scholarly journals A Lantern Retort for Small-Scale Gold Extraction

2014 ◽  
Vol 2 (5) ◽  
pp. 161
Author(s):  
Richard Kwasi Amankwah
Keyword(s):  
Small Scale ◽  
Gold Extraction

scholarly journals The Borax Method of Gold Extraction for Small-Scale Miners

2012 ◽  
Vol 2 (3) ◽  
pp. 5-10 ◽  
Author(s):  
Peter W.U. Appel ◽  
Leoncio Na-Oy
Keyword(s):  
Heavy Metal ◽  
Melting Point ◽  
Scientific Research ◽  
The Philippines ◽  
Toxic Element ◽  
Heavy Mineral ◽  
Small Scale ◽  
Gold Extraction ◽  
Reducing Costs ◽  
Capture Rates

Background. More than ten million small-scale miners (SSM) worldwide use mercury to extract gold, releasing large amounts of the toxic element into the environment. Alternatives to mercury have been suggested over the years to little avail. A group of miners in the Philippines has demonstrated that borax, when used as a flux for smelting gold out of heavy mineral concentrates, is an effective and safer substitute for mercury. Objectives. To present a basic comparison of the mercury amalgamation and borax methods of gold extraction for SSM. Methods. Borax was added to milled ore to reduce the melting point of gold to a level accessible to SSM. The amount of gold captured, and the amount of mercury released into the environment, was compared to two common amalgamation methods: whole ore and heavy metal. Discussion. The borax method appears to capture more gold, as well as eliminate the use of mercury. It is also less expensive. It is important to stop the use of mercury amongst SSM. However, health and environmental arguments alone are not enough to convince miners to switch. The argument of improving gold-capture rates while reducing costs is more compelling, and may help propagate the technique among small-scale miners. Conclusions. Scientific research should continue in order to further establish the uses and limitations of the borax method.

scholarly journals Optimizing soil washing remediation of mercury contaminated soil using various washing solutions and solid/liquid ratios

2020 ◽  
Vol 148 ◽  
pp. 05004
Author(s):  
Agus Jatnika Effendi ◽  
Vina Lestari ◽  
Mohammad Irsyad
Keyword(s):  
Distribution Coefficient ◽  
Potassium Iodide ◽  
Contaminated Soil ◽  
Soil Washing ◽  
Mercury Contamination ◽  
Small Scale ◽  
Gold Extraction ◽  
Washing Process ◽  
Fractionation Analysis ◽  
Solid Liquid

Most of the artisanal and small-scale gold miners in Indonesia as in the case of those who are in Banten Province, still use the amalgamation process in the gold extraction process. Therefore, mercury contamination could not be avoided. As a result, it was found that the concentration of mercury-contaminated soil in Lebak, Banten Province was detected as high as 136,9 mg/kg. Since the contamination process occurred for a long time, making the formation and mobility of complex mercury in soil increased by time. Soil washing is one remediation technology that can be applied in the recovery of mercury-contaminated soil. This study aims to determine the optimum conditions of the soil washing process: effect of pH, the concentration of washing solutions and ratio of solid/liquid. Furthermore, the value of the distribution coefficient, desorption of mercury in the soil and fractionation of mercury in the soil were also observed. Potassium Iodide was found to be the best washing solution among others used in this study. The optimum condition was obtained at pH 2, the concentration of washing solution at 0.25 M and the solid/liquid ratio of 1:15. Under these conditions, mercury desorption efficiency reached 86.9% with the value of the distribution coefficient of 0.185. Mercury fractionation analysis in the contaminated soil showed that the mobile > semi-mobile > non-mobile fractions. Potassium iodide was able to desorb at about 84% of mobile fractions, 97% of semi-mobile and 25% non-mobile mercury.

scholarly journals The Borax Method of Gold Extraction for Small-Scale Miners

2012 ◽  
Vol 2 (3) ◽  
Author(s):  
Peter Appel ◽  
Leoncio Na-Oy
Keyword(s):  
Small Scale ◽  
Gold Extraction

scholarly journals Analysis of the Mercury Distribution in Blood as a Potential Tool for Exposure Assessment — Results from Two Artisanal and Small-Scale Gold Mining Areas in Zimbabwe

2021 ◽  
Author(s):  
Anna-Maria Wahl ◽  
Stephan Bose-O’Reilly ◽  
Viola Mambrey ◽  
James P. K. Rooney ◽  
Dennis Shoko ◽  
...  
Keyword(s):  
Exposure Assessment ◽  
Whole Blood ◽  
Gold Mining ◽  
Sulfate Solution ◽  
Small Scale ◽  
Sufficient Information ◽  
Strongly Correlated ◽  
Gold Extraction ◽  
Mining Areas ◽  
Distribution In Blood

AbstractPeople in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to high levels of mercury (Hg). Hg analyses in urine and whole blood are the gold standard of biomonitoring, although this may not provide sufficient information about the source of exposure, e.g., due to the use of Hg for gold extraction or due to nutrition. To evaluate, whether the pharmacokinetic properties of individual Hg species may be useful for exposure assessment, we determined the Hg levels in different blood components from 199 participants. Therefore, whole blood was centrifuged on-site to yield erythrocytes and plasma. Globin was isolated from the erythrocytes by precipitation with ethyl acetate. Albumin was isolated from plasma by gradual precipitation with saturated ammonium sulfate solution. Hg levels in all samples were determined by using a direct Hg analyzer. Median Hg levels for whole blood, erythrocytes, and plasma were 2.7, 3.7, and 1.3 μg/l, respectively. In globin and albumin, median Hg levels were 10.3 and 7.9 μg/kg, respectively. The distribution of Hg was strongly correlated with whole blood Hg levels (p < 0.01) and the time between the last use of Hg and the date of the participation (p < 0.01). The results suggest that the distribution of Hg in blood is substantially affected by the extent and the frequency of the exposure to elemental Hg. Therefore, the analysis of Hg in erythrocytes and plasma may be a valuable tool for Hg exposure assessment in ASGM areas.

scholarly journals Biomonitoring of arsenic, cadmium and lead in two artisanal and small-scale gold mining areas in Zimbabwe

2021 ◽  
Author(s):  
Stefan Rakete ◽  
Given Moonga ◽  
Anna-Maria Wahl ◽  
Viola Mambrey ◽  
Dennis Shoko ◽  
...  
Keyword(s):  
Toxic Metals ◽  
Gold Mining ◽  
Limit Of Detection ◽  
Elemental Mercury ◽  
Cross Sectional Study ◽  
Internal Exposure ◽  
Small Scale ◽  
Gold Extraction ◽  
Cross Sectional ◽  
Mining Areas

AbstractPeople living and working in artisanal and small-scale gold mining (ASGM) areas are frequently exposed to elemental mercury (Hg), which is used for gold extraction. However, additional exposure to other toxic metals such as arsenic (As), cadmium (Cd) and lead (Pb) may result from mining-related activities and could be ingested via dust, water or food. In these areas, only limited biomonitoring data is available for toxic metals other than Hg. In particular, data about the exposure to As, Cd and Pb is unavailable for the Zimbabwean population. Therefore, we conducted a cross-sectional study in two ASGM areas in Zimbabwe to evaluate the internal exposure to these metals. In total, urine and blood samples from 207 people that identified themselves as miners were collected and analysed for As and Cd in urine as well as Pb in blood by GF-AAS. Median levels (interquartile ranges in μg/l) of As and Pb were 9.7 μg/l (4.0, 18.5) and 19.7 μg/l (12.5, 34.5), respectively. The 25th percentile and the median for Cd were below the limit of detection (0.5 μg/l); the 75th percentile was at 0.9 μg/l. The results were compared to reference values found for the general population in the USA and Germany, and a significant number of participants exceeded these values (As, 33 %; Cd, 27 %; Pb, 32 %), indicating a relevant exposure to toxic metals. Although not representative for the Zimbabwean population, our results demonstrate that the exposure to toxic metals is relevant for the public health in Zimbabwe and requires further investigation.

scholarly journals Knowledge of and Adherence to the Cyanide Code Among Small-scale Gold Miners in Northern Tanzania

2017 ◽  
Vol 7 (14) ◽  
pp. 4-14 ◽  
Author(s):  
Elias C. Nyanza ◽  
Petro Yohana ◽  
Deborah S.K. Thomas ◽  
Wilfreda E. Thurston ◽  
Eveline Konje ◽  
...  
Keyword(s):  
Management Practices ◽  
Cross Sectional Study ◽  
Primary Objective ◽  
Worker Safety ◽  
Research Review ◽  
Small Scale ◽  
Gold Extraction ◽  
Cross Sectional ◽  
Mining Sites ◽  
Financial Interests

Background. Tanzania has seen explosive development in small scale gold mining (SGM) operations. Recently, the use of cyanide has become more common in SGM, especially in the reprocessing of mercury-amalgamated tailings from artisanal mining sites. Objectives. The primary objective of this study was to examine the level of knowledge and adherence to the Cyanide Code among workers and managers at SGM operations in northwestern Tanzania that use cyanide for gold extraction, focusing on workers' safety. Methods. A cross-sectional study of workers and managers at 17 selected SGM sites was conducted. A random-cluster approach was used to recruit 215 mine workers and 23 mine managers who worked at the same sites for more than three months. Individuals participated in structured face-to-face interviews. Site evaluation checklists were also administered to assess adherence. Results. The majority of the SGM workers (61.4%, n=132) were not aware of the Cyanide Code. Among the mine managers, 64.2% (n=15) were aware of the Cyanide Code. Fifty-four percent of workers and 39.1% of managers did not adhere to the Cyanide Code. Workers who reported being trained on the Cyanide Code were significantly more likely to have knowledge about the Cyanide Code guidelines compared to untrained workers (adjusted odds ratio =20.3, confidence interval: 7.5 – 54.8). Discussion. Wide variations in knowledge of and adherence to the Cyanide Code were found. A manager's knowledge of Cyanide Code was significantly associated with workers' knowledge. High worker and manager knowledge was associated with increased site safety performance. Even though all the SGM sites were physically visited, some potentially hazardous practices may not have been revealed by managers and workers because of fear of possible regulatory actions due to disclosure of concerns related to their operation's safety compliance. Conclusions. The limited knowledge of the Cyanide Code among workers and managers, combined with poor adherence to cyanide waste management practices, indicates that there is a need for education, health promotion and sensitization among workers and managers to improve worker safety and minimize environmental health impacts. Participant Consent: Obtained Competing Interests. The authors declare no competing financial interests. Ethics Approval: Ethical approval was obtained from the Conjoint Catholic University of Health and Allied Sciences and Bugando Medical Centre Research Review and Ethics Committee (Ref. BREC/001/35/2014). Permission to conduct research in Geita District was obtained from the respective authorities at the regional and district levels and from owners of the SGM sites.

scholarly journals Characterization of potential mercury contamination in the ASGM area of Mandailing Natal, North Sumatera

2021 ◽  
Vol 882 (1) ◽  
pp. 012062
Author(s):  
H Astika ◽  
S Handayani ◽  
R Damayanti ◽  
W Surono ◽  
Maryono ◽  
...  
Keyword(s):  
River Sediments ◽  
Ecological Impacts ◽  
Mercury Contamination ◽  
Small Scale ◽  
Gold Extraction ◽  
Grab Sampling ◽  
The North ◽  
Soils And Sediments ◽  
Area Sampling

Abstract A large amount of Hg is used for gold extraction through the amalgamation process in the Mandailing Natal derived from artisanal and small-scale gold mining (ASGM) area located in the North Sumatera Province, Indonesia. The objective of this work was to characterize the potential contamination of total Hg in water, sediments, and soil in this ASGM area. Sampling was done in two locations in West Panyabungan and Huta Bargot Districts using grab sampling method. Results showed that accumulation of Hg in the studied soils and sediments was the highest, but Hg in aquatic solution was below the detection limit of the analytical method of the studied community wells and rivers. The highest concentration of Hg was found in the river sediments of the Saba Padang irrigation (1,63 mg/kg), and in the soil of the plantation area of Huta Bargot (1,62 mg/kg) respectively. These concentrations may pose a serious problem for aquatic and land life, related ecosystems, and human health. For further study, there is a need to study Hg availability in riverine biota to better understand the cycling of Hg in this ASGM area. Understanding the ecological impacts can assist in the prioritizing of impact mitigation efforts.

scholarly journals Introduction of Mercury-Free Gold Extraction to Small-Scale Miners in the Cabo Delgado Province in Mozambique

2018 ◽  
Vol 8 (19) ◽  
Author(s):  
Birgitte Stoffersen ◽  
Peter WU Appel ◽  
Leoncio D Na-Oy ◽  
Asta Selloane Sekamane ◽  
Ivan Zahinos Ruiz ◽  
...  
Keyword(s):  
Urban Areas ◽  
Extraction Method ◽  
Extraction Methods ◽  
Gold Recovery ◽  
Small Scale ◽  
Gold Extraction ◽  
Governmental Organization ◽  
Free Gold ◽  
Financial Interests ◽  
Gold Bearing

Background. The majority of small-scale gold miners worldwide, including those in Mozambique, use mercury to extract gold. Over the last fifty years, gold production from small-scale mining has been accelerating and consequently the amount of mercury released to the environment has increased dramatically, causing major global health problems. In 2018, a team from the Danish non-governmental organization Diálogos introduced the mercury-free gold extraction method in the Cabo Delgado province in Mozambique in the villages of Waqueia and Nanlia. Objectives. The objective of this project was to teach local miners this method to reduce mercury pollution. An additional objective was to compare the local gold extraction method and the mercury-free gold extraction method in terms of gold recovery. The hypothesis was that the level of gold recovery would be higher with the mercury-free method compared to the locally used amalgamation method. Materials and Methods. An experimental study comparing the two gold extraction methods was carried out where local miners processed gold-bearing ore using their standard procedures with the amalgamation method and the Diálogos team processed an equivalent amount of gold-bearing ore with the mercury-free gold extraction method. The tests were carried out once at each mining site. Results. Under even circumstances in a controlled setting, the mercury-free method yielded up to 78% more gold than the amalgamation method normally used by the miners. Conclusions. The strengths of the mercury-free gold extraction method include low costs, higher gold yield, benign environmental impact, legality and needed chemicals are more readily available compared with the amalgamation method. However, the mercury-free method may be more time consuming than the amalgamation method, especially for beginners. Borax is typically available in developed urban areas, as it is commonly used in the welding industry and by jewelers, but can be hard to find in more remote villages. Competing Interests. The authors declare no competing financial interests.

scholarly journals Introduction of Mercury-free Gold Extraction Methods to Medium-Scale Miners and Education of Health Care Providers to Reduce the use of Mercury in Sorata, Bolivia

2015 ◽  
Vol 5 (9) ◽  
pp. 12-17
Author(s):  
Peter W. U. Appel ◽  
Astrid Andersen ◽  
Leoncio D. Na-Oy ◽  
Rudy Onos
Keyword(s):  
Health Care ◽  
Health Care Providers ◽  
Small Scale ◽  
Health Providers ◽  
Care Providers ◽  
Gold Extraction ◽  
Gold Ores ◽  
Mining Communities ◽  
Medium Scale ◽  
Free Gold

Background. Artisanal and small-scale miners in Bolivia release on the order of 120 tons of mercury annually. The mercury finds its way to the Amazon with catastrophic consequences for the biosphere. A project aimed at reducing the release of mercury was carried out in 2013 and 2014. Objectives. The project had two objectives: to test whether the mercury-free gold extraction method could be an alternative to whole ore amalgamation in medium-scale mining in Bolivia and to teach mercury toxicology to health care providers in the gold mining area. The mercury-free gold extraction method has been successfully introduced in other countries, but mainly in very small-scale mining communities. Materials and Methods. The targets in Bolivia were medium-scale miners processing over a hundred tons of ore per day. The chosen gold ores proved amenable to gold extraction using mercury-free extraction. Demonstrations of the mercury-free methods were carried out by processing similar quantities of gold ores using the amalgamation and the mercury-free method. Miners, mining communities and local health providers were informed on the toxicity of mercury. Health providers were shown how to conduct epidemiological surveillance. Posters explaining the path of mercury from the processing stations to local households were prepared. Conclusions. The gold ores tested during the project proved amenable to mercury-free gold extraction using borax smelting. The miners also realized that gold recovery increased when performing mercury-free gold extraction. The miners decided to stop using mercury and a follow-up project cleaned their mining equipment for mercury and modified the processing lines. The health care providers were also successfully trained.

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