Mineralogical Properties Research Articles

A case study of crushed stone for road construction application: amphibolite and basalt varieties from Croatia

Crushed stone is one of the most exploited and important mineral raw material. Emphasis is given to determination of mineralogical and petrographic properties, of two genetically different rocks of silicate composition, commonly used as crushed stone for road constructions, as their physical properties depend on them. First is amphibolite from Vetovo, and second is basalt from Vratnik locality, both sourced from Croatia. Tests conducted according to European and Croatian norms evaluated the real and apparent density, open and total porosity, and water absorption of stones. The relationship between mineralogical and physical properties led to the following conclusions: the open porosity values of amphibolite samples are low, which is a consequence of the medium to high degree of metamorphism, (plagioclase and hornblenda), sosiritization, and undisturbed rock features. The total water saturation was achieved in a brief time, confirming this statement. The basalts have different porosity and water absorption values, which are consequences of differences their textural-structural properties (glassy, intersertal or intergranular groundmass), amount of amygdules, presence or absence of chlorite/volcanic glass. Furthermore, the percentage of plagioclase in the modal composition differs, and the plagioclase itself has been altered, and the amount of clay, sericite and calcite vary in two different varieties of basalt. Compared to amphibolites, basalts have notably higher water absorption values as well. Accordingly, the studied amphibolite has water absorption less than 0.5% and is suitable for use in a road construction application for wearing course in the asphalt pavement, and studied basalt is not.

Technosols Made from Iron Mine Tailings and Construction and Demolition Waste as an Alternative for Sustainable Solid Waste Management

ABSTRACTBrazil faces urgent environmental challenges due to large waste production from mining and construction activities particularly regarding the disposal and management of the solid waste generated by these activities. The extraction of iron ore and the storage of tailings in dams, most of which are at imminent risk of rupture, represent foretold environmental disasters. Additionally, the disposal of construction waste raises environmental concerns due to the decreasing vailability of inert landfill space. To address these challenges, we evaluated the potential of Technosols made from construction and demolition waste (CDW) and iron mining tailing (IMT) in different proportions (60:40, 70:30, 80:20, and 100% of IMT and CDW, respectively) to support grass development. The Technosols were compared to a natural soil (Haplic Ferralsol). The soils were cultivated with Urochloa brizantha cv. Marandu in a field experiment conducted for 120 days. At the end of experiment, soil samples were collected and analyzed their chemical, physical, and mineralogical attributes, while plants were analyzed for dry biomass. Plants cultivated in Technosols exhibited dry biomass production 3.3‐fold (825 ± 270 g) greater than those cultivated in the natural soil (251 ± 77 g). Higher biomass production in the Technosols, especially in the TEC70:30, was associated with the favorable chemical conditions of these soils, such as slightly neutral pH (~7.5), higher cation exchange capacity (68.1 ± 12.4 mmol dm−3) and nutrient availability, especially Ca and P (57.8 ± 0.8 and 28.2 ± 0.4 mmol dm−3, respectively). These results aim to provide insights for the effective use of different Technosols in mitigating environmental impacts and promoting sustainable land and waste management practices, primarily to prevent future environmental disasters.

Influence of parent rock on soil clay mineralogy and physicochemical properties: a case study from the O’Higgins region, central Chile

Influence of parent rock on soil clay mineralogy and physicochemical properties: a case study from the O’Higgins region, central Chile

Assessment of fly ash based sand as a perspective alternate backfill material for stowing in mining activity

Due to the paucity of river sand and increased regulations on sand mining, mine fill voids are kept emptied, fostering the demand for alternate backfilling material. This study attempts to develop fly ash based sand (FAB Sand) using abundantly available fly ash alone as resource material and explores its suitability as a stowing material in mine void applications, including both underground and open mining activity. Since sand within particle sizes from 4.75 to 0.075 mm is explicitly used for stowing applications, FAB Sand is developed within the same particle size range. Its applicability is evaluated in terms of physical, chemical, mechanical, morphological and mineralogical properties, and suitability is assessed by comparing vis-à-vis with river sand. Towards environmental acceptability, leaching characteristics and human health risks of FAB Sand are examined comprehensively. The findings of the study reveal that FAB Sand is not only doable and promising but could also become a sustainable alternate backfilling material for stowing in mining activities. Results pertaining to environmental acceptability endorse that FAB Sand poses no threat to ecology and human health. Overall, the proposed novel alternate backfill material and its employability alleviates the mining of sand from rivers while concurrently accentuating sustainable solutions for mining practices.

Enhancing bricks with titanium dioxide ore waste: Mechanical and environmental assessments

Using residues, generated in various production chains of goods and services through developing new materials for civil construction, has proven to be a promising approach to addressing environmental issues. The residue generated during titanium dioxide (TiO2) production, commonly called Unreacted Ore Waste (UOW), presents potential utilization routes in the ceramic materials production chain, thereby avoiding disposal in industrial landfills. This study aimed to investigate the effects of combining UOW with ceramic blocks for any beneficial results. The properties of ceramic blocks obtained from the mixture of clay and UOW were evaluated after adding 5 %, 10 %, 15 %, and 20 % of UOW relative to the clay’s total mass. The ceramic blocks produced were assessed for their mechanical, photocatalytic, morphological, granulometric, mineralogical, and chemical properties. The results indicated that UOW did not negatively affect the structural properties studied. The addition of UOW led to a significant 9 % increase in the self-cleaning efficacy of the ceramic block produced. The textural parameter values of the ceramic blocks decreased with UOW incorporation due to more efficient particle packing. The surface area reduced from 16.6 to 9.1 m2/g, and the pore volume decreased from 0.045 to 0.025 cm3/g for samples from 0 % to 20 % UOW, respectively. Decreased porosity values contributed to increased compressive strength, resulting in a 6.5 MPa increment. The results suggested that the addition of UOW causes an increase in Al concentrations in leachate samples, from 647.64 to 5128.92 ppb for samples from 0 % to 20 % UOW, respectively. The presence of leachate and solubilized components from UOW impaired the germination of Lactuca sativa seeds. Based on the results, although the addition of UOW resulted in toxicity from the leachate/solubilized components, it did not adversely affect any fundamental properties of the ceramic materials. It can be incorporated up to 20 % into the process, replacing traditional raw materials. This suggests promising future trends in sustainable construction, with broader applications in the development of eco-friendly building materials.

Characterizing nano-indentation and microstructural properties of mine tailings-based geopolymers

The mining industry's extraction processes produce vast amounts of waste, including mine tailings (MT), traditionally stored in large ponds, causing significant environmental harm due to a lack of effective recycling methods. This research explores the potential of converting MT into a resource i.e., precursors in geopolymer synthesis. By analyzing the physicochemical and mineralogical properties of MT, the study formulates four geopolymer composites, substituting up to 30 wt% MT for fly ash. The composites' mechanical and microstructural properties show a contribution of MT in the stability of the matrix. Compressive strength of 59 MPa when incorporating 30 wt% MT, along with water absorption, microstructural analysis, and environmental impact assessments, support the hypothesis that the matrix is improved. Nano-indentation techniques further evaluated the nanomechanical properties, such as Young's modulus and fracture toughness. The findings reveal that geopolymers with 30 wt% MT exhibits up to 130 % increased strength. This research highlights the potential for innovative, eco-friendly solutions in waste management and material production, contributing to sustainable mining practices and advancing the field of geopolymer technology.

Potential for the Recovery of Selected Metals and Critical Raw Materials from Slags from Polymineral Zn–Pb Ore Metallurgy—Part I

Slags from the Silesia–Cracow Upland (Poland), including ten historical slags (deposited in waste dumps) and four contemporary slags (from current production), were examined to compare their chemical and mineralogical properties as well as to assess their potential for the recovery of selected metals and critical raw materials. The historical slags associated with the smelting of polymetallic ores originating from Mississippi Valley-type (MVT) deposits consisted primarily of gypsum. The contemporary slags, obtained from industrial waste rich in zinc and lead, were predominantly spinels (magnesium-aluminate and ferric) that exhibited higher iron content (up to 46.6 wt% of Fe2O3) compared to the historical slags (up to 26.1 wt% of Fe2O3). The zinc content was similar for both the slag types (3.5 wt% Zn). The average titanium and arsenic contents in the old and contemporary slags were at the same level as well, with 0.21 wt% (Ti) and 0.13 wt% (As), respectively. The contemporary slags contained higher levels of critical raw materials, such as cobalt, nickel, copper, and manganese, compared to the historical slags. Rare earth elements (REEs) were also more abundant in the contemporary slags, with an average content of 212 ppm, while the historical slags averaged 124 ppm. These findings underscore the potential for recovering valuable metals and critical raw materials from such slags, presenting opportunities for resource optimisation and environmental management.

An overview of soil and plant assessment for predicting site quality and recovery strategies of one the largest tailings dam failures worldwide.

Brazil's Fundão dam collapse is one of the world's largest disasters of tailing dam failures. Previous research has evaluated toxic metals and non-metals (Cd, Cr, Ni, Pb, As, Hg) in the same soil samples used in this study, and results have indicated that only Fe and Mn concentrations increased above the original baseline (Melo et al., 2023). Consequently, the present study's focus has shifted towards assessing and integrating changes in soil quality regarding chemical fertility and morphological, physical, and mineralogical attributes in the floodplains post-dam collapse. Soil samples from 0 to 0.2 and 0.2-0.4m depths, and samples of Urochloa sp. were collected along ten transects, spanning 100km perpendicular to the Doce River channel. This sampling strategy targeted specific landscape positions including areas affected by deposited iron tailings (DIT), soil tailing mixture (STM), and control soil (CS) devoid of iron tailing interference. Results showed no discernible alterations in Ca, Mg, K, and P concentrations in Urochloa sp., and the most severe negative impacts observed regarded the replacement of kaolinitic pre-disaster matrix for hematitic matrix, reduction in organic carbon, and the prevalence of sand and silt particles. These factors collectively contributed to triggering: (i) decrease in chemical fertility and cation exchange capacity and (ii) significant decline in physical quality, evidenced by increased density and reduced total porosity and macroporosity. Addressing these adverse effects would require the augment of organic matter levels and offset the dominance of the hematitic matrix in the DIT. Furthermore, it is imperative to decompact the DIT by mechanized or plant cultivation means.

Immobilization of Cadmium Via Ureolytic Bacteria Isolated from Greywater Waste and Horse Faeces

With the constant growth of technology and pollution caused by urban expansion, heavy metal contamination has become an alarming concern. The performance of Microbial induced carbonate precipitation technology in immobilizing heavy metal has been demonstrated by several researchers. While various studies have successfully isolated ureolytic bacteria from a variety of sources, there are very limited studies that have focused on isolating them from local waste sources, specifically Greywater and Horse Faeces for MICP application, which benefits in terms of economical, sustainability, and efficiency for engineering purposes. The study aims to investigate the effect of urease-producing bacteria derived from Greywater and horse faeces on heavy metal immobilization. The methods include collecting waste samples, isolating and subculturing of ureolytic bacteria, testing the physiological characteristics of ureolytic bacteria, examining the tolerance test and evaluating heavy metal removal efficacy through Atomic Absorption Spectrophotometry (AAS) analysis, and last but not least, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray (EDX) analyses of morphological and mineralogical properties of biominerals formed after heavy metal immobilization treatment. The study found that bacteria from Greywater were more effective at heavy metal immobilization than those from Horse Faeces. Additionally, AAS analysis indicates the greywater-derived bacteria from the residential area sample's exceptional competence in Cd2+ removal, with a significant 80.19% removal rate exceeding the horse faeces bacteria sample's removal rate of 65.26%. The morphological analysis confirmed the presence of heavy metal carbonate in treated heavy metal samples, as well as presenting insight into the effectiveness and application of local ureolytic bacteria's potential for heavy metal toxicity degradation.

Application of a novel auxiliary collector for molybdenite fines recovery in sustainable froth flotation production: Combining DFT calculations and experiments

The recovery of molybdenite diminishes with a reduction in particle size, which causes serious resource waste and financial loss. In this work, 1-dodecanethiol (NDM) was explored as an auxiliary collector to enhance the flotation of molybdenite fines. The flotation performance and adsorption mechanisms were revealed by micro-flotation tests, Zeta potential, contact angle, X-ray Photoelectron Spectroscopy (XPS), and density functional theory (DFT) calculations. Economic and environmental risks were assessed by industrial-scale flotation tests. The micro-flotation tests showed that NDM was more effective in improving the recovery of the −20 μm grade compared to the −38+20 μm grade. Zeta potential and contact angle results indicated that NDM significantly enhanced the hydrophobicity of the finer-grained molybdenite surface. XPS and DFT calculations revealed that water molecules acted as a significant barrier to kerosene adsorption, and NDM overcame this limitation by selectively adsorbing on the edge of molybdenite. The economic and environmental assessment indicated that NDM increased monthly product profits by $319,283.38 and was environmentally friendly, which can be extensively employed for mineral sources with similar mineralogical properties.

Characterization of pegmatites in the La Motte Batholith area, Preissac-La Corne Plutonic Suite, Abitibi Subprovince and its implications for exploration

This project focuses on the study of pegmatite characteristics in the La Motte Batholith (LMB) sector in the Abitibi Subprovince, located between the cities of Rouyn-Noranda and Val d'Or, and approximately 30 km west of the North American Lithium mine (101.9 Mt @ 1.06 % Li2O; Sayona Québec). The study area hosts mineralizations in critical and strategic minerals, most notably the Authier deposit, which are exclusively associated with Li-Cs-Ta pegmatites. The aim of the study is to characterize the mineralogical and geochemical properties of the pegmatites in the sector to better target lithium exploration. This characterization enables the subdivision of various families of pegmatites in the LMB sector, ranging from barren pods to spodumene-rich dykes. Within the LMB, the pegmatitic facies exhibit chemical characteristics similar to those of intersecting pegmatite dykes, suggesting a genetic link between the La Motte Batholith monzogranite and the different pegmatite families despite a possible age difference of several million years. The results also confirm that elemental ratios from whole-rock analyses (K/Rb, K/Cs, Nb/Ta, Mg/Li, and Zr/Hf) within lithium-bearing dykes show the lowest values compared to other dykes, regardless of the sampling location within the same dyke. Potassium feldspar and muscovite microprobe analyses from different pegmatites also reveal K/Rb and K/Cs ratios similar to whole-rock analyses, thereby strengthening the assessment of the fractionation degree of the LMB pegmatites. These ratios thus allow for targeting sectors hosting highly fractionated dykes even where spodumene has not yet been identified.

Preliminary Characterisation of Thermal Upgrading of Nickel from Saprolite via Selective Reduction

The mineralogical properties and distribution of information established in saprolite from Indonesia were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy energy dispersion spectroscopy (SEM–EDS) and differential thermal analysis (DTA) measurements. The findings suggest that laterite ore has a complex inner core. The percentages of nickel, iron, magnesium, aluminium and silicon in saprolite are 1.82 wt%, 30.47 wt%, 10–20 wt%, 4.86 wt% and 8.1 wt%. Saprolite has 53.1 wt% iron oxide/oxyhydroxide, 38.3 wt% lizardite and 8.7 wt% silicate. According to DTA, saprolite undergoes a phase shift from goethite to haematite at low temperatures (200–300°C). This is a suitable phase to optimise nickel diffusion in iron. Furthermore, the thermal upgrading approach was utilised for this saprolite.

Mosaic Technology in the Armenian Chapel Birds Mosaic, Jerusalem: Characterizing the Polychrome Hidden Sinopia

Since the Hellenistic period, preparatory drawings known as sinopiae were employed as guidelines for mosaicists in creating mosaics. The sinopiae served as the basis for style and content, facilitating the placement of colored tesserae in the supporting mortar. The technology of the mosaic and pigments used reflect the capacity of the mosaic workshop and its master. This work explores a polychrome sinopia that was found under a Byzantine mosaic of an Armenian Chapel in Jerusalem, by a multi-analytical characterization of mineralogical and chemical properties. The composition of the pigments in the black and red areas of the sinopia include carbon black and red ochre, respectively, utilized in the fresco technique. Since colored tesserae are placed in wet mortar, it can be deduced that mosaicists worked together with painters during the executionary steps. This has corresponding implications for historical and artistic specializations at mosaic workshops, with deeper understanding of mosaic production processes. This research also highlights the importance of studying sinopiae under floor mosaics, which is a source of information on the pigments, paintings techniques, and the people who executed the work, all embedded in mortar which is well protected below the stone tesserae.

Evaluation of geotechnical, mineralogical and environmental properties of clayey soil stabilized with different industrial by-products: A comparative study

The utilisation of soil stabilization techniques employing binders like lime or cement enables the use of soils that are classified as disposable, thereby reducing the need for landfills and the consumption of natural resources. However, the production of lime and cement results in significant CO2 emissions. Therefore, the application of industrial by-products (IBP) for stabilizing expansive soils presents an opportunity to minimise the use of traditional binders. This study investigates the geotechnical, mechanical, mineralogical, and environmental properties of four IBP (biomass bottom ash, biomass fly ash, steel slag, and mixed recycled aggregate) combined with a silica-based nanomaterial for road layer applications. The technical feasibility of the use of IBP was demonstrated, especially in combination with nanomaterials, allowing a 66 % reduction in the percentage of added lime, obtaining significant improvements with minimal plasticity and swelling index and bearing capacity CBR values higher than 25 %, applying BBA, BFA and SS. An environmental assessment of leachate analysis was performance, showing an immobilization of heavy metals that makes the application of IBP feasible. In addition, a life cycle analysis study showed the environmental benefits of applying IBP, such as a 50 % reduction in CO2 emissions due to the reduction of lime, resulting from the use of these materials, thus promoting more sustainable economic models.

Mechanical, Mineralogical and Durability Properties of Pulverized Pond Ash Based Concrete

Mechanical, Mineralogical and Durability Properties of Pulverized Pond Ash Based Concrete

Mineralogical, chemical and physico-mechanical properties of fired bricks for refractory industry applications

This study aims to characterize soils for their use in the refractory industry applications. Two types of hydromorphous soil were sampled in the locality of Minkoameyos in the neighbouring city of Yaoundé-Cameroon: multicolored soil clay (A001) and grey soil clay (A002). Mineralogical, chemical and physico-mechanical properties were investigated. Bricks made from these soils were heated at 900 °C, 1100 °C and 1200 °C temperatures. Physico-chemical properties showed that these soils are light (A002), silty (A001), inorganic and acidic, with pH values of 5.45 and 4.47 for A001 and A002, respectively. Chemical analysis revealed that these soils are essentially composed of silica (40 and 46%), alumina (35.9 and 32.5%) and coloring oxides (8.5 and 6.3%) for A001 and A002 samples, respectively. Mineralogical analyses of these soils revealed the presence of quartz, kaolinite, illite and muscovite. Bricks heated at 900 °C, 1100 °C and 1200 °C showed a variation in color from orange to reddish brown for A001 sample; from light orange yellow to dull orange for A002 sample and a sound ranging from dull to slightly metallic. Residual mechanical performance showed a slight drop in strength at the heating temperature of 900 °C (8.8 and 8.3 MPa for multicolored soil clay A001 and grey soil clay A002, respectively). This temperature seems sufficient for this type of floor. Above 900 °C, the impact of carbon is significant. These results showed that Minkoameyos hydromorphous soils clay have remarkable properties and can produce refractory materials.

Radiation stability and durability of magnesium phosphate cement for radioactive reactive metals encapsulation

The encapsulation of Radioactive Reactive Metallic Waste (RRMW) in ordinary Portland cement poses significant challenges due to its incompatibility with the alkaline environment of the matrix. To address this issue, magnesium phosphate cements (MPC) emerge as potential solutions for the safe and effective immobilisation of RRMWs. The radiation stability and durability of an optimised formulation have been examined for samples irradiated up to 1000 kGy, in particular concerning the leaching behaviour of the three main constituents of the cement hydration products, and on four artificially added elements used to simulate radionuclides commonly found in radioactive waste (caesium, strontium, europium, and cobalt). The mortars exhibited excellent leaching behaviour and a high mechanical resistance, even after irradiation, freeze-thaw cycles, and water immersion. No significant radiation-induced effects were observed in the mineralogical and microstructural properties of the mortars, thus supporting their stability at the examined doses. Having verified the compliance with the main Italian waste acceptance criteria, the results of this research represent an encouraging step for the future implementation of MPCs for RRMWs conditioning.

Lime Stabilization of Tropical Soil for Resilient Pavements: Mechanical, Microscopic, and Mineralogical Characteristics.

Lime stabilization is a sustainable technique due to its use of local materials, increased durability, reduced maintenance, and improved resistance to water action. This paper examines the impact of lime stabilization on the mechanical, microscopic, and mineralogical properties of a tropical soil. Two types of lime, calcitic and dolomitic, were tested at 3% and 5% by weight. Compressive, indirect tensile and flexural test results and statistical analysis revealed that calcitic lime mixtures had higher strength and stiffness, whereas dolomitic lime mixtures exhibited greater deformability with higher tensile strain at break. Scanning electron microscopy indicated that the soil's porous matrix closed within 7 days for both lime types due to flocculation, with increased matrix interlocking over time. The calcitic lime mixture developed a more closed matrix compared to the dolomitic lime, which showed weaker cementing. X-ray diffraction analysis indicated higher consumption of clay minerals and a notable reduction in calcium hydroxide peaks in the lime-treated soils. The study concludes that calcitic lime provides better pavement performance for stabilizing the soil, enhancing its engineering properties while also being sustainable by reducing the need for raw material extraction and improving resilience to climate-related issues such as floods.

INVESTIGATION OF PHYSICAL, MECHANICAL AND THERMAL PROPERTIES OF MINERAL ADMIXED AUTOCLAVED FOAM CONCRETE

In this study, the aim was to develop a non-combustible, economical, and entirely domestically sourced and technology-based autoclaved foam concrete thermal insulation material. In autoclaved foam concrete (AFC) with a density of 300 kg/m3, which meets thermal insulation material standards, the density, capillary water absorption coefficient, compressive and flexural strengths, ultrasonic pulse velocity, dynamic modulus of elasticity, thermal conductivity, and the mineralogical properties of hydration products based on XRD of some silica-based mineral additives (fly ash, amorphous silica, and metakaolin) substituted at different ratios (5%, 10%, and 15%) for cement were investigated. Autoclaving improved the physico-mechanical properties of mineral-added foam concrete. Among the mineral additives, the highest strength values were obtained in the foam concrete with 5% metakaolin, while the lowest thermal conductivity and capillary water absorption values were obtained in the foam concrete with 5% fly ash. The study concluded that autoclaving is highly effective in producing a sustainable thermal insulation material in foam concrete.

The relationship between mechanical properties and mineralogical composition of some sedimentary rocks

The physical and mechanical properties of rock material are remarkably associated with the comprising mineralogical composition and textural characteristics. Therefore, meticulous understanding of the role of mineralogical composition in engineering behavior of sedimentary rocks is essential. For this purpose, both matrix and aggregates of rocks must be thoroughly analyzed to obtain a comprehensive insight of this aspect. The main objective of this study is to investigate the extent of complexity of the relationship between mineralogical and mechanical properties of some sedimentary rocks. Several sedimentary rock samples from different regions of Iran were analyzed in this study. The same samples were then tested to determine uniaxial compressive strength, tensile strength, Schmidt hammer hardness, and Cerchar Abrasivity index. The relationship between these properties and the mineralogical composition were described by linear and multivariate regression analyses. The research unequivocally establishes a significant correlation between specific mechanical parameters and mineralogical composition. Moreover, the findings highlight the relative importance of each parameter, with some being more crucial than others.