Industrial Clay Research Articles

Towards Better Valorisation of Industrial Minerals and Rocks in Serbia—Case Study of Industrial Clays

The improvement in valorisation of industrial minerals and rocks in Serbia is related to improvement of legislation, and to adoption of best possible techniques for geological exploration and estimation of resources/reserves. Therefore, we analyzed the actual practice in the field of geological exploration which has not changed significantly in the last 30 years, as well as legislation related to the mining industry and access to land. The improvement of legislation mostly depends on the state authorities. Contrary to that, the enhancement of geological exploration methodology should be the issue of experts working in that area of the mining industry but is also very much related to the existing legislation. Serbia still has very strictly prescribed procedures, which are generally good; however, it is an overly complicated and restrictive system for performing geological exploration and evaluation of mineral deposits. The most important improvements in legislation in the last twenty years are presented and discussed, as well as problems that still need to be solved and solutions found to fully understand the potential of industrial minerals and rocks in Serbia.

Converting Saprolite (a Low-Grade Unutilized Material) into Refractory Aggregates: A Viable Substitute for Calcined Clay in the Refractory Industry

Converting Saprolite (a Low-Grade Unutilized Material) into Refractory Aggregates: A Viable Substitute for Calcined Clay in the Refractory Industry

Sintering and phase formation of ceramics based on pre-treated municipal incinerator bottom ash

Ceramics, based on 60 ​wt% of municipal incinerator bottom ashes (MIBA) and 40 ​wt% of industrial clays, were prepared by using two fractions of pre-treated ashes (above and under 2 ​mm) and three different industrial clays. The obtained six compositions with amounts of CaO from 12 to 14 ​wt%, with SiO2/Al2O3 ratio ranging from 3.5 to 1.6 and with Al2O3/CaO ratio - from 1.25 to 1.75 were investigated and characterized.These compositions were located in the crystallization field of anorthite (CaO.Al2O3.2SiO2); the ceramics with high SiO2/Al2O3 ratio are near to the eutectic with SiO2, while with low ratio – closer to the anorthite stoichiometry.The phase transformation and the subsequent melting were studied by non-isothermal DTA-TG analysis, while the densification process - by contactless optical dilatometry. Then, the optimal sintering temperatures and times were evaluated by isothermal dilatometric runs at different temperatures.At high SiO2/Al2O3 ratio the sintering temperature is lower but the sintering range is very narrow. This behavior can be explained by the formation of too high amount of liquid phase at the eutectic temperature. On the contrary, at lower ratio, the sintering temperature increases but, notwithstanding the decrease of viscosity and shorter sintering time, the densification range becomes wider. This last result is a very important technological finding with a view to industrial transferability.Additional tests performed demonstrated that a preliminary thermal treatment of ash with elevated residual organic phase is necessary, which leads to a lower firing shrinkage and to a shorter sintering time.

Hydrothermal alteration-related kaolinite/dickite occurrences in ignimbrites: an example from Miocene ignimbrite units in Avanos, Central Turkey

Miocene-Quaternary volcanic complexes associated ignimbrites from the Cappadocia Volcanic Province in Central Anatolia have been subjected to hydrothermal alteration which produced several industrial clay mineralizations. This study focuses on the hydrothermally altered Late Miocene dacitic to trachy-andesitic ignimbrites in the Avanos region and aimed to determine the alteration in terms of conditions and origin. Hydrothermally altered samples consist mainly of quartz and kaolin group clays, and minor amounts of goethite/limonite, alunite, jarosite, illite, and mixed-layered illite-smectite. The kaolinite and dickite associations were principally determined from the diagnostic XRD peaks and confirmed by FTIR and SEM data. They have fine-grained and pseudo-hexagonal uniform-kaolinite and prolonged-dickite-shaped platelets as tightly packed vermicular booklets. The kaolinite and dickite association with fine-grained alunite and jarosite point out the steam-heated igneous environments at shallow depth level. Hydrothermal alteration-related minerals occurred as replacement of volcanic glass/groundmass and neoformation in the pores from the acidic hydrothermal solutions. The mineralogical associations suggest that the hydrothermal alteration occurred in acidic and moderate temperature conditions. Major and trace element compositions of altered samples exhibit distinct differences with respect to the host-rock composition. Chondrite normalized LREE contents increase, whereas HREE contents decrease in altered ignimbrites with respect to unaltered ignimbrite. The oxygen and hydrogen isotope data of kaolinite/dickite demonstrate that magmatic vapor phases mixed with meteoric waters. The steam-heating-related igneous environment seems to be responsible for magmatic vapors which circulated along the crack zones within the acidic volcanogenic rocks, and therefore the acidic conditions caused kaolin-dominant alteration.

Effects of Geofoam Particles on Geotechnical Properties of Clay-dune Sand

Nowadays, new materials are widely used for improving the bearing capacity of the soils and geosynthetics include the type of these materials which are utilized in this regard. In addition, the geofoam panel type of geosyntethic materials is useful and an alternative for backfill in retaining wall or pavement layers. The present research mainly aimed to investigate sthe effects of geofoam particles (0.2, 0.5, & 1%) on improving the bearing capacity of the clay-sand mixture. To this end, dune sandy soil (passed from sieve No.30 and residue on sieve No.50) was provided from Shore of the Lake Urmia and mixed with kaoline industrial clay at 15, 30, and 50 percentages. Then, compaction, uniaxial in three loading speed (0.5, 1, & 1.5 mm/min), direct shear (in vertical stresses 1, 2, & 3 kg/cm2), and falling head permeability tests were performed to evaluate the influence of geofoam particles on geotechnical properties of the mixed soil. The results showed that maximum dry density and elastic modulus increased by a 0.5% increase in the geofoam in the soil mixture. Meanwhile, the shear strength of the specimens increased as well. Finally, permeability and the drainage condition improved by adding geofoam to the specimens.

Direct production of biodiesel from waste oils with a strong solid base from alkalized industrial clay ash

Biodiesel was directly one-step produced from waste oils without pretreatment catalyzed by a solid base alkalized from spent bleaching clay (SBC) ash. Optimized conditions were obtained with 99.1% biodiesel yield from soybean oil with an orthogonal design. The base catalyst was stable within 8 cycles (>95% biodiesel yield) and resistant to saponification (AV = 9.7 mg KOH/g, 96.5% biodiesel yield). The base was characterized with XRD, EDX-mapping, FT-IR, XRF and TPD, and it had similar strong basicity to Na2SiO3 (0.21 vs. 0.22 mmol/g for Na2SiO3) with active sites of Na2O and CH3ONa evolved from Na2SiO3 and NaAlSiO4 by reactions of NaOH with oxides (e.g., SiO2, Al2O3) in SBC ash. Furthermore, the base was magnetized with magnetism of 6.86 emu/g by carbonizing residual oil in SBC as carbon support and reductant (of Fe2O3 to magnetic Fe3O4 particles). It catalyzed soybean oil to produce biodiesel with 99.2% yield and blended oil (AV = 5.9) to biodiesel with 91.9% yield without any saponification. The catalyst was magnetically separated and reused for 3 cycles with 87% yield. The non-magnetic base could also efficiently catalyze actual SBC oil for the production of biodiesel with 95% yield at AV of 10. This work realized the full use of inorganics in SBC, and its oil for direct biodiesel production at a low temperature (i.e., 65 vs. 120 °C with sulfuric acid process) without wastes produced and results can easily find practical applications for waste oils.

Imparting water repellency in completely decomposed granite with Tung oil

Engineered water repellent soils have great potential as construction materials for seepage barriers. By adjusting the water repellency of the soil, an impermeable or semi-permeable seepage barrier can be constructed to suit various engineering applications, such as impervious materials to contain water or semi-permeable materials to allow vegetation growth. Industrial clays, geosynthetics and grouting are proven solutions frequently used for similar applications. To provide a sustainable and low-cost solution to create an engineered water repellent soil, this study explored how Tung oil, a Chinese traditional vegetation oil, affected a Hong Kong completely decomposed granite (CDG). Tung oil has already been used in historical structures and suggested as a self-healing agent for concrete. A natural wettable soil from Hong Kong, CDG, was mixed with Tung oil and heated at different temperatures for different durations. The results reveal that the presence of Tung oil developed severe and persistent water repellency with heating, enhancing water repellency until a critical temperature threshold and heating duration was reached. However, a change to soil physical structure due to aggregation was also observed due to the mixing of the Tung oil with the soil. The newly formed Tung-oil impregnated aggregates were found to be (1) stable when immersed in water, regardless of the temperature and heating duration, (2) and to have increasing tensile strength with aggregate size up to a temperature threshold. Based on these findings, not only can Tung oil induce high and persistent water repellency in a natural soil through simple procedures (by mixing of soil with oil), but also aggregation may offer the opportunity to improve soils for other ground applications including to ameliorate erosion on slopes.

Characterization of Sardinian Bentonite

The employment of clays in industry and on laboratory scale is still of interest, despite their long history. The chemical-physical characteristics of such materials are strongly related to their geographical origin and the availability of proper characterization techniques is of great importance in order to gain as more information about their behavior when utilized as filling materials. In the present contribution, a physical characterization by meaning of Thermogravimetry and N2 physisorption analyses of samples of bentonite collected from the deposit of S´Aliderru in the north of Sardinia (Italy) is reported.

A probabilistic approach for identification of compressive strength of fly ash bricks

In the present industrial scenario, the production of fly ash being a waste from thermal power plants is increasing at an alarming rate. Fly ash not only creates a major problem at its disposal but also causes other environmental/health-related issues. To combat this waste is to find its application in the construction sector. In the past, fly ash is recognized as a promising replacement of clay in brick industry. The aim of the present work is to determine the characteristic compressive strength in a probabilistic approach for the Fal-G (fly ash–lime–gypsum) bricks constitutes the consumption of two waste products (fly ash and sludge lime) in brick manufacturing. For casting of Fal-G bricks, a semiautomatic, hydraulic operated brick manufacturing machine is fabricated and the compressive strength of the compacted bricks is observed. However, the compressive strength of the resulted bricks observed to be quite satisfied with the minimum value recommended as per IS 12894-1990. The study is further extended towards the fitting of randomly generated compressive strength values of Fal-G bricks to four different probability distribution functions and adopting Kolmogorov–Smirnov (KS) test to detect the best-fitted probability distribution of the present data. From the descriptive statistics of KS test results, it is inferred that the most common distribution, i.e. normal distribution, fits well to the data with the highest p value of 0.898. Normality test such as P–P and Q–Q plots is used to further confirm that the present data follow the normal distribution. Actual and expected z-scores are plotted to get all the data points on y = x line that follows the normal distribution. Determining the frequency factor of the normal distribution, the compressive strength is calculated at each probability level. At 95% probability level, the characteristic compressive strength of Fal-G bricks is obtained 4.8 N/mm2. Further, a curve fitting between a probability of exceedance and compressive strength shows logarithmic relationship which holds between the two variables with R2 = 0.932.

造形教育におけるインダストリアルクレイ活用の一考察 材料加工理論/実習IIの教育概要

造形教育におけるインダストリアルクレイ活用の一考察 材料加工理論/実習IIの教育概要

Reduction of Chlorophyll in Cold‐Pressed Hemp (Cannabis sativa) Seed Oil by Ultrasonic Bleaching and Enhancement of Oxidative Stability

The effects of ultrasonic bleaching on chlorophyll reduction and oxidative stability of cold‐pressed Cannabis sativa (hemp) seed oil is investigated using three different clays, Sepiolite, activated Bentonite, and an industrial clay. The chlorophyll content is significantly reduced (p < 0.05) from 56.3 μg g−1 in the untreated oil to 14.8 μg kg−1, 9.9 μg kg−1, and 7.8 μg kg−1 in oils treated with Sepiolite, activated Bentonite, and industrial clay, respectively. Oxidative stability is enhanced in all ultrasonically‐treated oils by a significant (p < 0.05) reduction in Peroxide Value (PV) with the highest reduction (97%) observed in the presence of industrial clay (PV = 0.11 mEq kg−1). A corresponding reduction in Conjugated Dienes (CD) is also found in the treated samples ranging from 0.073–0.095% compared to 0.102% for the control. During accelerated storage at 60 °C, increase in PVs and CDs are significantly (p < 0.05) slower for the ultrasonically treated oils in the presence of clays compared to the control. Accelerated storage at 40 °C shows that the PV is greater in hempseed oil bleached with Sepiolite clay compared to a combination of Sepiolite and ultrasonic bleaching. Based on these results it is evident that the rapid removal of chlorophyll from cold pressed hempseed oil is enhanced by a combination of bleaching clay and ultrasonic treatment.Practical Applications: Ultrasonic treatment of cold pressed hempseed oil combined with bleaching clays proves very effective in reducing chlorophyll content. The method is not only rapid and clean but requires significantly less bleaching clay. Hempseed oil treated in this way exhibits greater oxidative stability making it more attractive for industrial and consumer use. The results of ultrasonic bleaching suggest its potential for prolonging the shelf‐life. Utilizing the ultrasonic bleaching technique as an alternative to conventional bleaching would be beneficial to the edible oil industry.The results of ultrasonic bleaching prove effectiveness in reducing chlorophyll content in cold‐pressed hempseed oil and suggest its potential for prolonging the shelf‐life.

Fine-grained reservoir sediments: an interesting alternative raw material for Portland cement clinker production

The paper reports investigation results on the use of fine sediments to replace a part of the raw materials in Portland cement (PC) clinker. Representative samples of sediments from three different French dam reservoirs are studied. These materials have a mineral composition that includes some of oxides components essential to cement manufacturing, such as SiO2, CaO, Al2O3 and Fe2O3. Their potential for use as replacement of clays in cement industry was considered. Nine mixes of PC clinkers were synthesised with feedstock mixtures containing between 20.6 and 31.1% of sediments according to their chemical composition. In all cases studied, usual clay materials are completely substituted by dam sediments. Clinkers were characterised using ICP-AES, XRD and optical microscopy. Results showed that synthesised clinkers have similar chemical and mineralogical composition than ordinary PC clinker. Finally fine-grained sediments might be considered as natural resource, they are an interesting alternative raw material for PC clinker production.

Composites of styrene butadiene rubber/modified clay: mechanical, dielectric and morphological properties

PurposeThis paper aims to study the role of organobentonite (OB) as a filler to improve the mechanical strength of styrene butadiene rubber (SBR). Organoclay was first prepared by modifying bentonite with different concentrations of N-cetyl-N, N, N-triethyl ammonium bromide. A series of SBR composites reinforced with OB were prepared using master-batch method.Design/methodology/approachThe curing characteristics, mechanical properties, thermal behavior, dielectric properties and morphology of SBR/OB composites were investigated.FindingsThe elastic modulus and tensile strength of composites were increased by inclusion of OB, while the elongation at break was decreased, due to the increase in the degree of cross-linking density. Thermal gravimetric analysis revealed an improvement in the thermal stability of the composite containing 0.5 cation exchange capacity (CEC) OB, while the scanning electron micrographs confirmed more homogenous distribution of 0.5CEC OB in the rubber matrix. Also, SBR/0.5CEC OB showed low relative permittivity and electrical insulating properties.Research limitations/implicationsBentonite has been recognized as a potentially useful filler in polymer matrix composites because of their high swelling capacity and plate morphology.Practical implicationsOB improves the cured rubber by increasing the tensile strength and the stiffness of the vulcanizate.Social implicationsUsing cheap clay in rubber industry lead to production of low cost products with high efficiency.Originality/valueThe clay represents a convenient source because of their environmental compatibility. The low cost and easy availability make the modified clay used as fillers in rubber matrices, and the resultant composites can be applied in variety industrial of applications such as automobile industries, shoe outsoles, packaging materials and construction engineering.

Improvement of White Duekhla Clay properties by using Low-Density Polyethylene Fillers to use it in ceramic industries

The research was summarized in preparation and make samples of the ceramic body that are filled with Low-Density Polyethylene particles.The composite materials were manufactured by using ( Duekhla White Caly with Polymer particles) for purposes of improving the properties of clay for ceramic uses. The samples were prepared from The white Duekhla clay with fixed particle size (150µm) as a matrix and adding polymer powder particles (50µm) as fillers by different ratios in the range (2, 4, 6, 8, 10) %. Some essential materials such as feldspar and the fluvial sand. The results that were obtained from tests showed that higher contents of low-density polyethylene(LDPE) and that were added to the ceramic mixture gave good results and significant improvements for water absorbance resistance and less thermal conductivity. The mechanical properties of ceramic composites were improved by a higher ratio when adding (10%) of LDPE to ceramic composites. For example, the tensile strength was increased by an amount (175.5MPa) for the addition ratio (10%), compared with the pure sample (133MPa). The results of water absorbance and thermal conductivity decreased with increasing of the addition ratio for LDPE fillers. All obtained results indicated to the possibilities of improving the quality of the used clay in the ceramic industry for increasing the plasticity and disappear some disadvantages that were observed during the tests that were obtained on them

Production of Nano Amorphous SiO2 from Malatya Pyrophyllite

Pyrophyllite (Al4Si8O20(OH)4) is an important industrial clay mineral. In this paper, highly pure nano silica powder was synthesized by alkaline treatment method from the local pyrophyllite deposit which is in Malatya, Turkey. The morphologies, structures and properties of the raw pyrophyllite and the obtained nano amorphous SiO2 were determined by XRF, XRD, ATR, SEM and EDX. The results showed that the nano silica can be produced with a high purity (98%) and nano size (< 50 nm).

Designing of high voltage electric field for soybean and sunflower oil bleaching

Abstract To the best of our knowledge, this work for the first time in the world carried out at the Tarbiat Modares University. In the present research, high voltage electric field (HVEF) method was utilized for bleaching of soybean and sunflower oil. For optimization of the bleaching process, the effect of different independent variables such as clay percentage (0.5–2%), voltage (0–24 kV), distance (8–12 mm), different numbers of cathode–anode (4–8) and inert-electrolyte (HCl; 0–50 mM) was studied. In order to compare the properties of the bleached samples using HVEF and control (industrial condition) bleaching methods, the indexes of Lovibond, Hunter lab, carotenoid, chlorophyll, bleaching efficiency (BE), peroxide (PV), tiobarbituric acid (TBA), free fatty acid (FFA), tocopherol, sterol and fatty acid composition were measured. According to the results, the BE value of HVEF technique in bleached soybean (88.35%) and sunflower oil (75.41%) were higher in comparison with the soybean (85.80%) and sunflower (58.14%) oils bleached using control method. Consequently, the HVEF bleaching method seems to be an alternative to the industrial method as it reduced clay percentage (50 and 66%), temperature (28% and 28%) and process time (35% and 35%) in soybean and sunflower oil bleaching, respectively. Industrial relevance High voltage electric field (HVEF) method for bleaching of soybean and sunflower oil was done, for the first time in the world to the based of our knowledge, and was optimized under different conditions including clay percentage (0.5–2%), voltage (0–24 kV), distance (8–12 mm) with different numbers of cathode–anode (0–8), inert electrolyte (HCl; 0–50 mM). HVEF could be an alternative for bleaching method in the oil industry; HVEF could reduce %clay, temperature and time consumption in oil industry with low energy consumption; HVEF could produce micro and Nano clay by pulsed corona and pulsed spark type systems. -To Patent No: A23D ; C11B ; C11C ; H03 , “Design of high voltage electric field for the oil bleaching”, Tehran-Iran (2015).

Prokaryote community dynamics in anaerobic co-digestion of swine manure, rice straw and industrial clay residuals.

The aim of this study was to analyze the effect of the addition of rice straw and clay residuals on the prokaryote methane-producing community structure in a semi-continuously stirred tank reactor fed with swine manure. Molecular techniques, including terminal restriction fragment length polymorphism and a comparative nucleotide sequence analyses of the prokaryotic 16S rRNA genes, were performed. The results showed a positive effect of clay addition on methane yield during the co-digestion of swine manure and rice straw. At the digestion of swine manure, the bacterial phylum Firmicutes and the archaeal family Methanosarcinaceae, particularly Methanosarcina species, were predominant. During the co-digestion of swine manure and rice straw the microbial community changed, and with the addition of clay residual, the phylum Bacteroidetes predominated. The new nutritional conditions resulted in a shift in the archaeal family Methanosarcinaceae community as acetoclastic Methanosaeta species became dominant.

A new ultrasound-assisted bleaching technique for impacting chlorophyll content of cold-pressed hempseed oil

Ultrasonic treatment was applied to reduce chlorophyll of cold-pressed hempseed oil in conjunction with various clays. Bleaching clays such as bentonite (activated/non-activated), sepiolite and clay from a canola oil refining industry (industrial clay) were used. Ultrasonic bleaching of hempseed oil for 20 min at 20, 40 and 60% power (expressed as ultrasound amplitude) with bleaching clays (40 g/kg) reduced chlorophyll in decreasing order of effectiveness from industrial clay > activated bentonite > sepiolite > non-activated bentonite together with an increase in ultrasound power to 40%. At 20% ultrasound power, chlorophyll reduction (%) was found to be 99.4% (industrial clay) > 97.8% (activated bentonite) > 82.7% (sepiolite) > 47.1% (non-activated bentonite). The reduction in total phenolic content was 27.3%, 33.4%, 27.9% and 34.7% when treated at 20% ultrasound power with 40 g/kg clay from canola industry, activated bentonite, non-activated bentonite and sepiolite, respectively. The corresponding reduction in the peroxide value for the oil samples, due to the adsorptive nature of the clay, followed the trend of industrial clay > sepiolite > non-activated bentonite. This process proved promising for impacting hempseed oil color through reduction of chlorophyll.

Experimental Investigations on the Properties of Coal-Ash Brick Units as Green Building Materials

ABSTRACTIn India, production of electricity by thermal power plants accounts for more than 50% of the total electricity generated. While doing so, the thermal power plants produce about 117 million tons per year of coal ash as waste materials. Improper disposal of this ash poses a threat to the environment. It requires allocation of vast land area for dumping/storing and it pollutes the land. Ash generated in thermal power plants falls into two categories, namely, fly ash and pond ash. One of the ways to minimize the harmful effects due to unsafe disposal of ash on the environment is to utilize the ash in the construction industry as an admixture in brick making, cement manufacture, etc. Moreover, in the conventional brick making, a precious natural soil resource is overexploited. One of the essential requirements of green building is to use environmentally friendly building materials as well as to reuse/ recycle industrial waste products like fly ash and pond ash. If the fly ash and pond ash are used optimally by replacing clay in the brick-manufacturing industry, then this waste material can be treated as greener material. This will also reduce the pressure on the excavation of soil. Besides energy-saving methodologies, green building involves the application of all technologies and using of materials without affecting the natural resources. In this investigation, an attempt was made to devise ways for the optimal use of pond ash in manufacturing coal-ash bricks. This article presents the experimental results for coal ash brick made up of pond ash with fly ash, lime, gypsum, and stone dust. The fundamental strength and durability tests were conducted to evaluate the basic properties of bricks. An energy dispersive x-ray diffraction study and a scanning electron microscope (SEM) study were carried out for elemental analysis and to analyze the chemical composition of the abovementioned materials.

Suitability of Some Selected Clay Deposit from Edo, Ogun, Ondo and Ekiti State of Nigeria for Ceramic Water Filters Production

This study is designed to investigate the suitability of selected Nigeria clay deposit for clay based ceramic water filters (CWFs). Clay samples were taken from five randomly selected locations in Nigeria Namely: Okpella (Edo1) and Ojirami (Edo2) in Edo; Ikere in Ekiti state; FUTA in Ondo state and Onibode in Ogun to determine their suitability for clay based ceramic water filters (CWFs). Experimental analysis for linear shrinkage, water absorption, bulk density, compressive strength X-ray diffraction (XRD) and X-ray Fluorescence (XRF) was carried out on each of the clay samples. Test results reveal that all the clays contain high contents of alumina (Al2O3) and silica (SiO2) with minor contents of P2O5, Fe2O3, MgO, K2O, MnO and TiO2. The average crystal sizes of the clay were between 15 and 27 nm. Lattice structure indicates that the sample is Monoclinic and Anorthic. Ceramic water filters (CWFs) were made from a mixture of clay and sawdust at different volume ratios, and processed into test samples. Water absorption, linear shrinkage and compressive strength of the clay based ceramic filters (CWFs), reveal that as the volume ratio of sawdust increases these properties decrease. Flow rate analysis indicates that Edo and Ekiti ceramic water filters (CWFs) have higher flow rates. The research indicates that Edo and Ekiti Clay with specification of some industrial clays shows that the samples can be recommended for use in clay based ceramic water filters production.