Exploring new ways to find critical mineral deposits

The Intelligent Miner has an exceptionally high readership in India. So, when the team at DMT Group, who contributed to our recent article on agility through digital transformation, mentioned that they also had some cutting-edge work underway in India on mineral exploration, we jumped at the opportunity to talk further…

Through its subsidiary in India, DMT Consulting Private Ltd India, the company has carried out exploration-related services for the Indian government and private companies. In addition to this, the DMT headquarters in Germany sells equipment to companies that carry out exploration services in the Indian market.

“Our work in India is really just beginning, and we see huge potential especially for the exploration story there,” said Pankaj Pankaj Sinha, managing director at DMT Consulting Ltd UK.

“The government of India is placing a lot of emphasis on developing the raw materials sector, and this relies on large-scale exploration, reliable readings and an enabling environment that helps the private sector expedite the market potential.

“Over the past 5-10 years, the government has been exploring an area of around 80,000km² and looking for areas of ‘obvious geological potential’ which has resulted in the selection of an initial set of 100 blocks for further geological/geophysical exploration.”

In Sinha’s opinion, DMT is very well placed to respond to this need. “Our geologists are already working extensively with government and private sector players on exploration, post-exploration modelling and data analysis,” he told me.

“We can anticipate exploration work accounting for around 70-80% of our practice in India, and we are anticipating total revenues to multiply by 10 within the next 6-7 years.”

India’s unique challenges

In addition to using traditional exploration technologies, the DMT team in India is investigating the use of new exploration techniques.

“The unique geology of India presents two distinct challenges to exploration activity,” said Ajay Kumar Singh, director of DMT Consulting Private Ltd India.

“The first is the thick layer of clay (weathered top) that covers much of the country and acts as an enormous conductive screen, and limits the efficacy of traditional exploration methods. The second is the ‘Deccan Traps’, which are large lava flows that cover central India’s subsurface to a depth of between 40-100m, and are equally resistant to traditional measuring technologies and even to seismic exploration.”

To overcome these geological challenges, DMT India has been using new technologies on both the instrumentation side and on the sensing side.

“The first is magnetotellurics (MT) and audio-frequency MT (AMT), which use the passive energy source of lightning storms to provide unhindered, unlimited depth evaluation of deposits,” explained Singh.

“Over a period of up to 48 hours, this technology uses lower and lower frequencies to penetrate the thick lava and clay, exploring for base metals to a depth of around 1,200m and beyond.”

In addition to this, the team is using controlled source audio-frequency magnetotellurics (CSAMT), where they charge the ground with an artificial source and measure the responses, which are frequency dependent.

Singh said: “This allows us to increase and decrease the charge depending on the depth or resolution needed. These technologies are inexpensive, they are not manpower intensive, and they are helping us to overcome the unique challenges presented by India’s geology.”

He noted that the government of India has made development of the raw materials sector a priority, and a new effort around research and development (R&D) is required to meet the sector’s potential.

He added: “Partly this is driven by India’s current reliance on imports for raw materials, but India’s population is also growing quickly and demands on raw materials will only increase.”

The challenges of India’s unique geology have been the stumbling block, but Singh thinks that new technologies have transformed this challenge into an opportunity.

“We now have a fast-growing industry for deep exploration in areas of obvious geological potential down to around 2,000m,” he said. “At the same time, the processing side has improved greatly too, so increasingly it is possible to extract even the lowest grade of material at an affordable level.”

Funding exploration

In 2015, India established a non-profit body called the National Mineral Exploration Trust (NMET) to enhance mineral exploration activities in the country.

“Several years ago, the government of India realised there was an urgent need to fund exploration work, so introduced a new levy on every single tonne of mineral produced in India which paid into the NMET fund,” recalled Sinha. “Over the last five years, this fund has grown to around US$1billion to cover the need for exploration.”

He called it a ‘clever system’ because the money is recycled; the levies from mining fund new exploration, which leads to new processed materials and new contributions to the fund.

“In many ways, the only question now is where to spend it,” he said. “But this is where the private sector has an important advisory role to play, as well as an implementation role, and this is where DMT came into the picture initially.

“As part of the creation of the NMET, the government formulated a national mineral exploration policy to guide and prioritise exploration activity.

“This was led by industry players from across the raw materials value chain – like DMT – and we produced a whitepaper to make recommendations on a consensus basis not only on how to channel funds, but which materials the government should prioritise to meet demand. DMT has played a key role in this advisory work.”

Lessons from India

Singh commented that DMT Group is happy to contribute to the growth story of India by actively participating and adding a lot of value to the sector.

“We are implementing the absolute best global practice, and we are seeing very good revenues,” he said, adding that the company’s experience in India is also forming best practice in other parts of DMT’s work in exploration around the world.

“There are two examples that really demonstrate how the lessons of one story can be applied to the challenges of another,” he explained. “Our experience exploring for chromite in India has directly informed our approach to chromite exploration in Madagascar.

“The precision of our work there has seen a significant percentage of the boreholes drilled return detections of chromite. So much so that this mineral is now one of the major mining resources in Madagascar.”

In addition, DMT’s experience overcoming the geological challenges of India’s Deccan Traps has been of immense value to the company’s work in Mozambique.

Singh said: “On the border between Malawi and Mozambique there is an extensive lava sheet, which conceals potential mineral deposits and results in coal burn-out. Our work here on geophysical exploration has allowed us to identify coal deposits beneath the lava flow, and to make clear assessments of where coal is intact and where it has deteriorated.”

He added that many of the R&D breakthroughs seen in exploration instrumentation and software have come from Australia, Canada, France and Germany, which is why it is so useful to draw on DMT Group’s global footprint to meet the challenges presented in India.

The NEXT project

In Europe, DMT was involved in the New Exploration Technologies (NEXT) project that ran from 2018-2021 with the aim of developing new geomodels, novel sensitive exploration technologies and data analysis methods that are fast, cost-effective, environmentally safe and potentially more socially acceptable.

Torsten Gorka, NEXT exploitation manager at DMT Group, commented: “We believe that the only way for mineral exploration to remain competitive, cost effective, and acceptable in civil society is to transform its sustainability footprint – partly through better technologies, partly through better policies.”

The NEXT project, which ended in September this year, was funded by the European Union’s Horizon 2020 research and innovation programme and coordinated by the Geological Survey of Finland (GTK).

It had 16 partners from research institutes, academia, service providers and mining industry from six EU member states – Finland, France, Germany, Malta, Spain and Sweden – representing the main metal-producing regions of Europe: the Baltic Shield, the Iberian Variscan Belt and the Central European Belt.

The mineral deposits in these belts are the most feasible sources of critical, high-tech and other economically important metals in the EU.

Gorka said that the expertise, technology and approach of the group set out to “achieve a vision in which European sourcing for the raw materials required in chips and batteries is both sustainable and self-sufficient. And, in which every company or organisation involved in the exploration or sourcing of raw materials is using the NEXT project’s advanced tools and methods.”

Developments in data fusion

The NEXT project was composed of seven interactive work packages (WPs). Some of the focus areas included machine learning and artificial intelligence (AI) technologies, geochemical techniques, mineral systems modelling and novel geophysical survey systems using drones.

Work package 4 (WP4) focused on data fusion, developing new, modern and environmentally-friendly software and tools for data processing and data integration.

In the past, mineral exploration involved gathering and interpreting multiple data sources and data sets to identify geologic patterns for prospect definition – including results from geological mapping, surface sampling, drilling, mineralogical and geochemical analyses, geophysical measurements and remote sensing satellite data.

“For so many sources of information, manual analysis is highly complex and correlation is time-consuming and rather inefficient to compare and identify meaningful results,” added Gorka.

“This is where data fusion tools come in, and where we are seeing the benefits for mineral exploration. The latest developments in computational data analysis, with the help of AI and machine learning algorithms, allow us to analyse multiple sources of different data quickly, accurately and in-depth.”

Some of the aims of WP4 were to develop a multi-scale and multi-sensor approach fusing spectral data from laboratory, field, drone and remote sensing measurements, and to come up with a new software technology for more accurate 3D electromagnetic inversion modelling.

In addition, new software tools and methods applying self-organising maps (SOM) were developed together with an artificial neural network (ANN).

Gorka said: “This approach, together with new software, enabled the analysis of complex data sets from multiple sources, i.e. geophysical data, magnetic and electromagnetic surveys, spectral data from satellites, surface sampling (river and streams sediments) chemical data and general geological maps, in order to identify mineralisation-related patterns and delineate prospective areas.”

He noted that the novel electromagnetic (EM) survey system on unmanned aerial vehicles (UAVs) for mineral exploration has already been identified by the EC Innovation Radar as a product of the NEXT project with high market potential in the near future.

The NEXT project’s work package 5 (WP5) also led research into the social licence to operate within the mineral exploration context, applying a transdisciplinary research effort combining social science, practice and stakeholder knowledge.

It also explored attitudes to the new sensitive versus conventional exploration technology and practices.

Gorka explained that it involved “working closely with communities to understand the key factors influencing social licencing at the exploration stage and beyond, and to design a toolkit to assist exploration companies to improve their relations with local communities.”

A new market leader

Looking to the future, Singh predicts that the next breakthroughs in mineral exploration will be delivered through geochemical assessment, and the marriage of geochemistry with modern geophysical tools based on better geological understanding of the deposit model.

“I think in India in particular, the breakthrough will be in base-metal sulphides like pyrrhotite, chalcopyrite and pentlandite,” he concluded. “I can see India really breaking out as a market leader in these minerals, with exploration reaching depths of up to 1,500m.”