STUDY OF THE INFLUENCE OF FILLER BASED ON PORCELAIN WASTE ON PHYSICAL AND MECHANICAL PROPERTIES OF HOT FINE-GRAINED ASPHALT CONCRETE

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.

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.

Influence of different types of chamot on a structure and properties of porous ceramics

The results of research of porous materials on the basis of products of ceramic production - chamot as a fractionating filler are given.. The features of formation of structure of material at the use of chamot with different chemical and mineralogical compositions in the conditions of speed baking are shown. Porous ceramics for filtration and aeration is obtained by a technology based on the regulation of porosity parameters by the use of chamotte of a certain granulometric composition and special binders. However, the granulometric composition of chamotte is a necessary but not sufficient factor to optimize the properties of porous filter ceramics. Along with the granulometry of chamotte, its chemical and mineralogical composition and surface energy must be taken into account. It depends in turn on the technological properties and the firing parameters of the original clay raw material. This paper presents the results of a study of porous materials based on ceramic products - chamotte as a fractionated filler. The chemical and mineralogical composition of chamotte made of poly-mineral clay at maximum firing temperature of 950°С and of refractory clay at firing at 1320°C was analyzed. The energy state of the surface of the chamotte particles was determined with the wetting by polar and non-polar liquids (water and benzene respectively). The differences in the specific effective surface area, lyophilicity and filtration coefficients was determined. The peculiarities of the formation of the pore structure of ceramics obtained using the specified samples of chamotte in the conditions of high-speed firing in the roller oven are shown. Significant differences in the formation of open and closed pores were observed, the predominant specific proportion of open pores in the material using polymineral clay. The possibility of properties regulation of the pore structure and the energy state of the surface of the filter material when applying a mixture of chamotte varieties was experimentally confirmed.

Mineralogical and Thermal Characterization of Kaolinitic Clays from Terra Alta (Catalonia, Spain)

This research characterizes the kaolinitic clays from Cretaceous–Paleocene lateritic deposits of Terra Alta (south Catalonia) to evaluate their possible applications. The outcrops and quarries belong to the Horta de Sant Joan and Pinell de Brai areas. The chemical composition, mineralogy, rheological behavior, particle size distribution and plasticity are determined. The Fe and Ti4+ contents prevent them from being directly used as raw material for white ceramics. The mineralogy consists of kaolinite with quartz, illite, hematite, and minor K-feldspar and calcite. Most of the area comprises medium plastic clays that are classified as fired clays and can be used as ceramic and construction materials. In Horta de Sant Joan, a kaolinitic-rich level, up to 75 wt % of kaolinite, is highly crystalline with low plasticity and can be classified as flint clay, useful as a refractory clay. The evaluated kaolinitic clays can also be used to obtain a triaxial ceramic when they are mixed with feldspar to act as a fluxing agent and chamotte.

REFRACTORY CLAY RAW MATERIALS OF REPUBLIC OF BELARUS FOR PRODUCTION OF THE PORCELAIN TILE

The possibility of replacing imported refractory clays and kaolines, which are part of porcelain stoneware mix, with refractory clay materials of the Republic of Belarus, in particular quartz-pyrophyllite-kaolinite rock and kaolin of “Dedovka” and “Sitnitsa” deposits, was explored. Porcelainised stoneware body formulations of JSC “Keramin” (Minsk, Republic of Belarus) was taken as the basis. It was found that physico-chemical properties and operational characteristics of porcelain tiles comply with the requirements of EN 14411: 2014, when adding 2.5–15.0 wt.% quartz-pyrophyllite-kaolinite rock. Incorporation of quartz-pyrophyllite-kaolinite rock in percentage higher than 15.0 wt.% resulted in reduction in the total amount of the vitreous phase of porcelain stoneware, thus increasing water absorption, apparent porosity as well as reduces flexural strength and bulk density. The main crystalline phases in the synthesized materials were quartz and mullite. It was also revealed that imported kaolines could be completely replaced by kaolines of “Dedovka” and “Sitnitsa” deposits. In this, required physico-chemical properties and operational characteristics of porcelain tiles was maintained. SEM analysis revealed that specimens synthesized using considered kaolines show quite dense microstructures, with a high degree of vitrification. The gas phase in these materials was practically absent, the presence of only individual small irregular pores was found. XRD analysis indicated that the major phases were mullite, quartz, microcline and hematite. It was hematite that gives the obtained porcelain stoneware samples a dark gray color scheme. Thus, the use of domestic refractory clay raw materials provides import substitution and declining production costs.

High-alumina masses based on plasticized bauxite suspensions

The results of studies of the reotechnological properties of plastic refractory masses based on bauxite suspensions plasticized with refractory clay are presented. The regularities of the influence of the filler diameter and the content of the binder in the mass on the structuralmechanical and operational properties of samples based on it are established. Samples from the developed masses intended for molding at low pressure (up to 10 MPa) are characterized by high compressive strength (100‒110 MPa) and relatively low porosity (up to 20‒21%) after heat treatment at 1300 oC. Ill. 5. Ref. 20. Tab. 4.