Refractory Clay Research Articles

The potential of the Russian raw material base of zirconium for production of ZrO2-based refractory materials

The article is devoted to solving the problem of providing Russian manufacturers of refractory ceramic materials based on ZrO2 with domestic zirconium raw materials. The relevance of the study lies in the need to expand the Russian production of zircon refractories in order to ensure the technological integrity of Russia and the provision of consumable components in steelmaking. Zircon raw materials for the production of refractories belong to the group of metals that are mostly imported from abroad for domestic use. Deposits, production and logistics of refractory clays and kaolin, quartzite and magnesite in Russia are sufficiently developed and allow providing refractories manufacturers with domestic raw materials. The purpose of the article is to analyze the potential of the domestic raw material base of zirconium compounds for the production of refractory materials and products based on them. The technology and experience in the production of heat-resistant structures in ceramics based on ZrO2 at ONPP «Tekhnologiya» named after A. G. Romashin for the aviation, aerospace industry, nuclear energy using domestic raw materials of zirconium dioxide. It is determined that the consumption of ZrO2 in Russia is about 10 thousand tons per year, which is mainly represented by imported zircon concentrate (more than 90 %) and in a small amount by domestic baddeleyite concentrate. Based on the analysis of mineral resources, it has been established that the Russian raw material base of zirconium is sufficient to meet the needs of Russian enterprises in zirconium raw materials, but its development is hindered by the deep hard-to-reach occurrence of the metal, the lack of industrial ore dressing technology and the complexity of further processing of the resulting concentrates. With the planned indicators for the development of the Tuganskoye deposit, by 2026, a complete transition of the Russian industry to domestic zircon raw materials is possible, and if the enterprise reaches full capacity by 2030, the production volume of the concentrate will be four times higher than the current volume of consumption, which will allow organizing its export.

მდინარე დურუჯის დანალექი ლამის ბაზაზე შემცხვარკეციანი კერამიკული ნაკეთობების მიღება

It is known that alcohol-containing (alcoholic) drinks are more aggressive than water-containing liquids, which is very important to consider when storing them in fired ceramics (dishes, containers), since such dishes should not let liquid through and should ensure long-term storage of the drink without changing its color and taste. Therefore, it is interesting to study the sedimentary silt of the Duruji River and use it to obtain lowtemperature, sintered pottery products that are resistant to water and alcoholic beverages. Obtaining masses of a new composition based on natural raw materials, silt from the Duruji River, was carried out by pouring into plaster molds, drying, firing in electric furnaces and determining water absorption. Based on the sludge of the Durudzhi River, lowquality (III, IV) kaolins of Ukrainian origin and refractory clays, low-temperature, artistic ceramic products with a sintered shard were obtained, characterized by low water absorption and resistance to alcoholic beverages.

Mineralogical–Geochemical Features, Genesis, and Age of Refractory Clays in the Shulepovo Deposit (Ryazan Region, Central European Russia)

Mineralogical–Geochemical Features, Genesis, and Age of Refractory Clays in the Shulepovo Deposit (Ryazan Region, Central European Russia)

Development and Characterization of PLA Composites with High Contents of a Brazilian Refractory Clay and Improved Fire Performance

Aiming to overcome poly(lactic acid) (PLA) limitations regarding flammability and high costs, a highly refractory clay (RC) was employed to produce PLA/RC composites. The composites with clay contents of 0, 2.5, 10 and 15 wt% were produced by extrusion, conformed by injection molding, and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), mechanical analysis, scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), statistical analysis of variance (ANOVA) and flammability tests. The overall thermal stability of the materials was not affected by the incorporation of clay to the polymer matrix; improvements around 25% for Young’s modulus and slight increase in flexural and impact strength, when compared to neat PLA, were obtained; ANOVA showed the possibility of incorporating higher loads of clay, 10-15 wt%, in order to make the final material more cost effective. PLA/RC composites demonstrated self-extinguish behavior for the flame even at a lower clay content.

ПОЛОГІВСЬКЕ РОДОВИЩЕ КАОЛІНУ: ГЕОЛОГІЯ, МІНЕРАЛЬНИЙ ТА ХІМІЧНИЙ СКЛАД, ТЕХНОЛОГІЧНІ ВЛАСТИВОСТІ

The area of the Pologivskiy deposit of kaolins and refractory clays is located on the border of two geological regions: the Azov crystalline massif and the Konksko-Yalynska depression. Precambrian crystalline rocks and sediments of the Cretaceous, Paleogene, Neogene, and Quaternary systems take part in the geological structure of the district. The geological structure of the district is based on the results of field exploration (23–25) and geological surveying works. Deposits of the Quaternary system are widespread in the territory and are similar to mantle on the underlying rocks. The lower border of the Quaternary system is formed at the base of the Berezanskiy climatolite in accordance with the Geological Map of Ukraine legend (the scale 1:200 000) of the 1996 Central Ukrainian series. The underlying rocks are red-brown Pliocene clays in most parts of the territory, in the rest there are rocks of crystalline basement of Cretaceous, Paleogene and Neogene systems. The thickness of the Quaternary deposits is 10–20 m. Deposits of the Novopetrivska Neogene suite are productive for the extraction of clays and kaolins, in the base of which the undivided deposits of the Upper Eocene (Kyivska suite) and Oligocene (Kharkivska suite) lie. These are coastal-marine deposits – marls, calcareous clays, siltstones, weakly cemented sandstones and glauconite quartz sands. The total thickness of the Kyivska and Kharkivska suites varies from 0,0 to 60–70 m. Clays and kaolins are characterized by almost the same mineral composition. Most of them are composed of fine-grained kaolinite, and quartz predominates among impurities. Accessory and ore minerals are represented by zircon, rutile, ilmenite and hematite. Quartz is present in clays and kaolins in the form of rolled, semirolled and unrolled grains. High-quality aluminosilicate products are obtained from the kaolins of the deposit. Pologivskiy kaolin can be used to make chamotte without the clay addition, as well as a binder. The ratio of chamotte and binder is 80–20 %. The refractories obtained in the laboratory meet the requirements of high density for Class A blast furnace bricks and other products of appropriate determination. Pologivskiy clays are recognized as suitable for the production of 100 % refractories, as well as a binder component instead of ChasovYarska clays. Products made entirely of semi-acid clay meet the requirements for semi-acid refractory products of class B. Pologivskiy kaolins and clays have long been used in refractory, machine-building, ceramic, cement and other industries.

RESEARCH OF PHYSICO-CHEMICAL REGULARITIES OF ENVIRONMENTALLY SAFE TECHNOLOGY FOR EXTRACTION OF METALS FROM DUMP SLAG

Pollution of the environment with metals such as lead, nickel, copper, titanium, and zinc is a worldwide public problem, as evidenced by the elevated levels in the blood of people living in polluted areas. The physicochemical analysis of the initial waste slags determined the phase and mineralogical features, as well as the elemental composition of the waste slags of lead production and refractory clays of the Sairam district of the Turkestan region. Thermodynamic studies of the calculation of the Gibbs energy of possible reactions of joint chlorinating roasting of non-ferrous and refractory metals have established the probability of reactions involving lead oxides, and nickel oxides in the presence of aluminum oxides, iron, and calcium chloride. An analysis of the obtained calculated data of the Gibbs energy showed that only in the high-temperature region is possible the joint chlorination of copper and nickel oxides in the presence of aluminum oxide, and in the presence of iron oxide, thermodynamic reaction 6 is likely. Mathematical planning of the experiment determined the technological parameters of the process, ensuring the extraction of nickel up to 94% when firing a mixture of slag and clay at 87-8%.

ИЗУЧЕНИЕ ВЛИЯНИЯ ЗАПОЛНИТЕЛЯ НА ОСНОВЕ ОТХОДОВ КЕРАМОГРАНИТА НА ФИЗИКО-МЕХАНИЧЕСКИЕ СВОЙСТВА ГОРЯЧИХ МЕЛКОЗЕРНИСТЫХ АСФАЛЬТОБЕТОНОВ

The results of research are presented when replacing finely crushed mineral part of asphalt concrete with waste from the production of porcelain stoneware, which is a product of high-temperature firing of a mixture of refractory clay raw materials and feldspar rocks, which provides high physical and mechanical properties of waste and further road surface.

Pristine Clay Mineral Deposit For Water Purification and Other Potential Industrial Applications

Clays are used extensively in water purification and several other industrial processes due to their porosity, large surface area and cation exchange ability. Given their vast potential importance, four Nigeria clay samples were characterized taking into consideration their potential application for water purification and some other industrial interests. The chemical and mineralogy composition were determined using the EDX, XRF and XRD while FTIR investigated the functional groups of the clay minerals. Clay morphological properties were characterized using SEM, CEC, BET and the zeta potential carried out to analyse the stability in aqueous solution. The study revealed that the clays were mainly kaolinite, while the clay minerals were primarily quartz having other associated minerals like anatase and pyrite. The clay samples were found to show satisfactory fitting for water purification owing to their exchangeable cations, zeta potential, and BET results. Additionally, they were also found to be suitable for industrial applications for production of firebricks, production of super-heat duty fireclay refractory materials, inhibition of shrinkage during sintering process, inhibition of bacteria growth, and refractory clays. The study outlines the usefulness of the clay mineral deposits in Nigeria that will improve the natural water purification, thereby creating a cheap and readily available purifier for locals and global usage.

Relationship of Properties, Phase Composition, and Microstructure of Clinker Brick

Clinker brick was obtained on the basis of polymineral raw materials, including low-melting and refractory clays, loams, and granitoid screenings in the plastic method of manufacturing. The interrelation of the physical and chemical properties of products was determined as a function of the mass content of the components and the oxide composition of the charge, and the optimal temperature_time regimes of firing were determined — 1150 ± 5°C with exposure of 4 h at an optimal temperature. The data obtained on the oxide and mineral composition make it possible to predict the composition of the charge for producing clinker brick, the heat-treatment regimes, and the properties of the products.

FEATURES OF DEVELOPMENT, LITHOLOGICAL STRUCTURE AND MINERAL RESOURCES OF THE EOCENE CONTINENTAL DEPOSITS CENTRAL PART OF UKRAINIAN SHIELD

We clarify conditions for the occurrence of Middle Eocene continental river sediments within different part softhe paleo valley, and the lithological structure and facial conditions for the formation of deposits have been clarified. Mineral deposits have been studied with in the prospective areas of Middle Eocene paleo valley and the irdigital models have been constructed, in particular maps: the surface relief and the solesof the productive strata; capacity deposit sofmineral sand the containing mineral deposit soflitho facies.Eocene river paleovalleys central part of the Ukrainian shield survived to this day in the form of winding lanes. The river valleys were not only ways of transporting the material to the board on its slopes and adjacent structures (Dnieper-Donets depression and PreBlacksea depression), but also the seat of various minerals, such as ilmenite, gold, secondary kaolin, refractory clay, brown coal. The evolution of river paleovalleys had a decisive influence on the configuration and placement of mineral deposits.

Factors Influencing Mullite Formation in Refractory Grog

The mineral mullite has many outstanding refractory properties. The content of aluminum oxide in the raw material is the basic factor influencing the content of mullite in the final product. Depending on Al2O3 content, silica-alumina materials can be divided into fireclay and high-alumina with the Al2O3 content of 45 % and more. The study describes the influence of raw material, the influence of homogenization of raw material and influence of firing temperature on the mullite formation in fireclay refractory material. Three kinds of refractory clay with different chemical composition were used as raw material for fireclay grog production. Three kinds of homogenization and three different temperatures were studied as factors influencing mullite formation. Powder X-ray diffraction was used to determine mullite content in material. Quantitative phase analysis was conducted by the Rietveld method. Mullite crystals morphology was observed by scanning electron microscopy.

The Way of Utilization of Fused Corundum Dust Waste for the High-Alumina Chamotte Production

High-alumina chamotte with an Al2O3 content of more than 62% is a desirable raw material to produce high-alumina refractories. The production of high-alumina aggregate (chamotte) is carried out in various ways, using plastic or semi-dry technology for briquetting from commercial alumina and refractory clay. When grinding fused corundum, the dust containing 93–95% Al2O3 is formed; it is currently a substandard material. It is of interest to involve this waste product in the production of high-alumina chamotte. The developed technology allows obtaining the desirable material and utilizing production waste. In this project the briquetting parameters to produce high-alumina chamotte using corundum waste and refractory enriched kaolin were determined.

Mineral Composition and Morphological Features of Kaolinite in Ceramic Clays of the Shulepovo Deposit (Ryazan Region, Central European Russia)

This paper addresses for the first time the internal structure of lens 2 of the Shulepovo refractory clay deposit. The SEM study of representative samples from the entire lens section revealed relationships between the major minerals: kaolinite, halloysite, illite, and quartz. The lens was previously considered homogeneous, but its detailed study revealed a clear internal zonality. The structural forms of kaolinite (hexagons, vermicules, and films), halloysite (acicular or columnar and stellate crystals), and illite (intergrowths and bands) are distinguished. Their variable relationships define the vertical zonality of the lens.

On the effectiveness of the addition of refractory clays in ceramic concrete technology (Review article)

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Production of Chemically Resistant Refractory Concrete Mixes from Metallurgical Waste and Their Physical and Chemical Properties

The results of research on obtaining a new composition of chemically resistant, refractory concrete mixture are presented. The basis of the resulting mass is production waste, which is a slag of electrothermal reduction of niobium pentoxide — crushed and purified fused alumina — electrocorundum, ferrosilicon slag, ferrochrome slag, refractory aluminosilicate mortar and refractory clay. High chemical resistance, fire resistance, mechanical strength, hardness and wear resistance determine the scope of its application—the production of chemically resistant, refractory concrete.

Efficiency of Refractory Clay Additions in Ceramic Concrete Technology (Review Article)

The efficiency of insignificant additions of clay and kaolin in relation to the production of molded and unmolded ceramic concretes, based on the use of HCBS of silica, aluminosilicate, high-alumina and corundum compositions, is shown. These additions can be made both as part of HCBS and in molding systems in the manufacture of ceramic concrete. Clay additives are especially effective in the manufacture of monolithic linings based on the Al2O3–SiO2–SiC–C system by vibro-pneumatic ramming. By introducing additives, it is possible to improve the rheotechnological properties of both initial HCBS of various compositions and matrix systems of ceramic concretes formed by various methods.

Cement-Free Refractory Concretes. Part 6. Comparative Evaluation of Natural (Clay) and Artificial Ceramic Binders (HCBS)

Comparative assessment of artificial (based on highly concentrated ceramic binders suspensions - HCBS) and natural (based on clay and kaolin) ceramic binders of similar composition is conducted. Analysis of their properties and characteristics shows both their significant similarity and significant difference. As with HCBS, the binding (strength) properties of clay and kaolin are determined by the colloidal particle content and nanoparticles within them. In contrast to HCBS, clay and kaolin have a significant content of chemically bonded water, a high water requirement for molding systems, and clearly different (by an order of magnitude and greater) shrinkage during drying. If binders based on clays are considered from the point of HCBS classification, then according to their chemical composition they may be classified as acid-amphoteric (similar to materials based on chamotte). However, in terms of chemically bonded water and volume concentration of a suspension, they are closer to HCBS of amphoteric and basic compositions. Addition of refractory clay and kaolin is very effective in ceramic concrete production.

Modeling an Increase in the Cement Activity Using Dispersed Mineral Additives

The researches’ results show that it is possible to obtain a ceramic crock, which water absorption meets the requirements of facade ceramic tiles at a charge firing temperature of 1150 ° C, consisting of 60% low-melting and 40% refractory clay raw materials from deposits in the Novosibirsk Region. Additives influence nature of directed action was studied: wollastonite and cullet by the mathematical planning method of the experiment. It was found that the introduction of additives helps to improve the physical and mechanical properties of the ceramic crock. The introduction of 10% cullet allows increasing the tensile strength by 10.3% compression and reducing water 27.1% absorption. The amount of 15% wollastonite contributes to a greater increase in mechanical strength and a decrease in water absorption, compared with the control composition. The joint introduction of mineral additives leads to a decrease in tensile strength A method for producing high-quality facade and building ceramics from low-grade, poor in clay minerals raw materials with carbonate inclusions, which consists in mechanically activating these raw materials and purposefully creating a hierarchical structure of semi-dry pressed products, is proposed in the research work. The developed technology of preparing a press-mass that is uniform in humidity and dispersion by rolling mechanically activated powders based on aggregate grains (micro level), firmly coated with clay mineral nanoparticles, to the state of spherical granules (macro level). This approach to mass preparation significantly improves the subsequent stages course of pressing and firing products. Its effect is the possibility of obtaining various types of building and facade ceramics with high performance characteristics.

Use of Technogenic Additives in Facade Ceramic Tiles Production

The researches’ results show that it is possible to obtain a ceramic crock, which water absorption meets the requirements of facade ceramic tiles at a charge firing temperature of 1150 ° C, consisting of 60% low-melting and 40% refractory clay raw materials from deposits in the Novosibirsk Region. Additives influence nature of directed action was studied: wollastonite and cullet by the mathematical planning method of the experiment. It was found that the introduction of additives helps to improve the physical and mechanical properties of the ceramic crock. The introduction of 10% cullet allows increasing the tensile strength by 10.3% compression and reducing water 27.1% absorption. The amount of 15% wollastonite contributes to a greater increase in mechanical strength and a decrease in water absorption, compared with the control composition. The joint introduction of mineral additives leads to a decrease in tensile strength.

Cement free castable. Part 6. Comparative assessment of natural (clay) and artificial ceramic binders (HCBS)

A comparative assessment of artificial (based on highly concentrated ceramic binders suspensions - HCBS) and natural (based on clays and kaolins) ceramic binders of similar composition has been carried out. Analysis of their properties and characteristics shows both their significant similarity and significant difference. As with HCBS, the binding (strength) properties of clays and kaolins are determined by the content of colloidal particles and nanoparticles in them. In contrast to HCBS, clays and kaolins are characterized by a significant content of chemically bound water, a high water requirement of molding systems, and a sharp, different (by an order of magnitude and higher) shrinkage during drying. If binders based on clays are considered from the position of HCBS classification, then according to their chemical composition they can be classified as acid-amphoteric (like materials based on chamotte). However, in terms of chemically bound water, volumetric concentration of the suspension, they are closer to HCBS of amphoteric and basic compositions. The addition of refractory clays and kaolins is very effective in the production of ceramic concrete.