Stone Processing Research Articles

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.

Enzymatic Activity as a Measure of Total Microbial Activity on Historical Stone

Stones of historical monuments exposed to the open air deteriorate over the course of time depending on physical, chemical, and biological factors acting in co-association. Among the biological factors, microorganisms play a key role in the deterioration process of stones. Detecting the level of microbial activity on stones is an essential step in diagnostic and monitoring studies of stone biodeterioration, and aids in controlling the performance of treatments applied to the stones. Therefore, this study aimed to develop a practical and rapid method for the determination of microbial activity on historical stones and use this method on the Mount Nemrut monuments (MNMs) (Adiyaman, Turkey). For that purpose, the fluorescein diacetate (FDA) hydrolysis method, frequently employed for soil environments, was adapted for the estimation and assessment of total microbial activity to understand whether microorganisms posed a potential risk for the biodeterioration of the limestones and sandstones of the MNMs. The traditional plate count method was also applied simultaneously to the same stone samples to compare and assist in the interpretation of the results of the FDA hydrolysis method, which relies on the quantitative determination of bacterial and fungal colonies in nutrient agar and malt extract agar medium, respectively. The results of the FDA hydrolysis and plate count methods showed consistency. The total microbial activity determined by the FDA hydrolysis method was low for both types of stone samples. In addition, the plate count method showed low bacterial and fungal counts on all of the samples. This revealed that microbial activity did not play an important role in the stone deterioration process on the MNMs, although different lichen species were frequently observed on both the sandstones and the limestones. Hence, further investigation must be undertaken for determination of their long-term behavior and effects on the stones of the MNMs. On the other hand, the results of the FDA hydrolysis and plate count methods showed correlation. Lower bacterial counts were observed when lower enzymatic activity was observed in the stone samples, and likewise, higher bacterial counts were observed when higher enzymatic activity was observed. Consequently, the application of the FDA hydrolysis method was determined to be reliable for the estimation of total microbial activity on historical stones. The method had obvious advantages in terms of its rapid measurement rate and sensitivity, even on small samples.

Reduction of Marble Waste Landfills through the Enhancement of CaCO<sub>3</sub>

The purpose of this research is to show how to reduce the amount of landfilled marble waste/scraps by collecting and re-purposing the marble microfine sawdust, which is produced after the sawing and processing of carbonate dimension stones. Our ultimate goal is to identify alternative uses, rather than landfilling. The current solution so far preferred - landfill - does not fully meet sustainable development criteria. Our reduction strategy is based on a regulatory framework which identifies waste, by-product and end of waste status clearer. After a careful characterization, the marble sawdust can be reused and marketed for industrial applications, that employ micronized calcium carbonate, as a new material. During the first few years of study, the research focused on the construction industry (i.e. concrete – plaster - brick), by assessing the extensive use of marble sludge. The building industry is able to incorporate and reuse waste materials deriving from different industries, although, in this way, such material would be regarded as of poor quality. The current trend is to add high economic value to this waste. Since product specifications for calcium carbonate vary depending on its application, a comparison with the paper - rubber - and tyre calcium carbonate requirements is described herein and, in addition, the final results of the tests carried out on marble sawdust in tyre mixtures are also reported in detail.

The stone inventory on the Neolithic settlement Evstyunikha I (Middle Trans-Ural)

The place of the Evstyuninsky type ceramics in the early Neolithic materials of the Middle Trans-Ural has been one of the problem areas of interest to the Ural archeologists until today. The Evstyuninsky type of Neolithic ceramics is presented in the archeological literature of the Urals fairly good. But it is still unknown what kind of stone products accompanies ceramics of this type. This paper fills this gap. The site is situated 300 meters from the village Evstyunikha, which nowadays is a northern outskirt of the Nizhny Tagil (Sverdlovsk Region). The collection of finds contains more than 9000 items. Among them there are about 6000 fragments of ceramic and 3500 stone products. The complex is very indiscrete 96% of ceramics refers to the Neolithic. The rest of the ceramics is presented by materials of later epochs. The use of stone tools in them was already limited. The full cycle of stone processing is presented at the site. The technology of splitting was used for obtaining knife-shaped plates from the butt nucleuses. They used large plates of 24 cm width and small ones of 0,51,0 cm width as well. In addition to the plates tiles processed by bilateral edge retouch were also widely used. Flat retouch was very rarely used it was used for producing of arrowheads only. A large percentage (nearly 70%) of products with tile cork indicates the use of the local mineral raw. 77% of all products are made of siliceous slate. Then there are volcanotectonic sandstone products and products made of light grey layered siliceous rock 6,5% each. Milky quartz and multi-colored jasper artifacts are 2% each. 6% are accounted for the other types of mineral raw (flint, chalcedony, slate carbonaceous, light grey slate, grey quartz, alevrotuf, sandstone, granodiorite, quartzite, serpentinite).

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.

Performance of self-compacting mortars with granite sludge as aggregate

Waste produced in the extraction and processing of granite stone severely damages the environment when it is deposited in landfills. This research aims to use granite sludge as an alternative to conventional aggregates (natural sand and siliceous filler) in self-compacting mortars production. In a previous stage, the granite sludge was characterised by chemical and mineralogical composition, specific gravity, scanning electron microscopy, particle size distribution and environmental evaluation by leaching test. Subsequently, three replacement percentages (0%, 20% and 40%) by volume of conventional aggregate with granite sludge were evaluated for their self-compactability properties. Compressive and flexural strength at 7, 28 and 91 curing days were measured. The mineralogical phases using X-ray diffraction techniques, microstructure by mercury intrusion porosimetry, shrinkage and mass loss, water absorption by capillarity, water absorption capacity, bulk and skeletal density, open porosity for water and wettability of hardened mortar specimens were all studied. The granite sludge incorporation did not affect the cement hydration phases, although the microstructure of the self-compacting mortars was slightly modified. The morphology of the granite sludge particles reduced the filling effect of pores and required a slight increase in the w/c ratio to maintain the self-compacting parameter. This fact justifies the slight increase in porosity, the lower bulk density and the slight decrease in the mechanical strength of mortars with granite sludge. The durability properties were also slightly affected compared to the self-compacting reference mortar. From an engineering point of view, the results show the feasibility of incorporating up to 40% of granite sludge in self-compacting mortar. This study explores a sustainable alternative to conventional aggregates in the manufacture of self-compacting mortar by reducing the consumption of raw materials and avoiding granite sludge landfill.

Местонахождение Константиновна/«Строминкон» – новые предварительные данные о древности палеолита юго-востока Украины

Публикация содержит результаты предварительных исследований нового местонахождения раннего палеолита на территории г. Константиновка Донецкой области (Юго-Восточная Украина). Каменные изделия найдены в слое гравийно-галечного аллювия, который предварительно соотносится с позднелубенским климатолитом Схемы палеогеографической этапности Украины, который коррелируют с OIS 13 океанической изотопно-кислородной шкалы.

Effect of Vacuum Hot Pressing Temperature on the Mechanical and Tribological Properties of the Fe–Cu–Ni–Sn–VN Composites

The mechanical (hardness and elastic modulus) and tribological (friction force and wear rate) properties of the Fe–Cu–Ni–Sn–VN composites produced by cold pressing and subsequent vacuum hot pressing at different temperatures are studied. The starting iron, copper, nickel, and tin powders have 5–50 μm particles and the vanadium nitride powder has 0.1–0.7 μm particles. When vacuum hot pressing temperature rises from 800 to 1000°C, the hardness increases from 3.75 to 5.37 GPa and the elastic modulus decreases from 176 to 125 GPa. As a result, the friction force reduces from 115 to 80 mN and the wear rate from 1.93 ∙ 10–5 to 0.45 ∙ 10–5 mm3 ∙ N–1 ∙ m–1. The factors promoting improvement of the mechanical and tribological properties of the sintered composites are discussed. In particular, the main factor improving the mechanical properties is that the grains are refined from 5–50 μm to 20–400 nm through the α → γ → α transformation when VN dissolves in α-Fe. In this case, the composite consists of a supersaturated solid solution of nitrogen and vanadium in α-iron, intermetallic Cu9NiSn3, and primary and secondary particulate vanadium nitride phases. A relationship between the structure and mechanical and tribological properties is established. The H/E and H3/E2 parameters that describe the elastic strain resistance and plastic strain resistance correlate with the wear resistance. The sintered composites are regarded as promising materials for developing a new generation of diamond-containing composites for stone processing industry.

THE ANALYSIS COMPARISON OF BASALT VIA MELTING PROCESS FROM MATARAM BARU (EAST LAMPUNG) WITH SLOW AND FAST COOLING METHOD OVER XRD APPROACH

The process of melting basalt stone from Mataram Baru, East Lampung has been carried out over a mini shaft furnace with a temperature of 1600 ˚C. Basalt stone with the smelting process was modified with slow and fast cooling methods. Based XRD result shows the methods were significant applied to the liquid of basalt stone. By a slow cooling process, the crystal structure is unchanged from the original material but the mechanical characteristics increased. While by a fast cooling process, the amorphous crystal structure and weak mechanical properties are obtained from the original material. The results show, both products have a great potential to be used as advanced material. With a slow cooling process, it can be applied as a friction resistant material while by fast cooling method, the products can be used as ceramic materials.

Manufacturing process and mechanical properties of a novel acrylonitrile butadiene styrene-based composite, with recycled natural granite micro-particles

Manufacture and characterization of a novel, environmentally friendly stone composite based on acrylonitrile butadiene styrene (ABS) and recycled natural granite stone particles is introduced. The proposed composite can be considered as a byproduct of natural stone processing, and potentially lead to a solution to the associated waste management problem. Results indicated that the composite’s tensile strength and fracture property generally deteriorated with increasing the stone particle content, especially beyond 50%. Stiffness and thermal conductivity, however, continually increased with the addition of the granite powder, which would suggest multi-functional applications of this material.

Experimental analysis of the correlation between ultrasonic velocity and metallographic and cutting performance parameters of boron carbide-doped diamond sockets

The natural stone cutting process is carried out by cutting tools called diamond socket (DS) consisting of two parts diamond and matrix. DS performance in rock cutting highly depends on the production cost of the socket, cutting precision, and energy costs. However, DS performance can be demonstrated after the circular saw with DS is connected to the cutting machine and performs the cutting operation. This trial and error method causes negative effects such as time loss, an increase in labor costs, and disruption in production for natural stone processing plants. For this reason, ultrasonic velocity measurement (UVM) processes are performed on DS to predict DS performance. Within the scope of the study, eight groups of boron carbide (B4C)-doped DS are produced. In the one group of these DSs, no-doped is made, and therefore it is considered as a reference socket. The other seven groups are B4C-doped at different rates. Metallographic parameters (MPs) (unit volume weight, porosity, Knoop hardness, weight wear loss) of DSs produced before cutting experiments are determined. Then cutting performance parameters (CPPs) (specific cutting energy, power consumption, specific abrasion) of circular saws prepared with DS groups are obtained by performing cutting experiments on granite samples. After ultrasonic velocity (UV) in diamond sockets is measured experimentally, the correlations between UV and MPs and CPPs are analyzed. As a result of the experimental analyses, it has been determined that there is a significant correlation between these parameters and UV. Based on these correlations, it has been determined that the UVM method can be used both in the quality control of DSs and in the prediction of cutting performance.

КАМСКАЯ НЕОЛИТИЧЕСКАЯ КУЛЬТУРА НА СЕВЕРО-ВОСТОКЕ ЕВРОПЫ

The author summarizes and systematizes the data on the Kamskaya Neolithic culture in the northeast of Europe (the territory of the modern Komi Republic, Arkhangelsk Oblast and the northern part of the Perm kray). At present 18 sites belonged to this culture have been identified in the basins of the rivers Vychegda, Pinega and Vishera. They represent its northern province of distribution, the length of which in the region is more than 1000 km (from southeast to northwest). The data of geochronometry and comparison of analogies from the territories of the East European and West Siberian plains determine that the most probable time of existence of this culture in the region was the VI millennium BC. A stable feature of the Kamskaya culture is ceramic ware made of clay with an admixture of chamotte and decorated with comb ornament. Its peculiarities in the basin of the Vychegda River are a small number of pots in complexes (from 1 to 5) and typological homogeneity. It indicates the short-term duration of this tradition and the lack of links with the population of other cultures. Ceramics in the basin of the Vyshera River are characterized by a great variety of decoration and provide an evidence of the connections between the population of different cultures. Flint knapping is situational and selective. The special and most stable feature of toolkit is the bifacial diamond-shaped or leaf-shaped arrowheads of short proportions. The tools made of other rocks are relatively well represented with chopping tools, abrasives, and fishing weights. In the assemblages of the Vishera river basin the signs of correction of traditions of stone processing to the peculiarities of raw materials of the region are revealed. It can indicate their more significant metamorphoses as they moved away from the original territory of culture. The complex data such as topography of monuments, qualitative and quantitative characteristics of stone tools, indicate a signifi cant role of fi shing in the Kamskaya culture’s economy. As a result of the research the peculiarities of this culture in the northeast of Europe and possible transformations of its elements in different habitats of the Vychegda and Vishera rivers basin were revealed. The main factors that influenced this difference were natural and climatic conditions and different population densities.

Application of raman spectroscopy for characterization of natural stone sludge waste

The proper management of a vast amount of natural stone waste generated from various stone processing industries of economic and environmental importance. The current study characterizes four different types of sludge stone waste to understand their potential as building material. The different types of stone wastes were characterized using Raman spectroscopy and identified through different bonds present in the material. In the end, conclusions were drawn to recommend the potential application area for different types of natural stone wastes.

Prospects for the use of stone processing waste to obtain architectural and building ceramics

The article presents the results of a study of stone processing waste in order to justify the implementation of the technological process of manufacturing architectural and construction products with their use. The structure of the distribution of waste arising from stone processing processes is given. The analysis of the relevance of the problems of utilization of slurry waste stone processing. Studies were conducted to determine the chemical, mineralogical and phase composition of stone waste. It was found that these wastes belong to gabbro-diabase rocks, which was confirmed by their chemical and mineralogical composition. The main mineral components are plagioclase, pyroxene and minerals of the iron group. The moisture content of the initial pulp and the particle size distribution of dry sludge were determined. Based on the results of establishing the melting temperature and fire resistance of baked sludge samples, the possibility of obtaining architectural and construction products based on dry sludge using ceramic technology (semi-dry pressing and sintering) was established, for which a selection of technological parameters and initial mass compositions was carried out. The promising compositions of ceramic masses with a significant sludge content (up to 60%), as well as the temperature-time regimes of the formation of ceramic materials, which are in the range from 1100 to 1200°C, are determined. The physicomechanical properties for sintered ceramic materials are studied, namely, mechanical strength compression (up to 55 MPa) and wear resistance (up to 0,45%), which corresponds to the properties of clinker ceramic materials. Based on the foregoing, a conclusion was drawn on the prospects of using stone slurry for obtaining ceramic products for architectural and construction purposes.

Environmental impacts, management and potential recovery of residual sludge from the stone industry: The piedmont case

The management of residual sludge from dimension stone processing activities (EWC 010,413) represents a large concern for stone industry. Such sludges are characterised by a fine size distribution, high heavy metal contents and, potentially, TPH (Total Petroleum Hydrocarbon) contents. The objects of the present study are represented by gang-saw with abrasive shot (GSS), diamond frame-saw (DSS) and mixed (MS) sludges. The first one is high in Cr, Ni, Cu and TPH, the second presents high contents in Co, Cr and TPH, and the third represents a mix of the first two ones. Present legislation indicates that they can be disposed of in landfills or can be recovered (R5-R10) as filling material for environmental rehabilitation or as feeding materials for cement production.The sampled materials were obtained from the Verbano Cusio Ossola (VCO) and Luserna Stone quarry basins (Piedmont, Northern Italy). These materials were physically and chemically characterised, and magnetic separation was performed to rapidly evaluate the heavy metal contents in the sludge. Afterwards, three different experiments were carried out for environmental and civil applications. The first one, for substrate production, was carried out using GSS, DSS and MS from VCO area. The second one, for CLSM and plaster production, was performed on materials from VCO and Luserna stone quarry basins (CLSM using GSS from VCO and plaster using DSS from Luserna stone quarry basin). The results here reported are promising for the three applications.

Modeling and optimization of the flocculation process of polydisperse travertine suspension employing an eco-friendly hybrid flocculant

One of the major problems in the stone processing industry is the creation of wastewater with a high degree of residual turbidity and the use of high water volume. Therefore, the treatment of waste water and its reuse is very important in terms of economic and environmental considerations. In the present study, the flocculation performance of hybrid flocculant naturally derived from chitosan and plant was statistically investigated for the clarification of travertine processing wastewater, in terms of the residual turbidity/turbidity removal efficiency and settled sludge volume, containing micron and sub-micron particles with median particle sizes of 9.32 μm and negative surface charges dominating at all pHs that produced a high degree of stability. TOPSIS (technique for order preference by similarity to ideal solution) method by using the Taguchi factorial design is used to optimize the operating variables such as hybrid flocculant dosage, suspension pH, and mixing time to find out the optimum operating conditions optimizing selected quality criteria such as turbidity removal and settled sludge volume. The flocculant dosage affected significant residual turbidity of the suspension as well as the turbidity removal efficiency and the settleable solid volume. A total of 87.90% in the residual turbidity value and 1.67% in the turbidity removal efficiency improvement rate was obtained with the use of TOPSIS-based Taguchi optimization methodology. Another important factor was determined as the suspension pH. The amount of settleable solid increased with the increasing of suspension pH. The residual turbidity value indicated a tendency to increase at first and then decrease with the increasing of suspension pH. A total of 8.15% improvement rate in the residual turbidity value was achieved compared with the values in the literature using hybrid flocculant and multi-response optimization techniques.

Indoor radon concentrations in residential houses, processing factories, and mines in Neyriz, Iran.

This study aimed to determine radon concentrations in mines, stone processing factories, residential houses, and public areas, as well as calculating its effective dose in Neyriz, Iran. A total of 74 alpha Track detectors (CR-39 detector) were installed at the desired locations based on the US-EPA's protocol. After 3months the detectors were collected and delivered to a Radon Reference Laboratory for analyzing. Mean ± SD, minimum and maximum radon concentrations in the sampling buildings were 29.93 ± 12.63, 10.33, and 66.76Bq/m3, respectively. The effective annual dose was calculated to be 0.75mSv/year, which was lower than the recommended value. Significant positive correlations were found between radon concentrations and some studied variables including smoking cigarettes, number of cigarettes smoked, duration of smoking, building's age, number of floors, having cracks, use of colors in the building, use of ceramic for flooring, use of stone for flooring, and gas consumption. The number of cigarettes smoked by the residents was the most important predictor of radon concentrations. Radon concentrations were lower than standard values in all sampling locations. It is necessary to conduct further studies in the field of regional geology and determine the sources that release radon in these areas to prevent further increases in radon concentration due to the proximity and plurality of mines and factories.

Performance Prediction of Circular Diamond Saws by Artificial Neural Networks and Regression Method Based on Surface Hardness Values of Mugla Marbles, Turkey

Sawing of natural stones with diamond-impregnated circular saws is extensively implemented in stone processing plants in variety of applications that include sawing, cutting, splitting and trimming. Hence, the cost of diamond saws and energy have become important input in terms of estimating the hourly areal slab productions (HASPs) from the standpoint of effective cost analyses, feasible and sustainable designing of stone processing plants prior to reaching a decision for the investment. This study aimed at estimating the HASPs of the machines with circular diamond saws during the dimensioning of marble blocks quarried in Mugla (Turkey) Region. Thus, the models were generated to estimate the HASPs by artificial neural networks (ANN) and regression method (RM), based on Shore and Schmidt hardness values of rocks. Also, HASPs were acquired through in-plant measurements in order to justify the HASPs estimated by ANN and RM models. The analyses of the models generated using ANN proved to yield very strong consistencies with HASPs measured in the plants. Hence, the HASPs can be estimated reliably by the ANN models which also may be considered as a tool in designing of natural stone processing plants based on rock surface hardness.

Description and effective parameters determination of the production process of fine-grained artificial stone from waste silica

In this study, waste silica from Alborz silica mineral processing factory was recycled as raw material for the production of a novel artificial stone to be used in civil construction. The size of the waste materials of this plant is less than 100 microns. Waste silica powder was mixed with unsaturated polymer resins as a binder. Under pressure, vibration and vacuum conditions, artificial stone with high compressive strength of 100 MPa, the tensile strength of 37 MPa and flexural strength of 98 MPa was produced within 15 min. Furthermore, in all of the produced artificial stones, due to the usage of resin, the flexural strength is higher than the tensile strength whereas, in natural stones, tensile strength is more than flexural strength. Moreover, using bentonite made a positive effect on the strength and quality of the stone, whereas kaolin declined the quality and the resistance of the artificial stone. Besides, the produced artificial stone has a lower specific gravity (2.14 g/cm3) and water absorption (0.06 g) than natural stone, which is one of the most prominent advantages of artificial stone. What’s more, low corrosion and were obtained against diluted sulfuric acid (0.0097 g) and hydrochloric acid (0.0313 g). Besides, due to the presence of impurities in the waste materials of Alborz silica factory, the produced artificial stones are brown. To reach the desired color, there are several metal oxides which could be added to the combination.

Satellite monitoring features of crystalline rocks mining territories within Zhitomyr region based on optical and radar remote sensing data

Opportunities of optical and radar satellite data application for ecological state and reclamation quality assessment of disturbed by crystalline rocks open cast mining lands are considered in the article. Digital elevation models analysis is proposed for the problem of identification of mines among rock dumps and rocky outcrops solution. Radar interferograms were used as source data for DEM creating. The research was performed on three study sites within Korostishiv, Cherniahiv and Khoroshiv districts of Zhitomir region. As result of the study an abandoned quarry with no reclamation done and an illegal stone processing waste dump were found. It is stated that environmental impact of crystalline rock open cast mining not as serious as ilmenite or amber open cast mining impacts and facts of violation of law caused by mining activities were not found.