Sustainable Ways and Methods of Recycling Epoxy Fiberglass Waste

This article presents two technological ways of recycling the wastes of the production and application of products made of highly oriented fiberglass bound by the epoxy matrix. The first technology is aimed at shredding the epoxy-based products obtained by pultrusion to create fine and ultrafine powders (up to 2-10 microns) used as fillers in various composites. The second technology offers a way to obtain coarse powders with a particle size of up to 100 microns, used in the composition of heat-insulating materials and fire-retardant intumescent coatings. Proposed is the mechanical grinding of fiberglass to a finely dispersed state with subsequent heating to a temperature of 400 °C in the presence of a foaming coke and liquid glass. This technology allows the full utilization of waste from the production and application of epoxy fiberglass, such as windmill blades and parts of molded products, leading to the creation of an environmentally friendly fire-resistant and heat-insulating material in the form of plates, blocks and other products with operation temperature up to 400C, as well as fire retardant coatings for building materials and structures. By varying the content of the foaming agent and soluble glass in the composition of the intumescent mixture, one can regulate the average density, thermal conductivity and strength of the material within significant limits, achieving characteristics that exceed those of traditional heat-insulating materials. The proposed material based on recycled epoxy fiberglass is inflammable and resistant to unfavorable environmental impacts; it has high biostability and provides heat and mass transfer during the operation in buildings and structures.

STUDY OF DEFORMATION PROPERTIES OF ALKALI ACTIVATED CONCRETES USING ACTIVE AGGREGATES

Results of study of deformative properties of fine-grain concrete are shown using slag alkali activated cement and active aggregate, represented by fraction 0-2.5 mm. It had been shown that expansion deformations of concrete specimens, supplying process of alkaline corrosion of aggregate in concrete, directly combined with component composition and conditions of hardening and storing of material. Thus, it was show, that using alkaline component in the state of dry salt (sodium carbonate) shrinkage/expansion deformations are varying in the shorter ranges comparing to alkali activated concrete with the alkaline component represented by soluble glass. Introduction of active mineral admixture represented by metakaolin also leads to the decreasing of deformations comparing to the compositions without such admixture. Different conditions of hardening and storing of the specimens are also influence well on the development of shrinkage deformations. It is shown that drying of specimens with active process of alkaline corrosion of concrete makes it possible to stop development of expansion deformations in concrete. Hydrophobization of the dried specimens make it possible to store for some time linear characteristics of concrete specimens. This opens the possibility to store lifeability and exploitation terms of construction with destructive corrosion processes in concrete without spending significant costs and without canceling of construction exploitation. Hydrophobization of specimens without drying leads to the intensification of structure formation processes and higher rates of development of shrinkage/expansion deformations. That means, that traditional method of protection of concrete constructions (covering of concrete constructions by painting materials) is not able to prevent, but also possible to activate development of destructive processes of alkaline corrosion of concrete, becoming dangerous to be used.

Melt-Quenched Porous Organic Cage Glasses

The discrete molecular nature of porous organic cages (POCs) has allowed us to direct the formation of crystalline materials by crystal engineering. It has also been possible to create porous amorphous solids by deliberately disrupting the crystalline packing, either with chemical modification or by processing. More recently, organic cages were used to form isotropic porous liquids. However, the connection between solid and liquid states of POCs, and the glass state, are almost completely unexplored. Here, we investigate the melting and glass-forming behaviour of a range of organic cages, including both shape-persistent POCs formed by imine condensation, and reduced and synthetically post-modified amine POCs that are more flexible and lack shape-persistence. The organic cages exhibited melting and quenching of the resultant liquids provides molecular glasses. One of these molecular glasses exhibited improved gas uptake for both CO2 and CH4 compared to the starting amorphous cage. In addition, foaming of the liquid in one case resulted in a more stable and less soluble glass, which demonstrates the potential for an alternative approach to forming materials such as membranes without solution processing.

Melt-Quenched Porous Organic Cage Glasses

The discrete molecular nature of porous organic cages (POCs) has allowed us to direct the formation of crystalline materials by crystal engineering. It has also been possible to create porous amorphous solids by deliberately disrupting the crystalline packing, either with chemical modification or by processing. More recently, organic cages were used to form isotropic porous liquids. However, the connection between solid and liquid states of POCs, and the glass state, are almost completely unexplored. Here, we investigate the melting and glass-forming behaviour of a range of organic cages, including both shape-persistent POCs formed by imine condensation, and reduced and synthetically post-modified amine POCs that are more flexible and lack shape-persistence. The organic cages exhibited melting and quenching of the resultant liquids provides molecular glasses. One of these molecular glasses exhibited improved gas uptake for both CO2 and CH4 compared to the starting amorphous cage. In addition, foaming of the liquid in one case resulted in a more stable and less soluble glass, which demonstrates the potential for an alternative approach to forming materials such as membranes without solution processing.

Sustainable utilization of a converter slagging agent prepared by converter precipitator dust and oxide scale

A converter slagging agent was prepared using converter precipitator dust and oxide scale as raw materials and bentonite, calcium oxide, and soluble glass as binders. The influence of different binders on the strength of the converter slagging agent was studied. The optimum ratio of bentonite, calcium oxide, and sodium silicate was determined by orthogonal experiments. The chemical composition, strength, moisture content, alkalinity, and other indicators of the prepared converter slagging agent met the requirements for converter smelting. The drop intensity of the green pellet was 3.7 times, and the compressive strength of the dry pellet could reach 988.72 N/m2. Therefore, the sustainable utilization of converter precipitator dust and oxide scale could be realized by the preparation of a converter slagging agent.

SAWBOBETONE ON MODIFIED CEMENT BINDER

The article considers the principles of production of sawbobetone on cement binder modified with additives of soluble glass and ash of hydraulic removal of local CHP. The material based on the modified cement binder using local secondary raw materials: sawdust as a filler of sawdust and waste ash as a fine filler is effective in low-rise construction conditions.