Geology of Meghahatuburu Iron Ore Mines
Meghahatuburu Iron Ore Deposit is located in the Bonai Iron Ore Range in the State of Bihar, India and lies between the latitudes 22°5̍46̎ and 22°5̍59̎ north and longitudes 85°16̍30̎ and 85°18̍39̎ east and is covered in the survey of India TopoSheet No. 73/F/8. This is one of the typical deposits of iron ore in this range and is being developed to meet the demand of the Bokaro Steel Plant along with the existing Kiriburu Iron Ore Project at the second phase of expansion. The deposit is located about 350 km by rail road from the Bokaro Steel Pland. It is situated at a distance of about 20 km from the Barajamda Railway Station on the Rajakharswan-Gua Section of the South Eastern Railway and is approachable by all-weather PWD road from Jamshedpur.
The deposit includes aggregatively ore reserves of about 121.8 million tonnes at an average grade of Fe-63.29%, SiO2-2.44% and Al2O3-2.65%. The amount of lateritic/limonitic ore and waste materials are about 10.76 and 15.42 million tonnes respectively. The maximum thickness of the deposit is 120 meters. It has a length of approximately 1.2 km in the north-east and south-west direction and width of about 600 meters across. The deposit is a hilly one with two distinct hillocks.
The deposit consists mainly of three ore types- Hard Laminated Ore, Soft Laminated Ore and Blue Dust. The Hard Laminated Ore occurs mainly at the top of the deposit and comprises only 4.5% of the aggregate reserves, this will be expected to yield larger proportion of lump ore. The Soft Laminated Ore constitutes the major portion (about 93%) of the reserves and the Blue Dust occurs in patches nearly uniformly throughout the deposit. The distribution of the waste in the deposit is not uniform and is more pronounced at the bottom portion of the deposit.
From an analysis of the bench wise reserves, it may be seen that the Fe percentage is the lowest at the top three benches, a higher Fe-grade persist for the next seven benches. Al2O3 decreases continuously from the top to the bottom benches whilst SiO2 percentage is maximum in the two benches at the bottom.
The entire output of Meghahatuburu Project, after beneficiation, is earmarked for the Bokaro Steel Plant.
Lease area falls in reserve forest, village forest, and protected forest. For land acquisition de-reservation proposal submitted to forest department for getting the diversion of the forest land. As per the guidelines of MoEF
1. List of documents to be submitted
a. Form B
b. Copy of all the forest clearances obtained from MoEF, New Delhi.
c. Copy of the Environment clearance obtained from MoEF, New Delhi for the entire lease area of 1936.06 Ha.
d. Undertaking for regeneration of safety zone.
e. Reclamation & rehabilitation plan.
f. Details of other leases pertaining to Kiriburu – Meghahatuburu Mines, SAIL.
g. Copy of the lease Deed.
h.Certificate from District Mining officer about non –availability of the same mineral in surrounding/nearby non- forest areas.
i. Copy of the notification vide order NO,C/F – 18(B)- 36/67- 2031. Rdt.17-07- 1967 for the denotified land.
2. List of Plans
a. Location map of lease no 1 in toposheet no 73 f/8(scale 1: 50,000)
b. Lease plan of Kiriburu ML –I (scale 4” = 1 mile)
c. Land use plan for both existing & proposed area (scale 1:10,000)
d. Proposed land use plan (scale 1:10,000)
e. Safety zone plan (scale 4” = 1 mile)
f. Reclamation plan of existing mines (scale 1: 5,000)
g. Reclamation plan of proposed south Block (scale 1:1,000)
h. Reclamation plan of proposed Central Block (scale 1:2,000)
Analysis and Evaluation of the Geological Data of the Deposit
The major and important application of geological data specially the assay grade value of the iron ores, lies in their application in preparation of the procedure for quality control during production as well as preparation of contingent plan for production rescheduling in case of equipment breakdown. For this purpose it is extremely necessary to have a isograde of iron percentage map available at bench level. If need arises isograde map for SiO2, Al2O3 as well as their ratio should be prepared for stricker quality control purpose. By superposing the four maps bad and poor grade patches may also be identified. The iron assay value, available as on the supplied bench slice plan, has been geostatistically treated to reveal additional information, amongst which the directional grade variability is the most important. This directional semi-variogram analysis and subsequent model fittings of the experimental semi-variograms.
For the purpose of the preparation of the Fe iso-grade map, iron assay values, the data as supplied on a 120 meter grid of the bench level, formed the starting base. Values in thinly adjacent as well as in between available drill points were obtained by applying the standard procedure of extrapolation by both moving term average as well as by inverse square distance methods. To check upon the variance of the extrapolated data, the procedure of Kolmogorov-Smirnov filtering technique was carried out in a few places and it was found that the infilling by the process of increase-square distance method not only produced results within the tolerable limit of accuracy but also by this method the variance was considerably reduced.
Thus with the data at 60 meter apart being available contour line at 1% interval of iron content was generated specifically for the purpose of producing an acceptable ore body configuration. In many cases contour patterns at a particular level was modified to have high correlation with the ore body configuration as indicated in the bench below and above that particular bench.
In general it may be concluded that the resultant iso-grade map exhibits some trend to indicate an alignment feature of the deposit and is in conformity with the field observations.
1) It is 904m level.
2) It is developed western side in the middle of deposit with bench face progressing towards north side. This bench has 1,125,134 tonnes of the ore.
3) The total length of the haul rod(R1) is 1690m maintaining the average gradient of six percent.
1) The second bench has 892m level.
2) It is developed from west side. It contain 3,271,800 tonnes of ore and 620690 cum of waste.
3) The length of the face in this bench is 260m and it lag behind the upper bench by 40m to 100m.
4) Length of haul rod is 1650m.
5) Haul rod is connected to the upper bench at a distance 60m and later from a common haul rod (R2).
1) It is 880m.
2) About 100,440 tonnes of the ore and 2,000 cum of waste material.
3) It lags behind second bench by 45m to 140m.
4) The haul rod R5 from this bench maintains level gradient upto a distance of 400m before it joins the haul rod R1.
5) Later, the single common haul rod for all the four benches is laid over a distance of 920m to the crusher point maintaining an average gradient of six percent.
1) It is 868m level.
2) It has separate haul rod R6 maintains a level gradient upto a distance of 440m before joining rod R5.
3) The total ore and waste material minded on this level amount to 1500 tonnes and 46,000 cum waste respectively.
Meghahatuburu towards Sustainable and Eco-Friendly Mining
SAIL is the leading steel ranking company in India. It is fully integrated Iron and Steelmaker producing basic and special steel for domestic construction, engineering, power, railways, automotive and defense industries and for sale in export market. SAIL is in area of six state of Maharashtra of the Central Public Sector Enterprises under the administrative control of the ministry of Steel Govt. of India. The present capacity is about 14.6million tonnes (MT) of tsteel per annum.
Raw Material Division (RMD) is the second largest mining outfit in the country. The mines of SAIL started their operations as captive sources of raw materials for its integrated steel plants. Major portion of the mining activities is managed by RMD. Other mines are the Bhilai group of mines, the mines of VLSI and the coal mines of IISCO. The RMD was formed in 1989 with the purpose of creating synergy of all the SAIL mines in the eastern sector, to rationalize supply of the basic raw materials to the steel plants so as the achieve self-sufficiency in the quality production of Iron ore. Presently RMD, with its headquarters at kolkata, manages 7 iron ore mines and 3 operating flux mines.
Waste Dump Management
Meghahatuburu has eight dumps over an area of 12 Ha. Six of them have been systematically and scientifically stabilized and rehabilitated by plantation. On the above waste dumps enormous plantations have been done. Two active dumps are also stabilized.
Water Dump Management
Overburden of the deposit mainly comprises laterite with the practically no soil cover. The OB/waste dumped into the lower most branches of the exhausted area of 4.02 hect. Of existing mine pit and it is proposed to backfill the area in 14 hec. Upto 2015.To prevent wash offs the top surface of the dump should have an in-wards slope. Plantations has been done on the stabilize dumps in 12 hect. Retaining wall has been constructed at a length of 1500m around the waste dump yards followed by garland drains and setting pits for arresting the wash offs. It has been proposed that Geotextile color Matting will be done along the slope of external waste dumps to avoid wash offs and landslides during rainy seasons.
Geological Aspects of the Study
Geological aspects of the Meghahatuburu deposit including detailed variogram analysis show that due to effects of secondary supergene enrichment processes which operated on the ore body during their formation and which may also have acted on the ores after formation, there exists a variability in the Central benches and at depth. Summary of findings may be concluded that mining along E-W direction of the iron ore deposit is less preferred because of its greater & poor structural continuity whereas the iron ore bodies provides better geological conditions along N-S direction specially for quality control purpose as it exhibits good continuity with the calculated range of influence.
Sampling and Quality Control
The following points are in the line of guidance purpose and are only of suggestive nature:-
1. In view of the average range ‘a’ in each bench being around 200 mt, 5 to 10 sample per 200mt of face may be collected either from blast holes or post blasting grab samples from the mine face.
2. In the ODP circuit if automatic sample cutter is available then it is a suggested sample be taken half an hour. The number of sample points should be such that each sub-process is covered.
3. Normally in view of the large number of sample need to be processed in a very short period mechanized volume and size reducing system line jaw crushers & ball mills, sample dividers etc are preferred.
4. To get a rapid yet accurate analysis of the principal radicals like Fe, SiO2 and Al2O3 XRF method of analysis of the ore is suggested. For the purpose of preparation of either glass-or borax-disks one of the most advanced technique is by use of “claisse-Fluxer BIS” sample preparation equipment.