AMA-GCMF GLobal Community Miners Forum reposted this
The journey towards reducing and eventually eliminating the uncontrolled use of mercury in artisanal gold production progressed this week. Testing the four parts of Appropriate Process Technologies (APT) GroundBreaker system by Solomon Opiyo and John Asembo continued on John’s mining site in western Kenya. This system is so new that it is not yet being marketed by APT and only three of their brand-new GoldKacha-mini (miniGK) gravity concentrators have been manufactured to date. So, getting a prototype for end user testing by miners has been quite a coup, although nerve wracking! APT ran tests on the device at their workshops in Harare and Johannesburg before giving me the thumbs up to purchase a prototype, and these are the very first results from an operating mine. The guys are very impressed by the simplicity, good gold particle recovery and labour-saving speed of the miniGK over present sluicing methods, which are muddy, messy, slow and require hessian blankets to be periodically washed and re-laid on makeshift planks. It is this capacity of the GoldKacha (GK), and now the miniGK, to improve the working lives of women miners, particularly when re-treating dump materials that caught my attention originally. I introduced the first application of the GK into Uganda some years ago and women in mining were pleased with its productivity. It has now taken off in artisanal and small-scale gold mining, especially in Ghana; however, this much smaller version, the miniGK is now proving itself commercially. The second device in the system is the GoldGrader sluice which Solomon Opiyo attached to the miniGK and whose job is to catch any gold particles that may have escaped in the overflow waste slurry. Using his electronic scale, Solomon established that the gold captured on the sluice mat was only about ten percent more than that extracted by the miniGK. This means the miniGK is very efficient in gold recovery, as well as being much quicker than traditional sluicing. So far, the guys have only treated tailings from nearby dumps with newly mined, higher-grade ores to be tested next, which is when the ten percent extra recovery will be significant. John and Solomon are now building a shed over an even floor to mount the miniGK and GoldGrader and sort out the optimum water flow by fitting a backup pump, hoses, and gate valves. A correct and then consistent flow of water-based slurry is presently being determined and this will further improve gold recoveries. Word limits mean I will report on other equipment supplied with the GroundBreaker system in my next post, but it’s good news all round. Solomon and John are very positive. There is still work to be done, as would be expected, to optimize the miniGK and GoldGrader throughputs. Then we can invite miners and mining enterprise owners in the vicinity to see a way forward for an absolutely bottom-up approach to mercury-free mining...