Market Survey on Copper - Indian Bureau of Mines

activities ranging from mining, beneficiation, smelting, refining and continuous
cast rod manufacturing.
A short write up in respect of ore processing and metal production is
given below:
i) Khetri Copper Complex, Rajasthan
Khetri Copper Complex of Hindustan Copper Limited (HCL), a
Government of India enterprise, was established in 1967. Khetri is located in
Jhunjhunu district of Rajasthan, about 190 km southwest of Delhi and 180 km
north of Jaipur. The complex houses concentrator, smelter and refinery.
Process Description
Crushing: ROM (-300 mm) skip hoisted from Khetri mines is conveyed
to an open conical stockpile. Similar sized material from Kolihan and
Chandmari mines is brought to worksite by aerial ropeway and delivered to a
second stockpile; while recycled slag from smelter is conveyed to the third
stockpile. The slag is processed separately.
Four Elliptex vibratory feeders from each stockpile draw off ore at
variable rates and deliver to a double deck scalping screen. The oversize from
both the decks is fed to standard cone crusher. The crushed material is sized on
a single deck screen into +25 mm and -25mm fractions.
The + 25 mm material is conveyed to two surgebins (used for both ore
and slag) from where it is delivered by feeders to two shorthead tertiary cone
crushers. Tertiary crushed product is screened on two single deck screens (25
mm apertures), the oversize being returned to the surgebins, undersize from the
various screens is conveyed to the fine ore bins ahead of grinding section. There
are two parallel grinding circuits for ore, each having rod mill in open circuit
and two ball mills in closed circuit with hydrocyclones. Cyclone overflow, from
all four batteries of cyclones is delivered to a single distributor feeding pulp to
the flotation section. Conventional flotation practice is followed. As described
earlier, it involves roughing, cleaning and scavenging.
In entire operation measures are taken to control pollution such as, no
water or slurry is allowed to go to the drains, catch pits have been constructed in
the plant area whereas the drain material is collected and sent back to the tailing
dam, water is reclaimed and recycled back to the operating plant.
The process control measures involve, electronic belt weigher to control
feed rate, onstream XRF analyser, auto control of flotation cell level, metal
detector/collector, auto lifting and leveling devices of rake in tailing thickener,
autosampler, a part of onstream analyzer systems, and collect samples at 15
minutes interval.
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