scholarly journals Co-Disposal of Coal Gangue and Red Mud for Prevention of Acid Mine Drainage Generation from Self-Heating Gangue Dumps

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1081
Author(s):  
Zhou Ran ◽  
Yongtai Pan ◽  
Wenli Liu

The seepage and diffusion of acid mine drainage (AMD) generated from self-heating coal gangue tailings caused acid pollution to the surrounding soil and groundwater. Red mud derived from the alumina smelting process has a high alkali content. To explore the feasibility of co-disposal of coal gangue and red mud for prevention of AMD, coal gangue and red mud were sampled from Yangquan (Shanxi Province, China), and dynamic leaching tests were carried out through the automatic temperature-controlled leaching system under the conditions of different temperatures, mass ratios, and storage methods. Our findings indicated that the heating temperature had a significant effect on the release characteristics of acidic pollutants derived from coal gangue, and that the fastest rate of acid production corresponding to temperature was 150 °C. The co-disposal dynamic leaching tests indicated that red mud not only significantly alleviated the release of AMD but also that it had a long-term effect on the treatment of acid pollution. The mass ratio and stacking method were selected to be 12:1 (coal gangue: red mud) and one layer was alternated (coal gangue covered with red mud), respectively, to ensure that the acid-base pollution indices of leachate reached the WHO drinking-water quality for long-term discharge. The results of this study provided a theoretical basis and data support for the industrial field application of solid waste co-treatment.

2006 ◽  
Vol 43 (11) ◽  
pp. 1167-1179 ◽  
Author(s):  
M Paradis ◽  
J Duchesne ◽  
A Lamontagne ◽  
D Isabel

Acid mine drainage (AMD) is an environmental problem produced when sulphides come in contact with an oxidant (± bacteria) and water, producing acid generation and metals leaching. One solution proposed is to use red mud bauxite (RMB), which is very alkaline, to neutralize oxidized acidic tailings. A column leaching test has been set up to evaluate major aspects of field constraints. First, a field investigation was conducted in which RMB was spread in aggregates before mixing with tailings. This setup has been reproduced in the laboratory and compared with a homogeneous mixture. The analyses of the water effluent do not show any important difference between the two mixtures. Second, some studies show that the addition of Cl brine to RMB helps to maintain the long-term neutralization potential. Brine addition increased the concentrations of Ca, Mg, Na, K, and Cu in drainage water. Columns were set up with 10% and 20% RMB to evaluate the effect of the quantity applied. Addition of greater than 20% RMB increases the leachate alkalinity and concentrations of Al, Cu, Pb, As, Fe, and SO42– in drainage waters. The addition of 10% RMB, however, significantly improves the quality of drainage water over a period of 125 days and results in concentrations and pH values within the ranges of those recommended by Directive 019 of the Ministère de l'environnement, Québec.Key words: acid mine drainage, red mud bauxite, tailings, environmental geochemistry, neutralization.


2018 ◽  
Vol 30 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Mirabelle Perossi Cunha ◽  
Rafael Marçal Ferraz ◽  
Giselle Patrícia Sancinetti ◽  
Renata Piacentini Rodriguez

2020 ◽  
Vol 989 ◽  
pp. 559-563
Author(s):  
Ashimkhan T. Kanayev ◽  
Khussain Valiyev ◽  
Aleksandr Bulaev

The goal of the present work was to perform bioleaching of uranium from low grade ore from Vostok deposit (Republic of Kazakhstan), which was previously subjected to long-term acid leaching. The ore initially contained from 0.15 to 0.20% of uranium in the form of uraninite, but ore samples used in the study contained about 0.05% of uranium, as it was exhausted during acid leaching, and uranium was partially leached. Representative samples of ore were processed in 1 m columns, leach solutions containing 5, 10, 20 g/L of sulfuric acid and bacterial cells (about 104) were percolated through the ore. Leaching was performed at ambient temperature for 70 days. In one of the percolators, the leaching was performed with leaching solution containing 10 g/L of H2SO4, cells of A. ferrooxidans, and 0.5 g/L of formaldehyde. Leaching with the solution containing 5, 10, and 20 g/L of sulfuric acid made it possible to extract 50, 53, and 58% of uranium. Addition of formaldehyde in leach solution led to the decrease in uranium extraction extent down to 37%. Thus, the results of the present work demonstrated that uranium ore exhausted during long-term acid leaching may be successfully subjected to bioleaching, that allows extracting residual quantities of uranium. Leaching rate of uranium from exhausted ore depended on both sulfuric acid concentration and microbial activity of bacteria isolated from acid mine drainage, formed on uranium deposit. In the same time, acid mine drainage may be used as a source of inoculate, to start bioleaching process.


2010 ◽  
Vol 213 (1-4) ◽  
pp. 437-458 ◽  
Author(s):  
Mariam Ouangrawa ◽  
Michel Aubertin ◽  
John W. Molson ◽  
Bruno Bussière ◽  
Gérald J. Zagury

2006 ◽  
Vol 2006 (2) ◽  
pp. 582-597 ◽  
Author(s):  
Omar Fala ◽  
John Molson ◽  
Michel Aubertin ◽  
Bruno Bussière ◽  
Robert P. Chapuis

2009 ◽  
Vol 71-73 ◽  
pp. 677-680 ◽  
Author(s):  
D. Carnicero ◽  
E. Díaz ◽  
O. Escolano ◽  
D. Rubinos ◽  
O. Ballesteros ◽  
...  

Limestone is commonly used for neutralization of acid mine drainage (AMD). Its main advantages are its lower price, sustained generation of alkalinity and production of low sludge volumes. Nevertheless, armouring of limestone by ferric hydroxides is a problem in oxic limestone drains and in active limestone treatment systems, reducing the efficiency of the process. Due to these disadvantages, there is a permanent search for cheaper and more effective neutralization agents. Many alkaline industrial wastes are gaining importance in the treatment of AMD. The possibilities to use two different industrial by-products, red mud from a bauxite exploitation and low grade magnesium hydroxide from a magnesite mine, as neutralizing and bacterial inhibiting agents, and the comparison with conventional limestone treatment has been studied in this paper. An AMD from Rio Tinto mine site with an initial pH of 2.4 and a ferric concentration of 1 g/L was used. Comparative test were done percolating the AMD in a continuous form with a peristaltic pump through three different columns filled with limestone, red mud and low grade magnesite, during one month and in same conditions of flow rate and amount of each compound used to fill the columns. The evolution of pH, iron and heavy metals, sulphates and microbial populations in the percolate were monitored at different times. The results showed that the best neutralization capacity was obtained with low grade magnesite during the month treatment. By contraire limestone and red mud loosed their neutralization capacity after 10 and 13 days respectively. The control of microbial populations showed that there is an inhibition of chemolithotropic bacteria as long as the materials maintain their neutralization capacity, reverting to the initial conditions when this capacity was loosed.


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