Chemical and nano-mineralogical study for determining potential uses of legal Colombian gold mine sludge: Experimental evidence

Abstract

The present study is focused on the chemical and nano-mineralogical characterization of sludge from gold mine activities, in order to put forward diverse solution alternatives, where lack of knowledge has been found. The sample was collected from "La Estrella" mine of Suarez, located in Department of Cauca, south-west Colombia. The sludge micro-structure and chemical composition were analyzed using a high resolution transmission electron microscopy (HR-TEM) equipped with a dispersive X-ray detector (EDS). X-ray diffraction technique was employed to identify the mineralogical phases present in the sludge. Additional mineralogical characterization was done by using RAMAN spectroscopy. Main findings points to its potential to be used as a fertilizer, this is why, mine sludge contains macronutrients such as P, Ca and S, together with micronutrients like Cu. However, the presence of goethite could decrease the mobilization of nutrients to soils, thus additional alternatives, for instance, a mixture with humus or another material containing Humic Acids should be done, in order to minimizing its retention effect. Additionally, another possible uses to explore could be as construction and ceramic material or in the wastewater treatment for nutrient retention and organic material removal. Rutile (TiO nanoparticles) particles have been also detected, what could cause health concern due to its nanoparticle toxic character, mainly during gold extraction process.

Photosynthetic pigments in acid mine drainage: Seasonal patterns and associations with stressful abiotic characteristics

“…One of the most extreme environments caused by human actions is produced by acid mine drainage (AMD), mainly related to legacy of historic coal and metals mining (De Vallejuelo et al, 2017;Gomes et al, 2018;Olías et al, 2019;Nordin et al, 2018;S anchez-Peña et al, 2018). AMD results from the oxidative dissolution of sulfides in a process with a strong biochemical component, as it is accelerated by the presence of microorganisms (e.g.…”

Geochemical and environmental assessment of potential effects of trace elements in soils, water, and sediments around abandoned mining sites in the northern Iberian Peninsula (NW Spain)

“…However, it contains significant levels of As, Cd, Hg, Pb, and Sb in average concentrations of 1.5, 0.2, 0.08, 13, and 0.2 mg/kg, respectively, in the earth's crust [ [7] , [8] , [9] ]. The composition of water resources can be affected by different factors, one of which can be acid mine drainage and leachate, suspended solids, soil erosion, mining waste in surface waters [ 10 ], dispersion in rivers rainfall, and other hydrological processes [ 11 , 12 ]. Acidic solutions produced by mine drainage and industrial activities can reach the surface water or groundwater according to the hydrogeology of the site, leading to the deterioration of water quality by accumulation and transport of sediment that is detrimental to health [ 13 , 14 ].…”

Characterization of high-grade gold deposits of the northeast of Antioquia-Colombia

“…In municipalities in northeastern Antioquia that exploit gold, such as Segovia, Remedios, Anorí, Amalfi, and Vegachi, artisanal mining has a significant presence, along with its parallel problems of illegal exploitation, indiscriminate use of mercury and cyanide, informal gold extraction, mining accidents, and river contamination. Two alternatives for solving the problem of mercury in gold mining have been proposed [13]: mining legalization, which is the government's responsibility from a social policy standpoint [14,15,16], and improvement of mining processes [17][18][19].…”