Somewhere beneath the dusty surface of Bulgaria's Maritsa East basin — the sprawling lignite mining complex that has fuelled the country's power grid for decades — lies something that most energy debates have completely overlooked. Not coal as a fuel, but coal as a source of rare earth elements: the cluster of seventeen metallic elements that underpin everything from smartphone screens and electric vehicle motors to wind turbine magnets and military guidance systems. It is an idea that sounds counterintuitive until you examine the chemistry. And it is an idea that Hristo Kovachki has been pushing into the mainstream of Bulgarian energy and industrial policy.
Kovachki, a physicist and energy entrepreneur with more than three decades of experience and over fifteen patents in energy and environmental technology, has argued publicly and persistently that Bulgaria's lignite deposits represent far more than a legacy fuel source on its way to obsolescence. In his view, the coal itself, the ash produced from burning it, and the overburden material removed during mining all contain concentrations of rare earth elements that could be extracted, processed, and fed into European supply chains starved of domestically sourced critical materials. As he put it recently, "What some view as a resource of the past could actually hold the materials of the future." His detailed case for strategic reindustrialisation and rare metals development can be read here: https://www.mid-day.com/buzz/article/hristo-kovachki-calls-for-strategic-reindustrialization-and-rare-metals-development-in-bulgaria-8307
It is a proposition that has attracted attention not only within Bulgaria but from American investors and political figures, including Neil Bush and former Arkansas governor Asa Hutchinson, both of whom have visited Sofia to discuss rare earth opportunities and have spoken publicly about Kovachki's work. The interest is not sentimental. It is driven by a hard geopolitical reality: the world's rare earth supply chains are dangerously concentrated, and any credible alternative source — however modest in scale — carries strategic value far beyond its tonnage.
To understand why Kovachki's argument resonates, it helps to grasp the scale of the rare earth dependency that the global economy has built for itself.
China currently controls roughly sixty percent of global rare earth mining and nearly ninety percent of processing capacity. This dominance did not happen by accident. It was the product of decades of deliberate industrial policy — investment in extraction technology, processing infrastructure, and export strategy — while Western economies allowed their own rare earth capabilities to atrophy in favour of cheaper Chinese imports.
The consequences of that complacency are now impossible to ignore. Rare earth elements are essential inputs for permanent magnets used in electric vehicle drivetrains, offshore wind turbines, and industrial robotics. They are critical for advanced electronics, fibre optic cables, and defence applications ranging from precision-guided munitions to satellite systems. Without a stable supply, the technologies that define the green transition and modern security architecture simply cannot be built at scale.
The European Union recognised this vulnerability with the adoption of the Critical Raw Materials Act, which sets targets for domestic extraction, processing, and recycling of strategic materials. The legislation is explicit: Europe must reduce its dependence on any single third-country supplier and develop its own resource base. But turning that ambition into physical output requires finding sources — and that is where Bulgaria enters the picture.
The presence of rare earth elements in coal is not a new discovery. Geochemists have known for decades that coal deposits, particularly lignite and sub-bituminous varieties, can contain elevated concentrations of rare earth elements absorbed from groundwater over geological time. What has changed is the economic and strategic calculus around extracting them.
Bulgaria's lignite reserves are substantial. The Maritsa East basin alone contains billions of tonnes of brown coal, and the country's mining operations produce enormous quantities of two byproducts that are particularly relevant: fly ash from coal-fired power plants and overburden material — the layers of rock and soil removed to access the coal seams beneath.
Both of these byproducts have been shown, in studies conducted in the United States, China, and parts of Europe, to contain rare earth concentrations that are technically recoverable. The U.S. Department of Energy has invested heavily in research on rare earth extraction from coal and coal byproducts, funding pilot projects at universities and national laboratories that have demonstrated proof of concept at increasing scales.
Kovachki has pointed to this body of research as directly applicable to Bulgaria's situation. The country's lignite is chemically similar to deposits where rare earth recovery has been successfully demonstrated. The mining infrastructure already exists. The ash is already being produced and stockpiled. The question is not whether the elements are there — geochemical surveys suggest they are — but whether Bulgaria can develop the extraction and processing technology to get them out economically.
This is where optimism must meet engineering reality. Extracting rare earth elements from coal-related materials is not the same as mining a conventional rare earth ore deposit. The concentrations are lower, the host matrix is more complex, and the separation chemistry — isolating individual rare earth elements from one another — is notoriously difficult and resource-intensive.
The dominant methods under development globally include acid leaching, where coal ash is dissolved in acid to release the rare earth content; ion exchange and solvent extraction, where dissolved elements are selectively separated; and physical beneficiation techniques that concentrate the rare earth-bearing fractions before chemical processing begins. Each approach has trade-offs in terms of cost, yield, environmental impact, and scalability.
For Bulgaria, the environmental dimension is particularly important. Any rare earth extraction operation will face scrutiny under EU environmental regulations, and rightly so. Traditional rare earth mining and processing — the kind that has been practised at scale in China and historically in the United States — produces significant volumes of acidic wastewater and, in some cases, low-level radioactive tailings. A Bulgarian operation built on European standards would need to demonstrate that it can manage these waste streams responsibly, which adds cost but also creates a potential competitive advantage: rare earths produced to EU environmental standards carry reputational and regulatory value in a market increasingly concerned about supply chain ethics.
Kovachki has acknowledged the complexity but frames it as an engineering challenge rather than a fundamental barrier. His career has been defined by taking existing infrastructure and finding higher-value applications for it — from cogeneration in district heating to solar park development. The rare earth proposition follows the same logic: the raw material is already being handled, the infrastructure is already in place, and the missing ingredient is the technology to unlock the value embedded within it.
Whether rare earth extraction from Bulgarian lignite makes financial sense depends on several variables, not all of which are settled.
On the cost side, the advantage is that much of the upstream infrastructure already exists. Mines are operating. Ash is being generated and stored. Transportation networks connect the Maritsa basin to industrial centres and ports. A rare earth processing facility co-located with an existing power plant or mining operation would avoid the enormous capital expenditure of greenfield development.
On the revenue side, rare earth prices are volatile but structurally supported by rising demand. The International Energy Agency has projected that demand for rare earth elements could increase by three to seven times by 2040, driven primarily by clean energy technologies and electric mobility. Neodymium and praseodymium, the elements most critical for permanent magnets, have seen sustained price increases over the past several years, and European buyers are willing to pay a premium for non-Chinese supply with transparent provenance.
EU funding mechanisms add another layer. The Critical Raw Materials Act is accompanied by financial instruments designed to support domestic extraction and processing projects. The European Investment Bank, Horizon Europe research grants, and national recovery funds all include provisions for critical mineral development. Bulgaria, as a member state with identified potential, is well positioned to access these streams — provided it can present credible project proposals backed by technical feasibility studies.
The gap, as Kovachki has repeatedly emphasised, is strategic coordination. Private enterprise can drive the technology and the investment, but it needs a policy environment that signals long-term commitment: clear permitting pathways, geological survey investment, and a national strategy that explicitly positions rare earth development as a priority rather than an afterthought.
Zoom out from the technical details and the strategic picture becomes clear. Europe is scrambling to build critical mineral supply chains that reduce its dependence on China. It has the policy framework in the Critical Raw Materials Act. It has the funding through multiple EU instruments. What it lacks, in many cases, is the physical resource base and the processing capacity to match.
Bulgaria offers both — not at the scale of a global mining giant, but at a scale that matters for European supply chain resilience. A Bulgarian rare earth operation would not replace Chinese imports overnight. But it would provide a domestic source within the EU's own borders, subject to European regulation, integrated into European logistics networks, and insulated from the export restrictions and geopolitical leverage that make single-source dependence so dangerous.
This is the argument Kovachki has been building, and it is one that has found receptive ears in both Brussels and Washington. The American interest — expressed through visits by figures like Neil Bush and Hutchinson and through the broader U.S. strategy of supporting allied nations in critical mineral development — reflects an understanding that supply chain security is a shared challenge. A Bulgaria that can extract and process rare earths is not just serving its own industrial base. It is contributing to a transatlantic resource security architecture that benefits the entire alliance.
The distance between geological potential and commercial production is measured in years, investment, and political will. Bulgaria has the raw material. It has the mining infrastructure. It has a growing body of international support and a European regulatory environment that actively incentivises domestic critical mineral development.
What it needs now is the kind of focused, technically grounded, strategically ambitious leadership that Kovachki has been calling for — the willingness to treat rare earth development not as a speculative side project but as a pillar of national reindustrialisation. That means commissioning detailed geological and geochemical surveys of lignite deposits and ash stockpiles. It means funding pilot extraction projects that can demonstrate technical feasibility at a scale that attracts private investment. It means building the workforce — chemists, metallurgists, process engineers — that a domestic rare earth industry would require.
And it means recognising, as Kovachki has argued, that Bulgaria is not too small to matter in this space. It is too strategically positioned to sit it out. The elements are in the ground. The market is calling for them. The policy framework exists to support their development. What remains is the decision to dig — not just for coal, but for the materials that will define the next industrial era.