On possibility of using silicomanganese slag and ladle electric steelmaking slag in manufacture of welding fluxes

Analysis of the existing trends in development of technologies for production of welding and surfacing fluxes showed that one of the actively developing areas is the production of fluxes using man-made waste (including metallurgical one) as components of the initial charge. This is due to the fact that the slag waste of metallurgical production contains a large amount of manganese and silicon, which in turn are the basis in welding fluxes. Within the framework of this direction development, the article describes principal possibility and efficiency of using materials based on ladle electric steelmaking slag from JSC “EVRAZ United West Siberian Metallurgical Combine” and slag produced by silicomanganese from LLC “West Siberian Electrometallurgical Plant” in the charge for production of fluxes used in the surfacing of rolling rolls. All the laboratory tests were made using the equipment of the scientific and production center “Welding Processes and Technologies”. For surfacing steel samples, the authors used a flux additive obtained by mixing ladle electric steelmaking slag of a fraction less than 0.2 mm with liquid sodium glass in a ratio of 62 and 38 %. The resulting flux additive was mixed with slag from the production of silicomanganese of a fraction of 0.45 - 2.50 mm in various ratios. Studies of the chemical composition (by the spectral method) and metallographic studies of the deposited layer revealed a tendency to an increase in sulfur content and in contamination with non-metallic inclusions in it with an increase in content of the flux additive in the charge of more than 20 %. According to the results of visual quality control of the deposited layer macrostructure, the absence of defects was established with a flux additive content of up to 30 %.

WET METHOD FOR PREPARING LIQUID GLASS ON SILICA ADDITIVES

Сравнительный анализ технологий вяжущих веществ показал, что водный раствор натриевых щелочных силикатов обладает высокой вяжущей способностью, способствует образованию прочного цементного камня, хорошо совмещается с компонентами как минерального, так и органического происхождения. В работе приводятся факты перспективности применения в строительстве жидкого натриевого стекла. Предлагаемая ускоренная методика получения натриевого жидкого стекла мокрым способом с использованием кремнеземистых добавок позволит решить проблемы выбросов углекислоты в атмосферу и расширить сырьевую базу за счет применения некондиционного местного сырья. A comparative analysis of the technologies of binders showed that an aqueous solution of sodium alkaline silicates has a high binding capacity, promotes the formation of a durable cement stone, and is well combined with components of both mineral and organic origin. The paper presents the facts of the prospects for the use of liquid sodium glass in construction.The proposed accelerated method for obtaining sodium water glass by the wet method using silica additives will solve the problem of carbon dioxide emissions into the atmosphere and expand the resource base through the use of substandard local raw materials.

A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K+ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The 31P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at −103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

Increase the Performances of Lime Finishing Mixes Due to Modification with Calcium Silicate Hydrates

Lime plaster mixes are becoming more and more popular in the world’s building materials market every year. Therefore, the issue of increasing the efficiency of lime finishing coatings is relevant. The paper aim is the modification of lime binders with specially synthesized calcium silicate hydrates (CSHs). To obtain the CSH filler, liquid sodium glass was used with a silicate module of 1.53–2.9 and a density of 1130–1663 kg/m3. Using differential thermal analysis (DTA), X-ray diffraction (XRD) patterns, synthesized calcium silicate hydrates, as well as dry plaster mixes, and finishing coatings based on using them were studied. The regularities of the filler synthesis were established depending on the temperature, density, and silicate modulus of liquid glass, the amount of the precipitant additive, the rate of its introduction, and the drying mode. As a result of processing the obtained experimental data, a mathematical model was obtained for the composition “lime + CSH”. The phase composition of the filler was revealed, which is characterized by the presence of calcium silicate hydrates of the tobermorite group, a solid solution CSH (B) in the form of a weakly crystallized gel, a solid solution of C–S–H (II), hydrohalites, and calcites. It was found that the use of the fillers into the lime compositions, obtained with the rapid introduction of CaCl2 additive into water glass during the synthesis of the filler, promotes the acceleration of the plastic strength gain of lime compositions. It was revealed that the lime composites with the CSH filler are characterized by reduced shrinkage deformations up to 45%. The introduction of the CSH filler into the lime compositions increases the water resistance of the lime finishing layer by 36%. A technological scheme for the production of the lime dry plaster mixes has been developed; it can be introduced at existing factories of building materials without significant re-equipment of production.

Highly filled, non-toxic of material with increased strength and fire resistance

Presents the results of research and testing of a newly developed composite material, the unique properties of which make it possible to use it, both as a special fire-resistant coating for habitable objects and in construction (door blocks, liners for effective thermal insulation). The heterogeneous structure of the cured composite does not contain toxic components, and when exposed to an open flame, it is even more hardened as a result of reflow and does not emit harmful chemical compounds. The developed material was obtained using dispersion and mechanical activation by mixing individual components with subsequent stage curing at normal and elevated temperatures., using sodium soda glass as a binder. Unique properties are provided by the presence in the recipe composition of mainly silicon-containing components — a mixture of dispersed fillers, including discrete glass fibers with a length of 4...7 mm, using liquid sodium glass as a binder.

Decorative Coating Based on Composite Cement-Silicate Matrix

The designed is a cement-silicate coating based on liquid sodium glass and Portland cement, modified with a complex ultra-and nanodispersed additive that includes titanium dioxide, expanded perlite sand and a dispersion of multilayered carbon nanotubes. The advantage of the designed coating is the use of Portland cement as a silicizer instead of conventionally used zinc oxide. The presented cement-silicate coating is water resistant, steam and gas proof, has good adhesion to the base and an increased durability, providing 4-5 times longer service life than those of the existing analogs. The presence of multilayered carbon nanotubes in the coating leads to the absorption of technogenic electromagnetic emission, and ultradisperse titanium dioxide promotes self-cleaning of the coating surface due to the photocatalysis effect. Expanded pearlite sand makes the coating surface textured when applying it to the base. The cement-silicate coating is used for facades decorative finishing of buildings made of ceramic bricks, cement concrete and plastered surfaces.

Nature Conservation Technology for Producing Slag-Foam Glass as a Structural and Thermal Insulating Material

The purpose of the research is to determine the starting material composition, the conditions for its heat treatment and operation, and also the development of the recommendations on the technology of manufacturing and use of slag-foam glass as a structural and thermal insulation material for low-rise construction. Research and development of the composition and technology of ferrosilicate dust - a secondary product of the Novokuznetsk ferroalloy plant and Kemerovo chemical enterprises - slag-foam glass production, were carried out taking intoaccount the need for recycling of waste generated during the production process. The liquid sodium glass production waste is a mixture offerrosilicate dust that is not completely exhausted in the reactors and anaqueous Na2OSiO2 solution. Its density varies from 1.2 g/cm3 to 1.5 g/cm3, and the binding properties are extremely unstable, they depend on the soluble glass and water ratio in the waste. The use of this material as the basis for the production of structural and thermal insulating slag-foamglass with the stable strength index, the average density and the long-term durability is quite relevant.

Influence of Exposure Time on the Photosensitive Properties of Borosilicate Photosensitive Glass-Ceramics

Photosensitive glass-ceramics have been extensively studied in recent years in that it is an attractive high diffraction efficiency grating materials. It is based on Stookey’s mixed fluoride sodium glass system for us to adopt, design prescriptions on the basis of SiO2-Na2O-Al2O3-ZnO for the glass main component and a series of glass doped with CeO2, AgNO3 and NaF etc. melted at about 1450 °C, and the glass have good optical property (homogeneity, without bubble and stripe, high transparency). The borosilicate glass was exposed by ultraviolet light, and then after the heat treatment of the sample, the measurement of ultraviolet-visible-near infrared absorption spectrum and the X ray diffraction of exposure part was performed.

Increase Water Resistance Decorative Coatings on the Basis of Calcareous Dry Building Mixtures

Data about regularities of influence of filler, based on the calcium hydrosilicate, on properties of limy dry construction mixes and coverings in their basis are given. Higher water resistance of limy coverings with application of containing silicate filler is established.The conducted researches established efficiency of application in a compounding of limy dry construction mixes (DCM) the nanostructuring additives based on aluminosilicates [1, 2]. For regulation of structure and properties of limy dry construction mixes (DCM), intended for restoration of historical building, and also finishing of again constructed facilities, we offered to enter into their compounding an additive based on the synthesized hydrosilicates (HSC) [3, 4].Hydrosilicates of calcium (HSC) are received by synthesis from liquid sodium glass in the presence of calcium chloride CaCl2 with the subsequent drying of sediment at a temperature 105-300°C and its crushing. Studying of material composition of the filler, made by methods of the X-ray phase analysis (RFA) and infrared (IK) spectroscopy, and also structure on the electronic scanning microscope of PhenomTM G2 pro showed the existence in synthesizable material the calcium silicates of various basicity.The conducted researches show that the filler based on HSC possesses hydraulic activity. The activity of filler, defined according to a technique [5], makes 195-250 mg/g depending on the synthesis mode.At developing of compounding of DCM the modifying additives: softeners, redispersion powders were applied. As the plasticizing additives the Kratasol, Hidetal P-4, S-3, SP-3, MelmentR F15G and MelfluxR 1641F were entered into a compounding. Additives of “Kratasol” series represent salts of naphthalenesulfoacids with the high maintenance of high-molecular fractions, an additive Hidetal of P-4 – hyper softener based on polikarboxylate.