scholarly journals Lead Mobilization and Speciation in Mining Waste: Experiments and Modeling

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 606
Author(s):  
Clémentine Drapeau ◽  
Rabei Argane ◽  
Cécile Delolme ◽  
Denise Blanc ◽  
Mostafa Benzaazoua ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mine Drainage ◽  
Geochemical Modeling ◽  
Buffering Capacity ◽  
Mining Waste ◽  
Accurate Identification ◽  
Geochemical Model ◽  
Neutralization Capacity ◽  
Mineral Phases ◽  
Solid Phases

Mining produces significant amounts of solid mineral waste. Mine waste storage facilities are often challenging to manage and may cause environmental problems. Mining waste is often linked to contaminated mine drainage, including acidic waters with more or less elevated concentrations of trace metals such as lead. This work presents a study on the mobilization of lead from waste from two typical mining sites: Zeida and Mibladen, two now-closed former Pb–Zn mines in the Moulouya region of Morocco. Our research investigates the mobilization potential of Pb from the waste of these mines. The study involved acid–base neutralization capacity tests (ANC–BNC) combined with geochemical modeling. Experimental data allowed for the quantification of the buffering capacity of the samples and the mobilization rates of lead as a function of pH. The geochemical model was fitted to experimental results with thermodynamic considerations. The geochemical model allowed for the identification of the mineral phases involved in providing the buffering capacity of carbonated mining waste (Mibladen) and the meager buffering capacity of the silicate mining waste (Zeida). These cases are representative of contaminated neutral drainage (CND) and acid mine drainage (AMD), respectively. The results highlight the consistency between the ANC–BNC experimental data and the associated modeling in terms of geochemical behavior, validating the approach and identifying the main mechanisms involved. The modeling approach identifies the dissolution of the main solid phases, which impact the pH and the speciation of lead as a function of the pH. This innovative approach, combining ANC–BNC experiments and geochemical modeling, allowed for the accurate identification of mineral phases and surface complexation phenomena, which control the release of lead and its speciation in drainage solutions, as well as within solid phases, as a function of pH.

scholarly journals ANC–BNC Titrations and Geochemical Modeling for Characterizing Calcareous and Siliceous Mining Waste

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 257
Author(s):  
Clémentine Drapeau ◽  
Cécile Delolme ◽  
Clément Vézin ◽  
Denise Blanc ◽  
Thomas Baumgartl ◽  
...  
Keyword(s):  
Mine Drainage ◽  
Geochemical Modeling ◽  
Mining Waste ◽  
Main Element ◽  
Liquid Phases ◽  
Neutralizing Capacity ◽  
Mineral Assemblages ◽  
Ph Range ◽  
Neutral Conditions

Pyrite and calcite are mineral phases that play a major role in acid and neutral mine drainage processes. However, the prediction of acid mine drainage (AMD) or contaminated neutral drainage (CND) requires knowledge of the mineral composition of mining waste and the related potential for element release. This paper studies the combination of acid–base neutralizing capacity (ANC–BNC) with geochemical modeling for the characterization of mining waste and prediction of AMD and CND. The proposed approach is validated with three synthetic mineral assemblages: (1) siliceous sand with pyrite only, representing mining waste responsible for AMD, (2) siliceous sand with calcite and pyrite, representing calcareous waste responsible for CND, and (3) siliceous sand with calcite only, simulating calcareous matrices without any pyrite. The geochemical modeling approach using PHREEQC software was used to model pH evolution and main element release as a function of the added amount of acid or base over the entire pH range: 1 < pH < 13. For calcareous matrices (sand with calcite), the results are typical of a carbonated environment, the geochemistry of which is well known. For matrices containing pyrite, the results identify different pH values favoring the dissolution of pyrite: pH = 2 in a pyrite-only environment and pH = 6 where pyrite coexists with calcite. The neutral conditions can be explained by the buffering capacity of calcite, which allows iron oxyhydroxide precipitation. Major element release is then related to the dissolution and precipitation of the mineral assemblages. The geochemical modeling allows the prediction of element speciation in the solid and liquid phases. Our findings clearly prove the potential of combined ANC–BNC experiments along with geochemical modeling for the characterization of mining waste and the assessment of risk of AMD and CND.

GEOCHEMICAL MODELING OF HARD-ROCK MINE DRAINAGE AND MINE-IMPACTED WATERS

2019 ◽  
Author(s):  
Kate M. Campbell ◽  
◽  
Charles N. Alpers ◽  
Christy L. Grettenberger ◽  
Thomas N Wallis ◽  
...  
Keyword(s):  
Hard Rock ◽  
Mine Drainage ◽  
Geochemical Modeling

Developing Alternative Building Materials from Mining Waste

2014 ◽  
Vol 976 ◽  
pp. 202-206 ◽  
Author(s):  
Javier Flores Badillo ◽  
Juan Hernández Ávila ◽  
Francisco Patiño Cardona ◽  
Norma Yacelit Trápala Pineda ◽  
José Abacú Ostos Santos
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Subsequent Treatment ◽  
Mining Waste ◽  
Mineralogical Characterization ◽  
Green Strength ◽  
Mineral Phases ◽  
Heavy Clay ◽  
Industrial Materials ◽  
Strength And Plasticity

In this paper we present the production of alternative industrial materials from the mining waste in the form of tailings, this study was made with the tailings of Dos Carlos, establishing 4 sampling zones, dividing them into three strata in the bottom, middle and top. The sampling method used is quartering, to homogenize the material and anticipate the possible use of it as a building material, having for this purpose 12 ceramic mixtures for subsequent treatment. Chemical composition was determined as 70.43% SiO2, 7.032% Al2O3, 2.69% Fe2O3, 0.46% MnO2, 3.98% K2O, 3.34% CaO, 2.50% Na2O, 56 grams per tonne of Ag y 0.6 grams per tonne of Au. In the mineralogical characterization the tailings presents silica, albite, berlinite, orthoclase and potassium jarosite as the main mineral phases, among other mineral phases in lesser concentration such as gypsum, calcite, anorthoclase, pyrite, sphalerite and galena. The determinations of the tailing material granulometry in the range of 60% in a size less than 270 mesh (53 μm). Afterwards, the alternative industrial materials were produced by using the tailings and heavy clay in order to give the composite a good green strength and plasticity during development, but above all to give it a compressive strength similar or higher than that of products derived from conventional processes. Keywords: Tailings, green strength, compressive strength, plasticity, heavy clays, alternative industrial materials.

Development of the Acidic Mining Wastewater Treatment Technology

2013 ◽  
Vol 295-298 ◽  
pp. 1372-1375 ◽  
Author(s):  
Guang Wei Liu ◽  
Run Cai Bai
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mining Waste ◽  
Formation Condition ◽  
Research Development ◽  
Treatment Technology ◽  
Acid Mine ◽  
Mining Wastewater

The main formation condition and harmfulness of the acidic mining waste water's were analyzed in this paper. The treatment technology of the acid mine drainage's was briefly introduced. The research development of acid mine drainage was summarized in recent years. It was the fact that developing the efficient, cheap, safe and easy treatment technology of acid mine should be necessary and inevitably and some success management experiences of acidic waste water were applied in acidic mining wastewater.

scholarly journals Removal of Arsenate and Arsenite in Equimolar Ferrous and Ferric Sulfate Solutions through Mineral Coprecipitation: Formation of Sulfate Green Rust, Goethite, and Lepidocrocite

Soil Systems ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 68
Author(s):  
Chunming Su ◽  
Richard T. Wilkin
Keyword(s):  
Amorphous Solid ◽  
Arsenic Species ◽  
Green Rust ◽  
Geochemical Process ◽  
Batch Tests ◽  
Sulfate Solutions ◽  
Mineral Phases ◽  
Groundwater Systems ◽  
Solid Phases

An improved understanding of in situ mineralization in the presence of dissolved arsenic and both ferrous and ferric iron is necessary because it is an important geochemical process in the fate and transformation of arsenic and iron in groundwater systems. This work aimed at evaluating mineral phases that could form and the related transformation of arsenic species during coprecipitation. We conducted batch tests to precipitate ferrous (133 mM) and ferric (133 mM) ions in sulfate (533 mM) solutions spiked with As (0–100 mM As(V) or As(III)) and titrated with solid NaOH (400 mM). Goethite and lepidocrocite were formed at 0.5–5 mM As(V) or As(III). Only lepidocrocite formed at 10 mM As(III). Only goethite formed in the absence of added As(V) or As(III). Iron (II, III) hydroxysulfate green rust (sulfate green rust or SGR) was formed at 50 mM As(III) at an equilibrium pH of 6.34. X-ray analysis indicated that amorphous solid products were formed at 10–100 mM As(V) or 100 mM As(III). The batch tests showed that As removal ranged from 98.65–100%. Total arsenic concentrations in the formed solid phases increased with the initial solution arsenic concentrations ranging from 1.85–20.7 g kg−1. Substantial oxidation of initially added As(III) to As(V) occurred, whereas As(V) reduction did not occur. This study demonstrates that concentrations and species of arsenic in the parent solution influence the mineralogy of coprecipitated solid phases, which in turn affects As redox transformations.

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