Khaidarkan and the World's Last Primary Mercury Mine

OJSC Khaidarkan Mercury Joint-Stock Company (KhRAO), located in the Batken region of the Kyrgyz Republic, represents a unique yet highly problematic facility on the global industrial map. As the town-forming enterprise for the city of Aidarken¹, the plant is the last legally operating primary mercury mining and exporting facility in the world².

In the context of a fundamental shift in the global paradigm regarding toxic heavy metals, definitively consolidated by the Minamata Convention on Mercury, the operation of KhRAO exposes a sharp conflict between the socio-economic needs of a depressed region and international environmental safety standards. This report presents a comprehensive structural analysis of the historical development, geological potential, current financial and economic state, and the environmental situation surrounding the Khaidarkan Mercury Plant. The analysis relies on identifying deep causal links between the macroeconomic shocks of the post-Soviet period, growing anthropogenic risks, and the prospects for Kyrgyzstan’s international integration in the field of chemical waste management.

Historical and Economic Evolution of the Enterprise (1926–present)

The evolution of the Khaidarkan deposit is inextricably linked to geopolitical, military-industrial, and macroeconomic cycles. The historical path of the enterprise clearly demonstrates the transition from the status of a critical strategic asset to a vulnerable link in the global supply chain.

Discovery and Early Geological Exploration (1920s–1930s)

Prerequisites for the industrial development of the region emerged in the first quarter of the 20th century. In 1926, the Khaidarkan (Aidarken) mercury deposit in Southern Kyrgyzstan was discovered by V.E. Poyarkov and V.I. Popov, members of the Tajik-Pamir expedition of the USSR Academy of Sciences⁴. According to historical data, in the early 1920s, student V.E. Poyarkov, studying at the Central Asian University in Tashkent, had the opportunity to spend up to eight months a year in field expeditions, which played a decisive role in the detailed mapping of the region².

Shortly after, in 1927, the deposit area was explored by an expedition led by the prominent academician A.E. Fersman and D.I. Shcherbakov⁵. The future academician V.I. Smirnov worked as the chief geologist of Khaidarkan for several years⁶. The efforts of Soviet geologists made it possible to outline colossal reserves of cinnabar, confirming that Khaidarkan is one of the world’s largest mercury ore deposits².

Military Industrialization and the Establishment of the Plant (1940s–1950s)

The accelerated construction of the enterprise was dictated by the imperatives of the beginning of World War II. The occupation of the Nikitovka Mercury Plant in Ukraine by German troops deprived the Soviet defense industry of a critically important raw material - mercury was used on a massive scale in the production of detonators and in the chemical industry⁷.

In response to this logistical and military shock, the first retort furnace was urgently built in the settlement of Khaidarkan in 1940, which began to produce trial batches of the metal¹. Already in 1941, an enterprise codenamed “Combine No. 5” was officially formed, becoming the sole supply base of mercury for the USSR¹. To rapidly expand the raw material base, an intensified Khaidarkan geological exploration party was formed in 1944⁷. In 1950, the secret status was partially lifted, and the facility received its official name - the Khaidarkan Mercury Plant (KhRK)⁷.

Prosperity, Diversification, and Peak Production (1960s–1980s)

During the Cold War and the arms race, the demand for mercury and antimony from the military-industrial complex of the USSR remained consistently high⁸. The Khaidarkan plant provided up to 50% of the Soviet Union’s total mercury requirements⁸. At the peak of its development, metal production volumes reached 800 tons per year, which accounted for about a quarter of global production⁶.

An important technological milestone was 1968, when the commissioning of a new processing plant initiated the production of not only pure metallic mercury but also mercury-antimony and fluorite (fluorspar) concentrates⁷. During the same period, the plant transitioned from exclusively underground mining of monometallic ores to the open-pit mining of complex ores (quarries of the “Mednaya” and “Plavikovaya Gora” sections)⁷. Infrastructure expansion was accompanied by the creation of a massive waste storage system: in 1986, the largest tailings facility was commissioned⁹. By 1990, the enterprise employed over 3,000 people, turning it into a powerful driver of socio-economic development in the Batken region¹.

Post-Soviet Shock and a Cascade of Bankruptcies (1990s–2000s)

The collapse of the USSR led to the instant collapse of established production and supply chains. The end of the Cold War provoked a global drop in demand for strategic metals, and global mercury use began to steadily decline due to environmental and health concerns⁸. The plant suddenly lost state subsidies, guaranteed sales markets, and access to cheap electricity¹⁰.

The macroeconomic blow proved devastating: in 1993–1994, world mercury prices collapsed to 110 US dollars per ton, while the cost of producing one ton of Khaidarkan mercury - due to the low metal content in the ore and complex mining conditions - was 300 dollars¹⁰. As a result, annual production fell to 200 tons, and the enterprise was officially declared bankrupt¹⁰.

In 1995, with the support of the World Bank, an attempt was made to resuscitate the enterprise. The plant received a grant of 24 million soms and a loan of 4 million soms to replenish working capital¹. Restructuring was carried out, work at the mine was intensified, and the government of Kyrgyzstan reduced the royalty rate from 12% to 2%¹. However, these measures treated the structural sales crisis as a localized liquidity problem. A sharp increase in fuel and electricity tariffs completely offset the financial injections. The economic situation improved only marginally, and the workforce was forcibly reduced from 3,500 to 1,300 people¹.

In 1996, against the backdrop of continuing declines in world prices, KhRK was declared bankrupt again¹. Under the Enterprise Structural Adjustment Program (PESAC), tax debts were written off, and the plant was transformed into a state joint-stock company⁸. In 2002, the status of “state” was removed from the name, forming the modern OJSC Khaidarkan Mercury Joint-Stock Company (KhRAO)¹. According to retrospective estimates, over the entire period of operation since 1941, the total volume of mercury production in Kyrgyzstan has amounted to approximately 45,000 tons¹⁰.

Geological Structure, Minerageny, and Resource Potential

The economic model and environmental risks of the enterprise are directly determined by its geological specifics. The Khaidarkan ore field is located on the southern slope of the Katrantau ridge and is confined to the Ishmetau ore echelon, parallel to the Aktash-Boardinskaya echelon, within the vast South Tien Shan ore belt⁷.

Tectonics and Structural Control of Mineralization

The main role in the structure of this region belongs to sedimentary carbonate and volcanogenic strata of the Middle and Upper Paleozoic⁶. The main folding phase, which formed the enclosing structures, belongs to the Upper Paleozoic epoch⁶. The ore field is controlled by the powerful zone of the sub-latitudinal Ishmetau thrust-fault⁷.

Structurally, two key anticlines stand out within the field: the Northern and Southern. This division is of critical importance for the typology of ores:

• Northern Anticline Located closer (in the footwall) to the main ore-controlling fault zone. It is characterized by the predominant development of complex polymetallic mineralization - mercury, antimony, arsenic, fluorite⁷.
• Southern Anticline Located 1–2 km away from the main thrust-fault. It is distinguished by a pronounced three-part geological section (Devonian-Carboniferous limestones, underlain by Silurian-Devonian shales) and represents a box fold. Simple monometallic (mercury) mineralization predominates here⁷.

Physicochemical Parameters of Ore Formation

Genetically, the Khaidarkan deposit belongs to the telethermal jasperoid (quartz-fluorite-cinnabar) type of hydrothermal deposits⁶. The ore formation process was accompanied by large-scale jasperoidization (silicification) of both limestones and shales. As a result of intra-ore tectonic movements, massive zones of brittle brecciation were formed, which served as ideal traps for hydrothermal solutions⁷.

Researchers of the deposit have established that the formation temperatures of the main ore minerals fell within a relatively low-temperature range from 284 °C to 68 °C⁶. At the same time, the crystallization of cinnabar (the main stage of the ore process) occurred at temperatures below 110 °C⁶. Such genesis explains the extremely uneven (nest-like and vein-disseminated) distribution of useful components in the rock, which historically required the processing of gigantic volumes of rock mass, leading to the formation of colossal tailings facilities.

Balance Reserves and Mining Prospects

During its operation, the plant has depleted the reserves of several local deposits, including Chauvai, Symap, and Chonkoy. Currently, these sites are mothballed due to unfavorable mining conditions, despite the fact that reserves of low-margin ores are not exhausted there¹.

Kyrgyzstan has deposits with colossal mercury resources - just two of them contain over 40,000 tons of the metal - and Khaidarkan is the largest¹. Today, deep horizons of the deposit are being mined. The main division, Underground Mine No. 1 (RPR-1), was initially designed for the extraction of monometallic ores with an annual volume of up to 150,000 tons².

Of particular strategic interest are the deep horizons of the “Zapadnaya” (Western) shaft, at depths of 600–800 metres. Geological exploration has confirmed the presence of commercial reserves of complex ores here: 141,000 tons of fluorite, 20,000 tons of antimony, and 5,000 tons of mercury¹¹. The demothballing and extraction of these reserves, with a focus on antimony and fluorspar (fluorite) which are in demand on the global market, is the only geologically justified path for production diversification.

Financial and Economic Analysis and Operations

An analysis of the financial model of OJSC KhRAO reveals deep structural imbalances. The enterprise operates on the brink of profitability, burdened by outdated fixed assets, environmental liabilities, the high energy intensity of underground mining, and complex logistical chains.

Corporate Structure and Tax Discipline

Despite its formal status as an open joint-stock company, OJSC KhRAO is a quasi-state asset. The state, represented by the State Property Management Fund (FGI), is the majority shareholder, with its share estimated in the range of 95% to 99.98% of the authorized capital¹. The legal entity (TIN 00109199510030) underwent its last re-registration on 5 August 2008, under the leadership of Tuliboy Zhanivalievich Saliev¹.

The enterprise’s tax deductions to the budget demonstrate high volatility, correlating with periods of resumed operation of the processing plant. In 2017, deductions amounted to 8,187,606 soms, and in 2018, they increased to 16,944,467 soms⁷. Nevertheless, a systemic liquidity crisis led to the fact that as of 1 July 2026, OJSC KhRAO is officially included in the list of payers with large tax and insurance premium arrears to the budget of the Kyrgyz Republic¹².

State Audit Results and Management Imbalances

Financial discipline at the enterprise has been systematically subjected to harsh criticism by supervisory authorities. Inspections by the Accounts Chamber revealed significant violations in the corporate governance of the company. Consolidated audit reports recorded the following financial anomalies:

• Unjustified and undisclosed growth of accounts receivable amounting to 27.6 million soms¹⁰.
• A catastrophic overspending of the payroll fund - by 146% compared to the approved plan, which in absolute terms amounted to 20.6 million soms¹³.
• An excess of administrative expenses by 11.8 million soms and the admission of unplanned other expenses amounting to 7.9 million soms¹³.

The 146% overspending of the payroll fund against the backdrop of existing tax debts indicates that the enterprise primarily performs a social rather than a commercial function. Management is likely forced to maintain excess employment to preserve social stability in the company town, which inevitably leads to the depletion of working capital.

Investment Climate and Asset Modernization

The key processing plant of KhRAO, commissioned in 1967, had been in a state of profound idle time for the last decade⁷. The main technical reason that paralyzed mining on highly prospective horizons was the massive flooding of mine shafts by groundwater.

To solve this critical problem, the state attracted a domestic investor - financial and industrial structures affiliated with Global Metallurg Group¹. The investor injected about 1 million US dollars into the enterprise’s fixed capital⁷. These funds were distributed as follows:

1. Purchase and installation of high-performance pumping stations to pump water out of the “Zapadnaya” shaft¹.
2. Completion of the major overhaul of the roof of the idle processing plant⁷.
3. Covering cash gaps: payment of current wage arrears, as well as expenses for electricity and gas consumption⁷.

The investor’s strategy is clearly articulated: after completely draining the “Zapadnaya” shaft, it is planned to resume full-scale mining and shift the production focus from toxic mercury to highly profitable antimony and fluorite¹⁵.

Supply Chains Under Global Restrictions

Following the final closure of the famous Almadén mine in Spain in 2004, Kyrgyzstan remained virtually the only state in the world carrying out stable supplies of primary mercury to the global market³. During the period 2005–2008, operating without state subsidies, the plant ensured the production of 300–350 tons of mercury annually, which accounted for about 10% of global supply³.

The export sales system is complex and non-transparent due to high international reputational risks. Primary mercury was exported exclusively through a network of traders and intermediaries from the USA, the Netherlands, Russia, and Kazakhstan². By-products - fluorspar and antimony concentrates - are sold primarily in the CIS countries (Russia, Kazakhstan, Tajikistan, Uzbekistan)². The material and technical supply of the mine also critically depends on the import of equipment and reagents from neighbouring countries².

Environmental Situation and Anthropogenic Impact Assessment

The environmental situation around the Khaidarkan mercury hub is classified by the scientific community as extremely severe, in some places transitioning into a zone of ecological disaster. About 80 years of intensive mining of polymetallic ores have left a colossal toxic footprint in the biosphere of the Batken region. The main vectors of impact are emissions of mercury vapour, uncontrolled storage of millions of tons of waste, and systemic poisoning of the hydrographic network⁸.

Morphology and Volumes of Industrial Waste

The problem of tailings facilities is of a national scale. There are 92 tailings facilities and mining dumps in Kyrgyzstan (58 of which are under the jurisdiction of the Ministry of Emergency Situations of the Kyrgyz Republic), with a total volume reaching 11.9 million cubic metres of toxic and radioactive substances¹⁶. Khaidarkan represents one of the densest zones of chemical hazard.

The main Khaidarkan tailings facility was commissioned in 1968². It is located at an altitude of 1,700 metres above sea level in the Kazarkar gorge².

In addition to the tailings facility, about 13 million tons of mining dumps and slags are stored directly around the production areas and the settlement⁸. These man-made mounds reach a height of 50 metres - comparable to a 16-storey building - and were piled up without proper engineering stabilization of the slopes⁸.

This fact presents an existential threat due to the high seismicity of the Fergana Valley and its mountainous surroundings¹⁸. The region is prone to powerful mudflows and landslides. Catastrophic mudflows in the basin of the transboundary Shakhimardan river (water discharge up to 1,000 cubic metres per second), recorded in 1977 and 1998 due to the outburst of the high-altitude Lake Kurban-Kul, demonstrate the reality of a hydrodynamic accident scenario in which millions of tons of waste could be washed down into densely populated plains¹⁹.

Environmental Geochemistry: Toxicology and Exceedance of Maximum Permissible Concentrations

Scientific studies of soils, water, and the waste itself confirm extreme levels of heavy metal accumulation, multiple times exceeding the maximum permissible concentrations (MPC).

As can be seen from the presented data, the tailings facility is a polymetallic generator of pollution, where the antimony concentration exceeds the norm by 110 times²⁰.

Degradation of Water Resources and the Food Chain

Chemical elements actively migrate into the hydrosphere through the filtration of precipitation through the bodies of the dams. The MPC standard for mercury in drinking and fishery reservoirs is 0.005 mg/L, and for recreational reservoirs it is 0.0003 mg/L.

Systemic exceedances of these indicators are recorded in the region’s surface watercourses: in the Chatmazar-Sai river, the mercury content reaches 0.0008 mg/L, and in the Chauvai-Sai river 0.0006 mg/L. Local environmentalists point out that the “smelling lakes” - a system of seven to nine toxic technical ponds of the plant - cause colossal damage to the atmospheric air and are the main sources of mercury and antimony pollution of the transboundary Shakhimardan river².

Further migration of pollutants occurs through agricultural chains. In the village of Eshme, due to a lack of clean water, local residents use mine drainage waters for irrigation. As a consequence, the mercury content in the tubers of fresh potatoes grown in these fields exceeds sanitary standards by 2 to 2.5 times. Consumption of such products leads to chronic bodily intoxication. Exposure to mercury vapours causes severe damage to the central nervous system, but the low medical literacy of the population leads to poisoning symptoms being massively written off as age-related diseases².

Transboundary Risks and Remediation Prospects

The Khaidarkan problem is exacerbated by the demographic factor: the Fergana Valley has the highest population density in Central Asia, up to 360 people per square kilometre¹³. In the same region, in addition to mercury waste, about 80 million tons of uranium tailings are concentrated at Mailuu-Suu, Shekaftar, Taboshar, and other sites¹³.

In 2023, the government of Kyrgyzstan lifted the moratorium on the development of uranium and thorium, which catalyzed cooperation with the Russian state corporation Rosatom in the field of remediation¹⁷. Rosatom specialists are already applying advanced methods at the “Dalneye” and “Tuyuk-Suu” facilities, including acid decontamination and melting in induction furnaces, which reduces the radioactivity of materials by hundreds of times. This technological precedent could potentially be adapted for the processing and stabilization of Khaidarkan’s complex mercury-antimony raw materials, provided that interstate financing is attracted.

International Legal Regime and Global Environmental Initiatives

Given Khaidarkan’s status as the last exporter of primary mercury, the enterprise has become the object of close attention from UN system institutions seeking to minimize the entry of new volumes of this toxicant into the global market.

Architecture of the Minamata Convention on Mercury

In 2013, in the Japanese city of Kumamoto, 128 countries signed a new international treaty - the Minamata Convention on Mercury, which entered into force on 16 August 2017¹³. The document was named in memory of the 1956 tragedy in the city of Minamata, where over 1,700 people suffered, many fatally, from consuming fish poisoned by industrial discharges of mercury compounds¹⁵. By the spring of 2019, 107 states had ratified the convention²³.

The Convention radically restructures the global market. Since 2020, it has banned the production, import, and export of a wide range of mercury-containing products (batteries, relays, fluorescent lamps) and established a strict course toward the elimination of primary mining².

National Position of the Kyrgyz Republic: The Ratification Dilemma

Kyrgyzstan has still not joined or ratified the convention². This creates a profound legal and economic dilemma.

The State Agency for Environmental Protection and Forestry (SAEPF) is an active supporter of ratification. The director of the Center for State Regulation under SAEPF, B.M. Tolongutov, emphasizes that the convention prohibits participating countries from importing mercury from non-party states²¹. Consequently, if Kyrgyzstan remains on the sidelines, OJSC KhRAO will completely lose its sales markets and will be forced to work “for the warehouse”, which will lead to immediate financial paralysis³. Furthermore, ratification opens access to international accounting systems and funds for building a comprehensive chemical risk management system²¹.

On the other hand, ratification contains protective mechanisms for operating enterprises. Paragraph 4 of Article 3 of the Convention allows primary mercury mining to continue during a transition period of up to 15 years³. Moreover, according to Paragraph 6 of Article 6, this period can be extended upon request for another five years³. Thus, the treaty guarantees Khaidarkan a legal 20-year window for the phased closure of its mercury operations, and Article 33 retains the sovereign right to withdraw from the convention three years after its entry into force³.

UN (UNEP/GEF) Project Activities in Khaidarkan

Realizing that Kyrgyzstan does not have the budget for an independent diversification of the plant, the international community initiated a massive support program. From 2012 to 2018, a project by UNEP and the Global Environment Facility (GEF) was implemented under the auspices of the State Agency for Environmental Protection of the Kyrgyz Republic in partnership with UNITAR and the Zoï Environment Network³.

The project, with a GEF grant of 944,000 US dollars and co-financing of over 3,000,000 dollars (supported by Norway, Switzerland, and the USA), pursued an ambitious goal: to ensure a socially acceptable economic transition for the population from mercury mining to safe activities¹. The areas of work included:

• Reducing direct threats from contaminated areas³.
• Developing feasibility studies for the transition to mining alternative minerals, including gold, antimony, and fluorite³.
• Promoting alternative employment for the local population¹.

The project helped create a high-quality analytical base, including pollution cadastres and socio-economic profiles²⁷. However, the final Terminal Evaluation of the project, conducted by UNEP, revealed critical discrepancies between the intent and reality²⁹. The main goal - the actual cessation of mercury mining - was assessed as “highly unlikely” to be sustainably achieved without constant external tranches²⁸.

The fundamental reasons for the stalling were political instability in the country, resistance from local mining authorities and trade unions fearing total unemployment, and an acute shortage of capital financing for the physical remediation of the tailings dams²⁸. Today, UNEP and GEF are trying to address similar challenges within the global planetGOLD program, aimed at eliminating mercury from artisanal gold mining³².

Socio-Economic Context and the Town-Forming Factor of Aidarken

The social landscape around the plant is a key barrier on the path to its ecological transformation. The city of Aidarken historically formed as a classic company town, where the entire social sphere, including municipal services and heating, was tied to the energy infrastructure of KhRAO⁷.

Under conditions of chronic unemployment in the Batken region, the population is forced to make a tragic choice between environmental safety and basic economic survival⁸. Despite the visual presence of the “smelling lakes” and morbidity statistics, local residents, lacking alternative sources of income, desperately hope for a full-scale revival of production at the plant³.

To reduce the load on the region’s outdated coal and fuel oil energy facilities, the state initiated microcredit programs. In particular, households gained access to state concessional loans of up to 1,000,000 soms at a subsidized rate of 8% per annum for up to 60 months for the purchase and installation of modern, environmentally friendly heating systems³³. Nevertheless, such targeted measures cannot compensate for the loss of thousands of jobs in the event of an uncontrolled closure of the mine.

Strategic Implications

A comprehensive analysis of the historical, economic, and environmental profile of OJSC Khaidarkan Mercury Joint-Stock Company leads to the conclusion that the systemic crisis of the enterprise in its current configuration is irreversible.

Khaidarkan has become a hostage to the change in global technological eras. The geological potential of the deep horizons of the “Zapadnaya” shaft, containing significant balance reserves of fluorite and antimony, proves that the ore body is not exhausted¹¹. However, attempts to revitalize production through the extraction of toxic mercury are economically doomed due to the implementation of the Minamata Convention, which will inevitably close legal export markets for non-ratifying countries²¹.

The accumulated environmental damage - 4 million tons of highly toxic tailings deposits, with an exceedance of the MPC for antimony by 110 times and mercury by 10 times²⁰, and 13 million tons of waste rock dumps in the seismically active zone of the Fergana Valley⁸ - poses a threat on a transboundary scale. It is obvious that without large-scale external investments, potentially involving the technological expertise of structures at the level of Rosatom¹⁷, the Kyrgyz Republic is incapable of independently eliminating this hotbed of chemical hazard.

The only sustainable development vector is the immediate ratification of the Minamata Convention. This will provide the plant with a legal 20-year transition period to export residual batches of mercury³. During this time, relying on funds attracted from investors to drain the shafts and grants from international institutions, the enterprise must execute a radical technological pivot toward the extraction and enrichment of exclusively antimony and fluorite ores, simultaneously launching full-scale physical remediation of the historic tailings facilities.

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