Cyanide in mining


What is sodium cyanide?

Sodium cyanide is a chemical compound, highly toxic which is based on the anion CN.One teaspoon with a 2% cyanide solution can kill a man (1). In general, fish and aquatic creatures die because of significantly lower levels of cyanide, measured in microgram per liter (proportion / billion), while birds’ and mammals’ death occur in concentrations of milligrams per liter (part / million) (2).

Contrary to the RMGC propaganda, there is no scientifical study to support that there is sodium cyanide in coffee.

Coffee does not contain cyanides

Coffee does not contain sodium cyanides. There is no study, nowhere in this world, no measurement, to prove that sodium cyanide is present in coffee. 
Excerpts from Fight for Rosia Montana

The argument that coffee contains cyanide is one of the mining companies favorite argument to convince the world of the safety of cyanide mining. Projects’ websites such as Newmont Mining Corporation (shareholder at the project Rosia Montana) or Kingsgate Consolidated Limitedclaim the existence of cyanide in coffee and respectively give concentrations of 5-10 ppm, but there is no source from where they offer this data.

I read the scientific studies mentioned on the websites of these companies and other studies from international literature (major sudy reviews of Eisler R. 1991, US Fish Wildlife Service, Biol. Rep. 85, si cel al lui Conn E., 1980, Ann Rev Plant Physiol31:433-451), but there is only mentioned the potential generation of HCN (cyanhydric acid) by certain types of plants.

I haven’t found anywhere data on the presence of sodium cyanide (used in mining) in coffe beans, and even less information about a possible concentration of cyanides in coffee. What is known for sure, is that some plans’ seeds, as apples or apricots, contain compounds that react with the acid in the stomach and thus generate cyanhydric acid, that can lead to acute poisoning.

Sodium cyanide used in mining is far from similar, even in low concentrations, to cyanogen compounds present in certain plants in nature.

The scientific studies of Ronald Eisler (U.S. Geological Survey) and others: annually, more than 20,000 tons of hydrogen cyanide are released into the atmosphere from the gold mining.

Cyanhydric acid (extremely toxic, used for gassing prisoners in extermination camps) remains fairly stable in the atmosphere (it’s not rapidly destroyed by the action of ultraviolet rays as claimed by RMGC), with a time of persistance of over 267 days (see Korte & amp; Coulston, 1998).

Following the questions raised by companies producing coffee, two of them denied the existence of cyanide in the coffee they sell. Below you can find their answers:


What is cyanide used for?

Sodium cyanide (NaCN) is used in mining of precious metals, particularly gold mining. In mining, cyanide has been used for around 40 years as a large scale agent for obtaining gold and silver. Using cyanide, 97% of the gold can be extracted from the ores. After the gold is extracted, the solution contaminated not only with cyanide, but with a large amount of heavy metals too is deposited in tailings ponds. These residues resulting from gold mining activities pose a serious threat to human health and the environment and should not be released into the environment.

Gold mining is the largest consumer of cyanide, with over 180 000 tonnes / year. The cyaniding method is most often used irresponsibly (3) causing spills (4) with devastating effects on the environment and human health. In addition, cyanide reacts with the other components, being broken down into hundreds of cyanide-containing compounds at various concentrations. Studies show that these compounds are deposited in the plants and fish tissues and can persist into the environment for a long time.

How is cyanide being used in mining?

Cyanide leaching allows the extraction of gold microscopic granules from poor ores and involves:
Surface quarrying produces huge size craters that destroy ecosystem and leave behind lunar landscapes
Crushing large amounts of rock in huge tanks and spraying them with cyanide solution which separates the gold for further processing.Cyanide combines with 97% gold (5), including those particles too small to be seen with the naked eye.
Obtaining from a ton of ore aproximately 2 grams of gold. (6)

In 2010, MEPs voted with 488 votes in favor, 48 against and 57 abstentions, a resolution that bans the use of mining technologies based on cyanides in the European Union. Unfortunately, European Commission left the implementation of this resolution into the national laws to the Member States. Czech Republic, Hungaria, Bulgaria, Germany, Costa Rica, several provinces of Argentina and the U.S. states of Montana and Wisconsin have banned cyanide mining.

Cyanide effects –case study: Marlin Mine, Guatemala

Experts say that skin rashes and respiratory effects “are specific to cyanide exposure,” but the many cases reported in the Marlin Mine in Guatemala have not been the subject of study. Tthus, the Goldcorp representatives allowed themselves to state that “there is no evidence of a direct link between the use of cyanide and these cases” … Although:


“Maximum concentrations of cyanide, copper and mercury are more than 3, 10 and 20 times the standard IFC” – water tests conducted by E-tech International into the tailing ponds in 2006;
“Biological samples taken from some residents in the vicinity of the mine revealed higher levels of mercury, copper, arsenic and zinc in urine and lead in blood, compared to people living at 7 km away from the mine.” – Study researcher from the University of Michigan, published in 2010.




Cyanide is one of the poisons with the most rapid effect. Cyanide inhibits respiration, altering cellular transport of oxygen to the brain, blood pressure decreases. An initial symptom of cyanide poisoning is blushing, because the victim can not process oxygen in the blood. Upon the ingestion of 100-200 mg of sodium cyanide heart rate drops below 60 beats per minute, and the poisoned person falls into a coma or convulsions in just few minutes. Death by suffocation or cardiac arrest may occur within a few hours depending on the strength of the body. (7)

Lethal dose for humans is 1 mg CN‾/ kg body weight.Only 0.03 mg of CN ‾/ l water is deadly to some fish, others can tolerate up to 0.2 mg / l. At concentrations above 3 mg NC ‾/ l, a river is dead.

Sodium Cyanide (8)
Chemical formula: NaCN
Aspect: white, solid
Water solubility: 48 g/100 ml (10°C)
Solvent solubility: Alcohol
UE Classifications: very toxic (T+) dangerous for the environment (N)


Cyanides – Associated risks (9)

Complex chemical behaviour

The term refers to chemical compounds formed by CN (one carbon atom and a nitrogen atom). Although there are some bacteria and plants that naturally produce cyanide compounds, generally only polluted rivers contain identifiable concentrations. As cyanide based compound is a C – organic compound – it reacts rapidly with other organic compounds, including organisms. However authorities require mine operators to monitor only three cyanide compounds – free cyanide, weak-acid-dissociable (WAD) cyanide and total cyanide. Other compounds such as cyanates and thiocyanates often exceed values of tens of milligrams per liter (mg/l) although values above 0.05 mg/l are considered very toxic (0.02 mg/l in Germany).

Accidents and cyanide spills

bijuterii cianura

In recent years, leaks, spills and accidents which have as a common denominator cyanide were recorded worldwide. These accidents raise questions about the practice and application of regulations regarding cyanide management. Thus cyanide affect local communities watercourses, groundwater.

Environmental pollution (10)

Incredibly small amounts of cyanide kills river fish which is then turned into a dead stream. Effects of cyanide discharges persist in the environment for years, and the solution of cyanide tailings lakes that are affecting the ecosystem, but also birds and wild animals who drink poisoned water. Cyanide is a powerful solvent for heavy metals such as mercury, cadmium and chromium who end up in open spaces after ore treatment.

Example. The amount of cyanide (120 t), which has been discharged into the environment in 2000 when the accident occurred at a gold processing plant in Baia Mare gold would have been sufficient to kill about 1 billion people. In few days, the fauna of the 700 miles of river courses in Romania and Hungary was completely destroyed. (11)

Mining Accidents

 Mining Accidents (1998 – 2006) (12)
Ghana –On July 18, 2006 a discharge of Bogoso Gold Limited (BGL) mine tailings polluted Ajoo river killing fish and lobsters. 30 people who consumed fish and water from the river required medical treatment.
Romania – On November 28, 2005, a cyanide spill at the Borsa mine threatened to pollute the Tisa river. (source: Bucharest Daily News).
Philippine –Between 11 and 31 October 2005 cyanide spills were recorded from the Lafayette – Rapu Rapu exploitation, causing pollution of nearby rivers. (source:
Laos –On June 20, 2005 a cyanide spill at Phu Bia mine owned by Pan Australian Resources poisoned the water sources surrounding communities within a radius of 3 km. Between 60 and 100 people required medical attention. (source: The Mineral Policy Institute).
Ghana – On October 23, 2004 a cyanide spill happened because of the Bogoso Gold Company Limited newly constructed dam. The rivers Aprepre, Egya Nsiah, Benya and Manse were polluted(
Australia – A report commissioned by the government of Western Australia in October 2004 shows that the Kalgoorlie Gold mine tailings lakes are responsible for groundwater contamination with cyanide and heavy metals. This study comes after a ten years period during which time there have been complaints from local communities on water quality, but the mining company denied the existence of these problems.(source: Robin Chapple, MLC, WA Legislative Council).
New Guinea –On August 7, 2004, a leak of cyanide from the Misima Mine; Placer Dome company caused the pollution of the ocean, seriously affecting marine life.(source: The National, PNG, 11 of August).
China – Chinese authorities released on June 25, 2004 informations on the production of seven toxic accidents that killed 21 people. The last of this series was a gas leak (hydrogen cyanide gas) from the processing plant of a mining operation that led to the deaths of three people and hospitalized another 15. (Source: People’s Daily Online).
New Zeeland – On March 24, 2004, 35 people were evacuated from the Lower Hutt company’s warehouse due to a leak of 360 liters of cyanide solution .
Romania – On March 18, 2004, Siret river was found polluted with cyanide . The leak occurred at the processing plant in Baia Mare, because the international standards for storage were not met. It is estimated that 10 tons of toxic substances leaked into the river. (Source: Reuters).
Ghana – On May 29, 2003 one of the three new drains used for waste cyanide at the Tarkwa mine broke, releasing significant amounts of toxic into the environment. (Source: Mining Watch Canada).
Nicaragua – On January 14, 2003 a cyanide spill from mines Hemconic / Greenstone led to the pollution of the river Bambana. Representatives of local community reported the deaths of 12 children who allegedly drank water from the river. (Sursa: Buletinul WRM, nr. 74, septembrie 2003).
Honduras – A massive cyanide spill occurred in January 2003 at the Andrés mine, polluting Lara river , the drinking water supply of the city of Santa Rosa de Copán. 18 000 fish died, the river is now considered dead.
USA – On December 2nd, 2003 has been reported a cyanide spill near the Balleratt Briggs mine.
Nevada, USA – On June 9th, 2002, 21 kg of cyanide leaked into the environment at the Denton-Rawhide mine.
Nevada, USA – In May 16, 2002, 104 cubic meters of cyanide solution leaked from the mine Twin Creeks belonging to the Newmont company. A Nevada state official said that approx. 45 I arrived in the golf polluting its waters. In recent years, the developer of the Crandon mine caused two major spills: 5.8 tons of cyanide in the state of Arizona and 229 000 m in the Arizona Gulf. (Source: Humboldt County News – 16 mai 2002).
China –In November 2001, 11 tons of sodium cyanide leaked into a affluent of the Luohe River, as a cause of a road accident.
Ghana – In October 2001 in Ghana there were two spills at the Goldfields mine. The first decimated the Asuman River, while the second polluted a marshy area which was the local’s supplier of fish, herbs and bamboo.
Papua New Guinea – On June 30, 2000, cyanide discharges from Rio Tinto mine leaked into the ocean, polluting the water around the island.
Colorado, USA – Summitville Mine owned by Galactic Resources Ltd. Caused the poisoning of Alamosa River for a distance of 17 miles. The mine was closed in 2002 because the company went bankrupt. Greening costs of $ 150 million were supported by the American state.
Nevada, USA – Following the dam cracking of a tailings lake at the Gold Quarry mine in Nevada in 1997, 1000 cubic meters of cyanide were spilled into two bays nearby. Between 1998 and 1990, eight cyanide accidents occurred at mines McCoy / Cove – thus Echo Bay Company releasing 408 kg of cyanide in the environment.
Guyana –In 1995, more than 3 million of cubic meters of waste cyanide leaked into a river in Guyana when a dam of the Cambio mine collapsed – Omai mine crumbled.
Dakota, USA – On May 29, 1998, seven tons of cyanide leaked from the tailings pond at the Homestake mine in Gulf Whitewood that caused massive death of fish.
Spania – A dam at Los Frailes zinc mine broke in April 1998, 13 million cubic meters of waste from heavy metals reached the nearby river and the farmlands.
Kyrgyzstan – On May 20, 1998, a truck transporting cyanide to the Kumtor mine overturned, two tons of sodium cyanide reaching surface waters in the region. Hundreds of people received medical attention and one person died.

Cyanide and jeweleries

• A single ring leaves behind 20 tons of mine waste.
• Huge risks for the environment and human health are taken for producing new jewelry – rings, bracelets, necklaces. 85 % of the gold extracted is directed to the manufacture of jewelry and only 12% is used in industry.
• In addition, gold reserves held by banks worldwide are at 35 000 tonnes , which would meet the global demand of gold for the next 8 years . If our demand for gold jewelry could be significantly reduced, bank reserves would last for a century. (Continued on page 4 ) Cyanide and jeweleries.
• Exploiting ores need only 0.09 % workforce globally and consumes 10% the world’s energy. • Exploiting ferrous ores is No. 1 toxic polluter in the U.S.,responsible for 89 % arsenic pollution and 85 % mercury pollution.
• The largest mine in the world, Bingham Canyon in Utah is visible to astronauts in space; it is 1.5 km deep and 4 km wide. Hycroft mine spill / Crowfoot , Nevada.
• In the last 25 years , the major causes of pollution with cyanide were breaking / cracking tailings dams lakes ( 76 % ) , rupture of pipes (18 % ) and accidents during transport ( 6%). (x)


References (1)

(1) Project Underground. ‘The Gold Album’ 19 February 2004
(2) Moran, Robert. ‘Cyanide Uncertainties: Observations on the Chemistry, Toxicity, and Analysis of Cyanide in Mining-Related Waters’ 1998. Mineral Policy Center. 20 February 2004
(3) Blouin, Dave. ‘Crandon Proposal: Cyanide Issues’ February 2000. Wisconsin Stewardship Network. 20 February 2004 <>.
(4) Huff, Andrew. ‘Gold mining threatens communities’ 11 July 2000. The Progressive. 20 February 2004,
(7) Chemical Agent Fact Sheet, Federation of American Scientists
(x) ‘Development of an International Code for the Management of Cyanide in Gold Mining’ Washington, D.C.: United Nations Environment Programme, Division of Technology, Industry, and Economics, 26 September 2002. Mineral Resources Forum. 19 February 2004 <>.
(9) ibidem (2)
(10) ‘Sodium Cyanide Hazards to Fish and Other Wildlife from Gold Mining Operations’ Ronald Eisler -Donald R. Clark Jr. -Stanley N. Wiemeyer -Charles J. Henny,
(11) UNEP, March 2000, Cyanide Spill at Baia Mare, Romania

Decoding Cyanide.