Comparing cyanidation with amalgamation of a Colombian artisanal gold mining sample: Suggestion of a simplified zinc precipitation process

Torkaman, P.; Veiga, Marcello M.

doi:10.1016/j.exis.2022.101208

Cited by 6 publications

(8 citation statements)

References 26 publications

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“…Based on the results of field observations and laboratory analysis, the grind size is between 44-61% passing 74 µm, causing the recovery of gold leaching results to be less than 60%. The study results showed that obtaining gold with cyanidation was 95% (Hylander et al, 2007); in other studies, it was 84% (Torkaman and Veiga, 2023). Improper process parameters, such as the shape and size of the grinding medium, rotation speed, and volume composition of material in the grinding body, can cause the lack of an optimal grinding process.…”

Section: Introductionmentioning

confidence: 85%

Optimization of adaptive and sustainable gold ore grinding processes for better environmental and land conditions in the small-scale gold mining sector in Indonesia

Nurjaman,

Titah,

Kawigraha

et al. 2024

J. Degrade. Min. Land Manage.

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The artisanal and small-scale gold mining (ASGM) sector largely relies on mercury in gold processing, posing potential environmental contamination, health issues, and land degradation. In the villages of Tatelu and Talawaan, ASGM operations, guided by local knowledge and resources, have transitioned to using cyanide leaching for gold processing sustainably. These operations utilize andesitic stones from river deposits as grinding media in the grinding process. However, the cyanide leaching results were not optimal, with a gold recovery below 60%. This leaves significant amounts of gold in the waste, necessitating further processing and the incomplete treatment of free cyanide waste. The suboptimal gold recovery in cyanide leaching is attributed to the inadequate grain size liberation during grinding. This study optimized grinding by comparing andesitic stone grinding media with steel balls and rods. The findings indicate that to achieve a grain size of 75% passing 74 um, grinding with andesitic stones takes 4 hours, while steel rods and balls take 3 hours. For a grain size of 75% passing 44 um, grinding with andesitic stones, steel balls, and rods requires 6 hours. With more precise process parameters, locally available andesitic stones can be an effective grinding medium to optimize gold recovery. In line with optimizing gold recovery, this will enhance ASGM's revenue, encouraging the adoption of waste management practices to alleviate environmental impact, health risks, and land degradation. This aligns with the promotion of sustainable practices within the ASGM sector.

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Section: Introductionmentioning

confidence: 85%

Optimization of adaptive and sustainable gold ore grinding processes for better environmental and land conditions in the small-scale gold mining sector in Indonesia

Nurjaman,

Titah,

Kawigraha

et al. 2024

J. Degrade. Min. Land Manage.

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“…The leaching tests further support the non-refractory nature of this gold. Specifically, when this ground sample was treated with 1 g/L CN (sourced from NaCN) for 24 h, at pH 10.5 and at ambient temperature, gold extraction peaked at 84% [26]. Impressively, increasing the CN concentration to 5 g/L yielded a 97% gold extraction under identical conditions.…”

Section: Ore Samplementioning

confidence: 99%

Experimenting with Dimethyl Sulfoxide to Leach Gold from a Colombian Artisanal Gold Ore

Torkaman,

Yoshimura,

Lavkulich

et al. 2023

Metals

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The diverse uses of gold and its crucial role in the global economy are growing, particularly during cycles of economic crises. The broad use of cyanide by conventional gold-mining companies and mercury by artisanal miners poses environmental and health concerns for local communities. This article introduces an innovative gold-leaching process using a non-toxic organic reagent, dimethyl sulfoxide (DMSO), a water-free lixiviant that extracts gold from ores/concentrates in combination with copper halides. The results of laboratory experiments using dimethyl sulfoxide and a sample of high-grade gold ore from Colombia show that 96.5% of the gold was extracted in 2 h at room temperature. The typical cyanidation process using 5 g/L of CN− at pH 10.5 on the same ore sample obtained 97% gold extraction in 24 h at ambient temperature. The gold extracted using DMSO was precipitated by adding a mild acidic solution, and the reagent can be recycled via distillation and reused in repeating cycles. The results show that DMSO can be used as a promising agent for gold leaching, offering a straightforward, cost-effective, and eco-friendly procedure with minimal chemical waste.

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“…Workflow and performance Most of the mercury-free technologies have the potential to outperform the amalgamation process with respect to gold recoveries, although this depends on ore type. For example, Torkaman and Veiga (2022) reported gold recoveries of approximately 84% with cyanide leaching versus approximately 19% with mercury amalgamation, in a study on Colombian gold ore. The potential for higher recovery and thus increased profits can be a key motivator for adoption of new technology (although other factors, discussed later, can limit adoption despite this potential).…”

Section: Operational Requirements and Costsmentioning

confidence: 99%

Mercury and artisanal and small-scale gold mining: Review of global use estimates and considerations for promoting mercury-free alternatives

Keane

Bernaudat²,

Davis³

et al. 2023

Ambio

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Artisanal and small-scale gold mining (ASGM) is present in over 80 countries, employing about 15 million miners and serving as source of livelihood for millions more. The sector is estimated to be the largest emitter of mercury globally. The Minamata Convention on Mercury seeks to reduce and, where feasible, eliminate mercury use in the ASGM. However, the total quantity of mercury used in ASGM globally is still highly uncertain, and the adoption of mercury-free technologies has been limited. This paper presents an overview of new data, derived from Minamata ASGM National Action Plan submissions, that can contribute to refining estimates of mercury use in ASGM, and then assesses technologies that can support the phase out mercury use in ASGM while increasing gold recovery. The paper concludes with a discussion of social and economic barriers to adoption of these technologies, illustrated by a case study from Uganda.

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Comparing cyanidation with amalgamation of a Colombian artisanal gold mining sample: Suggestion of a simplified zinc precipitation process

Cited by 6 publications

References 26 publications

Optimization of adaptive and sustainable gold ore grinding processes for better environmental and land conditions in the small-scale gold mining sector in Indonesia

Optimization of adaptive and sustainable gold ore grinding processes for better environmental and land conditions in the small-scale gold mining sector in Indonesia

Experimenting with Dimethyl Sulfoxide to Leach Gold from a Colombian Artisanal Gold Ore

Mercury and artisanal and small-scale gold mining: Review of global use estimates and considerations for promoting mercury-free alternatives

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