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Organically-bound foundry cores are substituted by inorganically-bound cores increasingly. This trend is due to regulatory efforts, workplace safety issues, and increasing costs for waste deposits. Changing the binder system reduces the emissions to mostly water vapor, solving health and safety issues. Yet, the difference in the behavior of the gas phase, namely, the condensation potential of water, changes the casting process drastically. In contrast with the continuous generation and discharge of combustion products in the case of organic binders, water accumulates within the foundry core. Only once the cold spots of the core reach boiling temperature noteworthy amounts of vapor are created, increasing the chance for gas defects of the cast parts. Countermeasures have to be taken when designing the core’s geometry. We conducted the following research to improve the understanding of core gas release and its interactions with the foundry core’s binder content and storage conditions. Both binder content and relative humidity during storage were varied in three steps. Their influence on the core gas amount, time of gas generation, and gas permeability of the cores were investigated. The experiments were performed in the institute’s Induction Analysis Furnace and an aluminum melt bath. We found a strong dependency of storage humidity, further increased by increasing binder content on the gas amount and time of the gas release.

In this study, we investigated the effect of different organic binders on the morphologic structure of ceramic membrane support. Natural raw clay material (kaolin) was used as the main mineral for ceramic membrane support. The physical and chemical properties of kaolin powder and the supports were identified by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), particle size and zeta potential distribution. Based on the XRF test, the main composition of kaolin powder was SiO2 (47.41%) and Al2O3 (38.91%), while the rest were impurities. The FTIR spectra showed the functional groups of Si-O and Al-O. The XRD diffractogram of natural raw clay powder identified kaolinite and nacrite were the main mineral phase whereas muscovite and quartz were detected in small quantities in the sample. After prepared the ceramic membrane supports, XRD diffractogram showed that anorthite and gehlenite were detected as the main mineral phases for ethylene glycol (EG), gelatin, methocel and for polyethylene glycol (PEG), respectively. According to BET analyses, the maximum and the minimum pore width were obtained for PEG and gelatin organic binders.

The aim of the present research is to shape zeolite 13X and study the effect of singular and binary systems of binders. For this purpose, zeolite 13X was successfully synthesized under hydrothermal conditions. Different combinations of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) were used for shaping. Physical properties of granules were measured by nitrogen adsorption-desorption, and results showed that increasing the binder content up to a certain amount enhanced the physical properties. However, the surface area decreased with a further increase in binder content. In addition, it was found that mechanical strength was decreased with increasing binder content after burnout.

In this work, the results of the examinations of the effect of the mold material and mold technology on the microstructure and properties of the casts parts of ductile cast iron have been presented. Four different self-hardening molding sands based on fresh silica sand from Grudzen Las, with organic binders (no-bake process), were used to prepare molds for tested castings. A novelty is the use of molding sand with a two-component binder: furfuryl resin-polycaprolactone PCL biomaterial. The molds were poured with ductile iron according to standard PN-EN 1563:2018-10. The microstructure of the experimental castings was examined on metallographic cross-sections with PN-EN ISO 945-1:2019-09 standard. Observations were made in the area at the casting/mold boundary and in a zone approximately 10 mm from the surface of the casting with a light microscope. The tensile test at room temperature was conducted according to standard PN-EN ISO 6892-1:2016-09. Circular cross-section test pieces, machined from samples taken from castings, were used. In the present experiment, it was stated that interactions between the mold material of different compositions and liquid cast iron at the stage of casting solidification led to some evolution of casting’s microstructure in the superficial layer, such as a pearlite rim observed for acidic mold sand, a ferritic rim for alkaline sand, and graphite spheroids degeneration, especially spectacular for the acidic mold with polycaprolactone (PCL) addition. These microstructural effects may point to the interference of the direct chemical interactions between liquid alloy and the components released from the mold sand, such as sulfur and oxygen. Particularly noteworthy is the observation that the use of molding sand with furfuryl resin with the addition of biodegradable PCL material does not lead to an unfavorable modification of the mechanical properties in the casting. The samples taken from Casting No. 2, made on the acidic molding sand with the participation of biodegradable material, had an average strength of 672 MPa, the highest average strength UTS-among all tested molding sands. However, the elongation after fracture was 48% lower compared to the reference samples from Casting No. 1 from the sand without the addition of PCL.

Pellet ore not only has excellent metallurgical and mechanical properties, but is also an important metallurgical raw material used to solve the problem of increasing depletion of global high-grade iron ore resources. Bentonite has long been widely used in pellet ore production, which is not only expensive but also causes serious metallurgical pollution. Organic binders can form stronger adhesion and cohesion with mineral particles inside the green pellets than capillary forces, which greatly improves the pelletizing rate and significantly increases the strength of green and dry pellets, and it becomes an indispensable alternative to bentonite because it volatilizes pyrolytically at high temperatures, leaving almost no inorganic contaminants inside the pellet ore. In order to let more pellet researchers fully understand the research status and pelletizing theory of organic binders, this review systematically summarizes seven common organic binders, and elaborates on their adhesion mechanism and process characteristics, so as to provide references for pellet researchers and readers to further prepare cost-effective pellet binders and improve advanced pelletizing technology.

Due to the observed increase in the amount of waste in landfills, there has been an increase in the demand for products made of biomaterials and the composition of biomaterials with petroleum-derived materials. The problem of waste disposal/management also applies to waste from the casting production process with the use of disposable casting moulds made with the use of organic binders (resins), as well as residues from the process of regeneration of moulding sands. A perspective solution is to add a biodegradable component to the moulding/core sand. The authors proposed the use of polycaprolactone (PCL), a polymer from the group of aliphatic polyesters, as an additive to a casting resin commonly used in practice. As part of this study, the effect of PCL addition on the (bio) degradation of dust obtained after the process of mechanical regeneration of moulding sands with organic binders was determined. The (bio) degradation process was studied in the environment reflecting the actual environmental conditions. As part of the article, dust samples before and after the duration of the (bio) degradation process were tested for weight loss by thermogravimetry (TG) and for losses on ignition (LOI).

The article contains an overview of Russian and foreign standard documents used for organic binder quality evaluation, the description of the main principles of organic binders selection for asphalt mixes according to the Superpave Mix Design Method, the analysis of climatic conditions of the Southern region of the Russian Federation impacting the performance of Highway M-4 Don asphalt concrete pavements, and selects suitable binder grades for Southern Russia depending on maintenance conditions.

The historical monuments of the ‘City of Temples’ (Kathmandu) represent an intrinsic component of Nepal’s cultural heritage. The 2015 devastating Gorkha earthquake, besides human casualties, has led to a widespread demolition or partial damage of monuments at UNESCO World Heritage Sites, including the ones in Durbar squares. This study, through an integrated material characterization of masonry binders, used in four case monuments from Hanuman Dhoka and Patan Durbar squares, intends to contribute to the knowledge of the technological know-how of the past in order to maintain as much as possible the original traditions and to provide appropriate conservation strategies. The analytical characterization of the ancient mortars was carried out by means of X-ray Diffraction (XRD), Attenuated Total Reflectance–Fourier Transform-Infrared Spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), petrographic analysis, X-ray Fluorescence spectroscopy (XRF) and Pyrolysis–Gas Chromatography–Mass Spectrometry (Py-GC-MS). The composition of the mortars has been determined and is in accordance with previous research in traditional materials used in the Nepalese architecture. Chromatographic techniques proved to be particularly important in the analysis of mortars with organic binders as they revealed the possible composition of the binding media, providing additional information valuable for the future conservation/restoration of the stone monuments of the ‘City of Temples’.

The article presents an overview of the methods of producing alternative building materials by strengthening soils with organic binders based on synthetic resins. Their use in road construction would meet the needs of construction organizations in high-quality building materials and ensure reliable operation of soil masses of subgrade road transport structures throughout estimated service life. The authors proposed a new, alternative method for soil stabilization using urethane foam sealants, which have proven themselves in civil engineering in the form of mounting foams. The paper describes a method for strengthening soil with sealants, its labor production technology, properties and physical and mechanical characteristics. The results of the trial experience of soil strengthening with polyurethane foam sealant are described and conclusions are made based on the work.

Recently, some major changes have occurred in the structure of the European foundry industry, such as a rapid development in the production of castings from compacted graphite iron and light alloys at the expense of limiting the production of steel castings. This created a significant gap in the production of heavy steel castings (exceeding the weight of 30 Mg) for the metallurgical, cement and energy industries. The problem is proper moulding technology for such heavy castings, whose solidification and cooling time may take even several days, exposing the moulding material to a long-term thermal and mechanical load. Owing to their technological properties, sands with organic binders (synthetic resins) are the compositions used most often in industrial practice. Their main advantages include high strength, good collapsibility and knocking out properties, as well as easy mechanical reclamation. The main disadvantage of these sands is their harmful effect on the environment, manifesting itself at various stages of the casting process, especially during mould pouring. This is why new solutions are sought for sands based on organic binders to ensure their high technological properties but at the same time less harmfulness for the environment. This paper discusses the possibility of reducing the harmful effect of sands with furfuryl binders owing to the use of resins with reduced content of free furfuryl alcohol and hardeners with reduced sulphur content. The use of alkyd binder as an alternative to furfuryl binder has also been proposed and possible application of phenol-formaldehyde resins was considered.