Search Results (19)

The relict bedding and slaty cleavage structure in slate directly influences the crushing characteristics and strength properties of slate aggregates. When slate aggregates are used in asphalt concrete, it may have risks of insufficient resistance to crushing and uncertain long-term durability. In order to investigate the crushing behavior of slate coarse aggregates in asphalt mixtures, a comparative study was conducted using limestone and basalt aggregates as reference. Various tests were carried out including crushing value tests, single-particle compression crushing tests, Marshall compaction resistance tests, and gyratory compaction resistance tests. The crushing patterns, crushing strength, and gradation changes of slate aggregates after crushing were systematically examined. Based on the Weibull distribution function, the statistical distribution of single-particle crushing strength was analyzed. Additionally, the particle distribution patterns were studied for single-sized aggregates, blended aggregates, and asphalt mixtures after these were subjected to crushing under Marshall compaction and gyratory compaction. The test results indicated that the crushing value of slate coarse aggregates was 9.2%, which indicates superior crushing resistance compared to traditional limestone and basalt. After long-term exposure to water immersion at 60 °C, high-pressure steam treatment, and heating at 220 °C, the increase in crushing value of slate coarse aggregates was less than 1.5%, indicating excellent water and heat resistance. The two-point and four-point crushing strengths of single particles of slate coarse aggregates were higher than those of limestone and basalt coarse aggregates, and the single-particle compression crushing strength followed the Weibull distribution pattern. Both single-sized and blended slate aggregates exhibited lower proportions of crushing during Marshall and gyratory compaction compared to basalt and limestone aggregates. Asphalt mixtures prepared with slate coarse aggregates also demonstrated better crushing resistance than those made with basalt and limestone, confirming that the bedding structure of slate does not cause excessive crushing in asphalt mixture. The obtained findings were limited to the tested slate aggregates from a single quarry and thus necessary performance verification should be conducted on slate aggregates from other sources before practical engineering applications. Full article

Road construction has historically played a pivotal role in infrastructure development, addressing society’s growing mobility needs. Selecting sub-base and base layer aggregates requires materials that are mechanically durable, compliant with engineering standards, cost-effective, and sustainable. Locally sourcing aggregates enhances economic efficiency while reducing the environmental impact. In Southeastern Anatolia, particularly in Diyarbakır, extensive investments in roads, highways, and high-speed rail have increased the demand for high-quality aggregates. Karacadağ basalt, a locally abundant volcanic rock, offers a promising alternative. Its use not only reduces raw material costs but also aids in rehabilitating surface agricultural lands, supporting sustainable urban development and resource conservation. This study assesses the suitability of Karacadağ basalt as a sub-base and base material for highway construction. Two mixtures, namely PMT (Primary Mixture Type) and PMAT (Primary Mixture Alternative Type), were prepared and tested by the Ninth Regional Directorate of Highways using standardized methods including sieve analysis, methylene blue index, Los Angeles abrasion, Weather Resistance, and California Bearing Ratio (CBR) tests. Results indicate that Karacadağ basalt meets all relevant Turkish Highways Technical Specifications. These findings highlight the material’s potential as a sustainable, locally sourced aggregate for infrastructure applications, while suggesting that further testing across diverse quarry sites could enhance reliability and promote wider adoption. Full article

Blasting operations in surface mining pose a risk of flyrock, which is a critical safety concern for both personnel and infrastructure. This study presents the use of unmanned aerial vehicles (UAVs) and photogrammetric techniques to improve the accuracy of blast design, particularly in relation to controlling burden values and reducing flyrock. The research was conducted in a basalt quarry in Lower Silesia, where high rock fracturing complicated conventional blast planning. A DJI Mavic 3 Enterprise UAV was used to capture high-resolution aerial imagery, and 3D models were created using Strayos software. These models enabled precise analysis of bench face geometry and burden distribution with centimeter-level accuracy. The results showed a significant improvement in identifying zones with improper burden values and allowed for real-time corrections in blasthole design. Despite a ten-fold reduction in the number of images used, no loss in model quality was observed. UAV-based surveys followed software-recommended flight paths, and the application of this methodology reduced the flyrock range by an average of 42% near sensitive areas. This approach demonstrates the operational benefits and enhanced safety potential of integrating UAV-based photogrammetry into blasting design workflows. Full article

Concrete and mortar production consumes significant natural resources, leading to environmental concerns and sustainability challenges. Sustainable alternatives, such as industrial byproducts, have been explored to replace clinkers and aggregates. Basalt rock powder (BRP) is a promising option due to its physical and chemical properties, including its better particle size distribution and compatibility with cementitious composites, and studies have highlighted its pozzolanic activity and its potential to improve mechanical properties (compressive strength, flexural strength, and durability). Reusing rock dust as a raw material could transform it into a mineral byproduct, benefiting the new material and reducing waste volumes. This article presents a systematic literature review on the use of BRP in construction materials, conducted using the Scopus, ScienceDirect, PubMed, and Web of Science databases and following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) procedures. The search resulted in 787 articles (up to December 2024) and, after the screening process, 17 met the inclusion criteria. From the selected articles, information regarding the utilization of this waste product; its influence on mechanical properties, pozzolanic activity, and durability; and the sustainability associated with its use was compiled. The risk of bias was low as the search was comprehensive, all the papers were peer-reviewed, and all authors reviewed the papers independently. In conclusion, the studies demonstrate the potential of using BRP as a component of cementitious materials, indicating it as a possible innovative solution to the current challenges in the construction industry. Full article

A two-year study (June 2022–May 2024) on the reliability and maintainability of technological equipment at the Pătârș basalt quarry identified critical wear issues in metal components impacting operational continuity. The analysis focused on identifying causes of operational interruptions and evaluating solutions to improve equipment performance. Results showed that speed and load significantly impact wear rate and material selection significantly influences abrasion resistance. Laboratory tribological tests provided valuable data on the influence of basalt properties on wear, complementing field data. The study highlighted the low reliability of critical components, such as the sorting station trough, front loader bucket knife, and excavator bucket tooth, necessitating frequent replacements. For example, the trough has only a 40% probability of operating without defects after 182 days, with average roughness reaching 1.2 μm and wear profile height up to 22.5 μm. Similarly, the bucket knife and tooth require replacement at significantly reduced intervals compared to their nominal operating life to achieve 80% reliability. To address these findings, the study proposes two solutions: (1) manufacturing experimental prototypes with alternative materials for the trough to improve wear resistance and reliability; and (2) on-site welding reconditioning of metal components to reduce costs and downtime. Full article

Basalt rock dust (RD) is a rock quarry byproduct that may improve soil health in organic farming systems. RD was applied at two contrasting organic farms (the no-till VT-Farm in Thetford, Vermont, and the tilled MA-Farm in Barre, Massachusetts) and in soil batch reactors to investigate the impacts of basalt RD applications (6.7 tons ha⁻¹) on physical and chemical soil health properties. Triplicate soil pits at two fields (RD and no RD) at each farm were sampled down between 80 to 110 cm depths in 2020. Median coarse (>2 mm) and very coarse aggregates (>50 mm) increased by 15% to 25%, and soil organic carbon concentrations increased by 69% to 135% for RD added, compared to no RD, in the top 20 cm of the soil profile at both farms. Plant-available Ca, Mg, and K increased between 62% and 252% in the top 30 cm for both farms. Plant-available micronutrients (B, Mn, Cu, and Zn) showed limited increases from the RD addition at the two farms. The laboratory batch reactor results confirm the increased Ca and Mg release rates tested across soils, but K, P, and the micronutrient batch reactor results did not increase from the RD addition. One contrary finding was (−41% at the VT-Farm) the lower plant-available P and soluble P (−5 to −29%) under the RD addition, suggesting that further studies on the interactions with Fe and pH from the RD addition are warranted. Full article

We obtained original glasses and glass-ceramics through the controlled melting and recrystallisation of basalt rocks extracted from several quarries in the Canary Islands. The electrical measurements of the resulting glasses and glass-ceramics were conducted in a complex impedance at temperatures in the 250–700 °C range. These electrical determinations made it possible to follow the nucleation and crystal growth processes. The main crystalline phases were pyroxenes, feldspar (anorthite) and magnetite, which decorate the dendritic crystallisation of pyroxenes. The magnetite is present as nanocrystals, being the component chiefly responsible for the electrical conduction properties of these glass-ceramics. Electrical conduction is facilitated by the presence of magnetite nanocrystals on the axes of dendrites of pyroxene crystals, enabling polar electron conduction in these materials. Thus, the Fe²⁺/Fe³⁺ ratio was related to the total Fe²⁺/Fe, which made it possible to express an electronic conduction model. Full article

The demand for mineral fertilizers has increased over the years. In the states of Amazonas and Roraima, acquiring conventional fertilizers used in agriculture is challenging due to the distance from large production centers. In these regions, alternative fertilizers are needed to maintain food security. However, research in agrominerals of silicate rock powders (SRP) is still incipient. The objective of this research was to characterize three important Units of Agrogeological Interest in the Manaus/Boa Vista axis in the Amazon region of Brazil: (i) EBAM Quarry: quartz monzonites from the Água Branca suite, partially potassified, (ii) Granada Mining Quarry: basalts from the Apoteri formation, and (iii) Samauma Quarry: riolites from the Iricoumé Group. Samplings were carried out followed by chemical analyses for determining macro and micronutrients, in addition to potentially toxic elements; petrographic analyses were performed for mineralogical characterization as well as granulometric analyses of the powders collected in the quarries. The results showed that the EBAM quarry rock powder meets the standards established by Brazilian legislation. It also has low levels of potentially toxic elements and only 15% quartz, indicating good safety in the use of this SRP, in addition to the large supply of the material already crushed, for which there is still no market. At the Granada Mineração quarry, SRP also has the necessary characteristics to classify as a soil remineralizer, including K₂O content above 1%. At Pedreira Samauma, although SRP does not qualify as an agromineral, it has more than 5% K₂O and 77% aphanitic matrix, which could result in a more accessible release of abundant K and Si to the soil–plant system. Using laser granulometry analysis, it was possible to make some considerations about the effects of the crushing process in such different lithotypes and, finally, to characterize and classify the prospects of greatest interest for “rochagem” in the Amazon. Full article

A fundamental step in the best preservation of heritage materials is investigating their chemical and physical characteristics, and understanding how they interact with the surrounding environment. For this reason, the stone masonry of the monumental UNESCO site of Panamá Viejo was subjected to a thorough study to characterize the materials and evaluate their state of conservation. Additionally, potential outcrops were explored in order to identify sites for the supply of raw materials. The methodological approach encompassed mineralogical-petrographic investigations using stereomicroscopy, polarized light microscopy (PLM), X-ray powder diffraction (XRPD), scanning electron microscopy and energy dispersive X-ray spectrometry (ESEM-EDS) and X-ray fluorescence (XRF). The results revealed that the masonries primarily consists of polygenic breccia, basaltic andesite, rhyodacite, tuffite, and rhyolite. In addition, at the potential quarries, breccia and basaltic andesite were identified. The porous structure was studied using mercury intrusion porosimetry (MIP). Possible issues due to salt dissolution/crystallization cycles were considered. Consequently, ion chromatography (IC) was conducted on samples exhibiting alteration patinas to study the presence of soluble salts. In assessing the state of conservation, prevalent forms of deterioration included biological colonization, detachments, material loss, potential salt weathering, and chromatic alteration. In conclusion, the outcomes of this work provide a valuable resource for the current and future preservation of this site. Full article

In the Canary Islands and in other parts of the world where it can be found in its natural state, basaltic tephra, or “Picón” as it is known locally, is commonly used as a soilless substrate for crops. The aim of this study is to learn more about the physical properties of the Canary Islands’ tuff, and to find a simple method to predict the hydraulic behaviour of these substrates due to their heterogeneity. To accomplish this, 32 tuff samples were collected from all the quarries on the island of Tenerife (Canary Islands) that were authorised for the study. The tuffs had hydraulic properties that were highly influenced by the particle size. Coarse tuffs had an aeration capacity greater than 35% v/v and easily available water of less than 5% (v/v), while fine tuffs had aeration capacities below 20% v/v and elevated water retention (20 to 26% v/v). The intermediate tuffs had characteristics that varied between those of the two previous groups. Particle size fractions of less than 1 mm demonstrated the best correlation to common air:water ratios and present the best predictive capacity to relations involving air. By focusing on air:water ratios and the previous assumption, an attempt was made to predict the suitability of new pyroclastic material samples emitted by the La Palma Volcano as growing substrates for vegetables. Full article

In the Ordovician limestone of the Thorsberg quarry (South Sweden), about 130 meteorites have been found. Among the extraterrestrial material, several terrestrial Cr-spinels and zircons have been found too. In particular, in the interval 416–447 cm above the Arkeologen bed, terrestrial Cr-spinels, compositionally different from previous studied Cr-spinels of the same sequence, are present. Previous studies on zircon provided depositional ages that range from 464.22 ± 0.37 Ma to 465.01 ± 0.26 Ma. The trace element content of zircons suggests different possible source rocks. In fact, zircons from the oldest ash layer resemble those from dolerite, while those in the youngest layers are similar to zircons commonly found in granitoids, with more than 65% wt. SiO₂. The chemistry of Cr-spinels suggests a strong alteration, so that it is difficult to assign them to a specific area, however they recall the chemistry of altered spinels from ophiolitic occurrences (among other possibilities). The geological setting of the Laurentia and Baltica areas, including the description of basalts to rhyolite association and the presence of ophiolitic slices, makes us confident about the derivation of these zircons and Cr-spinels from those areas. Full article

Carbon footprint reduction of paving materials could be explored through recycling mining by-products into different applications, which will preserve natural resources and decrease environmental issues. One possible approach is to reuse quarry dust and mining ore waste as precursors in geopolymer applications. geopolymers are mineral polymers rich in aluminosilicates with an amorphous to a semi-crystalline three-dimensional structure. The current review aims to summarize the studies conducted during the past decade on geopolymers containing quarry dust and mine tailings. The first section discusses various precursors used for geopolymer cement production such as metakaolin, ground granulated blast furnace slag (GGBFS), fly ash, and quarry/mining ore wastes including silt, tungsten, vanadium, copper, gold, zinc, marble, iron, basalt, and lithium. Different calcination treatments and curing conditions have been summarized. In some cases, the precursors are required to be calcined to increase their reactivity. Both ambient temperature and elevated temperature curing conditions have been summarized. Less attention has been paid to room temperature curing, which is necessary for field and industrial implementations. Engineering properties such as compressive strength, density, durability and acid resistance, water absorption and abrasion of geopolymers containing mining waste were reviewed. One of the main barriers preventing the widespread use of waste powders, in addition to economic aspects, in geopolymers could be due to their unstable chemical structure. This was shown through extensive leachate of Na⁺ or K⁺ cations in geopolymer structures. The review of over 100 articles indicated the need for further research on different aspects of quarry waste geopolymer productions before its full industrial implementation. Full article

This study aimed to analyze and assess the spatial and temporal trends in distribution of reserves and production of igneous and metamorphic dimension stones and crushed rocks in the Lower Silesia region, which with 90% of total supply is the key source region of these rock raw materials in Poland. The research utilized descriptive statistics to examine temporal variations of production, as well as to determine sufficiency of these resources for four different scenarios and seven main lithological groups of rocks. Spatial statistics in the geographic information system was used to map changes in spatial distribution of production with the density function, as well as to determine areas of highest concentration in the 2010–2018 period. Then, 169 communes in the region were assessed using the multicriteria analytical hierarchy process (AHP) technique to identify local communities prospective for development of this mining sector. Strong, positive correlation (r = 0.645) between year to year production change with annual rate of gross domestic product was determined. Sufficiency of economic reserves was estimated, in four scenarios, as being the lowest for melaphyre and porphyry (25–49 years), and the highest for marble (380–389 years). Reserves of basalt and amphibolite should last for approximately 50 years (32–60 and 36–67 years, respectively), granite for 82 to 110 years, and gabbro and gneiss for over 100 years (78–159 and 76–189 years, respectively). Maps revealed a possible trend of increasing production in quarries located in the central and eastern parts of Lower Silesia, whereas multicriteria analysis allowed for the identification of nine communes with the highest potential for rock raw material quarrying. The practical outcome of this study is a knowledge database for authorities, upon which sustainable management of regional rock raw materials can be based in the context of economic, social, and environmental impacts of their extraction. Full article

Sardinia was affected by an intense igneous activity which generated calc-alkaline products during the Oligo-Miocene period. The volcanic substance shows large variations, ranging from pyroclastic flow deposits, lava flows and domes. By composition, the deposits are all primarily dacites and rhyolites, with subordinate andesites and very scarce basalts. The rhyolite lavas show porphyritic and ash-flow tuffs. Ignimbrite structures are found in the dacitic domes and rhyolitic lavas. These rocks—commercially known as “Trachytes of Sardinia”—used to be quarried in all historical provinces, mainly in the central part of the island to be used as ornamental and building stone. They continue to be commonly used nowadays, but their use dates back to the prehistoric age. They are easily found in many nuraghi, “domus de janas”, holy wells, Roman works (mosaics, paving, roads, bridges), many churches built in Sardinia and practically in all kinds of structural elements in public and private buildings, such as walls, houses, and bridges. Contrary to the granitoid rocks, whose appearance is largely influenced by the mineralogical composition, the aesthetic feature of volcanic rocks is rather affected by the widest range of colors, structure and texture, i.e., shape, size and distribution of mineral components, porphyric index, etc. “Trachyte” is quarried opencast with the “single low step” method, with descending development, with prevalent use of double-disc sawing machines. Whenever the stone deposit allows higher steps, the chain cutting machine, in combination with diamond wire, becomes the preferred extraction solution. This study aims to at look Sardinian “trachytes” from a geoheritage perspective. After a geological-petrographic framework, the paper discusses the historical uses of “trachyte” in Sardinia. The current state of the art of “trachyte” quarrying, processing and usage in the Island is also described. An analysis of the “trachyte” production has been carried out. Finally, a consideration about how to enhance geotourism in the area is suggested. Full article

Flood basalts of the Deccan Volcanic Province erupted between about 67.5 to 60.5 Ma ago and reached a thickness of up to 3500 m. The main part consists of compound and simple lava flows with a tholeiitic composition erupted within 500,000 years at about 65 Ma. Within the compound lava flows, vesicles and cavities are frequent. They are filled by secondary minerals partly of well development and large size. This study presents data on the secondary mineralization including detailed field descriptions, optical, cathodoluminescence and SEM microscopy, X-ray diffractometry, fluid inclusions, C and O isotope analyses, and Rb-Sr and K-Ar geochronology. The investigations indicate a multistage precipitation sequence with three main stages. During stage I clay minerals and subsurface filamentous fabrics (SFFs), of probably biogenic origin, formed after the lava flows cooled down near to the Earth’s surface. In stage II, first an assemblage of calcite (I) and zeolite (I) (including mordenite, heulandite, and stilbite) as well as plagioclase was overgrown by chalcedony, and finally a second calcite (II) and zeolite (II) generation developed by burial metamorphism by subsequent lava flows. Stage III is characterized by precipitation of a third calcite (III) generation together with powellite and apophyllite from late hydrothermal fluids. Rb-Sr and K-Ar ages of apophyllite indicate a large time span for stage III. Apophyllite formed within different time intervals from the Paleogene to the early Miocene even within individual lava flows at certain localities. From the Savda/Jalgaon quarry complex, ages cluster at 44–48 Ma and 25–28 Ma, whereas those from the Nashik area are 55–58 Ma and 21–23 Ma, respectively. Full article