Reaction of Cyanide with Hg0-Contaminated Gold Mining Tailings Produces Soluble Mercuric Cyanide Complexes

2020 ◽  
Vol 33 (11) ◽  
pp. 2834-2844 ◽  
Author(s):  
Caryn S. Seney ◽  
Christy C. Bridges ◽  
Sumeja Aljic ◽  
Matthew E. Moore ◽  
Sarah E. Orr ◽  
...  
Author(s):  
M. G. Lemos ◽  
T. Valente ◽  
A. P. Marinho-Reis ◽  
R. Fonsceca ◽  
J. M. Dumont ◽  
...  

2020 ◽  
Vol 8 (1) ◽  
pp. 85
Author(s):  
Ulfa Luthfiana ◽  
Melya Riniarti ◽  
Afif Bintoro

Artisanal small-scale gold mining tailings frequently used hazardous toxic materials that could contaminate land, rivers, and lakes which harmful to the environment and health. Phytoremediation is one way to overcome the mining waste. Mangium (Acacia mangium Willd.) is one of plant that often used for mining land phytoremediation. However, it was difficult for mangium to be able to survive on land with such extreme conditions, therefore additional input is needed. Using ectomycorrhiza fungi could be an alternative. This study aimed to measure the adaptation of mangium in gold mining tailings and analyze the function of ectomycorrhiza (Scleroderma sp.) in the growth of mangium. The experimental design used a completely randomized design with six growth media as treatments with five replications. The growth media used were: (1) topsoil with mycorrhiza, (2) topsoil without mycorrhiza, (3) topsoil + tailings with mycorrhiza, (4) soil + tailings without mycorrhiza,(5) tailings with mycorrhiza, and (6) tailings without mycorrhiza. Data were analyzed statistically using analysis of variance followed with a Least Significant Difference test. The results showed that the survival rate of mangium life in tailing media with mycorrhizae was fairly high with a percentage of life reaching 60% even though the growth was less when compared to topsoil media with mycorrhiza that reached 100%. The highest growth rate was achieved by mangium in topsoil media without tailings and mycorrhiza (control). This research showed that ectomycorrhiza did not have any significant effects on mangium growth in gold tailing.Keywords: Acacia mangium, ectomycoriza, gold tailings, phytoremediation, Scleroderma sp.   


2020 ◽  
Vol 4 (1) ◽  
pp. 58
Author(s):  
Rizal Adi Saputra ◽  
Meyla Riniarti

One of the strategies in rehabilitation of gold mining tailings is used pioneer trees. Pericopsis mooniana is one of pioneer types which capable to adapt to marginal and unproductivel lands. The objective of this research were to find out the growth and physical quality of P. mooniana seedling on artisanal gold mining tailings with the addition of compost elephant dung and humic acid. Growth observation and physical quality assessment were done to P. mooniana seedlings aged 3 months and 10 days, placed on polybag (15/7.5 cm x 20 cm). The experimental design used a completely randomized design with six growth media as treatments and five replications, (1) topsoil 100%, (2) talings 100%, (3) tailings 50% + elephant dungs 50%, (4) tailings 50% + elephant dungs 50% + humic acid (2,000 ppm), (5) tailings 75% + elephant dungs 25%,(6) tailings 75% + elephant dungs 25% + (humic acid (2,000 ppm).  Data were analyzed statistically using analysis of variance followed with a Least Significant Difference test. The stages of the research were: seedling activity, growth observations and physical quality assessment seedlings. The parameter observed were percentage of life, increment height and diameter, number of leaf, leaf area, number of nodules, total dry weight, robustness, ratio of leaves and roots, and seed quality index. The result showed that P. mooniana seedlings were able to grow and adapt to artisanal gold mining tailings with a seedlings quality indexs value of more than (0.09), but the addition of ameliorant did not have any impact yet.


2021 ◽  
pp. 100704
Author(s):  
Carolina Pereira dos Santos ◽  
Giovani Jordi Bruschi ◽  
Joãof Rodrigo Guerreiro Mattos ◽  
Nilo Cesar Consoli

2008 ◽  
Vol 22 (2) ◽  
pp. 154-173 ◽  
Author(s):  
G. B. Smith ◽  
D. B. Donato ◽  
C. G. Gillespie ◽  
S. R. Griffiths ◽  
J. Rowntree

2015 ◽  
pp. 11-18 ◽  
Author(s):  
Suwanit Parinyachet ◽  
Quanchai Leepowpanth

The study aimed to investigate residual cyanides and their potential stabilities in tailings from a gold processing plant deposited in the Tailings Storage Facility (TSF) of a gold mining site. For this purpose, several samples of tailings were taken from the recently abandoned TSF to a depth of 2.5 meters, representing 1 to 2 years old tailings. The samples were analyzed for pH, metals, residual cyanides, and Net Acid Generation Test (NAG test). The results showed that, in all samples, pH values were neutral to slightly alkaline. Fe concentrations were relatively high (22,800-35,000 mg kg-1) indicating that Fe can readily react with free cyanide (CN-) to form iron cyanide complexes (strong metal cyanide complexes). The residual cyanide concentration in tailings was found to be very low; free cyanide (CNFree), weak acid dissociable cyanide (CNWAD), strong acid dissociable cyanide (CNSAD) and total cyanide (CNT) were in the range of 0.16-0.64, 0.37-1.06, 1.96-3.89 and 2.33-4.95 mg kg-1, respectively. Cyanides in the tailings were predominantly strong metal cyanide complexes being more stable to dissociate. Total cyanide (CNT) concentration was quite low compared with Thailand’s environmental regulations for soil quality standards andwere environmentally insignificant. The NAG test for all samples revealed that NAG pH was in the range of 5.02-6.10 and NAG was in the range of 0.08-0.31 kg H2SO4t-1indicating all samples have low or non-acid forming potentials. The findings indicated a potential to form a high proportion of strong metal cyanide complexes in the tailings, which is difficult to dissociate and releasehigh toxic cyanide to the environment.


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