Working in zinc

Rajasthan, India. Many sounds blend together at the Rampura Agucha mine, the world’s largest zinc operation and one of the lowest-cost producers of the metal globally. A busy fleet of passing mobile equipment drowns out miners’ voices and ringing mobile phones.

It’s hot outside the decline – very hot. The machines run virtually nonstop even as temperatures top 45 degrees Celsius, while workers are scheduled around the clock in three eight-hour shifts.

Here, near Jaipur in north-western India, Hindustan Zinc Limited (HZL) is running the largest zinc operation in the world. The Rampura Agucha mine has been an open pit operation since mining began more than 20 years ago, but the company is now also going underground to extract ore with the development of a  950-metre hoisting shaft.

Sandvik fleet at Rampura Agucha

• Six Sandvik LH517 LHDs
• Six Sandvik EJC533 underground trucks
• Two Sandvik DD320 twin boom jumbo drill rigs
• One Sandvik DD321 twin boom jumbo drill rig
• One Sandvik DS421 cable bolter
• One Sandvik DP1524 surface drill

A fleet of Sandvik equipment simplifies the task of advancing deeper and deeper. The underground equipment includes jumbo drills, loaders, trucks and a cable bolter.

Sandvik DS421 cable bolter is used specifically for solving geotechnical issues underground, providing reinforcement and support for the wall, roof and floor of the mine.

“We recently commissioned the bolter, and we’re getting a lot of benefits out of it,” says Abhay Kumar Nalwaya, associate vice president, underground mines, Rampura Agucha, HZL.

“This mine has been having some ground-condition challenges, so we’re using the bolter to solve that problem. The installation of the bolter has completely changed our mine strategy. We’re saving a lot of time, so we are very happy with this machine.”

The mining jumbos drill holes for blasting to remove rock in the cave, which is then extracted by Sandvik LHDs working in tandem with Sandvik underground trucks.

“The Sandvik drills are giving very satisfactory results,” Nalwaya says. “Every day we get two or three blasts using this equipment.” He says he is very satisfied overall with the performance of the various Sandvik machines. “The most impressive thing is that we don’t have long downtimes, performance is high, and we’re working around the clock with these machines.”

Rampura Agucha commenced operations as an open pit mine in 1991, but to meet market demand HZL opted to also go underground.

“For the past 23 years we have been mining zinc at Rampura Agucha,” says L.S. Shekhawat, vice president and unit head, Rampura Agucha mines, HZL. “Initially it was an open pit mine, but now both operations are running parallel – open pit as well as underground.”

The company’s choice of equipment came down to productivity and efficiency. “Most of our underground equipment is from Sandvik,” Shekhawat says. “We also have a Sandvik drill rig in the open pit. In terms of productivity, the equipment from Sandvik is absolutely the best. Looking at the productivity and overall efficiency, we have chosen these machines for our operation.”

Shekhawat points to the equipment’s versatility as another important factor in the strenuous environment deep underground. There’s no escaping the heat – especially 950 metres below ground.

“The machines are very robust, and the operators are confident running them. The cabins are ergonomically designed, so you feel very comfortable in any environment. Here in Agucha, where the above-ground temperature exceeds 45 degrees Celsius, it’s comfortable to be inside the air-conditioned cabin,” he says.

About Rampura Agucha

Owned by Hindustan Zinc Limited (HZL), Rampura Agucha is the world’s largest zinc mine. Located in the state of Rajasthan in India, the mine is highly mechanized, using a variety of mining methods that include drilling, blasting, loading and hauling. The mine produces zinc concentrate and lead concentrate, which are transferred to HZL’s Chanderiya Smelter Complex, the world’s largest lead-zinc smelter complex. It refines lead-zinc ore and produces zinc, lead, cadmium and other metals.

Rampura Agucha is a thriving mine. Its predominant ore, which has a unique lens-shaped characteristic, consists of stratiform, sediment-hosted, high-grade zinc and lead deposits. The mine’s ore reserves and resources stand at 109.8 million tonnes.

The mine has developed from an initial capacity of 1 million tonnes in 1991 to today’s 6 million tonnes a year, and the Sandvik fleet has played a major role in the increase.

The open pit operation currently accounts for some 5 million tonnes of the total annual production, and a Sandvik DP1524 drill has worked in the pit for about a year.

Rajeev Shrimali, associate general mine manager, Rampura Agucha mines, HZL, says there was some doubt internally as to whether DP1524 could handle the type of drilling needed at Rampura Agucha. But its performance has exceeded expectations, with more than 18,000 metres of drilling per month, which is a landmark achievement by any single drill at the Rampura Agucha mine.

“Before putting this equipment into operation, we were worried whether or not it would get the required results,” Shrimali says. “But after deployment, the equipment availability and performance has been much better than expected. Our mine has had a sixfold increase in ore treatment, and for that kind of expansion we’ve needed a lot of improvements and productivity-driven equipment, such as Sandvik DP1524.”

Environment, health and safety considerations are always in focus at a mining operation, including engine emissions. HZL chose Sandvik equipment in part for the machines’ fuel-saving features.

“As for the environmental aspect, there are always many challenges,” says John Palmer, HZL general engineering manager, Rampura Agucha mines. “The Sandvik machines have the benefit of the engine exhaust that meets world emission standards. The lower emissions from the machines obviously support us as regards our underground ventilation.”

In the surface operation, the fuel-saving features of Sandvik DP1524 are helping to reduce overall mine emissions. Apart from the fuel efficiency, Shrimali also emphasizes the benefits of wet drilling when it comes to reducing dust emissions, both for workers and the environment.

“The Sandvik drill’s built-in water-injection system is very efficient and prohibits dust shedding during drilling,” he says. “While drilling, we’re also saving fuel in terms of metres. So environmentally it’s very eco-friendly.”

When mining operations started at Rampura Agucha, HZL was struggling to be able to obtain machines with attractive safety features. Today it has found sustainable solutions through the robust safety-oriented machines from Sandvik.

“At Rampura Agucha Mines, we’re proud to say that safety is our first priority,” Shrimali says. “Sandvik DP1524 drill rig is robust and has good safety features, such as the ROPS-
compliant cabin. Sandvik is also following all safety compliances, and in some cases even exceeds them.

“The service support is excellent, particularly for this type of equipment,” Shrimali says.

Preventive scheduled maintenance ensures optimal performance and upkeep of the machines.

“We have a service team of nine engineers, and all of them are trained in our academy,” says Kartikey Panwar, Sandvik senior operations manager. “They’re working very hard. All credit goes to them for achieving this kind of availability and reliability.”

A dedicated Sandvik team is on call 24/7/365 to maintain the machines and keep the fleet running. As a result, the equipment is available more than 85 percent of the time.

Nalwaya is very satisfied with the high service level for the underground equipment. “We’re getting regular support from Sandvik, and we’re satisfied with how the equipment performs,” he says. “Whatever issue we might have, Sandvik does everything to resolve it, and whenever we require it they’re available on site.”

Productivity in focus

Rampura Agucha has been a surface operation since mining started in 1991. To meet demand in the zinc market, the mine has developed an underground operation as well. This is where Sandvik entered the picture, as the new underground development required a range of different machines to carry out specific tasks within the areas of drilling, bolting, loading and hauling.

Drawing on its underground expertise, Sandvik has supplied a fleet to meet requests from Hindustan Zinc Limited. However, Sandvik has also demonstrated its surface mining strength. A recent addition to the Sandvik fleet at Rampura Agucha is a Sandvik DP1524 surface drill, which is delivering more than 18,000 metres per month in the open pit mine. DP1524 is a customized model from the former series Sandvik DP1500.

The whole Rampura Agucha fleet is designed with productivity and efficiency in focus.