Preliminary Study of Neutralization and Inhibition of Chemolitotrophic Bacteria in an Acid Mine Drainage from Rio Tinto Site

2009 ◽  
Vol 71-73 ◽  
pp. 677-680 ◽  
Author(s):  
D. Carnicero ◽  
E. Díaz ◽  
O. Escolano ◽  
D. Rubinos ◽  
O. Ballesteros ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Red Mud ◽  
Mine Drainage ◽  
Initial Conditions ◽  
Microbial Populations ◽  
Low Grade ◽  
Neutralization Capacity ◽  
Acid Mine ◽  
Rio Tinto ◽  
Río Tinto

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.

Mobility of Po and U-isotopes under acid mine drainage conditions: an experimental approach with samples from Río Tinto area (SW Spain)

2014 ◽  
Vol 138 ◽  
pp. 384-389 ◽  
Author(s):  
L. Barbero ◽  
M.J. Gázquez ◽  
J.P. Bolívar ◽  
M. Casas-Ruiz ◽  
A. Hierro ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Experimental Approach ◽  
Mine Drainage ◽  
Sw Spain ◽  
Acid Mine ◽  
Rio Tinto ◽  
Río Tinto

scholarly journals The Evolution of Pollutant Concentrations in a River Severely Affected by Acid Mine Drainage: Río Tinto (SW Spain)

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 598 ◽  
Author(s):  
Manuel Olías ◽  
Carlos R. Cánovas ◽  
Francisco Macías ◽  
María Dolores Basallote ◽  
José Miguel Nieto
Keyword(s):  
Acid Mine Drainage ◽  
Large Scale ◽  
Mine Drainage ◽  
Seasonal Pattern ◽  
Quality Data ◽  
Water Quality Data ◽  
Sw Spain ◽  
Acid Mine ◽  
Rio Tinto ◽  
Río Tinto

The Río Tinto, located in the Iberian Pyrite Belt (SW Spain), constitutes an extreme case of pollution by acid mine drainage. Mining in the area dates back to the Copper Age, although large-scale mining of massive sulfide deposits did not start until the second half of the 19th century. Due to acidic mining discharges, the Río Tinto usually maintains a pH close to 2.5 and high concentrations of pollutants along its course. From a detailed sampling during the hydrological year 2017/18, it was observed that most pollutants followed a similar seasonal pattern, with maximum concentrations during autumn due to the washout of secondary soluble sulfate salts and minimum values during large flood events. Nevertheless, As and Pb showed different behavior, with delayed concentration peaks. The dissolved pollutant load throughout the monitored year reached 5000 tons of Fe, 2600 tons of Al, 680 tons of Zn, and so on. While most elements were transported almost exclusively in the dissolved phase, Fe, Pb, Cr, and, above all, As showed high values associated with particulate matter. River water quality data from 1969 to 2019 showed a sharp worsening in 2000, immediately after the mine closure. From 2001 on, an improvement was observed.

Using red mud bauxite for the neutralization of acid mine tailings: a column leaching test

2006 ◽  
Vol 43 (11) ◽  
pp. 1167-1179 ◽  
Author(s):  
M Paradis ◽  
J Duchesne ◽  
A Lamontagne ◽  
D Isabel
Keyword(s):  
Acid Mine Drainage ◽  
Red Mud ◽  
Mine Drainage ◽  
Field Investigation ◽  
Drainage Water ◽  
Leaching Test ◽  
Column Leaching ◽  
Acid Mine ◽  
Column Leaching Test ◽  
Set Up

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.

Uranium Bioleaching from Low Grade Ore

2020 ◽  
Vol 989 ◽  
pp. 559-563
Author(s):  
Ashimkhan T. Kanayev ◽  
Khussain Valiyev ◽  
Aleksandr Bulaev
Keyword(s):  
Sulfuric Acid ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Sulfuric Acid Concentration ◽  
Acid Leaching ◽  
Leach Solution ◽  
Low Grade ◽  
Bacterial Cells ◽  
Acid Mine

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.

Sign in / Sign up

Export Citation Format

Share Document