Manganese (not to be confused with magnesium) is a hard, brittle, silvery-gray metal. Comprising approximately 0.1 percent of the Earth's crust, it ranks among the most abundant terrestrial elements, although it occurs only within complex minerals and ores rather than as a pure metal.
Roughly 90 percent of manganese is consumed in metallurgy, mostly steel production, where it helps remove impurities such as sulfur and improves strength, hardness and wear resistance. For these traditional metallurgical applications, the industry utilizes low-purity bulk alloys, such as ferromanganese, or standard electrolytic metal refined to roughly 99.7 percent purity. Smaller amounts are used in aluminum alloys and other materials.
The second largest use is batteries, at about five percent. This is also the most rapidly growing application, specifically involving high-purity manganese sulfate used as a cathode material in electric vehicle lithium-ion batteries. Unlike the steel industry, electric vehicle manufacturers require an ultra-high purity level exceeding 99.95 percent. Even microscopic trace impurities of other metals can cause internal short circuits, degrading battery life or causing fires. Manganese is very much in demand for this application because it can improve battery stability and safety while reducing reliance on more expensive materials such as nickel and ethically compromised cobalt, yet the manganese supply chain carries its own severe human rights and labor concerns.
As electric vehicle adoption accelerates, the escalating demand for high-purity manganese intensifies its ecological footprint. Most manganese is extracted via large-scale, open-pit mining. This invasive process mandates extensive vegetation clearing and topsoil removal, triggering severe habitat fragmentation, biodiversity loss and accelerated soil erosion.
While terrestrial mining remains the standard, the industry is increasingly eyeing polymetallic nodules on the seafloor. This threatens fragile deep-sea ecosystems, which remain largely unmapped and unprotected.
Downstream processing presents severe environmental and public health hazards. Physical crushing, hauling and open-air stockpiling of the ore generate massive volumes of airborne particulate matter. Wind easily transports this dust over dozens of kilometers, blanketing local flora and disrupting photosynthesis.
Achieving battery-grade purity requires extensive, multi-stage chemical refining. This process is highly energy-intensive, contributing to greenhouse gas emissions and regional acid rain. Furthermore, dissolving ore in sulfuric acid generates vast quantities of acidic wastewater and electrolytic manganese residue. If storage tailing ponds leak or break, the highly acidic runoff strips the surrounding soil of essential agricultural nutrients such as nitrogen and phosphorus, while simultaneously leaching dissolved toxic heavy metals directly into nearby rivers and groundwater.
Although manganese is an essential trace element for the survival of humans and other organisms,* it operates on a strict biological threshold. Exceeding this limit through overexposure to manganese-contaminated drinking water or airborne neurotoxic dust bypasses the body's natural regulatory mechanisms, leading to irreversible neurological damage, including a Parkinson's-like condition known as manganism.
Enforcement of safety standards is particularly weak in the developing nations, where the majority of extraction takes place. To maximize immediate profits, mining corporations frequently forgo investments in safer infrastructure, such as modern dust-filtering systems or lined tailing dams. Consequently, toxic output expands unchecked, outpacing the global development of clean mining technologies.
The environmental threat extends far beyond the mines and refineries. During battery manufacturing, chemical releases frequently bypass regulatory reporting systems, contaminating local ecosystems. Current recycling infrastructure focuses heavily on recovering high-value cobalt and nickel; consequently, manganese is often lost in the smelting process as slag, representing a significant failure in the transition to a circular economy. More critically, at the end of their lifecycles, millions of electric vehicle batteries are discarded improperly. When these spent batteries degrade in landfills, the embedded metals can leak into the surrounding environment, causing long-term contamination of the soil and groundwater.
Despite these compounding environmental issues, global regulation and industry remediation lag far behind market growth. Because manganese is heavily marketed as a "green" metal vital to the energy transition, governments often expedite approvals for new mining projects while overlooking environmental regulations.
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*Manganese makes up less than 0.0001 percent of the human body by weight, with the majority concentrated in the bones, liver, pancreas and kidneys. It is indispensable for bone formation, blood clotting and the regulation of metabolism. Common sources of manganese for humans include nuts, beans, whole grains and leafy green vegetables. While rare, a deficiency can occur if someone is severely malnourished, leading to weak bones or growth problems. In plants, manganese is an essential element for photosynthesis.