EXTRACTION OF URANIUM INDIA

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N.P.H. PADMANABHAN, A.K. SURI and S.K. GHOSH

Proceedings of the XI International Seminar on

Mineral Processing Technology (MPT-2010)

Editors: R. Singh, A. Das, P.K. Banerjee, K.K. Bhattacharyya and N.G. Goswami

NML Jamshedpur, pp. 628641

R&D INPUT TO EXTRACTION OF URANIUM FROM DIFFERENT

PRIMARY AND SECONDARY RESOURCES IN INDIA

N.P.H. Padmanabhan, A.K. Suri1 and S.K. Ghosh1

Bhabha Atomic Research Centre, Hyderabad - 500016, India1Bhabha Atomic Research Centre, Trombay, Mumbai - 400085, India

ABSTRACT

In order to maintain a sustained and planned economic growth rate of 8% in the coming years and to meet the

human development goals including eradication of poverty, India needs to increase her primary energysupply by 3 to 4 times and its electricity generation capacity by 5 to 6 times of the 200304 levels. All effortsare, therefore directed towards enhancing the electricity power generation and also the nuclear powercomponent. The Department of Atomic Energy (DAE) has launched a three stage nuclear power programme

based on utilization of the countrys vast thorium resources to increase the nuclear power componentsignificantly. In order to successfully go to second and third stages of the programme involving thoriumutilization, India has to build and operate adequate number of nuclear power reactors of first stage. These areessentially the pressurized heavy water reactors (PHWRs) burning natural uranium. The rising demand for

uranium in the power reactors requires intensive exploration to look for more workable uranium ore depositsin the country and techno-economic process flow sheets for exploitation. The new deposits require newtechnologies, which need to be developed by sustained R&D efforts.

At present the countrys uranium is produced at the two uranium mills located at Jaduguda and Turamdih,both in Dist. East Singhbhum, Jharkhand and operated by Uranium Corporation of India Limited (UCIL).These plants use acid leaching technique to bring the uranium values into solution. Efforts are on to enhance

the uranium supply by opening up uranium mines at Tummalapalle and Lambapur-Peddagattu (AndhraPradesh), Gogi (Karnataka) and Kylleng-Pyndengsohiong-Mawthab (KPM) (Meghalaya). While Lambapur-Peddagattu and KPM uranium ores can be processed by the well-trodden acid leaching route, some of theother ores like the ones from Tummalapalle and Gogi need to be processed by alkaline leaching because of

the preponderant presence of acid consuming carbonate minerals in the ore. Even though the Meghalaya oreis slated for acid leaching route, the technology to be followed is still to be finalized. Intensive R&D studiesare being carried out in various laboratories of the Department on process development and techno-economicevaluation on these ores. A pilot plant has been set up by Bhabha Atomic Research Centre (BARC) with the

active collaboration of UCIL, Atomic Minerals Directorate for Exploration and Research (AMD) and NuclearPower Corporation of India Limited (NPCIL) to carry out large scale semi-continuous studies on variousores. Revival of gravity plants to recover uranium from copper ores/concentrator plant tailings is also beingcontemplated by UCIL. This paper presents and discusses the R&D effort by the Department in this direction

and the salient features of the Pilot Plant and R&D studies carried out on different uranium ores.

Keywords: Uranium ore, Leaching, Acid leaching, Alkaline leaching, Process flow sheet.

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INTRODUCTION

India has been showing in the recent years a very healthy economic growth rate with fast growingeconomy in all sectors. Still the country has to sustain the present growth rate of 810% over thenext 25 years, if it has to eradicate poverty, raise the standard of living of the common man andmeet its human development goals. To achieve a consistent and sustained growth rate of 8%through 203132 and to meet the energy needs of all citizens, India needs, at the very least, toincrease its primary energy supply by 3 to 4 times and, its electricity generation capacity/supplyby 5 to 6 times of their 200304 levels. By 203132 power generation capacity must increase tonearly 8,00,000 MW from the current capacity of around 1,65,000 MW inclusive of all captiveplants

[1](http://www.powermin.nic.in/JSP_SERVLETS/internal.jsp).

While coal and other carbon based primary sources will continue to play a significant role in thetotal electricity generation, efforts are also continuously on to augment the electricity generationby nuclear and other means including the renewable energy resources. The Department of AtomicEnergy (DAE) has ambitious plans to improve the contributions of nuclear energy to as much as10% by the year 2020. Indias nuclear power policy is based on utilization of its vast resource of

thorium, which by itself is not fissile, but fertile and can be converted into fissile material byirradiation in fast nuclear reactors. In order to achieve this, the Department of Atomic Energy (DAE)has charted out a three stage programme, which in the third stage culminates into full utilization ofthe thorium resource for supply of sumptuous electricity for significantly long time. However, thiscan be achieved only by effectively and successfully going through the initial two stages.

The strategy has been presented and discussed many times in various international forums andalso in IAEA meetings and conferences. Nevertheless, for the sake completeness, it can be simplystated as construction and operation of (i) an adequate number of Pressurized Heavy WaterReactors (PHWRs) using the natural indigenous uranium and associated fuel cycle facilities in thefirst stage, (ii) Fast Breeder Reactors (FBRs) using plutonium as fuel and backed by suitablereprocessing plants and plutonium based fuel fabrication plants and (iii) Advanced Heavy WaterReactors (AHWRs) in the second stage and AHWRs and thermal breeders in the third stage.

[2]But

both the second and third stages necessarily require operation of adequate number of the first stage

PHWRs for sufficient duration to generate enough fuel material for the second stage. The PHWRsuse natural uranium as fuel with heavy water as the moderator and primary coolant. So the success ofthe Indian nuclear power programme greatly depends on the availability of adequate supply of thenatural uranium resource, its exploitation and judicious utilization. This calls for adequate strengtheningof the front end of the nuclear fuel cycle, which comprises of exploration, exploitation and fuelfabrication stages. Intensive efforts have already been commenced in exploratory activities. Whilemost of the ores can be processed by the conventional acid leaching route, some ores requirealkaline leaching techniques. Since the ores vary widely in their characteristics with respect to thenature of occurrence of uranium mineralization, gangue mineralogy, associated minerals etc., dedicatedR&D efforts are needed for characterization and to develop techno-economically feasible process flowsheets. This paper presents and discusses the activities in this regard undertaken by the department.

R&D ON URANIUM ORES BY ACID LEACHING ROUTE

R&D on Jaduguda uranium ore

The exploration for uranium and other atomic minerals is carried out by Atomic Minerals

Directorate for Exploration and Research (AMD), the exploration agency of DAE, The explorative


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efforts have been initiated seriously from the middle of twentieth century and have resulted in

discovery of uranium-copper mineralization in the Singhbhum Shear Zone (SSZ) and the

subsequent milling for uranium extraction from Jaduguda uranium ore deposit in the SSZ byUranium Corporation of India Limited (UCIL), the exploitation wing of DAE.

The Jaduguda deposit consists of two ore bodies in chlorite-biotite schist of Proterozoic age. Uranium

in the Jaduguda ore is disseminated in the metamorphic rock mainly as uraninite, which is essentially

a combination of tetravalent and hexavalent oxides of uranium in the ore. Dissolution of uranium

is possible in conditions facilitating oxidation of the tetravalent uranium. The process flow sheet

was developed based on intensive R&D laboratory studies carried out at Bhabha Atomic Research

Centre (BARC) and also large scale studies carried out in the Ghatsila Pilot Plant set up especially for

the above purpose. The pilot plant was, however, dismantled after the setting up of the mill at Jaduguda

and commencement of successful production of uranium concentrate as Magnesium Diuranate

(MDU). At that time the pilot plant had lived its purpose and no need was anticipated in future.

The main uranium extraction process followed in Jaduguda mill involves multistage crushing

followed by rod and pebble milling to get about 50% passing through -200 mesh ground material.Dewatering of the ground ore slurry is carried out by thickening followed by filtration. The filter

cake is repulped to the required pulp consistency and is then leached in air agitated Pachuca tanks.

Dilute sulphuric acid (at about pH 1.8) is used as the lixiviant in presence of pyrolusite as the

oxidant. The leach slurry is filtered and clarified to get the uranium bearing mother liquor. During the

leaching process, the tetravalent uranium gets oxidized to hexavalent uranium and gets solubilized

in the acid medium and is present as anioninc uranyl sulphate complex. Further purification /

concentration is carried out by ion exchange using an anioninc exchange resin. The eluate from

this stage is first treated with lime to increase the pH to about 3.5, wherein the iron and excess

sulphate present in the system gets precipitated as Iron-Gypsum Cake (IGC). Dewatering is then

carried out and from the clear liquor uranium is precipitated as Magnesium Diuranate (MDU)

using magnesia liquor at a pH of 6.5 to 7. The dried product, known popularly as the Yellow Cake

is packed and sent to Nuclear Fuel Complex at Hyderabad for further purification to nuclear grade

and fabrication into fuel bundles. The flow sheet followed in Jaduguda mill is given schematically

in Fig. 1. The uranium leach recovery from Jaduguda is over 90%. Initially the Jaduguda uranium

mill started with processing only Jaduguda uranium ore; but over the years with the demand for

uranium going up in the country and with the depletion of ore from Jaduguda mines, UCIL opened

up three more mines at Bhatin, Narwapahar and Turamdih located in the vicinity of Jaduguda.[3]

The mill generates two wastes, (i) the solids waste from filter after leaching and (ii) the barren

liquor from ion exchange. The barren liquor is neutralized initially with limestone slurry to ph 4.2

followed by further neutralization to pH 1010.5 by lime slurry. This is mixed with solids waste in

tailings neutralization pachucas to have a final pH of 9.5 to 10 and at this pH the residual uranium,

manganese and other pollutant ions get precipitated and fixed. The neutralized slurry is processed

in Low Intensity Magnetic Separators (LIMS) to recover the magnetite concentrate as an

economic by-product and the non-magnetic product from this stage goes for classification in

hydro-cyclones. The cyclone underflow is pumped to mines as back-fill and the overflow product

is pumped to the tailings pond. The solid fines settle to the bottom of the tailings pond and thesupernatant water is decanted off to the Effluent Treatment Plant (ETP). Although the lime

neutralization in the tailings neutralization takes care of most of the harmful constituents in the

effluent, radium and traces of manganese still remain. Radium is fixed by treatment with barium

chloride and the residual manganese by precipitation at pH 10 with lime.


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Fig. 1: Schematic process flow sheet followed in Jaduguda

and Turamdih uranium mills.[4]

Even after commencement of the commercial production of uranium from the Jaduguda uranium

mill, consistent R&D was being carried out in BARC as well as in the Control, Research and

Development Laboratory (CRDL) of UCIL to sustain the uranium leach recovery and also to take

care of the ore grade variations. It was only due to the consistent R&D efforts by BARC that the

sulphide minerals present in the Jaduguda ore could be advantageously recovered as mineral

concentrates. Jaduguda ore contains minor amounts of sulphide minerals comprising of

chalcopyrite, molybdenite, pyrite and pyrrhotite, millerite and pentlandite (essentially sulphides of

copper, molybdenum, iron and nickel). An attempt was made to recover these sulphide minerals in

the form of marketable concentrates of copper molybdenum and nickel. Based on laboratorystudies in BARC a by-products recovery plant (BRP) was set up which started production in 1974.

Molybdenite and chalcopyrite concentrates were produced and sold. However, this plant had to

close down after nearly 20 years of successful operation due to the dilution of sulphide minerals,

caused essentially by blending of ores from other satellite mines in the Jaduguda plant.


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The R&D efforts also led to augmentation of uranium supply by recovering uranium values from

the copper ores from the mines surrounding Jaduguda. The copper ores mined from the Surda,

Mosaboni and Rakha mines located in the vicinity and processed by the Hindustan CopperLimited (HCL), contain trace amounts of uranium (in the range 0.007 to 0.012% U3O8). Attempts

were made to recover these by processing the tailings from the copper concentrator plants using

simple gravity concentration techniques. These formed a cheap source for uranium and the

uranium recovery plants were being operated by UCIL to produce uranium concentrates, which

were again processed in Jaduguda mill. A lot of research has gone into improving the recovery of

uranium values from the copper plant tailings. These plants were operating till recently, but had to

close down because of the closure of the copper mines at these places. Efforts are on to open up

with the restart of mining activities in these copper mines by HCL.

A lot of research was carried out to improve the recovery of uranium from the copper ores. It was

found that the recovery was sub-optimal mainly because of the inefficiency of the conventional

shaking tables in recovering very fine and ultra fine uranium values and also the significant

uranium values associated with micaceous minerals. An integrated gravity and high intensity

magnetic separation process flow sheet was developed to address above the problems. While thegravity part included Bartles Mozley Separator (BMS), Cross Belt Concentrator (CBC) and small

diameter hydrocyclone assemblies, the magnetic part included Wet High Intensity Magnetic

Separator (WHIMS). A superconducting high gradient magnetic separator was developed to

effectively separate ultra fine uranium values and micaceous minerals (Fig. 2).

Fig. 2: Superconducting high gradient magnetic separator developed in BARC.

R&D on Narwapahar uranium ore

With the necessity for going for deeper mining in Jaduguda and also due to the depletion of ore in

the Jaduguda mines, the ore from the nearby mines like Narwapahar and Bhatin were also

processed in the Jaduguda mill. The Narwapahar mine is located at a distance of about 12 km from

Jaduguda and is already in production stage. The ore has lower grade than the Jaduguda ore and its


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leachability is also lower. Mineralogically also the ore is not similar to the Jaduguda ore. A

comparison of the mineralogy of the different uranium ores from the various mines of Singhbhum

is given in Table 1. An intensive R&D was called for to enhance the uranium leachability fromthis ore. The studies indicated that the nature of uranium mineralization in the Narwapahar could

be the main reason for its lower leachability. It was found that Narwapahar ore had a higher

content of micaceous minerals in the form of chlorite and biotite with significant uranium

distribution in them (Table 1). Estimation of the uranium distribution in the different mineral

constituents of Narwapahar ore revealed that significant uranium was found to occur as ultra-fine

inclusions within the mica platelets (The figures corresponding to the Methylene Iodide Lights

(MIL) in Table 2). Nearly 35% of the uranium values are distributed in 58% of the micaceous

minerals. Only part of this uranium gets solubilized during the leaching stage and the remaining

part was not probably accessible to the lixiviant sulphuric acid. On the other hand in Jaduguda ore,

the micaceous minerals constituted only about 22% with about 11% uranium distribution. Detailed

grinding and liberation studies were carried out to find out whether finer grinding will lead to

enhanced uranium liberation. It was observed that on fine grinding the liberation did not improve

significantly, the finely ground material posed problems in solid-liquid separation.

Table 1: Typical mineralogical composition of uranium ores from Singhbhum shear zone

MineralJadu-

guda

Narwa-

paharBhatin

Tura-

mdih

Quartz

Chlorite/Biotite

Magnetite

Other Opaques*

Apatite

Tourmaline

Other transparent minerals

68.0

22.0

3.0

1.5

3.0

2.5

36.0

52.7

4.9

0.7

4.7

0.8

0.2

48.2

37.0

3.5

3.5

1.8

6.0

67.0

26.0

3.0

1.7

2.0

0.3

% U3O8

(Chemical assay)0.065 0.047 0.051 0.046

*

Preponderantly indicates sulphide minerals.

Table 2: Distribution of uranium in various density fractions in Narwapahar ore

FractionSp.gr.

range

Weight

%

% U3O8

Distbn.

BRL 3.3 4.4 54.3

Efforts were made to separate out the feebly paramagnetic micaceous minerals in a Wet High

Intensity Magnetic Separator (WHIMS) from the plant tailings and leach out the magnetic fraction

containing uranium using drastic conditions. Studies were also carried out on a superconducting

high gradient magnetic separator, designed, developed and built by BARC, in tandem with


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WHIMS. The laboratory studies did indicate positive and marginal improvement in the uranium

recovery, though cost and benefit analysis was not very favourable for the marginal recovery

improvement. R&D studies are in progress in various ways such as use of ultrasonics and microwavetechnology to get better results.

R&D on Domiasiat uranium ore

The exploratory efforts put up by AMD in finding new uranium ore deposits have yielded a number

of workable deposits. One of the important of these deposits is in the State of Meghalaya with a

substantial resource position at a reasonably high grade of 0.1 % U3O8 at Domiasiat (Kyelleng-

Pyndengsohiong, Mawtahbah KPM Project) and Wahkyn. The mineralization is in a medium to

coarse grained sandstone of the upper Cretaceous and lower Mahadek formation at Meghalaya,

comprising of quartz, feldspar and coaly fragments cemented by clay and carbonaceous matter.

Microcrystalline pitchblende and secondary uranium minerals are associated with coaly fragments

and the clay-carbonaceous cementing matrix. Domiasiat Ore body is situated at a shallow depth of

within 45 M depth from the surface.

Detailed process investigation studies have been carried out on Domiasiat ore samples. Themineralogical analysis of two of the ore samples (high and low grade) received in BARC is givenin Table 3. Bulk of the uranium values (nearly 88%) is associated with carbonaceous matter(organic matter), with some of the pieces assaying as high as 40%. The presence of organic matterin the Domiasiat ore has been derived from the decay of plants and radioactivity is essentially dueto uranium in the form of pitchblende, coffinite and urano-organic compounds. The closeassociation of uranium with the organic matter in Domiasiat ore can be explained as follows:Mobile hexavalent uranium gets fixed at reducing environment provided by the decayingcarbonaceous organic matter. Part of the uranium gets reduced to tetravalent and is precipitated asuraninite. The carbonaceous matter, having a large surface area due to its porous nature adsorbs orexchanges the hexavalent uranium also on its surface without reduction. Probably because of thissignificant amount of uranium from certain blocks was found to solubilize in process water itself.This ore also provided another paradoxical situation in that while part of the uranium values wasfound to get solubilized in process water, the remaining fraction was not solubilized even withvery high acid dosage. Acid requirement upto 200250 Kg/tonne of sulphuric acid was foundnecessary for adequate solubilization, in contrast to 1620 Kg/tonne of acid in the case ofJaduguda ore. Probably the uranyl and U

4+ions get attached to the broken bonds in the

carbonaceous matter present in the ore and get fixed in the myriads of sites within the fine andultra fine pores of the carbonaceous matter. During leaching the reagent is unable to reach the

myriads of uranium sites, leading to lesser uranium leachabilities. Three alternate processes weredeveloped at three different laboratories which involved.

1. Acid pug-cure-leach process (Pugging of ore with 100 Kg/t of H2SO4, and curing at slightly

elevated temperature followed by leaching).

2. Two stage leach process (Leach with 25Kg/t H2SO4 in the first stage and 100 Kg/t in the

second stage) and

3. Leach-grind-float-leach process (Leaching of crushed ore-followed by grinding and flotation

of uranium bearing carbonaceous material and roast-leach of the float).

Extensive laboratory studies on this ore followed by selective large scale tests have indicated that

uranium from this ore can be techno-economically recovered. However, exploitation of this

attractive near-surface deposit is yet to start due to a number of factors, involving relative


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inaccessibility and infrastructural bottlenecks, heavy rain fall throughout the year and also other

socio political reasons. UCIL is now carrying on with the pre-project activities to open the mine

and process the ore at the earliest.

Table 3: Mineralogical composition of Domiasiat ores

% by wt.Mineral Phase

High grade Low grade

Quartz, feldspar and clayey material

Garnet, Zircon, monazite etc.,

Pyrite and marcasite

Galena and chalcopyrite

Rutile/ Anatase, goethite etc.

Bitumen and uranium phases

97.4

0.2

0.5

Tr.

0.2

1.7

98.3

0.2

0.5

Tr.

0.2

0.8

% U3O8 (by Chemical analysis) 0.265 0.113

R&D ON URANIUM ORES BY ALKALINE LEACHING ROUTE

As far as the uranium ore processing was restricted to acid leach route, the laboratory scale batch

studies were being carried out at the laboratories of BARC, AMD and UCIL. But once the number

of operating PHWRs increased, the demand for uranium also rose up significantly, leading to the idea

of opening up those mines not considered due to techno-economic reasons and also to intensify the

exploratory efforts to discover new and exploitable deposits. In this category, the Tummalapalle

uranium ore occurrence, discovered by in late eighties, but not considered for exploitation due to

its low grade and also due to its geological characteristics. However, the ever-increasing demand

for then uranium led to a revisit into the problem and exploitation of this low grade deposit was

taken up as a challenge and development of process technology was taken up in all earnestness

and seriousness. The efforts resulted in developing a novel and environment-friendly processtechnology and also in setting up a pilot plant for carrying out large scale semi-continuous studies

to generate design and scale-up parameters and also for technology demonstration.

TECHNOLOGY DEMONSTRATION PILOT PLANT (TDPP), JADUGUDA

With the growing demand for the uranium for our PHWR reactors, currently operating and under

construction, it is imperative that the new uranium mines discovered and proved by AMD are

opened up for exploitation. Since the technology used in the Jaduguda mill may not be applicable in all

these cases, the new processes were needed to be developed and this requires apart from in-depth

laboratory studies on process development, large scale tests to confirm the laboratory process and

generate process engineering and scale-up data for effective translation of the laboratory process

to a process technology. Realizing this need, a Departmental pilot plant, christened as Technology

Demonstration Pilot Plant (TDPP) was set up in UCIL premises at Jaduguda with the active

collaboration and participation of BARC, AMD, UCIL and NPCIL. It was planned to have all the

stages present in a generic uranium process flow sheet from ore-to-yellow cake. The UCIL

premise was chosen as the site for the TDPP since all the required infrastructural and other logistic

supports and tailings processing facilities were already readily available there.


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The TDPP has a multistage crushing plant with primary and secondary crushers and screens. The

crushing facility installed in the TDPP is schematically shown in Fig. 3. The crushing plant is

located just outside the process plant and it has its own dust collection system.

Fig. 3: Schematic view of the crushing plant at TDPP, Jaduguda.

The product of the crushing plant is the fine ore, which is stored within the process plant in the

Fine Ore Bin (FOB). The grinding circuit is a ball mill in closed circuit with a rake classifier. The

ground material is stored in ore pits in the wet conditions. For the large scale experiments, the

required ore feed sample is drawn from the ore pits. Since during the initial stages of setting up of

TDPP, process technology development studies were in progress and this ore required alkaline

pressure leaching for maximal uranium leachability. Hence the alkaline pressure leach set up was

planned initially. The post-grinding facilities installed at TDPP process plant includes facilities for

feed preparation, pressure leaching, waste heat recovery, solid-liquid separation, uranium

precipitation as Sodium Diuranate (SDU) and product filtration. The facilities have a batch

pressure reactor (BPR) and 3-compartment cigar type Continuous Pressure Leach Reactor (CLR).

The continuous leach reactor has a spiral heat exchanger to recover the waste heat from the exit

stream of the reactor. The heating of the slurry in both the reactors is done using saturated steam

from an electrode boiler. The batch reactor has a steam coil and the continuous reactor has a steam

jacket. The steam coil in the batch reactor is used for cooling of the slurry after the leaching is

completed. The slurry exits from the continuous reactor and partial depressurizing and cooling

occur in the Spiral Head Exchanger (SHE). The leach slurry is filtered in a Horizontal Belt Filter

(HBF), which has 3-stage counter current wash facility. The pilot plant includes reagent recovery

facilities also. The facilities are schematically presented in Fig. 4.

R&D ON TUMMALAPALLE URANIUM ORE

The strata-bound type uranium mineralization of the Kadapa basin was discovered by AMD

during the later half of 1980s at Tummaplapalle in Andhra Pradesh. A reasonably vast resourcewas estimated at Tummalapalle Rachakuntapalle deposits. Uranium is hosted by dolostone

rocks. This strata-bound mineralization extends over more than 60 kM along the SW margin of the

Kadapa basin. Due to the alkaline matrix of the host rock alkaline leaching technology is the

process option for economic exploitation.


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Fig. 4: Schematic view of ore-to-yellow cake facilities set up at TDPP

for alkaline pressure leach route).

The host rock in the Tummalapalle ore deposit is Phosphatic Siliceous Calcitic Dolostone (PSCD).It was very difficult to identify any discrete uranium phase or mineral in the ore, but ultrafine sized

brannerite and pitchblende have been indicated. The uranium content is confirmed by chemical

and mineralogical analysis. The average chemical assay of the ore sample was found to be 0.042%

U3O8. The uranium mineralization may be due to ultrafine pitchblende and brannerite with minor


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quantities of organo-uranium complexes and suspected coffinite. The uranium association was

found to be mainly with the lighter (


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Fig. 5: Comparison of leachabilities obtained under different process conditions.

Based on the laboratory studies, a tentative process flow sheet was developed, which was further

tested on large scale batch leaching mode and attempts were made to regenerate most of the

reagents used in leaching and uranium precipitation stages. The special features of this process

technology are counter current leaching and multi-stage counter current washing after filtration ofthe leach slurry and elimination of uranium purifications step. The process technology is a near

zero-waste liquor process. The tentative process flow sheet is given in Fig. 6. The ore is shortly to

be taken up for commercial production.

Fig. 6: Tentative schematic flow sheet for processing Tummalapalle ore.


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SCOPE FOR EXPLOITATION OF OTHER DEPOSITS

A careful study of the distribution of uranium deposits under different categories in the world vis-

a-vis that in India (Table 5) indicates that there is a good scope for finding new uranium deposits

in the categories of Unconformity-related, Quartz-Pebble-Conglomerates and in Breccia

Complex. The exploration strategy is based on the presumption that the uranium mineralization in

India cannot be different from that in the world scene. The efforts have indeed borne fruits in that

indications have been obtained in Kadapa basin in the State of Andhra Pradesh and in Bhima

basins in Karnataka. One of the other promising areas is Rohil- Ghateswar in Rajasthan. Although

India has got more than 3 decades of plant experience in acid leaching technology from Jaduguda

mill and is now perfecting alkaline leaching technology in the exploitation of Tummalapalle

deposit, R&D efforts are absolutely necessary before taking up any ore for exploitation. Realizing

this fact, DAE has set up a Technology Demonstration Pilot Plant (TDPP), Jaduguda for carrying

out large scale studies on the process flow sheet developed in the laboratory and also for

generating process engineering and scale-up parameters for plant design. These are absolutely

essential to avoid any process shocks and surprises in future. The various laboratories of the

different units of DAE, including AMD, BARC and UCIL are well equipped with the necessaryequipment and instrumental facilities and adequate expertise exists in the Department to tackle any

type of uranium ore in the country.

Table 5: Comparison of world and Indian uranium deposits

In World In India

Unconformity-related

Sandstone

QPC

Vein

Breccia complex

Others

27

21

10

8

18

16

7.7

16.4

53.7

22.2

Total 100 100.0

CONCLUSIONS

India has intensified all its efforts to increase the nuclear power component in the countrys

overall electricity generation by well oriented exploration for uranium deposits, increased R&D

efforts to develop techno-economic process flow sheets and successful exploitation of uranium

deposits discovered and proved. In the train of activities R&D for development of economic and

environment-friendly process flow sheets occupies a very significant place. The Department is

fully geared up for tackling any type of uranium ore in the country by excellent laboratory

facilities in its various units and a technology demonstration pilot plant at Jaduguda.

ACKNOWLEDGEMENTSThe authors would like to place on record their sincere thanks to Dr. S. Banerjee, Director, Bhabha

Atomic Research Centre for his keen interest and encouragement.


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REFERENCES

[1] Integrated Energy Policy: Report of the Expert Committee. Planning Commission

Document, Government of India, 2006, p. 182.

[2] Padmanabhan, N.P.H. and Suri, A.K., Challenges in augmenting the uranium supply

position in India, 2007, In Proceed. International Seminar on Mineral Processing

Technology (MPT-2007), Pub.: Allied Publishers, New Delhi, p. 1.

[3] Gupta, R., 2004, Uranium MiningThe Indian Scenario, 2004, Proceed. National

Workshop on Atomic Mineral Deposits: Their Utility and Impact, Osmania Geology Alumni

Association, Geology Department, Osmania University, Hyderabad, p. 38.

[4] Suri, A.K., Ghosh, S.K. and Padmanabhan, N.P.H., 2008, Proceedings of the DAE-BRNS

biennial symposium on Emerging Trends in Separation Science and Technology (SESTEC-

2008), New Delhi.

[5] Suri, A.K., Padmanabhan, N.P.H. and Ghosh, S.K., Processing technologies for exploitation

of low grade and secondary sources of uranium, Proceed. IAEA technical meeting on

Uranium Small Scale and Special Processing Technologies, Vienna, June 2007.

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EXTRACTION OF URANIUM INDIA