Caterpillar offers a wide range of equipment and solutions for underground metal mining and coal mining in India. Kush Tandon, Commercial Manager, Underground Mining - India, Caterpillar Global Mining, elaborates on the underground mining methods, equipment and technologies.
What are the major underground mining operations in India? Which are the minerals involved in underground mining?
India hosts underground metal mines as well as underground coal mines. The geology of metallic mineral ore bodies differs greatly from the bedded seams of coal. As a result, the methods and machines to mine metal ores differ entirely from those used to mine coal underground.
Underground metal mining, also referred to as hard rock mining, involves drilling and blasting the ore with drill rigs and explosives loading machines specially designed for underground mining. After the ore is fragmented, underground mining loaders pick up the ore and carry it to a transfer point, or they load underground trucks, which haul the ore up a ramp and out of the mine or to a conveying system or mine hoist.
Coal is mined underground via room-and-pillar techniques using mobile equipment, or by longwall mining, which employs an integrated system to cut and convey the coal and support the rock above as the system moves.
Major machines for room-and-pillar coal mining include the continuous miner, which cuts coal from the seam using a rotary drum carrying carbide-tipped bits. The machine includes a gathering and conveying system that loads the coal into rubber-tyred coal transporters. The coal transporters move the coal to a feeder-breaker, which reduces oversize coal lumps and feeds the coal onto a belt conveyor for transporting out of the mine or to a hoisting system. Room-and-pillar coal mining also employs a roof bolter, which drills holes in the roof and installs roof bolts to stabilise the rock above the freshly mined area.
Major components of longwall system are the shearer, armoured face conveyor (chain conveyor), hydraulic roof supports (also known as shields), and beam stage loader, which feeds the mine's belt conveyor system. Longwalls are designed to mine large blocks of coal, usually 300-400 m wide and thousands of metres long. The system is designed to operate nearly continuously as the shearer traverses the width of the face. The cut coal falls onto the face conveyor, which moves the coal to the edge of the longwall panel and on to the stage loader.
Could you elaborate on your equipment for underground mining? Who are your major customers in India?
Caterpillar Underground Mining delivers equipment, technologies and collaborative support to help underground mining operations work productively and safely while minimising costs. With a worldwide team dedicated to underground mining, Caterpillar works with mining companies and Cat« dealers to adapt equipment and services to help meet the challenges at each mine.
For underground hard rock mining, Caterpillar designs, manufactures and supports a range of underground loaders and trucks. The core design and engineering team is dedicated solely to hard rock mining vehicles, and the machines are manufactured in a state-of-the-art factory constructed, especially for building these trucks and loaders.
The five models of Cat underground mining loaders (sometimes called LHDs) range in payload capacity from 6.8 to 20 tonnes. The low-profile loaders feature Cat diesel engines and drive train components proven in millions of hours of operation. Robust structures are designed to endure the challenging environment underground. Command for underground, part of Cat MineStar™ System enables remote and semi-autonomous operation of Cat underground loaders.
The Caterpillar line of four underground mining trucks ranges in payload from 22 to 60 tonnes. The Cat trucks, too, are purpose-built for the compact spaces and severe duty of underground mining. Cat LHDs are designed to match well with Cat underground trucks for optimum loading cycles.
Hindustan Zinc (HZL) is one of the world's largest integrated zinc-lead producers by volume and operates five underground mining complexes in the state of Rajasthan.
The HZL mines operate a large fleet of Cat underground loaders and trucks. Gainwell Commosales, the Cat dealer in north, east and northeastern India, has recently been commended by HZL for multiple achievements-including working with one of the mines to achieve more than 8,000 hours of operating time in 18 months with an R1300G loader, the smallest loader in the Cat line. The number of hours accumulated in the time period also illustrates the high utilisation of machines in mining applications.
In the south, central and western parts of India, Gmmco is the Cat dealer and supports a number of mining operations. Customers include Coal India, Singareni Collieries, Hindustan Copper, Neyveli Lignite, and iron ore mines and limestone producers.
For underground coal mining, Caterpillar offers complete longwall mining systems. Three different shearer models enable matching the machine to the seam height, and a wide range of armored face conveyor capacities and designs accommodate production requirements. Electrical power supply components and hydraulic power systems are also critical to longwall operations, and Caterpillar offers a complete line of those systems, too. Caterpillar also provides longwall control systems that enable remote and automated operation of the longwall. At this time, one complete Cat longwall system is operating in India. Caterpillar and Cat dealers also support legacy Cat room-and-pillar coal mining machines in India.
What are the new developments in equipment and technologies in underground mining? How are digital technologies evolving?
Caterpillar currently offers remote, semi-autonomous and autonomous operating systems for underground loaders. Using the system, Command for underground, a loader operator can be located in a safe area underground or on the surface. In semi-autonomous mode, the operator loads the bucket using remote control, and then the loader carries, dumps and returns without the operator intervention. The Cat R1700 loader, with 15 tonnes capacity, can be equipped with Auto Dig to enable fully autonomous operation via the addition of automated bucket loading.
Caterpillar is also offering machine tracking for underground hard rock mining vehicles, which enables production management, such as assignment and scheduling. The system also offers tracking for underground personnel-to enhance safety. In addition, the advent of wireless networks underground is facilitating machine health monitoring and decision making from remote locations.