Ornamental Stone Processing Research Articles

Transforming waste into beauty: Sustainable clay mask formulations using ornamental stone processing waste

Waste generated from ornamental stone processing presents a significant opportunity for repurposing in various technological applications. This study investigates incorporating such waste with calcium bentonite to develop an industrial clay suitable for cosmetology. The chemical composition and mineralogical properties of the mixtures were evaluated through comprehensive analysis, such as X-ray fluorescence (XRF) and diffraction (XRD), and scanning electronic microscopy with energy dispersive X-ray spectroscopy (SEM-EDS). Specifically, we investigated a 70/30 mixture of ornamental stone processing waste and calcium bentonite. The results revealed a diverse range of beneficial elements. Additionally, the fine granulometry of the sample renders them ideal for cosmetic applications. Microbiological analyses demonstrate the absence of harmful microbial populations, ensuring product safety. By repurposing waste materials, this research offers valuable insights into sustainable practices in cosmetics and environmental science, underscoring the importance of resource optimization in modern industry.

Sliding Wear Response of Marble Dust Coatings on Mild Steel Substrates

Reusing and organizing industrial solid waste not only tackles the problem of rising environmental contamination but also lowers landfill space. Furthermore, repurposing these wastes for certain possible uses lowers material costs and production costs. Consequently, the research focuses on the repurposing of marble dust, a by-product of ornamental stone processing, for use as a coating material on metal substrates. A well-designed high-velocity oxy-fuel spray coating equipment is used to deposit the material. In accordance with ASTM G 99-05, high-temperature sliding wear tests are performed on the depositions of coatings using a tribometer, incorporating Taguchi’s L16 orthogonal array. Control variables with a substantial influence on wear loss are discovered, and an ideal factor setting is determined based on the least wear loss. The morphologies of worn surfaces are studied to identify probable wear processes. Based on the outcome of parametric analysis, experiments are conducted using a diverse set of recognized significant control factors, while maintaining consistency in the other variables, to enhance the accuracy of assessing their individual impacts on the specific wear rate.

Resistência à compressão e desempenho ambiental de cimentos com resíduo de serragem de mármore.

Abstract Replacing limestone filler by waste marble dust is one of the paths to explore, at a regional level, to stimulate circularity and reduce environmental burdens of ornamental stone processing. This study investigated six blended cements which combined supplementary cementitious materials (SCMs) and limestone filler or waste marble dust, with a clinker factor of 50%. Compressive strength was determined at 3, 7, 28 and 91 days and evaluated based on the criteria standardized in ABNT NBR 16697:2018. The cementing efficiency at 7 and 28 days of the set of mineral admixtures used and greenhouse gas (GHG) emissions intensity of each cement were also calculated. The synergy between the combinations reduced the clinker factor and cement GHG emissions, whilst preserving the mechanical performance required by the construction market.

Influence of filler/cement and powder/total solids on the mixture design of self-compacting micro-concretes containing waste from the ornamental stone industry

The present work evaluated the effects of incorporating high volumes of waste from the processing of ornamental stones as fillers in self-compacting micro-concretes, considering physical–chemical, mechanical, microstructural and eco-efficiency results. A particle packing method assisted in the mix designs, and the experimental program followed a central composite rotational statistical design. Response surfaces and desirability analyses showed that the residue has a good packing function, filler effect, heterogeneous nucleation and workability, in addition to being effective in reducing the embodied CO2, delivering matrices more eco-efficient for conventional mechanical strengths.

Characterization and photocatalytic performance of cement mortars with incorporation of TiO2 and mineral admixtures.

As the main components of the building envelope, construction materials have a straight relation with air contaminants from anthropogenic origins. Titanium dioxide has been recently applied in construction industry products since its photocatalytic properties can be used for pollutant degradation purposes. This study evaluated the performance of cement-based mortars with the incorporation of TiO2 nanoparticles and mineral admixtures. Six mortar compositions were defined by considering two reference mixes (with and without TiO2 incorporation), two mineral admixtures (bentonite and metakaolin) as partial cement replacement and one waste from ornamental stone processing in two levels of partial substitution of natural sand. Consistency index, density, and entrained air content of mixtures were investigated at fresh state. Compressive strength, water absorption, sorptivity, and micrographs from scanning electron microscopy were used to characterize mortars at hardened state. It was observed that incorporation of TiO2 does not considerably change mortar's properties at fresh and hardened state, despite a denser microstructure and improved interfacial transition zone. In general, the relation between the water-to-cement ratio and porosity on the performances of TiO2-added mortars was shown, which is strongly related to their photocatalytic efficiency. Metakaolin mixtures were more efficient to NO conversion, and high selectivity was observed for the bentonite mortars.

Characterization of waste from the ornamental stone processing for incarnation in clay ceramics

Recently, new technologies are introduced to minimize the disorderly disposal of waste, not only from the processing of ornamental stones (OS), but also from other industrial sectors. A technological alternative to reduce the environmental impact and recycle waste is its incarnation into clayey ceramic products. This solution can improve the properties of the final product. Some studies using granite residues, from sawing blocks, showed great potential for their use in red ceramics, due to their characteristics such as a high content of alkaline oxides, fine granulometry, and low cost. The goal of this work is to characterize the residues from the processing of OS, with the aim to incarnate into clayey ceramics. The characterization will contribute to the knowledge of the residue (mud) and, through this fact, will favor the study of a possible solution to the problem of disposal of mud generated in the sawing of rocks, besides contributing to the practice of sustainable development, and the consequent use of waste discarded as unusable.

SLIDING WEAR BEHAVIOR OF MARBLE DUST PRE-MIXED WITH NiCr COATINGS ON MILD STEEL SUBSTRATES AT ELEVATED TEMPERATURE

In this research, microsized marble dust is spray-coated on mild steel substrates through a well-designed high-velocity oxy-fuel (HVOF) spraying route. For this, a standard spray set up Hipojet 2700 is used. Marble dust is an ornamental stone waste generated in huge quantities during the depletion and processing of ornamental stones to make them usable. Commercially available spray-grade NiCr powder is added with a proportion of 10% by weight in the marble dust prior to deposition to increase its flowability and adherence. The coating on the mild steel substrates is deposited with a spray distance of 200[Formula: see text]mm and a fuel (LPG) feed rate of 55–60[Formula: see text]g/min. Dry-sliding wear trials under controlled conditions on the deposited coatings are conducted as per ASTM G 99-05 using a tribometer capable of operating at a wide temperature range. A parametric analysis of the test results using MINITAB 18 software shows that the control factors such as sliding velocity, specimen temperature, sliding distance and normal load, in the declining sequence, are significant in affecting the specific wear rate (SWR) of the coatings. Based on this, further experimentations are carried out separately for a wider range of the sliding velocity and specimen temperature keeping all other factors constant to study their individual effects on the wear rate more precisely. The morphologies of the worn surfaces are studied to ascertain the possible mechanisms taking place during the wear process leading to coating mass loss.

Red Ceramics Produced with Primary Processing Fine Waste of Ornamental Stones According to the Circular Economy Model

The ornamental stone industry is growing and has a large production in Brazil, mainly in Espírito Santo, where the largest production in the country is concentrated. Brazil is part of the group of countries that produce the most ornamental stones in the world; however, the generation of waste in this sector is very large. These ornamental stone wastes when used for the manufacture of new materials, such as red ceramics, contribute to the reduction in the raw material clay and to the reduction in the environmental impact. The objective of this work was to incorporate fine wastes from the processing of ornamental stones called FIBRO in red ceramics and later, to contribute to the standardization of the use of these wastes in the ceramic industry, contributing to the manufacture of more economical and sustainable products. Wastes were incorporated in the proportion of 0 to 50% by mass that were prepared by extrusion and fired at 900 °C, 950 °C, and 1000 °C. After firing, the physical and mechanical properties of the ceramic material were evaluated. Specific mass apparent, water absorption, porosity, and flexural strength by three points tests were carried out. The results showed that from 30% at the lowest temperature, tile is already fabricated within the values stipulated by the standards, thus saving energy. The analyzed waste is a material with excellent chemical characteristics to be used in the ceramic mass, in addition to having improved the technological properties of the material, such as less water absorption and greater flexural strength.

Evaluation of use of marble and granite cutting waste to the production of self-compacting concrete

Due to the continuous storage of large quantities of marble and granite waste (MGW), generated during the processing of ornamental stones, researchers have been using this material in a sustainable way to reduce its adverse impacts on the ecosystem. In this study, the main objective was to evaluate the effect of using MGW on mechanical properties and durability of self-compacting concretes (SCC), as part of the fines required to ensure self-compacting characteristics. Also, it was investigated this material as a new possibility in the composition of a ternary cement modality. For this, an experimental program was developed with four SCC mixtures, in which tests were performed to determine the properties in the fresh state, hardened properties, durability, and microstructural analyses. The test results indicated that all mixtures complied the self-compacting requirements and the incorporation of MGW contributed to the stabilization of the concretes. The mixture with CPV-ARI cement and MGW incorporated as fine in the concrete, and the mixture with MGW both incorporated as fines in the concrete and in the composition of ternary cement CP-MMG did not present statistically significant differences for some results of the mechanical properties. Besides, these mixtures provided improvements and similar results of some durability and microstructural tests, respectively. In general, the different possibilities of utilization of the residue proposed in this study, generate an appropriate destination for MGW and propose a viable alternative for the reduction of clinker consumption in cement production.

Ornamental Stone Processing Waste Incorporated in the Production of Mortars: Technological Influence and Environmental Performance Analysis

The technological performance and environmental advantages of replacing sand by ornamental stone processing waste (OSPW) in the production of mortars for civil construction were studied. Technological properties associated with the standard consistency index, squeeze flow and bulk densities as well as the determination of water retention and calorimetry analysis were evaluated in the mortars’ fresh state, whereas capillarity tests as well as mechanical resistance by flexural and compression tests were determined in the hardened state for mortars incorporated with 10, 30 and 60 wt.% of OSPW substituting sand. Three different types of Portland Cements were considered in the incorporated mortars production. For these mortars environmental analysis, their corresponding life cycle assessment results were compared to that of conventional waste-free (0% OSPW) control mortar. It was found that the OPSW incorporation acts as nucleation sites favoring a hydration process, which culminates after 28 days of curing in the formation of more stable phases identified as hydrated calcium silicates by X-ray diffraction (XRD) amorphous halo. It was also revealed that both flexural and compression improved resistance for the incorporated mortars after 28 curing days. In particular, the calorimetry and XRD results explained the better mechanical resistance (12 MPa) of the 30 wt.% OSPW incorporated mortar, hardened with Portland Cement V, compared not only to the control, but also to the other incorporated mortars. As for the environmental analysis, the replacement of sand by OSPW contributed to the reduction in associated impacts in the categories of land use (−5%); freshwater eutrophication (−9%); marine eutrophication (−6%) and global warming (−5%).

Production of Belite Based Clinker from Ornamental Stone Processing Sludge and Calcium Carbonate Sludge with Lower CO2 Emissions.

Environmental concerns have come to the forefront due to the substantial role of the cement industry in the extraction and expenditure of natural resources. Additionally, industrial processes generate a considerable amount of waste, which is frequently disposed of inadequately. The objective of this study was to evaluate the simultaneous use of ornamental rock processing sludge and calcium carbonate sludge generated from the kraft process in the production of belitic clinker. These waste materials would be used in total or partial substitution of natural raw materials, namely, limestone and clay. Several formulations were produced and sintered at 1100 and 1200 °C. The raw materials were characterized physico-chemically and thermogravimetrically, with subsequent evaluation of the resulting dosed raw mixes. Mineral analyses determined that the mixtures with limestone and clay in substitution ratios of 95% and 100%, respectively, and sintered at 1100 °C have the potential to produce belite-rich clinkers. This temperature is considerably lower than those reported in reference studies. Additionally, full limestone and clay substitution could result in a 23.92% reduction in carbon dioxide in clinker production. The results confirmed the potential use of ornamental rock processing sludge and calcium carbonate sludge as viable alternative materials for cement production and, consequently, could contribute to a reduction in the negative environmental impacts of this industry.

Circular economy in marble industry: From stone scraps to sustainable water-based paints

Huge amounts of sludge waste are produced every day during the sawing and processing of carbonate ornamental stones. Most of these materials are landfilled and create serious environmental and health hazards. Thus, it is mandatory to find alternative solutions to recycle them. Since calcium carbonate is the most widely used mineral filler for interior and exterior emulsion paints, this investigation focused on the feasibility of trying out innovative methods of circular economy in a waste processing area. Focusing in the Orosei Marbles’ producing area (North-East Sardinia, Italy), the aim of this study was to compare the performance of water-based paints, through the use of marble sludge waste, as mineral fillers, rather than commercial CaCO3. According to standard normative tests were carried out on paint samples, prepared according to an experimental formulation, after a preliminary chemical and physical characterization of the fillers. The results indicate that the marble sludge waste can be successfully used as mineral filler in water-based paints, and that it requires only light pre-treatments consisting of deagglomeration and mechanical dispersion in a wet medium, thus confirming its environmental and economic benefits.

Sustainable glass foams produced with stone waste as a pore-forming agent: Assessing the role of heating rate in foamability and glass foams recyclability

This work provides insights into the role of heating rate in the foaming ability of glass foams produced from discarded glass bottles. The pore-forming agents used were calcium carbonate and ornamental stone processing waste (SW), the latter being assessed for the first time for this purpose. Glass foams were produced with different contents of pore-forming agents: 1-5 wt% CaCO3 and 1-15 wt% SW. Higher SW contents were necessary due to the relatively lower concentration of carbonate minerals contained (about 15 wt% of dolomite). The powdered raw materials were homogenized and uniaxially pressed (20 MPa) to obtain cylindrical samples, which were dried (110 °C/24 h) and fired at 900 °C with a holding time of 30 min. The effect of different heating rates on the foamability of samples, in the range of 3–20 °C/min, was investigated. The samples were compared for volumetric expansion, bulk density, porosity, thermal conductivity, compressive strength, and pore size distribution profile. The optimized contents of pore formers were in the range of 1-3 wt% CaCO3 and 5-10 wt% SW, producing foams with properties compared to commercial ones, including porosities between 75% and 90%, thermal conductivities between 0.04 and 0.07 W/m.K, and compressive strength between 1.0 and 4.3 MPa. The thermal conductivity was shown to be highly dependent on the total porosity of the samples and little influenced by the pore size, while the compressive strength was shown to be strongly influenced by both. The variation in the heating rate proved to be less influential for the samples with the above-mentioned optimized pore-formers contents. However, for contents close to the lower limit (1 wt% CaCO3 and 5 wt% SW), heating rates equal to or greater than 10 °C/min are recommended to improve the foamability. Preliminary results of the foam crystallization effect after sintering were also presented. Although the bulk crystallization of soda-lime glass is widely known, the literature on its crystallization in powder form is little explored. The crystallization of glass foams plays an important role in the recyclability of waste generated in its processing into different formats, since foamability is lost. The results show the crystallization of quartz, devitrite, and wollastonite in all samples. Although pore-forming agents do not appear to act as nucleating agents, they do favor the crystallization of devitrite.

Produção de placas em concreto granilite com agregados reciclados e lama do beneficiamento de rochas ornamentais

The ornamental rock industry generates millions of tons of waste in different stages of rock processing. These wastes are stored or disposed of inadequately, which causes environmental degradation. The objective of this study was to evaluate the concomitant use of ornamental rock processing sludge as partial replacement of Portland cement in contents of 0%, 5%, 10% and 20% and of recycled stone aggregate as total replacement of coarse natural aggregates in the production and performance of granilite concrete plates. Four concrete formulations were produced with different replacement contents and their characteristics were determined through tests of axial compression strength, flexural tensile strength, water absorption, impact strength and strength to stains. Mechanical results were inversely proportional: the higher the sludge replacement content, the higher the axial compression strength and the lower the flexural tensile strength. Water absorption tests showed a gradual decrease with an increase in sludge replacement, impact tests showed that the plates performed better at resisting shocks best up to a height of 50 cm and, in terms of stain resistance, multi-use products and butoxyethanol-based stain remover were more efficient on waterproofed granilite concretes and natural rock pieces, respectively. It was possible to conclude that it was viable to use up to 20% replacement of the aforementioned wastes in conventional concrete, with additional minimization of environmental impact associated with the extraction and processing of ornamental stones.

On the 60th Anniversary of the Ural University Toponymic Expedition: A Return to the Urals

The article is dedicated to the 60th anniversary of the Ural University (now the Ural Federal University) Toponymic Expedition and its new research project studying the toponymy, vocabulary, and ethnocultural information related to the extraction and processing of gems and ornamental stones in the Urals. Within the recent fieldwork of 2020–2021, the expedition visited many settlements of the so-called Gem strip of the Urals — the territory that holds lots of historical, linguistical, and ethnographic discoveries. It is found that back in the 18th–19th centuries, prospecting activities (search and extraction of gems, their processing, collection, and trade) were totally shaping the local lifestyle, folk culture, and linguistic consciousness of its residents. The present paper describes the toponymic system of the region, focusing on the types of topographic objects (deposits, veins, mines, quarries) and their naming features. It is shown that local toponymy cannot be interpreted without considering its connection to dialect vocabulary, ethnography, and knowledge of the cultural and historical traditions of semi-precious craft. The collected material falls into several lexical groups: dialectal, professional, and local slang. Given the present decline of the craft itself that leads to the destruction of unique toponymic systems, the author calls to the urgency of preserving this study material. The article shares some innovative methods of fieldwork used by the expedition with account to the peculiarities of the studied objects as well as those driven by the development of IT. It also unlocks new locations for materials collection, such as mineralogical museums, exhibition-fairs of minerals and comments on the specificity of using data from the geological and mineralogical forums on the Internet. The conclusion provides the list of publications for 2020–2021 by the Department of Russian Language, General Linguistics and Speech Communication based on the collected fieldwork data.

Development of Ceramic Materials for the Manufacture of Bricks with Stone Cutting Sludge from Granite

The manufacture of bricks for building purposes consumes large quantities of virgin materials, such as clay. On the other hand, the ornamental stone processing industry produces a huge amount of stone cutting sludge in its process. Therefore, this study presents the development of ceramic materials for the manufacture of bricks with stone cutting sludges, more specifically from granite. For this purpose, the physical properties of the stone cutting sludge and the chemical composition were mainly analyzed. Subsequently, different groups of ceramic samples were conformed and sintered with various combinations of clay and of stone cutting sludges. The conformed samples were evaluated with different physical tests and with the compressive strength test. The addition of stone cutting sludges to the ceramics reflected the creation of a material with lower density and higher porosity. The compressive strength of the different groups reflected a maximum allowable percentage of stone cutting sludges incorporation of 70%. Therefore, ceramic materials were developed with stone cutting sludges, developing a sustainable, lighter material with acceptable mechanical and physical characteristics. Avoiding the deposition of a polluting waste in a landfill and at the same time avoiding the extraction of new virgin materials.

Influence of the heterogeneity of waste from wet processing of ornamental stones on the performance of Portland cement composites

One of the difficulties of using some residues, such as those from stones beneficiation (cutting and polishing), is their heterogeneity. This study analyzes the influence of the heterogeneity of waste from wet processing of ornamental stones (marble, granite, slate, among others) on the performance of Portland cement composites when used at a 20% replacement of cement. The mechanical behavior (compressive strength, flexural strength, and elastic modulus) and durability parameters (porosity, water absorption, carbonation, and electrical resistivity) are analyzed. Results indicate that the waste can present considerable heterogeneity while maintaining composites properties, indicating little influence on their physicochemical properties. It can be inferred that the filler effect of the waste compensated to a certain extent the negative effects (the increase in w/c ratio and the reduction of important hydrates) due to reduced cement content, showing its viability as mineral addition, despite its heterogeneity.

Life cycle assessment of the ornamental stone processing waste use in cement-based building materials

Laboratory technical studies demonstrate the feasibility of using the ornamental stone processing waste (OSPW) for construction and building materials manufacturing. However, regarding the environmental aspect, there is still the need to justify its use quantitatively. Thus, this study presents the life cycle assessment (LCA) of using OSPW for cement-based building materials manufacturing, aiming to assess OSPW influence on environmental impact indicators (global warming potential, embodied energy and total impact). Altogether, 127 mixtures are analyzed, such as mortars, concretes, masonry and paving blocks. The impacts of OSPW drying and logistics are presented, as well as the impacts of the process (burning) to produce the heat-treated waste (HTOSPW). The results indicate that OSPW is a good alternative to reduce environmental impacts in the analyzed scenario (Espírito Santo (ES) state – Brazil), as a replacement for limestone filler, sand or stone dust. OSPW could be used as a cement partial replacement and presented satisfactory environmental results at high replacement levels (over 50%) in the production of self-compacting concrete, rendering and masonry mortars. The results also show that the artificial drying alternatives greatly increase the OSPW impact. Regarding the production of the mixtures, cement replacement was the approach most commonly used, causing a reduction in environmental impact indicators of 7.7 to 9.0% for each 10% of OSPW use.

Toxic effects of ornamental stone processing waste effluents on Geophagus brasiliensis (Teleostei: Cichlidae)

The ornamental stone industry generates considerable amounts of waste (OSPW), which may eventually reach natural environments and impact the local ecosystem. The aim of this study was to compare the toxic effects of two OSPW effluents in Geophagus brasiliensis: i) leachate effluent from a lagoon in an OSPW landfill (LE) and ii) decanted effluent from an ornamental stone processing industry (DE). G. brasiliensis were submitted to acute contamination with both OSPW effluents. After contamination, the gills were extracted for evaluation of histopathological alterations and ion concentration, while the liver underwent catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione s-transferase (GST) enzyme activity analysis. An induced biomarker response (IBRv2) index was determined to correlate the multi-biomarker response in G. brasiliensis. Fish gills exposed to DE showed increased concentration of Ca2+, Mg2+, Na+, and K+ when compared to those treated with LE. Histopathological lesions were observed in gills of animals exposed to both effluents. Micronucleus and comet assay were significantly greater in fish exposed to DE, when compared to those contaminated with LE. The evaluation of the enzymatic activity of CAT, GPx and SOD indicate greater oxidative stress in DE and LE-exposed fish, while GST activity was not altered. DE showed an IBRv2 value almost two-times higher in relation to LE, indicating that this waste may present higher toxic potential. The results demonstrate that both contaminants led to substantial toxic effects in G. brasiliensis, although the decanted waste induced the most remarkable responses in G. brasiliensis.

Effect of Granite Residue Incorporation on the Behavior of Mortars.

Civil construction is one of the most resource-consuming sectors in the world. For this reason, the last years have witnessed the study of reusing industrial residues in building materials. The ornamental stone processing industry has a considerable environmental liability related to residue generation during the cutting stages of granite blocks. The objective of this work is to analyze the viability of incorporating granite residues, up to 100%, to substitute sand in coating mortars for building construction. Mortars without residue, as control, and incorporated with 20, 40, 60, 80, and 100% of granite residue were subjected to consistency tests, incorporated air and water retention together with the rheological characterization using the squeeze-flow and the dropping-ball methods. The results show that mortars with 40% granite residues presented greater plastic deformation, helping their applicability by also presenting improved technological properties in the fresh state.