Busia gold ore processing competition

Months of preparation and why this was necessary

Many times, we hear about the comparison between two systems through mere theoretical estimations by product manufacturers, but how often do we check the realities? A practical comparison of sophisticated gold mining processing equipment was put to test against the conventional gold processing method that Busia’s Tiira Miners use, in their mining endeavours.

Cyrus Njonde, a mining engineer at the Impact Facility installed, tested and commissioned the Gold Kacha and Shaker Table in May 2019 in partnership with local equipment provider, Borassus. Busia gold miners, however, have been reluctant to use this resource citing inefficiency claims. They simply did not like the gold recovery amount and the mercury reduction technique employed by the system. It was therefore necessary to set a date, time and place where a comparison test would reveal which method yielded higher gold turnover out of the same amount of ore.

During a follow up visit late 2019 with representatives from RVO (the Netherlands Enterprise Agency) and Fairphone, promised mine leaders a $100 incentive should their conventional method beat the Gold Kacha method. The latter was imported from South Africa’s Appropriate Processing Technology (APT) through funding from Comic Relief in partnership with Fairtrade Foundation, Fair Trade Africa and The Impact Facility and local partners.. The objective of the comparison test was to help miners embrace the new method and incentivize behaviour change, if proven more effective.

The competition day

On 11th March 2020, partners and miners alike headed for Tiira to witness the conquest. The experiment was conducted in the presence  of three Artisanal Mining Groups namely, Busia United, Tiira Landlords and Tiira Small Scale Miners all boasting of 20 miners. Partners in attendance included Mr. Joshua Rukundo (Solidaridad), Mr Peter Kibathi (Fairtrade), Ms Rose Auma (EWAD) and Eng. Cyrus Njonde (The Impact Facility) who doubled up as the event’s coordinator.

One of the miners, a fully trained operator, who was well versed with the new equipment, set all things in order by making two mine workers available in preparing the crushed ore and assisting during both processes.

Ore preparation and equal division for precision

Crushed ore ready to be washed
The Impact Facility demonstrating with Gold Kacha

Approximately 90kg of crushed ore, prepared by Tiira Small Scale Mining Association, was brought in a sack. It was subdivided it using the standard 35kg basin to produce two and a half basins worth of ore, making two portions of 45kg each. 

New method: Gold Kacha

The first portion was taken through the Gold Kacha method, with Swiss journalist Magali Rochat documenting the event. It involved the use of a sluice mat to help capture any loose gold material that would end up as waste at the end of the processing. The recovered concentrate then was amalgamated with a few grams of mercury resulting in a ball amalgam, which was burnt to obtain gold pellets that were weighed on the scale.

Cyrus demonstrates the Gold Kacha as the first method

Traditional method: Sluice box technique

The second ore portion, sluiced and panned by locals, was processed using the conventional sluicing method.  Observing participants took a 50m stretch away from the facility plant to the sluicing pond, where the recovered gold was also amalgamated, burnt and weighed.  

Busia women washing by the traditional sluicing method

The second ore portion, sluiced and panned by locals, was processed using the conventional sluicing method.  Observing participants took a 50m stretch away from the facility plant to the sluicing pond, where the recovered gold was also amalgamated, burnt and weighed.  

Gold particles
Burning the mercury off without a retort.
Burning the amalgum
Weighing the gold

Weighed comparison test

The weight results for each of the amalgamated gold balls, sourced from every 45kg ore portion, registered as follows:

Community reaction

The process came to a close and the artisanal miners, leaders and the whole group in attendance verified that the Gold Kacha system was superior and effective compared to the localized processing method. One miner added that the new method produced smaller concentrate quantities, making it possible for miners to apply reduced amounts of mercury, in the amalgamation process. Unfortunately, due to the need for demonstration and video recording, both methods were not accurately timed therefore observing parties could not verify the actual time it took to get both processes done. Having said that, experts estimate that it takes half the time to process the crushed ore using the sluice box system, in the Gold Kacha and Shaker Table.  Given the visible proof on site, miners, now fully convinced, promised to use the facility brought to their trade for better results. In fact, one miner was seen engaging the Gold Kacha method shortly after the exercise was done. 

$100 promise for the winning system

The Impact Facility offered the $100 cash reward (an equivalent of about Kshs. 10,000) to the Busia Women team, awarded by RVO alongside Joshua Rukundo.  The team has a savings plan where they intend to keep some of the money as well as investing wisely, maintaining an accountability record for every purchase they make on behalf of their business. Mining groups were encouraged to try employing new technologies in their trade to maximize output through efficient means such as was demonstrated in this comparison test.

Memorandum of understanding for the new equipment to Busia miners

Cyrus Njonde then discussed the Memorandum of Understanding for subsequent investments in equipment with the Impact Facility with three Tiira Artisanal Mining Leaders, explaining to them the particulars they would discuss internally, before receiving any new mining equipment. This was necessary due to the new set of mining compressors and high-level water pumps miners would receive for their flooded mine pits. The leaders would furnish The Impact Facility with several requirements after which new machinery would be ordered, shipped and delivered to the community within a short period, giving miners the chance to repay the equipment with ease.  Mr. Peter Kibathi of Fairtrade Africa ended the evening by thanking everyone in attendance for their participation while the leaders of Busia United and the Tiira Landlord Association also thanked all partners for their overwhelming support for the artisanal mining sector.

The bigger vision

This is just one small step to mercury elimination, but it is hoped that by gaining the trust of local enterprises in the new processing equipment, in parallel with investments into mine productivity, that in the future, there will be sufficient ore production and momentum to enable a transition to mercury free processing at Busia and for surrounding mine sites.