The effect of molarity (from 3.64 to 1.74 M) of a solution of an alkaline activator (ALA) and temperature (from 10 to 20 ° C) of a mixture of alkali-activated materials (ALA) based on chamotte and metakaolin on the rheological properties was investigated. the development of the structure during curing and the strength of the samples after firing at temperatures of 800 and 1000 ° C. It has been established that a decrease in the molarity of the ALCA and an increase in temperature reduce the viscosity of the AHAM mixture. An increase in the molarity of the PCA and the temperature of the mixture accelerates the process of structure formation and leads to an increase in the strength of the samples during curing from 8.8 to 22 MPa and from 6.8 to 20 MPa after firing at a temperature of 1000 ° C. Also, the density of samples after firing increases from 1270 to 1510 kg / m 3 , and water absorption decreases from 15.4 to 13.4 & # 37;
The development of effective ceramic lining materials is an important industry challenge. Alumophosphate binder materials may be considered new for hydrocyclone applications. This work is devoted to the study of the content of the binder, its modification and calcination temperature on the properties of the final products. Particular attention is paid to the study of the main properties for the use of ceramic materials as lining: porosity, water adsorption, density. Several composite materials were obtained with improved properties due to reinforcement with coarse-grained silicon carbide
An algorithm for calculating the parameters of the structure of silicon carbide ceramic compositions of the system abrasive grain - bond - pores is described. The mathematical formulas required to use the algorithm are given. An example of the implementation of the algorithm in a production environment is given.
It is noted that when implementing the processes of magnetophoresis (one of the types of which is magnetic separation, used in various industries, including glass and ceramic), along with information about the fractional fraction of magnetoactive particles, information about their magnetic susceptibility is also fundamental. , depending on the strength of the applied field H. The data are given & # 967; for iron-containing particles-impurities of quartz sand, obtained from the results of measurements of the magnetic susceptibility of their powder samples. It is shown that the parameter & # 967;, being inversely dependent on H (with an exponent close to 0.75), significantly & # 171; suppresses & # 187; the role of the parameter H appearing in the basic expression for the magnetic force of particle capture. When creating magnetophoresis (separation) devices, it is recommended to pay increased attention not so much to the parameter H, as to the parameter characterizing the field inhomogeneity,? gradH, more responsible for the capture of particles
Clinker materials were obtained from non-ferrous metal waste, where the clay part of the tailings was used as the clay material. gravity of zircon-ilmenite ores (GZI), and feldspar concentrate (PShK) - a by-product of rare-earth metals without the use of natural traditional materials - as a flux. Studies have shown that the content is & # 171; dangerous & # 187; pore sizes 10-5 - 10-7 m in samples from HZI is 74 & # 37 ;. The introduction of PShK (feldspar concentrate) into the composition of ceramic masses reduces the content of & # 171; hazardous & # 187; pores with sizes 10-5 - 10-7 m up to 51 & # 37 ;. In addition, the introduction of PShK into the compositions of ceramic masses significantly changes the distribution of micropores, while the samples with feldspar concentrate are characterized by the appearance of a maximum of 32 & # 37; in the area of ??pores with sizes 10-6 - 10-7 m, which indicates a more uniform distribution of pores
The results of a study of the processes underlying the formation of hollow alumina-magnesia microspheres during chemical dispersion of aluminum-magnesium alloys with an increased magnesium content are presented. The mechanism of formation of microspheres and the factors that determine their structural features and sizes have been clarified. The effect of magnesium additions on the processes of formation of the structure of hollow microspheres and their amount is shown. Studied the fine structure of powders before and after heat treatment
The behavior of mixtures 6Al 2 Si 2 O 7 : 12NaOH and 6Al 2 Si 2 O 7 : 12NaOH: 2Al 2 O 3 during heat treatment. It was shown that after ultrasonic treatment of the suspension, its evaporation, granulation of the paste, and drying, a hydrated LTA zeolite is formed. It was found that at temperatures up to 700 & # 176; C, sodium aluminosilicate Na 6 Al 4 Si 4 O 17 . After heat treatment at temperatures above 800 & # 176; C, sodium aluminosilicate Na 8 Al 4 Si 4 O 18 < / sub>, mullite and nepheline. It is shown that calculations by the isoconversion methods of Friedman (differential) and Kissinger - Akahir - Sunose (integral), for which the temperature range 500 - 800 ° C is of interest, give close values ??of E. An increase in the apparent activation energy with an increase in the degree of conversion indicates changing the reaction mechanism
On the basis of the natural zeolite of Nakhchivan, zeolite faujasite was synthesized and its physicochemical properties were studied. The zeolite tuffs of the Nakhchivan Kukuchay deposit were used as a natural sample. It was found that the region of existence of faujasite is wide, and the optimal conditions for its hydrothermal synthesis were temperatures of 100 - 200 & # 176; C, the concentration of the thermal solution 10 - 15 & # 37; Ca (OH) 2 , treatment time 50 h
Modification of polyurea with glass microspheres has been carried out. Polyurea compositions of coatings based on them have been obtained. Their properties are assessed. The results of studying the compositions of coatings based on polyurea containing hollow glass microspheres are presented. It is proposed to use such coatings as waterproofing for pre-insulated heat supply pipes. The composition of a coating based on polyurea, containing hollow glass or aluminosilicate microspheres with a diameter of 200 - 300 ?m, functional additives selected from the series, including ammonium polyphosphate, wollastonite, microcalcite with a ratio of glass and aluminosilicate microspheres of 1: 1, was investigated.
A method is proposed for assessing the effect of the size and shape of alumina powder particles on the average radius of the capillaries of the porous structure of alumina ceramics by the geometric coefficient of the shape of particles and their specific surface area. The technique is based on a three-dimensional model of the porous structure of materials, taking into account the geometry of the capillaries. The resulting expression for the mean radius of capillaries is much more accurate than the Kozeny formula and methods based on the model with non-intersecting capillaries, which give underestimated values ??of the radius. It is noted that the effect of the thickness of porous ceramic samples on the gas permeability coefficient is insignificant.
