1. Home
  2. / Mining
  3. / What is mercury? How is it used to extract gold?
reading time 5 min read Comments 1 comments

What is mercury? How is it used to extract gold?

Published 04/02/2025 ร s 10:39
mercury, gold
Photo: Reproduction

Mercury is a fascinating metal, but its use in gold mining can pose serious risks. Find out how this process works and its consequences.

Mercury has played a key role in gold mining for centuries. Its unique ability to form amalgams with gold has made it an indispensable tool for prospectors and miners. handcrafted.

However, despite its effectiveness, the use of mercury has severe environmental and health consequences. This article examines the trajectory of mercury use in mining, its impacts, and emerging technological alternatives to mitigate its adverse effects.

Chemical characteristics and history of the use of Mercury

Mercury is a liquid metal at room temperature, an unusual characteristic among the elements in the periodic table. With a density of 13,6 g / cmยณ, it has high surface tension and a silver color. Its name derives from the Latin 'argentum vivum', or โ€œliving silverโ€, due to its shiny appearance and fluidity.

Historical records indicate that mercury was already known in Ancient Egypt, around 1500 BC, being used in medicine and alchemical processes.

However, its role in mining has been documented since around 750 BC, when ancient civilizations began using it to extract gold and silver from ores.

The process of amalgamation and gold extraction

The amalgamation method is based on the high chemical affinity of mercury with gold. When liquid mercury is mixed with sediments containing gold, an alloy called gold amalgam is formed. This process makes it easier to separate the gold from other minerals present in the rock.

After the amalgam is formed, the material is subjected to compression in a porous fabric, such as chamois leather, to remove excess mercury.

The mixture is then heated to temperatures above 356,7 ยฐC, promoting the vaporization of the mercury and leaving behind pure gold.

Vaporized mercury can be collected and reused, but in artisanal mining, it is usually released directly into the environment.

Environmental and public health consequences

Mercury volatilization during amalgam burning represents one of the greatest environmental challenges associated with mining.

Inhalation of elemental mercury vapor can cause chronic poisoning, affecting the central nervous system and causing symptoms such as tremors, memory loss and cognitive difficulties.

Furthermore, mercury released into nature can undergo methylation processes by bacteria present in soil and water, forming methylmercury, a highly toxic compound that bioaccumulates in aquatic organisms.

This poses a threat to communities that depend on fishing as a food source, as consumption of contaminated fish can lead to mercury poisoning.

The persistence of artisanal and small-scale mining (ASM)

Despite the known risks, artisanal mining still relies on mercury due to its low cost and simplicity of use.

An estimated 10 to 19 million people are involved in artisanal mining in more than 70 countries, mainly in developing regions.

This sector is responsible for approximately 37% of global gold production, releasing around 1.000 tons of mercury into the environment annually.

The lack of regulation and precarious working conditions contribute to the continuation of this method, especially in economically vulnerable communities.

Mercury contamination does not only affect miners, but the entire ecological and social chain surrounding the extraction areas.

Technological Alternatives and Sustainable Methods Faced with the need to reduce dependence on mercury, researchers and institutions have developed alternative methods for gold extraction. Techniques such as flotation, gravity concentration and the use of controlled cyanidation are being promoted as safer and more efficient alternatives.

The use of gravimetric centrifuges has shown promise, as it allows the separation of gold without the need for mercury.

Additionally, training and capacity building programs in sustainable mining practices have been implemented to raise awareness among communities about the risks of mercury and encourage them to adopt safer methods.

Global initiatives

Several international efforts have been made to reduce the impact of mercury contamination. The Minamata Convention, adopted by the UN in 2013 and ratified by several countries, establishes guidelines for the progressive elimination of the use of mercury in industrial activities and artisanal mining.

Furthermore, the implementation of portable sensors to detect the presence of mercury in mining areas can help mitigate risks.

Governments and NGOs have worked together to provide financial incentives for the adoption of clean technologies and to regulate small-scale mercury use.

Future Perspectives The transition to more sustainable mining methods depends on a multidisciplinary approach, involving effective public policies, technological development and social awareness.

With investment in innovation and a coordinated global effort, artisanal mining can be transformed into a safer activity for workers and the environment.

The use of mercury in gold mining, although historically relevant, poses a substantial risk to the environment and public health.

Mercury contamination remains a global concern, requiring continued efforts to mitigate its effects and replace its application with more sustainable methods.

Commitment to alternative technologies and effective regulations is essential to ensure that gold mining occurs in a responsible and environmentally conscious manner.

With information from iflscience

  • Reaction
  • Reaction
  • Reaction
  • Reaction
8 people reacted to this.
React to article
Registration
Notify
guest
1 Comment
Older
Last Most voted
Feedbacks
View all comments
Anti-scratch Dophata
Anti-scratch Dophata
05/02/2025 10:08

If the STATE stopped getting in the way of those who work, this would have a great chance of improving. The STATE wants gold? Let it pay for it, with a very low tax to discourage sales to competitors and legalize the money/product, for example 1%, and let the worker work.
Leave the market free, remove IBAMA and others from this, bring trustworthy people to the mines who can truly teach new techniques to the miners. Stop setting fire to machines and mistreating those who work there. Put an end to this story of indigenous lands the size of countries, and all sorts of prohibitions. Everything improves when everyone wants it to.

Fabio Lucas Carvalho

Journalist specializing in a wide range of topics, such as cars, technology, politics, shipbuilding, geopolitics, renewable energy and economics. I have been working since 2015 with prominent publications in major news portals. My degree in Information Technology Management from Faculdade de Petrolina (Facape) adds a unique technical perspective to my analyses and reports. With over 10 thousand articles published in renowned media outlets, I always seek to bring detailed information and relevant insights to the reader. For story suggestions or any questions, please contact me by email at flclucas@hotmail.com.

Share across apps
0
We would love your opinion on this subject, comment!x