MDPI - Publisher of Open Access Journals

13 pages, 14098 KiB

Open AccessArticle

Pit Lakes in Abandoned Slate Quarries in Northwestern Spain: Characteristics and Potential Uses

by José María Redondo-Vega, Javier Santos-González, Adrián Melón-Nava, Amelia Gómez-Villar, Sergio A. Peña-Pérez and Rosa Blanca González-Gutiérrez

Water 2024, 16(17), 2403; https://doi.org/10.3390/w16172403 - 27 Aug 2024

Viewed by 535

Abstract

Human activities play a key role in landscape evolution. Mining is one of the most important of these since it changes large parts of the Earth’s surface. In abandoned mines and quarries, pit lakes are quite common due to water table blocking. These lakes have remarkable ecological characteristics, but they are still poorly understood. Northwestern Spain has a long tradition in the use of slate for roofs. This exploitation, mostly open-pit, has caused a great transformation in the landscape including the generation of pit lakes. In this work, 27 pit lakes in abandoned slate quarries areas have been analysed using orthophotos of different years, UAV (unmanned aerial vehicle) images and field work. In each lake, the topographic context, geomorphological dynamics, morphometric parameters (including depth), pH, and ecological variables were measured. Other uses for these quarry pit lakes and their significance as a new geo-ecological environment are also discussed. The results show different types of pit lakes and, consequently, different potential uses in each case. Only six offer good conditions for recreational uses, whereas the rest (21) show slope instability or poor water quality. Full article

(This article belongs to the Section Water Resources Management, Policy and Governance)

► Show Figures

Figure 1

24 pages, 6685 KiB

Open AccessArticle

Underground Pumped Storage Hydropower Case Studies in Belgium: Perspectives and Challenges

by Alessandro Morabito, Jan Spriet, Elena Vagnoni and Patrick Hendrick

Energies 2020, 13(15), 4000; https://doi.org/10.3390/en13154000 - 3 Aug 2020

Cited by 13 | Viewed by 6021

Abstract

To avoid the geographical and topographical prerequisites of the conventional pumped hydro energy storage, the use of underground cavities as water reservoirs allows countries without steep topography, such as Belgium, to increase the potential of the energy storage capacity. Belgium abounds in disused mines and quarries convertible into water basins. In this article, two Belgian case studies are presented and discussed for their singularity. A slate quarry in Martelange is discussed in technical aspects proposing three operating scenarios. Moreover, a preliminary economic analysis of the underground pumped storage system and a greenhouse gas emission evaluation for the storage system’s lifetime are presented. The analysis for a 100 MW power plant estimates a total initial investment of over 12 million euros and two million of CO

_{2}

avoided over its lifetime. This article also proposes the use of the coal mine 500 m deep of Pérronnes-lez-Binche. The mine representation discussed here offers a high energy capacity, but the substantial head drop (from about 500 to 200 m) challenges the selection of the hydraulic turbomachinery. A 1D simulation computed in SIMSEN draws out the behaviour of the unusual hydraulic configuration of turbines in series. Full article

(This article belongs to the Special Issue Underground Pumped Storage Plants)

► Show Figures

Figure 1

12 pages, 4711 KiB

Open AccessArticle

Laser Microdrilling of Slate Tiles

by Joaquín Penide, Antonio Riveiro, Ramón Soto, Mohamed Boutinguiza, Felipe Arias-Gonzalez, Jesús del Val, Rafael Comesaña, Fernando Lusquiños, Félix Quintero and Juan Pou

Materials 2019, 12(3), 398; https://doi.org/10.3390/ma12030398 - 28 Jan 2019

Cited by 4 | Viewed by 3149

Abstract

Slate is a natural rock usually used in roofs, façades, and for tiling. In spite of this broad use, the production process of slate tiles requires substantial improvements. An important quantity of slate from the quarry is wasted during the manufacturing of the final product. Furthermore, processes are not automatized and the production lead times can be considerably shortened. Therefore, new processing methods to increase productivity, reduce costs and to provide added value to the final slate product are required. Drilling is an important part of these manufacturing processes. Conventional drilling processes usually cause the breaking of the slate tiles; then, even a higher quantity of material is wasted. To overcome these problems, lasers emerge as a feasible tool to produce holes in this material, since mechanical stresses are not induced on the workpiece. In this work, we have studied the CO₂ laser microdrilling of slate tiles. We used a Design of Experiments (DOE) methodology to determine the influence of the laser processing parameters on the hole quality. This work demonstrates the capability of a CO₂ laser to produce holes in slate with less than 100 microns in diameter, avoiding any fracture, and with a processing time of less than 50 ms per hole. Finally, this process demonstrates the viability of the production of high-density micron-sized holes in a slate tile for water draining purposes. Full article

(This article belongs to the Special Issue Laser Materials Processing 2019)

► Show Figures

Figure 1

Journals

Article Types

Countries / Regions

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI

Saved Queries

Search Filter Reset All

Years

Feature Papers

Subjects

Journals

Article Types

Countries / Regions

Search Results (3)

Further Information

Guidelines

MDPI Initiatives

Follow MDPI