Mining of Uranium in India- an overview

by- Satish Kumar Verma,

COO- mining, Sadbhav engineering ltd.

Uranium is..……. Omnipresent• The uranium is the only mineral which is omnipresent !• Only thing matters is the grade(quality) at which its

available in the host rock.• Even the desert of Sahara & Kutch and beaches of

Chennai have good amount of Uranium.

Uranium in India • The presence of uranium in

India was established well before independence by well know scientist – Dr. Bhabha.

• The Exploration and evaluation of minable deposits has started by AMD(Atomic mineral deptt).

• The Development galleries for the confirmation of deposits started my AMD & MECL jointly just after independence.

URANIUM CORPORATION OF INDIA LTD.

ISO 9001:2008, ISO 14001:2004 & IS 18001:2007

( A Govt of India undertaking)

Introduction:• The Uranium Corporation of India Ltd. (UCIL) was formed in 1967 with

the single mines at Jaduguda, Jharkhand. • UCIL is at the forefront of the Nuclear Power cycle fulfilling the

requirement of Uranium for the Pressurised Heavy Water Reactors, UCIL plays a very significant role in India’s nuclear power generation programme.

Intro……. UCIL • The uranium exploration and prospecting of Uranium

deposits was continued by AMD and after finalization of project by the central government a small mines ‘Bhatin’ was started.

• Due to increased demands of the uranium in the nation, Turamdih and Narwapahar projects were started after consultation with the AMD, during the decades of 1980- 90.

• The Banduhurang Opencast mines has added a new feather on the cap of UCIL having single opencast mines of uranium in India.

• The Bagjata and Mohuldih projects in the Jharkhand started in 2007.

• Tumarpalli and Gogi project in Andhara Pradesh were started in the period of 2006-07.

UCIL: TODAY

Jharkhand:Operating mines at Jaduguda, Bhatin, Narwapahar, Turamdih, Bagjata, Banduhurang; Mohuldih; Plants at Jaduguda and Turamdih;

Andhra PradeshMine and plant construction at Tummalapalle; Plan for construction of mine and plant at Lambapur

KarnatakaPlan for mine and plant construction at Gogi

MeghalayaPlan for mine and plant construction at KP M

Necessity of Uranium mining• Dr. Homi J. Bhabha:

• Founder and prime architect of the Indian Atomic Energy Programme

“ FOR THE FULL INDUSTRIALISATION OF UNDERDEVELOPED AREAS, FOR THE CONTINUATION OF OUR CIVILISATION AND ITS FUTURE DEVELOPMENT, ATOMIC ENERGY IS NOT MERELY AN AID, IT IS AN ABSOLUTE NECESSITY.”

HOMI J. BHABHA

Evolution & deployment of different Equipment in UCIL’s mines:

• The Jaduguda and Bhatin mines were started by pneumatic drills and Loaders and track mounted machines with small tub and diesel locomotives and continued with some modifications on these machines as -

• Introduction of GCs, EIMCO 824 Loader, Teledyne Twin boom drills (fixed at particular angles to drill upper holes ) .

Evolution & deployment of different Equipment in UCIL’s mines……

• Later on Electro- hydraulic drills and diesel operated LHDs and LPDTs were introduced for enhancement of the production and OMS.

• Electrical LHDs were also added to take proper care of the mine environment.

• But due to old system of access to the mines, depth and age of the mines, diesel LHD & LPDTs could not be continued in Jaduguda mines.

• Narwapahar, Turamdih and new projects are fully equipped with Diesel vehicles including passenger carriers & service trucks, as the main opening of mines is through Decline.

• We can reach to the working face directly from surface comfortably by passenger carriers.

• It give fast return in terms of production with the adaptation of diesel equipments.

Evolution & deployment of different Equipment in Ur. mines:

Adding up new projects• The UCIL has opened several new projects in

the last decade to meet the demand of the nuclear fuel and some more projects are in the process.

• The production capacity of the existing mines has been increasing by adapting some new modern machines and mining method

depending upon the various controlling parameters of the mines : -• Deepening of Jaduguda mines: 1st phase – upto 640 mts, 2nd phase – With a staple

shaft from 555 mt to 905 mt.- presently productioncomes from levels 620 mt and below with Jumbo drills.

New projects of UCIL ……….. Narwapahar mines: A large u/g

mechanized mines, capacity enhanced from 500 to 1000 and then up to 1400 TPD, in phased manner. Production by Diesel equipments as LHD, LPDT and Jumbo drill, Scissor lift, Lube trucks, passenger carriers etc.

Mining method- initially by step mining then following Cut & fill.

Turamdih mines:

Supporting system at Turamdih mines is modernized by introducing a “Boltec “ rock bolting machine which drills a hole, insert the cartridges and put a R. Bolt into it.

Commissioned in 2003 and capacity enhanced from 550 to 750 and then upto 1000 TPD, in phased manner. Production by Diesel equipment same as Narwa mines and with BOLTEC , rock -bolting machine.

Banduhurang mines: First open cast mines of UCIL

commissioned in 2009-production capacity 2400 TPD - enhanced up to 3500 TPD. - Tipper – Excavatorcombination used for production. Pit top crusher has been

commissioned.

Bagjata mines: Commissioned in 2009, capacity of

500 TPD. Entry through Decline & Vertical shaft. The shaft is in equipping stage.

Mohuldih mines: Opened up in 2007 and commissioned in April’ 2012, capacity 500 TPD.

- It is 06 km west of Turamdih project in Gamharia block of Saraikela – Kharsuwan district in Jharkhand

- Adapted forepoling system of support in Decline in bad rock condition and development in hard rock in progress.

- Second level development going on with trackless mining system.

- Main hoisting Shaft and Ventilation shaft sinking has been started.

- -

New projects of UCIL ………..

Mohulidh mines……..

Tumarpalle mines in AP Opened up in 2007 and commissioned in April’ 2012, capacity 3000 TPD thru u/g. -03 numbers of declines are running parallel to each other in low width Ore body.- The mining method is cut & fill trackless mining with diesel Equipment.

Delineation of Uranium ore body• The presence of Uranium cannot be felt thru naked eye.• It emits Alpha, beta & Gamma rays, which are used to ascertain the grade of uranium ore body

at a particular location.• Gamma ray emission is detected/counted in GM (Geiger – Mueller ) counter and Scintillation

detectors for computing the grade/quality.• Nuclear radiation is not easy to quantify properly. Radiation detection is always a multi-step,

highly indirect process. For example, in a scintillation detector, incident radiation excites a florescence material that de-excites by emitting photons of light. The light is focused onto the photocathode of a photomultiplier tube that triggers an electron avalanche. The electron shower produces an electrical pulse that activates a meter read by the operator.

• bore hole logging with GM tubes is done for exploration holes and scintillation counters used in delineation of orebody in mines.

• The boundaries are marked by paint on the rock as per the readings given by such instruments.

Adaptation of modern mining methods:

Jaduguda mines was started with Open stoping and later on different mining methods were adapted by UCIL in different phases depending on the influencing factors such as geological parameters and machine availability etc , such as : -

1. Shrinkage stoping2. Cut-and-fill method- mostly in practice.3. Step mining4. Open cast mining at Banduhurang mines5. Now sub-level stoping is to be adopted in Turamdih

mines, soon.

Shrinkage stoping

• This was started in Jaduguda mines while ‘open-stoping method’ was being practiced.

• It was initially started above ground level stopes and was subsequently used upto 230m below ground level selectively.

• Shrinkage was chosen in steep dip and narrow width (between 2m to 8m) areas. A tramming level was developed in ore and maintained throughout the life of the stope.

• A stope drive (2.40 m x 2.20 m) was made about 5 m above this main tramming level following the footwall contact of the ore body. • Chute raises were made at 10m interval and were bailed (sloped)to facilitate flow of ore.

Cut-and-fill method:• Due to easy availability of fill material from the processing plant

this method is proved to be successful and later on became a standard practice in U/G mines of UCIL with some modifications as ramp mining, room & pillar and Step mining.

• Selectivity of extraction and adoptability to wide fluctuations in width and dip of the ore body made this a favorable method of mining. • Disposal of mill tailings in U/Gvoids is an added advantage as it reduces the quantity of material disposed to tailing dam bringing down waste management costs.

• The Horizontal Cut and Fill (HCF) is a method to excavate one slice of ore and filling back the same by waste rock, mill tailings etc.

• This fill forms the platform for men and machinery to work on to excavate the next slice.

• A wide variety of equipment have been used, such as:• Scrappers• Track loaders• Pneumatic loaders as “Cavo” or “Hopper “ loaders)• Diesel Load-Haul-Dump (LHD)• and LPDT and Electric LHD

Cut-and-fill method:

Mining method in Banduhurang openpit- The deposit contains a moderately large reserve with very low grade.- It is now a conventional opencast mine using excavator-dumper combination

maintaining ore benches of 6m height, OB/waste benches of 6m/12m height while sustaining ROM grade and stripping parameters.

- Considering the strategic nature of mineral and low content of uranium, computerized ore body modeling and mine planning was carried out using SURPAC software.

- Open-pit mining method was chosen as the most favorable option and the pit limits were optimized using WHITTLE software. Layout of the mine was finalized with all finer details.

Radioactivity and Radiation

Natural Background Radiation Cosmic – from the sun and outer space – 0.4 mSv.yr-1. Terrestrial – from the Earth’s crust - 0.5 mSv.yr-1. Radon – from decay of U/Ra - 1.2 mSv.yr-1. Internal - sources in the body (e.g.40 K) – 0.3 mSv.yr-1. Total dose from natural sources - 2.4 mSv.yr-1.

- Radiation is part of our environment. - The food we consume also gives us some radiations. The average

dose that a person receives from background radiation in nature amounts to 1 to 2 mSv per year.

- In some areas of high natural background radiations such as the monazite rich thorium bearing mineral sands of kerala coastal tracts, radiation levels can reach upto 20 mSv per year.

- Radon gas emanated from building materials containing U and Th in trace quantities inside homes can add 1 to 3 mSv per year.

Radiation monitoring • At UCIL, monitoring is done on both external and internal radiation levels

that the mine and other workers receive . It has been found that the radiation doses received by individual workers had ranged from about 1 to 10 mSv/yr, which is far below the limit prescribed by ICRP (50 mSv/yr) and significantly below the annual average dose of 20-mSv set by AERB.

•

Monitoring External Radiation Monitoring

Survey meter TLD Surface and personal Contamination

Internal Radiation Monitoring Radon Monitoring and Dosimetry using Solid State Nuclear Track Detector. Air Activity Measurement. Lung Burden. Radon / Thoron in Breath. Bioassay.

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