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The government of Zimbabwe announced the ban of mercury use in mining and placed control on its release from industrial operations, joining several countries which have phased out the toxic metal, state media reported on the 29th of December. The ban will affect small-scale gold miners who used it to extract gold, but what are the alternatives in gold extraction and what business opportunities comes with the ban if enforced?
What is Mercury?
Mercury is a highly toxic element that is found both naturally and as an introduced contaminant in the environment. Research has shown that mercury is a threat to the health of people and the environment. It is considered by World Health Organisation as one of the top ten chemicals or groups of chemicals of major public health concern. The risk is determined by magnitude of exposure and the form of mercury present (some forms are more toxic than others).
What are the Effects of Mercury to Humans?
The effects of mercury exposure can be very severe, subtle, or may not occur at all, depending on factors such as the form of mercury, amount of exposure, age of exposed person, exposure period. The generalized dangers are:
- Permanent damage to the brain, heart, lungs and kidneys
- Toxic effects on the nervous, digestive and immune systems
- Loss of peripheral vision
- “pins and needles” feelings, usually in the hands, feet and around the mouth
- Lack of coordination of movements
- Impairment of speech, hearing, walking
- Muscle weakness etc.
Children are more susceptible to mercury poisoning than adults because their brains are still developing. For pregnant woman exposure to high levels of mercury can result in permanent damage to a developing foetus and causes miscarriages as well.
Who and how many people have been using it?
Small scale gold mining is one of the major release/emission source in Zimbabwe. It is estimated that the sector is responsible for over 1,600 tonnes per year of mercury emissions to the air and on land. It is estimated that Zimbabwe had approximately 500,000 artisanal miners, of which about 400,000 mine gold with a greater percentage using mercury in gold extraction. It is also said that only one in four miners knows the dangers of using mercury.
What are the effects of the barn to gold mining?
An estimated 500,000 Zimbabweans engage in ASM directly and at least 1.5 million people benefit from it directly and indirectly. For a number of years now, the ASMs Sector has been contributing more than 50% of gold deliveries to fidelity printers and refiners. Mercury made it easier for the majority of ASM to recover gold since it was not expensive to use and was simple. The barn, if enforced means less ASM will engage in gold mining and that means less deliveries to fidelity and families that benefited from ASM have to look for other means of survival.
Business Opportunities That Comes with the Barn:
- Cyanidation Technology Consultancy Services
Cyanide is the most used chemical for gold recoveries by the medium to large scale gold miners. It comes with less health hazards as compared to mercury, however, on the other hands it requires expensive technologies and has a bigger value chain so as to produce the bullion.
Cyanide being an alternative mineral, that means cyanide recovery technologies will be on a high demand and metallurgy technician and or engineers can offer consultancy services that will incorporate heap leaching and vat leaching, (being the cheaper technologies) intensive cyanidation (acacia plant) and also agitated leaching process design and improvement.
- Free Gold Recovery Machinery Sales
In most gold ores, there is what is called free gold. This is gold that can be recovered before applying chemicals and in most cases this is the gold that is recovered by mercury. To recover free gold, there is need to reduce ore size to the desired size and then use gravitational methods which includes the following machines: Knelson Concentrator (the most popular), Shaking Tables, Spirals only to mention a few. Manufacturing or retailing these machines can be a good idea since miners can sell the concentrates at a higher price than the ore.
- Free Gold Recovery Services
Since setting up cyanide recovery technologies and acquiring free gold recovery machinery might be expensive and uneconomic to some artisanal small scale miners, one may offer gold recovery services. These can be based on either one of the above mentioned technologies or both (cyanidation methods and free gold recovery).
Under cyanidation methods, one may set up processing plants, using any or all of the cyanidation technologies such as heap leaching, vat leaching (first two ideal for low grade ores, less 2.5g/t) agitated leaching (ideal for middle grade ores, above 3g/t), intensive cyanidation (ideal for concentrates recovered from free gold recovery methods, may be higher than 100Ggt).
- Gold Ore or Concentrate Buying
Gold ore or concentrate buying might be another business idea to consider. However, this comes as a bit complicated business that require accurate sampling and assaying procedures. Price will be determined by the nature of ore and grade.
In conclusion, most of the suggested ideas require expertise and it would be more ideal to hire or work with a metallurgy technician and or engineers
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