Making Paving Stones from Copper Mine Tailings as Aggregates
1
Chemical Engineering Department, Universidad Católica del Norte, Antofagasta CP 1270709, Chile
2
Construction Management Department, Universidad Católica del Norte, Antofagasta C.P. 1270709, Chile
3
School of Engineering Sciences, Lappeenranta-Lahti University of Technology, FI-53851 Lappeenranta, Finland
4
Mining Business School, ENM, Universidad Católica del Norte, Antofagasta CP 1270709, Chile
5
Mining and Metallurgical Engineering Department, Universidad Católica del Norte, Antofagasta CP 1270709, Chile
*
Author to whom correspondence should be addressed.
Int. J. Environ. Res. Public Health 2020, 17(7), 2448; https://doi.org/10.3390/ijerph17072448
Received: 17 February 2020
/
Revised: 24 March 2020
/
Accepted: 26 March 2020
/
Published: 3 April 2020
(This article belongs to the Special Issue Future Challenges in the Framework of Integrated and Sustainable Environmental Planning: Case Studies and Innovative Proposals)
Copper mining, the central axis of Chile’s economic development, produces a large number of tailings, which become a potential environmental risk. This study aims to evaluate the mechanical properties resulting from the making of Portland cement mixtures with tailings as aggregates so that they can be eventually used in paving stones for building inactive tailings dams. Tailings coming from two dams at a concentration plant located in Taltal (Chile) were used. Currently, Dam 1 is inactive, while Dam 2 is active. The tailings samples obtained from both dams were granulometrically characterized by sieving. In addition, pH, humidity, Eh, and mineralogical assays (sulfides, oxides, sulfates, carbonates, phosphates, and silicates) were measured. The fines content of the tailings from Dams 1 and 2 with a sieve size of N°200 ASTM were 76.2% and 29.6%, respectively. Therefore, owing to their high percentage of fines, they cannot be as used as concrete aggregates. Aggregates must contain a maximum percentage of fines so that mortars and concrete can meet Chilean standards. In this paper, to comply with a 7% and 15% fines content lower than 0.075 mm, tailings materials were mixed with conventional aggregates containing very little fines. In addition, a reference mixture was made with only tailings aggregates with and without a superplasticizer additive. To measure the mixtures of cement, aggregates, and tailings, bending and compression strength assays were made of the specimens after a 28-day curing, according to the Chilean standard. The results of the study show that the addition of only part of the tailings to the mixture increases bending strength by 26% and compression strength by 180% compared with the reference mortar, with a fines content lower than 0.075 mm in the 7% mixture, thus allowing paving stone manufacture with tailings materials. In addition, it was possible to increase the workability of the reference mixture by using superplasticizers as additives.
View Full-Text
Keywords:
tailing bricks; copper mine tailings; mine tailing stabilization; mining environmental liabilities
▼
Show Figures
Figure 1
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Lam, E.J.; Zetola, V.; Ramírez, Y.; Montofré, Í.L.; Pereira, F. Making Paving Stones from Copper Mine Tailings as Aggregates. Int. J. Environ. Res. Public Health 2020, 17, 2448. https://doi.org/10.3390/ijerph17072448
AMA Style
Lam EJ, Zetola V, Ramírez Y, Montofré ÍL, Pereira F. Making Paving Stones from Copper Mine Tailings as Aggregates. International Journal of Environmental Research and Public Health. 2020; 17(7):2448. https://doi.org/10.3390/ijerph17072448
Chicago/Turabian StyleLam, Elizabeth J., Vicente Zetola, Yendery Ramírez, Ítalo L. Montofré, and Franco Pereira. 2020. "Making Paving Stones from Copper Mine Tailings as Aggregates" International Journal of Environmental Research and Public Health 17, no. 7: 2448. https://doi.org/10.3390/ijerph17072448
Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
