Dear Commissioner Mrs Margot Wallström,

Commissioner

Mrs. Margot Wallström

EU-Commission

200 Rue de la Loi

B-1049 Brüssel

Dear Commissioner Mrs. Margot Wallström,

last month Prof. Korte (Emeritus of the Institute of Ecological Chemistry, Technical University Munich) being concerned about of cyanid in mining industry wrote a letter to the President of the EU-commission Prof. Romano Prodi.

One of the outstanding merits of Prof. Korte’s scientific work is the fixing of principles of chemical and biological testing of industrial chemicals. He made his conclusions more than 30 years ago, long before decision makers in industry became aware of side effects of chemicals. This testing scheme has been refined the last two decades but is still the basis of the chemical act in all EU-countries. In many aspects Prof. Korte is and was the leader of the understanding of chemicals which are suspected to accumulate in organism or men and hold to be responsible for ecotoxicological effects.

The role of cyanid in the gold recovery process is the subject of Prof. Korte’s research and political activities since the last 10 years. I adopted some of this ideas and would like present you some facts necessary to survey the dimension of the problem associated with the cyanid leaching gold recovery process (CLGR).

FACT 1

The term cyanide refers to numerous compounds, most of them are man-made but few are natural. More than 80 percent of the commercially produced cyanides are used to produce organic chemicals such as nitriles, nylon or acrylic plastics which are used all over the world in millions of tons. The production of these chemicals and the resulting products can be considered to be save because the best available technology in chemical industry is used and many safety precautions are obeyed.

FACT 2

In gold extraction, a diluted cyanide solution (0,05%) is sprayed on gold containing crushed material that is placed in open air piles, commonly called heaps. The cyanide readily forms a water soluble complex from which the gold can be recovered. The cyanide and not precipitated heavy metals remain in open air basins, many of which are present even after closing the mining activities.

FACT 3

Cyanide is highly toxic to organism and men (LD₅₀ KCN 3 mg/kg due to blocking of Fe³⁺ in cytochrome a) but also the degradation products like ammonia or nitrate are toxic to organism in the environment. The mining industry has claimed that diluted cyanide solutions can readily be decomposed to “almost” non toxic compounds thus making the process save.

The three best known “detoxification” processes are:

Chlorination:

Intermediates

cyanates, cyanogen chloride, chloramines, hypochlorite

SO₂/Air-Process (INCO):

Intermediates / End Products

thiocyanates, sulfuric acid, cyanates

H₂O₂-process (Degussa):

Intermediates

metal hydroxides, coppperhexacyanoferrate

All other processes are based on the same degradation procedures and the biological process is limited to low cyanide concentration and sophisticated, costly equipment is needed.

CONCLUSIONS

As to be seen from the above mentioned equations a complex mixture of cyanate (NCO^-), cyanogen chloride (ClCN), chloramines (NH₂Cl), thiocyanate (SCN^-), cyanogens (NC-CN), nitrate (NO₃^-) and ammonia (NH₄⁺) is formed many of which are not measured by routinly methods. For instance the WAD-method (weak acid dissociable cyanide) does not detect cyanates, thiocyanates, cyanogen chloride or iron cyanide complexes. Significant release of HCN and volatile metabolites are so far not considered although they are likely to occure and can act as climate relevant gases with high persistence. However, during processing the cyanide solution is kept at alkaline pH values to prevent the formation of HCN-gas and poisoning of mine workers.

From the environmental point of view almost no data are available on the chronic effect of the above mentioned anions and their complexes with heavy metals.

The problems with the CLGR-process could only be handled if one major problem would not exist: the quantity of cyanide used world-wide in gold mining industry.

To recover gold from 250.000 t of rocks with a gold content of 3 g /t 125 tons of sodium cyanide are needed and 365.000 m³ process water is generated. It is simply impossible to process these hough quantities as safe as it is required in chemical industry.

In fact the gold recovery process via cyanide is an open air chemical process which would never be tolerated under the rules of the chemical act. Therefore the gold recovery via the CLGR-process has nothing to do with conventional mining. World-wide nowadays approximately 2.500 t of gold is produced by means of the CLGR-process. Even if the gold content is 10 g/t (which is considered to be high) on a world-wide basis estimated 2.000 t of gold recovered via the CLGR-process (total gold demand year 2000: 3.000 t) would require more that 100.000 t of sodium cyanide and produce an unmeasurable amount of waste water which cannot be handled safe by any technology available in the present.

As we know from the chronology of the disasters encountered with the CLGR-process every second year a major accident occours the last one on January 30, 2000 near the city of Bai Mare in Romania. The next disaster is predictable if not immediate regulations for the CLGR-process are issued which are in agreement with the regulations for handling and processing of chemicals.

Respectable commissioner Mrs. Margot Wallström I urge you to prepare all necessary measures to prevent the environment and the people in the EU from a foreseeable accident caused by the CLGR-process. I’m sure that no independent EU-Council recognizes the problems encountered with the CLGR-process in its full dimension.

Together with Prof. Korte and many collegues of independent research institutions I suggest a roundtable discussion dealing with the present and future dangers and assure you of my help and assistance in the fight against this horrible but predictable environmental desaster.

Sincerely Yours

(M. Spiteller)

Dortmund, 12.03.2001