Hindustan Zinc: aiming for zero waste and maximum metal recovery
Hindustan Zinc is India’s only zinc producer and among the world’s top three zinc producers today. A subsidiary of Vedanta Resources, the company’s flagship operation, Rampura Agucha (Agucha) in Rajasthan, is the world’s largest mine for industrial metal. Allied to this, and strategic to the company’s growth, is the Sindesar Khurd (SK) mine offering a rich source of silver along with zinc and lead. Hindustan Zinc also runs three large smelting operations at Chanderiya, Dariba and Debari in north west India and 10 milling facilities across the country.
“How do we drive efficiency to support future growth across our operations?” asks Barun Gorain, Chief Technology & Innovation Officer at Hindustan Zinc, Vedanta Resources. “The whole point of our digital transformation is to build a foundation to prepare ourselves for the next phase of growth to support key outcomes of enhanced safety, improved productivity and reduced costs with true technology innovation.”
Gorain points out that few mining companies work in this way: “We take a very holistic view of this digital innovation with a portfolio focused on three areas to build that foundation. Critically, the first step is to integrate all of our operating data into one platform so it can enable the digital enterprise with all of the financial, commercial and HR systems.
“Secondly, with all the data on a single platform, we have begun a deeper analytics drive where we're looking not just at predictive and prescriptive controls, but also at developing business operation models for each and every part of a unit operation so that we can go beyond data analysis with a system based approach and official automation.
“This leads us into the third area. Digital alone is not going to help us so we must support our subject matter expertise. Many companies across the globe go digital but without strengthening their core know-how, which for us is mining, milling and smelting. The idea is to leverage digital, which is just the enabler to help us in optimising all of our individual operations. Now this approach is actually quite deep, compared to most companies, and this is where we see the benefits.”
In embracing Mining 4.0 Gorain’s team is using the OSI-PI system to bring all operating data - mining, milling, smelting and power plant - into one platform which will eventually be integrated with SAP. “We are looking to digitally integrate 1,500 people, over 200 pieces of equipment and several different outsourced business partners at our flagship SK and Agucha mines. It allows us to do real-time asset tracking, people tracking, asset management, short interval controls, automated scheduling & task management management,” he says. “We are doing this at a scale not seen before in any underground mining scenario, it’s a game changer.”
To change the game, Vedanta has recently inaugurated their Hindustan Zinc Collaboration Centre based at the company’s head office in partnership with OSIsoft and ABB to improve efficiency, safety and sustainability while enhancing value across Hindustan Zinc’s operations. “The unique thing here is that we're connecting all our operating people with OEMs, subject matter expertise and our data scientists,” explains Gorain. “OSIsoft and ABB are helping us to connect our operating data across all of our mines, mills, smelters and power plants. It’s a crucial initiative because, along with insights, we’ll be able to predict things in real-time and collaborate in a way that allows us to maximise the benefit that digital solutions from SMEs can have in helping us to optimise our operations. ABB, as one of the world's top experts in control innovation, is supporting us on this quest.”
Looking long-term, the company vision is moving towards converting all of its underground mining operations from batch to continuous with the support of next generation technologies, including underground hydraulic ored pumping solutions to enable mining with minimal or no tailings or waste. “From an extraction or recovery point of view, we’re looking at completely digitised equipment to aid the recovery of minor, major and precious metals,” adds Gorain. “In parallel, greater efficiency will come from fine tuning via digital means.”
Gorain’s team is targeting benefits on the mining side to improve efficiency by 15% which translates to 74,000 tons of extra metal, by 2021 - a huge gain. “Meanwhile, on the milling side we're looking at recovery improvement from 81% up to 92%,” he adds. “Silver recovery is forecasted to rise from 57% to 70% leading to an additional 70,000 tons of lead-zinc metals.” Gorain stresses that enhancing safety is a key aspect and one of the major reasons why SK mine is considered one of the most digitally advanced mines in the world. “With safety as a top priority, continuous mining, automation, digitisation, less man-machine interaction, remote monitoring and real-time visualisation of people will be a tremendous leap forward which will also lower the cost of production.”
Underground wireless communications are vital to be able to integrate new solutions. “It is the foundation, along with the sensor technology, on which everything else is built,” confirms Gorain. “To achieve this, we’ve partnered with Cisco at the SK mine and with Israeli company Eurotech at the Agucha mine. The whole idea is that networking is something that doesn't really finish anytime soon, we have to lay out the cables and the network on a daily basis. As we go deeper underground, the challenges keep evolving, so these partners make sure we have the best of the best with mobile networking and LTE to access all of our data in real time.”
Sandvik has been instrumental at the SK mine, where it provides Hindustan Zinc with around 90% of its equipment. “The first phase of this digitisation through our collaboration with Sandvik has now been completed focusing on driving efficiency,” confirms Gorain. Meanwhile, at the Agucha mine, the company is also partnering with Mobilaris who are providing connections for visualisation and equipment tracking. “They’re helping us to leverage digital to communicate in a way that keeps all of our teams aligned,” he adds. “We’re reducing the time of the track operations, improving the asset optimisation, and it’s helping us better predict our maintenance needs.”
Continuous alignment is a challenge that Gorain believes must be met to ensure all teams are looking at one truth with minimal manual intervention. “There’s always resistance to change,” he concedes. “We want to make people think more about how we plan for the future across such a large workforce. Change management is always an issue, so we are educating employees about how digital is not going to take jobs away but create new ones in safer areas of the business with less physical labour requirements in different roles where technology can support them.”
The benefits of new technologies are evident with Gorain’s team’s recent initiatives on advanced process controls. “We’ve had great success at Zawar,” he says. “We have experienced a 10% increase in crusher throughput, and around a 3 to 5% increase in recovery, which is really quite remarkable.”
Gorain notes that with so many technologies to choose from the problem can be selecting the right one. “To meet this challenge, our three-stage approach has been very useful,” he explains. “First, we must make sure to integrate all the data into one platform for one shared truth. Second, we deploy the right analytics solutions to enhance the working environment of everybody across the company. Third, we have to integrate the subject matter teams into the digital way of doing things. These three areas combine to help us identify the right technologies for the right purpose so that our guiding principles - in terms of enhancing safety, productivity, and reduced costs - are in alignment with our vision.”
Vedanta and Hindustan Zinc’s vision is to make the SK and Agucha operations one of the most advanced digital mines in the world. “Our goal is to achieve the highest benchmark of recovery and metal extraction in the zinc industry,” says Gorain. “Not just lead-zinc major metals, but also the minor and precious metals such as germanium, cobalt, and silver.” The vision for mining in India and a move towards zero waste looks set to welcome a new mining paradigm.