.

 

After detailed experimentation, the R&D laboratory came out with a cost effective simplified single stage leaching process for ilmenite beneficiation. The modified process involved single stage leaching in the presence of suitable additives.

 

The results of laboratory scale tests were revalidated in plant scale trials conducted in five phases. A month long continuous operation of a part of SRP and ARP proved that the modified process was capable of producing 92% grade SR with good TiO2 recovery. A patent has been filed for the know how so developed.

 

Value Addition on Zircon:

 

Zirconia, an oxide of zirconium, is one of the most important value added products from zircon. With the discovery of transformation toughening property in partially stabilized zirconia, a new generation of materials known as engineering ceramics or structural ceramics have started competing with metal/alloys due to excellent thermal shock resistance, greater strength and toughness including erosion and corrosion resistance. The laboratory has been working for last one decade in developing the process for producing various grades of zirconia.

 

The laboratory is credited in developing a chemical process for producing high purity zirconia containing very low impurities like iron oxide (<10 ppm) and silica (<100 ppm). Various grades of stabilized zirconia produced in this laboratory was tested successfully for the preparation of artificial diamond gem, high temperature nozzles etc.

 

The laboratory in collaboration with Central Glass and Ceramic Research Institute (CGCRI), Calcutta, Defence Metallurgical Research Laboratory (DMRL), Hyderabad and Department of Science & Technology, New Delhi, worked out a project for developing a technology for producing critical components for application in iron and steel industries.

 

Based on the process flow sheet developed, the laboratory has successfully commissioned a pilot plant for the production of hundreds of kilos (3.5 tpa) of various grades of stabilised zirconia starting from zircon sand as produced by IREL.

 

Environmental Activities of IREL
P. Panduranga Rao
Chief General Manager (Safety, Env. & Community Affairs),
Indian Rare Earths Ltd., Mumbai

 

 

Safety and Environmental Policy occupies an important place in the functioning of Indian Rare Earths Ltd. (IREL) which is engaged in mining and separation of beach sand minerals as well as subsequent value addition by chemical processing. An effort has been made here to briefly present the company’s activities in environment management and rehabilitation programmes.

  1. Mining and Mineral Separation:

     

    The mining operations from inland deposits are carried out by dredging at the units of Chavara, Manavalakurichi (MK) and Orissa Sands Complex (OSCOM). The dredged sand is concentrated by spirals thus obtaining concentrate A. The spirals are either integrated with the dredge called Dredge & Wet Concentrator (DWC) or installed on the shore. This concentrate A is further upgraded in the Concentration Upgradation Plant (CUP) to get a highly enriched concentrate with respect to heavy minerals for its further processing in the Mineral Separation Plant (MSP) where the separation of mineral constituents is carried out. The tailings of DWC, CUP and MSP are used for backfilling of mined out areas. Background radiation after mining and backfilling get reduced by a factor of upto ten due to the separation and segregation of monazite.

     


    Casuarina plantation in minedout and backfilled areas at OSCOM

  2. Value Addition on Minerals:

     

    Besides mining and mineral separation IREL is engaged in activities leading to value addition to its mineral through physical and chemical routes. Production of zirflour and microzir by physical grinding and synthetic rutile, thorium nitrate and chemicals of zirconium and rare earths all through chemical processing, are typical examples.

    1. Production of synthetic rutile at oscom:

       

      The synthetic rutile is produced at OSCOM in its two facilities viz. Synthetic Rutile Plant (SRP) and Acid Regenaration Plant (ARP).

       

      At the Synthetic Rutile Plant (SRP), the ilmenite is mixed with lecofines and roasted in rotary kiln to convert ferric oxide into ferrous form which is more amenable for acid leaching. The reduced ilmenite is treated with 20% HCl at elevated temperature and pressure to remove iron oxides. The leached ilmenite is washed with water, filtered and calcined to obtain synthetic rutile containing about 92% titanium dioxide.

       

      The waste acid from SRP contains large quantities of dissolved iron chlorides along with some unreacted HCl. This acid is processed in the Acid Regeneration Plant (ARP) to produce 18–20% hydrochloric acid and iron oxide powder which is disposed in mined out areas.

    2. Production of Thorium Nitrate at OSCOM:

       

      Thorium nitrate is produced at the Thorium Plant located at OSCOM by chemical conversion of thorium oxalate supplied by RED crude thorium nitrate solution. The crude thorium nitrate solution is purified through solvent extraction to recover pure thorium bearing solution which is evaporated to recover thorium nitrate crystals.

    3. Production of Zirconium Chemicals at MK Unit:

       

      Production of zirconium chemicals like frit, chloride, sulphate, etc. from the mineral zircon is carried out at the MK unit. This plant generates various kinds of effluents from such operations.

    4. Production of Rare Earth Chemicals at RED:

       

      The Rare Earths Division at Alwaye, called RED is engaged in recovering thorium concentrate and various rare earth chemicals.

    5. Treatment and Disposal Methods for Liquid and Gaseous Effluents OSCOM:

       

      The exhaust gases are passed through cyclones and scrubbers to remove particulate matters and acid fumes before it is discharged through the stacks of heights varying from 20–40 metres.

       

      The MSP contributes approximately 100 m3/day effluent from sillimainite circuit containing small quantities of HCl, sodium silicate, oleic acid and soda ash. The quantities of effluents from SRP, ARP, Boiler, Thorium Plant are treated with lime and discharged along with the process water.

       

      Both nitrate and non-nitrate effluents generated in the Thorium Plant are treated.

    6. MK:

       

      The strong and weak effluents from zirouinm oxide plant are collected and stored separately. The strong alkaline leach solution is sold to the silicate manufacturers. The excess strong alkaline leach solution and the weak alkaline solution are neutralized with acid to maintain Ph between 6.5 to 8.5. The neutralized effluent is allowed to settle in a settling tank after the addition of suitable flocs. The overflow from the tank goes to a collection sump and the sludge from the bottom of the tank is directed to sludge drying beds. The underflow from the sludge drying beds also goes to the collection sump from where it is pumped to the sea.

    7. RED:

       

      To minimize the release of the gases such as Cl2, H2S and HCl vapours, scrubbers are used in the Modernised Helium & Uranium Recovery (MOHUR), Heavy Rare Earths Oxide (HERO), Diversified Product Plant (DPP).

       

      A number of source control measures are adopted at the plant like floor mopping, reduction in quantity of water used for decontamination and their reuse, recycle of filter press washings etc. The effluent streams that needed chemical treatment are identified, neutralised and segregated. Total effluent requiring the treatment is about 200 m3/day. The two streams of effluents i.e. one of alkaline and other acidic are collected separately and mixed in a flash mixer to neutralize the combined waste. CaCl2 and FeCl3 are added to remove the PO4-F-,Ra228, Ra226 and Pb. The sludge is filtered and the filter cake is filled in HDPE bags and disposed of as land-fill in a controlled area.

  3. Disposal Methods for Solid Waste:

    OSCOM

    1. Thorium Plant:

       

      The radioactive solid waste from thorium plant is disposed off in specially designed RCC trenches. The radioactive solid waste is packed in HDPE bags and stored in underground RCC vault as per Atomic Energy Regulatory Board (AERB) guidelines. Additional barriers such as compact clay soil and a clay mix, phosphate, powdered rock, barytes and lime of appropriate thickness are provided. These barriers prevent the leakage in the event of structural failure of the containment system by retaining radioactive pollutants. Leachability studies are carried out on the solid waste for design of the disposal facilities. In addition, the groundwater is also monitored.

    2. Other Solid waste:

       

      The monazite concentrates from MSP are stockpiled in trenches with provision for recovery. Boiler ash is disposed off as a land-fill in the mined out area.

    3. RED:

       

      Approximately 90 tons of lead barium cake is generated at RED during the deactivation of the RE Chloride with activity of 1000–3000 Bq/gm. This lead barium cake is disposed in FRP lined RCC trenches.

    4. Land Management:

       

      The backfilling of the mined out areas is synchronized with mining activity keeping minimum time lag between the two. The contours/landscape of the area is brought back to the original contours/ landscape. Steps are taken to minimise the impact of mining operations on groundwater, land and aquatic life.

    5. Afforestation Programme:

       

      Massive afforestation programmes are carried out in OSCOM, MK and Chavara Units.

       

      The total no. of trees planted during the year 1999-2000 were as follows:

       

      UnitOSCOMMKChavara
      Plantation (no.of trees)5090099784250

       

      At OSCOM total trees planted were 4,03,000 during 1987-2000.

       

      OSCOM Unit has also won Atomic Energy Regulatory Board Green Site Awards for the years 1994, 95, 96 and 98.

    6. Environment Audit:

       

      Environment audit is conducted yearly by a group of environmental professionals from the units and Corporate Office. The environment statement is furnished for the financial year to the respective State Pollution Control Board.

    7. Environment Impact Assessment (EIA) and Environment Management Plan (EMP):

       

      EIA/EMP studies were carried out for thorium plant at OSCOM and MOEF clearance was obtained. Similar Studies for MK and Chavara have been conducted.

       

      Integrated Coastal Management System plans are being developed for preservation of the coastline at Chavara with the assistance of Centre for Earth Sciences, Trivandrum.

    8. Ressettlement & Rehabilitation (R&R) Programme at Chavara:

       

      The Chavara Unit had been dredging in its own lands since the inception of the first Mineral Recovery Plant (MRP-I) in the year 1990. The available land for dredging was exhausted in 1998. With the help of the district authorities a suitable compensation package was offered for acquiring additional land. The compensation package for people removed from the land containing valuable minerals for exploitation by mining comprises:-

      1. Appropriate monitary consideration towards the value of land, buildings, structures and trees owned by the concerned persons.
      2. Provision of land for resettlement in the back filled mined out areas with adequate infrastructural facilities like roads, drinking water, electricity, etc. besides paying shifting/goodwill charges.
Mineral Sands and Rare Earths - Marketing Challenge
V. K. Verma
Director (Marketing),
Indian Rare Earths Ltd., Mumbai

 

 

The Indian Rare Earths Ltd. (IREL) has been selling its products both in the domestic and export markets almost since its inception in the early 1950's. Around mid 1990's, the proportion of exports to domestic sales was almost equal. While the domestic marketing was easy, exporting was a tough exercise. Until the mid-1990's, IREL was virtually the sole organization in the country producing and selling beach sand minerals namely, ilmenite, rutile, leucoxene and zircon. M/s Kerala Minerals & Metals Ltd. (KMML), a Kerala State-owned undertaking has also been functioning in the field but on a much smaller scale of operation as compared to that of IREL. The latter therefore, had enjoyed a monopolistic or duopolistic position in the domestic market for the supply of aforesaid products. The position has undergone a sea-change in the latter half of 1990's with the increasing liberalisation of the economy. The winds of globalization have brought in their fold the forces that have made the marketing of these minerals and other products of the company a challenging task. On the other hand the developments in countries abroad during this period have also been such as to make exports of these products from India much more difficult. The factors impinging upon the domestic and export marketing are as follows:

 

Domestic Marketing:

 

The following developments are continuing to take place in the country:-

  1. Entry of private sector producers into the field.
  2. Liberal imports of mineral sands into the country and
  3. Export of mineral sands by the private sector organizations.

These have converged to create substantial competition from within the country for marketing the products in the domestic market and the competition is going to become progressively fiercer with the entry of more private sector players (both domestic and foreign) as and when they setup their shop in India.

 

Today, large quantities of zircon sand, zircon flour, zircon opacifier, zirconium compounds, baddeleyite (zirconium oxide) and garnet microgrits are being imported into the country. The company has to match the prices with the landed cost of these imports as India is a small player compared to the giants overseas who enjoy tremendous economies of scale besides a first class infrastructure. Consequently, there is a downward pressure on prices entailing reduced profitability.

 

Besides, a number of Indian private sector parties either on their own or in collaboration with foreign partners, are about to open shop by setting up large projects in the field of beach sands mineral separation. The fruition of these additional capacities is bound to make marketing of the minerals both within the country and abroad an increasingly difficult job. The advantages enjoyed by the private sector in terms of flexibilities, higher labour productivity and better work culture shall make the operations of public sector companies like IREL much more difficult.

 


Shri. V. K. Verma, Director (Mktg.), IREL receiving the Special Export Award for the year 1999-2000 from Shri. Omar Abdullah, Hon’ble Minister of State for Commerce and Industry, Government of India

 

Export Marketing:

 

IREL’s share of world exports for its key product is of the order of 5-6%. The growth in production during the 1990's could not keep pace with the world growth owing to prolonged teething problems experienced at Orissa Sands Complex (OSCOM), inadequate availability of land for mining at Chavara (Kerala) and for want of requisite quantum of beach washings at Manavalakurichi (Tamil Nadu). Besides, the recent tendency of mergers and acquisitions abroad has resulted into IREL having to compete with bigger giants who have got more competitive teeth because of the increased size of their operations. To cite an example, the merger of RGC, Australia with Westralian Sands, Australia has resulted into the formation of Iluka Resources Ltd. A company that enjoys a formidable 32% of the world market share in the field of titanium feedstocks like ilmenite, rutile, synthetic rutile and leucoxene. Compared to this IREL’s share is hardly 5%. Not only the mergers are confined to IREL’s competitors, they have also pervaded the user industry where a number of TiO2 producers have merged together to sharpen their sourcing clout. Consequently, the target customer group has sizably shrunk to the detriment of relatively small players like IREL. To cite an example, Bayer, Germany who had been sourcing their requirement for the last 25 years from IREL uninterruptedly could not sustain the same ever since they were taken over by Kerr-McGee Chemical Corpn (KMCC) of USA, two years ago. A somewhat similar phenomenon is on the cards where the French TiO2 producer (Thann et Mulhouse owned by Rhodia) has ceased to be a IREL customer after having been taken over by Millennium Pigments, USA. Recent takeover of Kemira’s pigment plants in USA and Netherlands by KMCC has also accelerated the phenomenon to the detriment of feedstock suppliers like IREL.

 

Notwithstanding the above, IREL has also to grapple with the following limitations in the market place:-

  1. A low TiO2 ilmenite of the Orissa-type which is not a preferred raw material for TiO2 pigment manufacture nor this ilmenite can be upgraded by electrosmelting for want of cheaper power in the country.
  2. Excessive presence of impurities like Al2O3 and SiO2 in IREL’s products like zircon and rutile also make the products somewhat inferior to the prime products supplied by Australia and South Africa. These impurities are due to excessive presence of sillimanite and garnet in the country’s resources.
  3. Presence of monazite and, therefore, of radioactive thorium and uranium in the company’s products.

Bulk of the rare earths products in the world are based on bastnaesite and, therefore, do not suffer from the debility of radioactivity presence.

 

Lack of Shipping Infrastructure:

 

Unlike our competitors in Australia and South Africa who enjoy easy access to all weather, extremely efficient ports like Fremantle, Bunbury, Sydney, Brisbane, Cape Town, Richards Bay and the like for the export of their produce, IREL is severely constrained by its compulsion to ship from virtually non-existent ports like Neendakara and Gopalpur which operate only for 3-4 months in the fair-weather season. The loading at these ports is midstream as these ports do not have any shore jetties. Consequently, the loading rates are abysmally low of the order of 1000-2000 tons per weather working day in sharp contrast to 10000 tons or even more per weather working day at the ports of our competitors. This makes the shipping a very costly exercise and erodes the FOB price realisation. The obstinacy of the trade unions controlling the shipping workers at these ports makes shipping a further costlier proposition.

 

Notwithstanding the plethora of constraints listed above, IREL has done exceedingly well on the marketing front by putting in tremendous amount of effort in increasing its sales turnover both in the domestic and export markets. New markets like France, China, Ukraine and South Korea have been successfully tapped. The sales revenue has grown by over 75% during the last 4-5 years and is going to touch an all time high over Rs 240 crore during the current year ending March 2001. The company’s export performance has in particular been acclaimed year after year by the export promotion agencies. IREL has to its credit over 32 prestigious export Awards the last having been won this year itself for its commendable export performance during 1999-2000.

 

The sales and export performance during the last decade is given below:-

 

YearValue in Rs Lakh
 ExportsTurnover
1990-912,2936,567
1991-923,9378,622
1992-934,6509,252
1993-945,28310,429
1994-956,69913,017
1995-966,73514,526
1996-975,524*14,569
1997-987,20317,270
1998-996,184+17,807
1999-007,82521,401
2000-01102 Crore#240 Crore#

 

* reduction due to labour strike

 

+ reduction due to discontinuation of export of high-value synthetic rutile

 

# provisional

 

Milestones of Indian Rare Earths Ltd.:

  1. 1950: IREL is incorporated as a private company jointly owned by the GOI & Govt. of Travancore, Cochin.
  2. 1952: Production commences at RED, Alwaye. Late Prime Minister Shri Jawaharlal Nehru dedicates RED to the Nation.
  3. 1953-55: Thorium Plant, Trombay owned by DAE is commissioned by IREL.
  4. 1963: IREL becomes a full-fledged Govt. undertaking under DAE.
  5. 1965: MK and Chavara Plants are taken over from Travancore Mineals Ltd. Production at MK and refurbishing of Chavara Plant commence.
  6. 1966: IREL completes Uranium Mill Project at Jaduguda, hands over to UCIL.
  7. 1967: IREL takes over H&W (Travancore) plant at MK. Mineral Division is formed comprising Chavara & MK.
  8. 1970: Refurbished Chavara Plant goes into production. Capacity of MK Plant is expanded.
  9. 1973: Pilot Plant is setup for separation of individual Rare Earths.
  10. 1977: Commencement of OSCOM Project.
  11. 1979: Preconcentrator Plant is commissioned at MK.
  12. 1985: Modernization and Helium & Uranium Recovery Project (MOHUR) commences at RED.
  13. 1986: New DWC Plant commences at MK. HERO Project at Alwaye is commissioned. Production is started at OSCOM.
  14. 1987: MOHUR is commissioned. New DWC Project commences at Chavara. New Thorium Plant commences at OSCOM.
  15. 1988: Commencement of CUP at OSCOM and MK.
  16. 1990: MRDC is launched at Quilon. HERO Plant is commissioned at Alwaye. DWCP at Chavara, CUP at OSCOM and MK are commissioned.
  17. 1990-91: IREL signs MOU with Government of India. Diversify Plant Project (DPP) starts trial production for augmenting Cerium Hydrate, Didymium Carbonate at Alwaye.
  18. 1993-94: Co-generation Plant is commissioned at RED. NTP starts commercial production.
  19. 1994-95: Ilmenite quality is enhanced in Chavara and OSCOM. MRDC, Quilon is fully functional.
  20. 1995 96: RED gets ISO 9002 certificate.
  21. 1996-97: Microzir Plant is commissioned in Chavra.
  22. 1997-98: OSCOM gets ISO 9002 certificate. PRYNCE 95% Nd2O3 is commissioned at RED. Thorium Plant at Trombay is closed.
  23. 1999-2000: MK and Chavara get ISO 9002 certificate. Corporate Plan is approved. IREL starts paying the Government loan. Additional Recovery of Rutile and Zircon project is implemented at MK. Joint venture proposals with SAL, AUSTPAC Resources are processed.

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