Tungsten is mined primarily through underground and open-pit methods, depending on the depth and type of deposit. The ore is then crushed, concentrated through gravity separation or flotation, and chemically refined into a usable product called ammonium paratungstate (APT). The entire process, from blasting rock to producing a marketable tungsten compound, involves several distinct stages that vary based on the mineral being extracted.
Where Tungsten Ore Forms
Tungsten doesn’t exist as a pure metal in nature. It’s locked inside minerals, and the two most important ones are wolframite and scheelite. Wolframite is an iron-manganese tungsten oxide, dark and dense, found in veins associated with granite intrusions. Scheelite is a calcium tungsten oxide that forms when hot magmatic fluids react with carbonate-rich rock layers, typically in what geologists call skarn deposits.
The type of mineral present at a site determines almost everything about how it will be mined and processed. Wolframite is heavier than most surrounding rock, which makes it well suited to gravity-based separation. Scheelite responds better to chemical flotation. Knowing which mineral dominates a deposit is the first decision point in planning a tungsten mine.
Choosing a Mining Method
Tungsten deposits fall into several geological categories, and each one lends itself to a different extraction approach. Skarn deposits, the most common source of scheelite, contain ore grades between 0.3% and 1.4% tungsten trioxide (WO₃) and can be mined either underground or in open pits. Vein and stockwork deposits, associated with granite intrusions emplaced 1 to 4 kilometers deep, are also mined by either method depending on how close to the surface the ore sits.
Porphyry deposits have lower ore grades, typically 0.1% to 0.4% WO₃, and are usually mined through open-pit operations because the ore is spread across a large volume of rock. Disseminated deposits, with similarly low grades of 0.1% to 0.5%, are more often mined underground because the ore body tends to be deeper and more confined.
In practice, the choice comes down to economics. Open-pit mining moves more rock at a lower cost per ton but requires the deposit to be near the surface. Underground mining is more expensive but necessary when the ore is deep or when the deposit geometry makes surface mining impractical. Most tungsten mines use conventional drilling and blasting to break rock, followed by hauling the ore to a processing plant on site.
Processing Wolframite: Gravity Separation
Wolframite’s high density, roughly 7.1 to 7.5 grams per cubic centimeter, makes gravity separation the go-to method for concentrating it. The ore is first crushed and ground to liberate the tungsten mineral from the surrounding waste rock. Then it moves through equipment designed to exploit the weight difference between wolframite and lighter gangue minerals.
Jigs and shaking tables are the workhorses for coarse-grained wolframite ores. Jigs pulse water upward through a bed of crushed ore, causing heavier particles to sink and lighter ones to rise and wash away. Shaking tables use a combination of flowing water and a vibrating, slightly tilted surface to separate particles by density. For finer material, spiral chutes and vibration chutes offer better recovery.
The finest fraction of crushed ore, called fine mud or slimes, is the hardest to process by gravity alone. These particles are so small that surface chemistry starts to matter more than weight. Mines increasingly combine gravity methods with flotation for this fraction, using chemical collectors and frothing agents to capture fine wolframite particles that would otherwise be lost to the tailings pile. Improvements in these flotation reagents have significantly boosted recovery rates for fine material.
Processing Scheelite: Flotation
Scheelite is lighter than wolframite, so gravity separation alone doesn’t work as well. Instead, scheelite operations rely primarily on froth flotation. In this process, finely ground ore is mixed with water and chemical reagents in a flotation machine. Air is blown through the mixture, and the reagents cause scheelite particles to attach to rising air bubbles while waste minerals stay behind in the slurry.
The chemistry of flotation is where the real complexity lies. Traditional scheelite flotation uses fatty acid collectors like oleic acid and sodium oleate, which bind to scheelite surfaces and make them hydrophobic (water-repelling) so they’ll cling to bubbles. A newer collector called benzohydroxamic acid has improved both recovery rates and selectivity, meaning it grabs more scheelite while leaving behind calcium-bearing waste minerals like calcite and fluorite that would otherwise contaminate the concentrate. Small amounts of lead nitrate are sometimes added as an activator to enhance the flotation response.
The result of either gravity separation or flotation is a tungsten concentrate, typically containing 60% to 70% WO₃. This concentrate is what gets shipped to a chemical plant for refining.
Refining Concentrate Into Usable Tungsten
The industry-standard end product for tungsten processing is ammonium paratungstate, or APT. Nearly all tungsten metal and tungsten chemicals are made from APT, so this is the critical conversion step.
The conventional process starts with digesting the concentrate in a concentrated alkali solution at high temperature. This dissolves the tungsten and leaves behind most impurities as solid residue. The alkaline solution is then treated through a series of chemical purification steps to remove iron, silica, magnesium, and other contaminants. The purified tungsten is precipitated as calcium tungstate, then dissolved in ammonia to form ammonium tungstate in solution. Finally, this solution is evaporated under controlled conditions, and APT crystallizes out as a white, granular powder.
APT is the benchmark product in the global tungsten market. As of early 2025, it was trading at around $415 per metric ton unit (MTU), a substantial rebound from $312/MTU in 2023. Market forecasts suggest $400 to $450 per MTU could become the price floor in coming years, reflecting tightening supply and growing demand.
What Tungsten Is Used For
About 60% of the tungsten consumed in the United States goes into cemented carbide parts: extremely hard cutting tools, drill bits, and wear-resistant components used in construction, metalworking, mining, and oil and gas drilling. Tungsten carbide is second only to diamond in hardness, which is why it dominates these applications. The remaining 40% goes into specialty steel alloys, electrical components like filaments and electrodes, heating elements, welding rods, and various chemical products.
Environmental Risks and Tailings
Tungsten mining generates significant volumes of tailings, the crushed waste rock and chemical residue left over after the valuable mineral has been extracted. These tailings can contaminate surrounding soil and water if not properly managed. Research at an abandoned tungsten mine in China found tungsten concentrations in surface soil reaching 1,250 mg/kg, and subsurface levels as high as 3,020 mg/kg. Both figures exceeded the U.S. EPA’s regional screening level of 930 mg/kg for industrial land. The highest contamination occurred where tailings had been repurposed to make sand, a practice that spread tungsten into the broader environment.
Leachable tungsten, the portion that dissolves in water and can migrate through soil, followed the same contamination pattern, with the highest leaching concentration (0.860 mg/L) found in the sand-making area. Health risk assessments at that site calculated a hazard quotient of 1.34, above the acceptable threshold of 1.0, indicating meaningful risk to human health from prolonged exposure. Modern operations address these risks through lined tailings ponds, water treatment systems, and strict controls on how tailings are stored and eventually reclaimed.
Worker Health and Exposure Limits
Workers in tungsten mines and processing plants face exposure to tungsten dust and fumes through inhalation, skin contact, and accidental ingestion. Chronic exposure can cause irritation of the eyes, skin, and respiratory system, along with loss of appetite, nausea, persistent cough, and changes in blood composition. Long-term inhalation of tungsten dust is associated with diffuse pulmonary fibrosis, a scarring of lung tissue that reduces breathing capacity.
The National Institute for Occupational Safety and Health (NIOSH) sets a recommended exposure limit of 5 mg/m³ as a time-weighted average over a work shift, with a short-term ceiling of 10 mg/m³. These limits apply to insoluble tungsten compounds generally. Notably, OSHA has not established a legally binding permissible exposure limit for tungsten, which means compliance with the NIOSH recommendation is voluntary in many U.S. workplaces. Mines in operation today typically manage dust through water suppression during drilling and blasting, ventilation systems in underground workings, and personal protective equipment for workers in processing areas.
Technology Improving Modern Operations
Tungsten mining is increasingly incorporating digital tools that improve both efficiency and safety. Digital twin technology, which creates a virtual replica of physical mine infrastructure, allows operators to monitor equipment in real time and detect problems before they cause failures. For example, mining excavators commonly develop cracks on their booms over time. A digital twin can flag these stress points at the millimeter level, letting maintenance crews intervene before a crack grows into a breakdown that halts production.
These models also help identify safety hazards by providing continuous data on structural integrity across the mine. Rather than relying on periodic inspections, operators get a live view of which assets are degrading and where risks are developing. The technology extends equipment lifespan, reduces unplanned downtime, and helps mines maintain output from deposits that are increasingly difficult to access as shallower, higher-grade ores are depleted.