In addition, hazardous chemicals, such as mercury, crystalline silica, carbon monoxide, diesel or hydrocarbon fumes, cyanide and mica, associated with mining are harmful to health (Patra et al. Sulfuric acid is a toxic chemical used in copper mining. It is also a by-product of many types of mining, since it mixes with water and heavy metals to form acid mine drainage. Sulfuric acid smells like rotten eggs.
Contact with sulfuric acid can cause burns, blindness, and death. Biosorption independent of metabolism using dead biomass occurs due to the physicochemical interaction between metal and functional groups (carboxyl, imidazole, sulfhydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl fractions) present on the cell surface of the microbial cell. The family of chemicals containing “cyanide”, a combination of carbon and nitrogen, has been used safely and effectively for more than 130 years for the efficient extraction and recovery of gold and silver from ore. Although cyanide is an extremely toxic chemical under certain conditions and when found in sufficiently high concentrations, with adequate management and control of its use, cyanide has been used and continues to be used safely and without harm to humans or the environment.
If cyanide spills underground, or if the weather is cloudy or it rains, it can continue to be harmful for a long time, killing fish and plants along rivers and making the water unsafe for drinking and bathing. Another source of environmental pollution from gold mines are chemicals used in gold processing. More than 1.1 million tons are used annually in the production of plastics, adhesives, flame retardants, cosmetics, pharmaceutical products, food processing, metal processing, production of organic chemicals, photography, insecticides and anti-caking additives for table (food) and road salts. Mineral processing, also known as beneficiation, aims to physically separate and concentrate mineral minerals using physical, chemical, and sometimes microbiological techniques.
In many cases, various chemicals and reagents are used in the separation process and often result in irritating or corrosive skin exposures as a result. Waste, sludge and solutions containing leached material, water and waste cyanide are treated with different chemical and physical methods to reduce or eliminate cyanide left over from the gold dissolution process before it is discharged into a tailings facility. This passive absorption of metal is fast and reversible and the examples are: physical adsorption, ion exchange and chemical sorption. Chemicals used in the extraction and processing of minerals pollute land, water and air, causing health problems for workers and people who live near mines.
This mechanism is subject to environmental modification, availability and toxicity of the metal, to intrinsic biochemical and structural properties, and to genetic and physiological adaptation. In mining wastes, redox potential, physicochemical conditions, metal speciation and co-contaminants limit bacteria-metal interactions and bacterial activity. Environmental pollution from gold mines is mainly associated with the release of harmful elements from tailings and other waste from mines.