Odissa and Konark have always attracted me. The chance to see them both was too much to pass up. It is also one of the first states to respond to the Right to Education Act and publish state rules. I had planned to visit school in the rural area, both government and private, which would enable me to understand the ground realities of RtE more clearly. Unfortunately, nature flooded out my plans. The schools were closed and teachers were off on ancillary tasks, in this instance providing flood relief to their students and their families.
However, there is always something new to learn. And I had the best guide possible in my uncle Mr. K.S.Ramachandran, with his long stint in Odissa. He had arranged for me to visit the iron ore mine and manganese smelting plant in Joda. He also has a wealth of information about the mines and minerals, which he has willingly shared. Look for the pictures on my Facebook.
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JODA IRON ORE MINE OF TATA IRON AND STEEL COMPANY
By
K. S. Ramachandran
Orissa Mining Corporation (1957-1964)
Joint secretary, Ministry of Mines and Metals (1969-1971)
Chairman, Mineral Development (1979-1981)
Chairman and Managing Director, National Aluminium Company, (1981-1983)
Tata iron and Steel Company (TISCO) was set up in Bihar State at Jamshedpur in the early part of the 20th century. It is now in the jurisdiction of the Jharkhand state. Originally, the plant drew it its iron ore input from the Mayurbhanj district of Orissa. But after independence, when TISCO began expanding it steel production, it had to open new mines in Karnjhar district of Orissa. Joda East was thus opened up in that district in 1957. Iron ore despatches began in 1959 by which time the rail link had been extended from Barajamda Railway station to Banspani, which is about 3 miles from Joda East mine. Banspani railway station has been an iron ore outlet and has been serving an ever-growing mineral traffic since then.
Size Specifications
Originally, the steel plants of India were able to accept only iron ore of the size of 10 mm or more and these were described as lumpy or direct ore. A few years after 1960, they began to use the sizes between 0.15 and 10 mm after they were agglomerated or ‘sintered’ together, by the use of binders. These are called sinters. Recently, they have begun to accept sizes even smaller than 0.15 mm. These materials are ground down to a fine mesh and pellets are made with the help of strong binding agents and fired to harden them initially, before being fed into the blast furnace.
Total Resources / Minimisation of Wastage of Minerals
Joda East mine has an iron ore deposit spread over 6 square kilometres and contains one of the richest deposits in the region. It was originally provided with an ‘ore dressing plant’ capable of delivering 4.2 million tonnes/year (mty) of high grade lumpy ore containing 63-65% iron. A few years after this ‘direct ore’ supply had started, TISCO had set up a sinter plant and so the sinter feed also began to be despatched from Banspani, thereby minimising the wastage of mined material. Still, substantial heaps of usable materials, which were less than 0.15 mm in size, had to be left at the mine end so far.
Production Planning
Till recently, the steel plant capacity was 5 mty for which the iron ore feedstock of 8 mty was required. (one tonne of steel requires 1.6 tonnes of iron ore ) It was assembled from direct ore, sintered ore and some marginal purchase of ore from other mine-owners.
In the near future, maybe within a year, the steel plant is being expanded to produce 10 mty. The iron ore supply has accordingly to be raised to 16 mty. The Joda East mine is therefore being expanded to meet this demand. A new additional ore dressing plant with a capacity of 6 mty is under construction at Joda, through a construction contract awarded to Larsen and Toubro. When this becomes operational, then the total supply of direct (lumpy) ore and sinter feed ore will amount to 10 mty. This would leave a gap of 6 mty. For fulfilling this requirement, a new pellet plant of 6 mty is being built at Jamshedpur. A new washing plant is also being added at the mine end to wash and beneficiate (i.e, upgrade) the ultrafine particles, (less than 0.15 mm size) which had so far been thrown away as rejects. The input for the washing plant would be drawn both from ultrafines, being currently generated as well as from all the old dumps. The beneficiated ultrafines will be taken for being agglomerated at the new pellet plant at Jamshedpur.
It is now realized that, in the future, from considerations of conservation of minerals, even low grade iron ore (containing 45 – 58% iron) - which is not even reckoned as ore of iron nowadays -- should be upgraded and made useable in Iron and steel making. TISCO is now conducting research for this purpose. In limited quantities, even the parent rock, Banded Haematite Quartz (BHQ), which contains barely 35% iron, can be used. TISCO plans to use it in carefully controlled doses. The silicon content in the quartzite part of the BHQ serves to balance high alumina iron ores and improves the chemistry of the total charge into the blast furnace.
Mine Operation
At Joda East, the mine benches are of 10 metres height. Blast holes are drilled at intervals of 4 metres and spacing 3 metres between two rows of holes. Everyday’s iron ore requirement is about 30,000 tonnes (roughly 10,000 cubic metres, as 1 cu.m. of ore weighs 5onnes). This will be yielded, if a 100 metre face length is blasted off to a width of 10 metres, the bench height being 10metres. Normally, blasting is done once in 3 days and the output of iron ore for three days’ requirement is blasted on each occasion. In this manner, blasting is done only on 10-12 days per month. This minimises the risk to men and materials, by reducing the number of occasions, when the mining area and the 500 metres around it has to be cleared of men and machinery for conducting the blasting.
The explosive used is ammonium nitrate. It becomes explosive only when it is mixed with certain chemicals. The actual mixing is done only in the borehole itself. The ingredients are individually non-explosive, till they are mixed. Once the mixture is made inside the blasthole, it is detonated from a safe distance. This modern procedure minimises chances of accidents and injuries.
The blasting patterns and explosive charges are carefully calculated and designed to produce rock pieces of maximum 1 metre size along any axis. These rocks are picked up by 5.9 cubic metre shovels. In each pass, a shovel can pick up 15 tonnes of ore. The shovels fill up 50 tonner quarry trucks in three passes. The mine also has some 100 tonner trucks which need 6 to 7 passes of the shovel to fill up. These trucks carry the ore rocks to the crushing plant and back dump the ore into the hopper of the primary crusher there. There are also a few 10 cubic metre frontend-loaders which occasionally substitute for the shovel loaders.
Modern Management System at Mineface
The mine has a very modern control system. Employing this, a supervising engineer could watch the performance of every individual shovel or other machines in real time on the computer screens in his control room. He can even direct which shovel will dig where, in order to maintain the uniformity of the product mix. When drill holes are made, samples are drawn and these are analysed in the lab. The physical and chemical specifications of each section are recorded and a matrix of such data is prepared in advance. The supervising engineer uses this matrix to control the quality of the product in real time. The position of each piece of machinery is indicated by a GPS system. By controlling the number of passes in each section, he is able to achieve a reasonably homogeneous output, not only in respect of the iron content but even the average silica, alumina, etc.
Environmental Concerns
On the periphery of the mining area, fairly wide berms have been laid out to contain the dust pollution. Fruit trees and decorative trees have been planted on them, both for their screening ability and for aesthetic purposes. On roads used by quarry trucks, sprinkler vehicles regularly sprinkle water on dusty days to avoid atmospheric dust pollution.
Ore Dressing Plant
At the ore dressing plant, the large rocks brought from the mineface are subjected to primary crushing. There is a rotary crusher which reduces the size of the ore to an average of 20 mm. After crushing, the material passes over a set of vibratory screens. These separate it into
a) Larger than 40 mm size which goes for secondary crushing.
b) 10 to 40 mm size which constitutes direct ore and goes to the Rapid Loading System (RLS) for direct shipment to Jamshedpur.
c) The fines is size between 0.15 mm to 10 mm are sent to a washing plant where they are washed to remove the superficial dirt. The washed material of this size range is described as “sinter feed”. It is despatched to the sinter plant.
d) The ultrafines (smaller than 0.15 mm) are treated in a hydrocyclone to separate the heavier iron ore particles from all the other gangue (waste) materials. The washed ultrafines go to the pellet plant.
Rapid Loading System at Railhead
A Rapid Loading System (RLS) has been set up at the railway siding of the company at Banspani railway station. It can load a full rake ( i.e. a freight train with 55 wagons of 58 tonnes capacity each) in 90 minutes. The wagons move slowly under the outlets of the RLS and the hoppers discharge through bottom openings into the wagons. A weight-feeder measures the discharged material as flows out and ensures that each wagon receives exactly 58 tonnes. This system minimizes the loading time, so as to enable the RLS to receive and load the maximum number of rakes per day. 9 or 10 whole rakes have to be despatched every day.
Conservation of Water
TISCO has set up a rain harvesting system, so that it could draw its water for the washing plant etc. mostly from its own water tank, thereby minimizing the water drawal from the local river. In this way, the lower riparian rights of downstream villagers are affected to a marginal extent only. Even the use of the water in the washing plant is economised in the best possible way by recirculation, settling tanks, etc.
Personnel Management System
TISCO has set up a management system which keeps a daily watch over the performance of each member of its personnel, under a large number of prescribed heads of activity. This affords every employee an opportunity to make up for inadequate achievement on any day or days, by exerting a little extra in the subsequent periods.
Social Consciousness
The company has also been a leader in social consciousness. An excellent hospital has been built up at Joda. There are several schools, a good residential colony, roads, water supply, etc. During our visit, there was an unprecedented heavy flood in the valley. The company offered substantial relief to flood-affected population.
