scholarly journals Treatment of Soil Contaminated by Mining Activities to Prevent Contamination by Encapsulation in Ceramic Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6740
Author(s):  
Juan María Terrones-Saeta ◽  
Jorge Suárez-Macías ◽  
Antonio Bernardo-Sánchez ◽  
Laura Álvarez de Prado ◽  
Marta Menéndez Fernández ◽  
...  

Mining is an essential activity for obtaining materials necessary for the well-being and development of society. However, this activity produces important environmental impacts that must be controlled. More specifically, there are different soils near new or abandoned mining productions that have been contaminated with potentially toxic elements, and currently represent an important environmental problem. In this research, a contaminated soil from the mining district of Linares was studied for its use as a raw material for the conforming of ceramic materials, bricks, dedicated to construction. Firstly, the contaminated soil was chemically and physically characterized in order to evaluate its suitability. Subsequently, different families of samples were conformed with different percentages of clay and contaminated soil. Finally, the conformed ceramics were physically and mechanically characterized to examine the variation produced in the ceramic material by the incorporation of the contaminated soil. In addition, in this research, leachate tests were performed according to the TCLP method determining whether encapsulation of potentially toxic elements in the soil occurs. The results showed that all families of ceramic materials have acceptable physical properties, with a soil percentage of less than 80% being acceptable to obtain adequate mechanical properties and a maximum of 70% of contaminated soil to obtain acceptable leachate according to EPA regulations. Therefore, the maximum percentage of contaminated soil that can be incorporated into the ceramic material is 70% in order to comply with all standards. Consequently, this research not only avoids the contamination that contaminated soil can produce, but also valorizes this element as a raw material for new materials, avoiding the extraction of clay and reducing the environmental impact.

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 819
Author(s):  
Pura Alfonso ◽  
Oriol Tomasa ◽  
Luis Miguel Domenech ◽  
Maite Garcia-Valles ◽  
Salvador Martinez ◽  
...  

Tailings from the Osor fluorite mines release large amounts of potentially toxic elements into the environment. This work is a proposal to remove these waste materials and use them as a raw material in the manufacture of glass. The chemical composition of the tailings was determined by X-ray fluorescence and the mineralogy by X-ray diffraction. Waste materials have SiO2, Al2O3 and CaO contents suitable for a glass production, but Na as NaCO3 has to be added. Two glass formulations, with 80–90% of the residue and 10–20% Na2CO3, have been produced. The crystallization temperatures, obtained by differential thermal analysis, were 875 and 901 °C, and the melting temperatures were 1220 and 1215 °C for the G80-20 and G90-10 glasses, respectively. The transition temperatures of glass were 637 and 628 °C. The crystalline phases formed in the thermal treatment to produce devitrification were nepheline, plagioclase and diopside in the G80-20 glass, and plagioclase and akermanite-gehlenite in the G90-10 glass. The temperatures for the fixed viscosity points, the working temperatures and the coefficient of expansion were obtained. The chemical stability of the glass was tested and results indicate that the potentially toxic elements of the tailings were incorporated into the glass structure.


2021 ◽  
pp. 128131
Author(s):  
Muhammad Azeem ◽  
Sabry M. Shaheen ◽  
Amjad Ali ◽  
Parimala G.S.A. Jeyasundar ◽  
Abdul Latif ◽  
...  

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1459
Author(s):  
Carlos Boente ◽  
Carlos Sierra ◽  
Julián Martínez ◽  
Eduardo Rodríguez-Valdés ◽  
Elías Afif ◽  
...  

Former industrial sites are now dedicated to other land uses in the Linares mining district. Here we selected five residential/farming areas (squares of 1 km2 each) and sought to evaluate the levels of contamination by Potentially Toxic Elements (PTEs) of the soils, and also to offer an insight into the threat these pollutants may pose to human health or the environment by means of risk assessment. High concentrations especially of Pb, and also of As, Cd, Cu and Zn were found in quantities that are considerably bioavailable. Moreover, risk assessment revealed unacceptable concentrations for Pb and As in all the areas as well as for Cd and Cu in some squares.


2019 ◽  
Vol 16 (4) ◽  
pp. 251 ◽  
Author(s):  
Sarah M. Hayes ◽  
Nicole A. Ramos

Environmental contextTellurium can be more toxic than arsenic, but its fate in the surficial environment is poorly understood. We studied tellurium behaviour in semiarid mine tailings and found that most tellurium is associated with iron (oxy)hydroxides as tellurate (TeVI), the less toxic oxidation state. Iron (oxy)hydroxides are likely to control the fate of Te in the surficial environment and may effectively sequester Te oxyanions released by oxidative weathering. AbstractTellurium (Te) is a critical element owing to its use in solar technology. However, some forms are highly toxic. Few studies have examined Te behaviour in the surficial environment, thus little is known about its potential human and environmental health impacts. This study characterises two physicochemically distinct Te-enriched mine tailings piles (big and flat tailings) deposited by historic gold (Au) mining in the semiarid Delamar mining district, Nevada, USA. The big tailings are characterised by smaller particle size and higher concentrations of potentially toxic elements (up to 290mgTekg−1), which are enriched at the tailings surface. In contrast, the flat tailings have larger particle size and properties that are relatively invariant with depth. Based on the sulfate to sulfide ratio, the tailings were determined to be sulfate dominated, which suggested a high degree of weathering, although the flat tailings did contain significant amounts of sulfides (~40%). Tellurium X-ray absorption spectroscopy of the big tailings indicates that tellurate, the less toxic Te species, is the principal form of Te. Electron microscopy indicates that most of the Te present at the site is associated with iron (oxy)hydroxides, and sometimes with other potentially toxic elements, especially lead and antimony. Physiologically-based extraction tests indicate that substantially more Te is solubilised in synthetic stomach fluids than in lung fluids, with gastric bioaccessibility ranging from 13 to 31% of total Te. This points to low to medium bioaccessibility, which is common for iron (oxy)hydroxide-associated elements. Together, these results represent a preliminary assessment of Te surficial behaviour in a semiarid environment and indicate that Te in these tailings represent a moderate health concern.


2008 ◽  
Vol 59 ◽  
pp. 39-41 ◽  
Author(s):  
Etele Albert ◽  
Marcela Muntean ◽  
A. Ianculescu ◽  
Florin Miculescu ◽  
B. Albert

A special ceramic material with specific performances for some extreme environments can be elaborated using basaltic-andesite as raw material. The volcanic rocks presents specific compositions, a complex structure and properties, so some of them, such as basaltic-andesite, may have multiple utilization. The elaborated basaltic-andesite compound ceramic material, in mixture with porcelain-clay and alumina was characterized with SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), X-ray diffraction and thermo-gravimetric analysis. Many of the properties of this sort of ceramic material surpass the electric insulator porcelain type KER 110 ceramic, and in some approximate the high alumina-content ceramic materials.


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