Extracting gold from the ore among artisanal farmers have traditionally involved metallic mercury in order to amalgamate the gold and afterwards evaporate the mercury. Mercury poses well-known hazards to health and environment. Therefore alternative methods have been introduced to replace mercury. An alternative method is using borax, which is mixed with a concentrate of the heavy metals collected by washing the ore, and heated with a burner thereby extracting the gold.
Substituting a method by another always leads to concern about introducing unwanted health risks to the miners, their families, and the environment.
Mercury on one hand is a neurotoxin and the concentrations reached during amalgamation and evaporation are within the levels causing health effects to the worker and to bystanders. Additionally, the exposure to the family may be considerable due to evaporation from spills and from the debris after mixing mercury with the ore.
On the other hand heating borax emits boron to the air and the worker may be exposed. In animals boron in high doses can cause testicular impairment and impairment of fetal and infant neurodevelopment must be considered. This and possible other hazards related to the method may be taken into account.
The presentation will discuss these pro and cons when introducing an alternative method to extract gold not using mercury.