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In the production of cast aluminum automotive parts, cores made of sand and binders are often used to create the complex features that cannot be formed by the mold, such as internal passages. Core binders can be grouped into two different categories: organic and inorganic, depending on the binder system used. Conventional organic binders use petroleum-based materials that are sources of harmful gases. In contrast, inorganic binders such as sodium silicates (water glass) are environmentally friendly. The fabrication of inorganic cores requires a drying step that involves thermal dehydration (using hot box and hot air injection) and chemical reactions (polymerization) to give the sand core the necessary strength to withstand the constraints developed during core storage and the casting process. This drying step increases the duration of the process and affects the production line. This study evaluated different thin layer drying models to understand the drying behavior of sand cores in the inorganic process that uses both hot air and warm box. The Page model was found to best describe the drying kinetics based on experimental measurements on a rectangular core. The sorption properties of the core were determined by characterizing the desorption isotherms at three different temperatures. The energy required to remove water from the core was estimated and it is found that the highest energy reached a theoretical maximum at a box temperature of around 135 °C. [ABSTRACT FROM AUTHOR]

The foundry industry is responsible for the production of several potentially polluting and hazardous compounds. One of the major sources of pollution is the use of organic binders for the manufacturing of sand cores and sand moulds. To address this problem, in recent years, the use of low-emission products, known as inorganic binders, has been proposed. Their use in ferrous foundries, otherwise, is limited due to some problematic features that complicate their introduction in the manufacturing process, as often happens when a breakthrough innovation is introduced. In light of this, the aim of this work is to provide a Green Innovation Practice (GIP) to manage the introduction of green breakthrough innovations, as previously described, within an existing productive context. This practice was applied to better manage the experimental phase of the Green Casting Life Project, which aims to evaluate the possibility of using inorganic binders for the production of ferrous castings. After describing the state of the art of GIPs and their application in manufacturing contexts, the paper described the proposed GIP and its application to a real case consisting of testing inorganic binders in a ferrous foundry. [ABSTRACT FROM AUTHOR]

Many years of foundry practice and much more accurate analytical methods have shown that sands with organic binders, in addition to their many technological advantages, pose risks associated with the emission of many compounds, including harmful ones (e.g., formaldehyde, phenol, benzene, polycyclic aromatic hydrocarbons, and sulfur), arising during the pouring of liquid casting alloys into molds, their cooling, and knock-out. The aim of this research is to demonstrate the potential benefits of adopting inorganic binders in European iron foundries. This will improve the environmental and working conditions by introducing cleaner and more ecological production methods, while also ranking the tested binders studied in terms of their harmful content. The article pays special attention to the analysis of seven innovative inorganic binders and one organic binder, acting as a reference for emissions of gases from the BTEX (benzene, toluene, ethylbenzene, and xylenes) and PAHs (polycyclic aromatic hydrocarbons) groups and other compounds such as phenol, formaldehyde, and isocyanates (MDI and TDI) generated during the mold pouring process with liquid metals. The knowledge gained will, for the first time, enrich the database needed to update the Reference Document on The Best Available Techniques for the Smitheries and Foundries Industry (SF BREF). [ABSTRACT FROM AUTHOR]

Inorganic materials form an emerging class of water‐soluble binders for battery applications. Their favourable physicochemical properties, such as intrinsic ionic conductivity, high thermal stability (>1000 °C), and compatibility to coat a diverse range of electrode materials make them useful binders for lithium‐ion and sodium‐ion batteries. Li and Na containing phosphates and silicates are attractive choices as multifunctional inorganic aqueous binders (IABs). This review discusses these binders' structural, thermal, and ionic properties, followed by exploiting their ionically conducting nature for all‐solid‐state batteries. Subsequently, the application of these compounds as binders and surface coating agents for different anodes and cathodes in lithium‐ion and sodium‐ion batteries is discussed. Eventually, a first evaluation of their environmental impacts and economic aspects is presented as well. [ABSTRACT FROM AUTHOR]

The paper provides an overview of selected scientific articles presenting research carried out in recent years on methods for producing autoclaved aerated concrete. Traditional technologies are briefly presented, together with innovative solutions for the production of low-density and ultra-lowdensity materials. In addition to the presentation of the manufacturing methods themselves, the results of research into the properties of the autoclaved aerated concrete obtained and their dependence on the technology used are also presented. A subjective selection and review of articles covering research into the thermal conductivity of concrete, the technological factors influencing them and the ways in which they can be shaped was also carried out. A significant number of the cited articles do not function in the world scientific circulation due to the language barrier (they are mainly in Ukrainian). In the meantime, they contain interesting research results which can inspire further research into the issues discussed concerning the production technology and the thermal and strength properties of autoclaved aerated concrete, with particular emphasis on lightweight and ultra-lightweight concrete.

The foundry industry is responsible for the production of several potentially polluting and hazardous compounds. One of the major sources of pollution is the use of organic binders for the manufacturing of sand cores and sand moulds. To address this problem, in recent years, the use of low-emission products, known as inorganic binders, has been proposed. Their use in ferrous foundries, otherwise, is limited due to some problematic features that complicate their introduction in the manufacturing process, as often happens when a breakthrough innovation is introduced. In light of this, the aim of this work is to provide a Green Innovation Practice (GIP) to manage the introduction of green breakthrough innovations, as previously described, within an existing productive context. This practice was applied to better manage the experimental phase of the Green Casting Life Project, which aims to evaluate the possibility of using inorganic binders for the production of ferrous castings. After describing the state of the art of GIPs and their application in manufacturing contexts, the paper described the proposed GIP and its application to a real case consisting of testing inorganic binders in a ferrous foundry.

In this article, aiming at the problems of low mechanical properties and the unstable structure of the binder in inorganic artificial stone, performance improvements were studied. The effects of 12 materials of blast-furnace slag (BFS), fly ash (FA), and kaolin on the properties and microstructure of inorganic binders were systematically studied and analyzed. As a result, the compressive strength of BFS-2, FA-1, and FA-2 binder was increased by 10.0, 6.0, and 1.5%, and the flexural strength was increased by 44.8, 79.2, and 1.3%, respectively. It was worth noting that BFS and FA could effectively promote hydration reactions due to active materials and boost the growth of C–S–H and CH, leading to the inorganic binder forming a stable structure. Thus, this work systematically designs and prepares inorganic binders with high compressive strength and excellent flexural strength. This reveals how inorganic materials affect the properties of inorganic binders on the microstructure and offer a new idea for the development of this field.

Reusing waste is essential for the sustainability of the planet. Among the waste, we highlight agricultural limestone classified granulometrically as filler. The present work tested pharmaceutical, food and inorganic binders, capable of producing briquettes that withstood at least 75 drops of 1.2 m and a minimum dissolution time in water at 25 °C of 8 h, presenting a lower cost (in dollars per gram) of the binder. The objective is that this briquette produced with limestone filler and binder has the possibility of being used as organomineral fertilizer. The most promising binder was xanthan gum, which produced briquettes capable of withstanding up to 300 drops of 1.2 m, 11.67 h of dissolution in water at 25 °C, at a cost of US$ 0.078/g. [ABSTRACT FROM AUTHOR]

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The results of studies on the effect that the type of binder and casting technology exert on the microstructure and properties of AlSi7Mg alloy castings are discussed in this paper. Comparative tests were carried out on three casting manufacturing technologies, i.e., conventional sand mould casting and cooling process, metal mould (die) casting, and sand mould casting with ablation breakdown of mould and cooling of castings. Moulds were made from four different sand mixtures with inorganic binders hardened by various technologies. The microstructure of test castings was examined at three different levels, i.e., in the upper part, central part, and lower part of each casting. The tensile test at room temperature was carried out in accordance with standards. The experimental results showed differences in the microstructure of castings. The differences resulted from changes in the crystallisation path due to the use of three different casting technologies, ensuring different rates of heat dissipation from castings; they were also due to the shape of castings. It has been shown that castings made by ablation technology are characterised by a high degree of the microstructure refinement (SDAS reduced by 18–30%), which gives higher strength properties than the properties of castings made in conventional sand moulds. Samples taken from castings made by the ablation technology in moulds with phosphate binder and microwave-hardened geopolymer binder were characterised by the mechanical properties comparable to gravity die castings. [ABSTRACT FROM AUTHOR]

The aim of the present work is to compare the properties of self-hardening moulding sands based on inorganic binders based on sodium silicate of different modules, geopolymer binders and phosphate binders and to prove they can be used in the ablation casting process. Ablation casting is a process in which, directly after pouring the liquid alloy, the mould is sprayed with water until it is completely eroded and a finished, cooled casting is obtained. The use of proecological water-dilutable binder makes it possible to recover the sand matrix after drying the suspension that remains after the process. Moulding sands were prepared on the basis of four inorganic binders available on the market. For each of the moulding sands the bending strength was tested after 1, 2, 4 and 24 h of hardening. Then, the masses with optimum bending strength were selected and subjected to gas emissivity tests. A thermal analysis of moulding sands selected for testing was also carried out in order to determine the loss of mass during annealing. The susceptibility of moulds to erosion under the influence of ablative medium was also assessed by measuring the time of mould erosion. Tests showed the possibility of using self-hardening moulding sands based on inorganic binders for the ablation casting process of aluminium-silicon alloys. [ABSTRACT FROM AUTHOR]

Mechanical and thermal properties and moisture and water resistance of composites based on an inorganic binder, modified potassium salt of polysilicic acid ("liquid glass") reinforced with basalt and linen felts and basalt cardboard were measured. The possibility of giving the sheet material an embossed shape is shown. It is concluded that the studied composites, according to the obtained characteristics and manufacturing technology, can have practical applications. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) could be utilized for a wide range of applications such as sorption, catalysis, chromatography, energy storage, sensors, drug delivery, and nonlinear optics. However, to date, there are very few examples of MOFs exploited on a commercial scale. Nevertheless, progress in MOF-related research is currently paving the way to new industrial opportunities, fostering applications and processes interconnecting fundamental chemistry with engineering and relevant sectors. Yet, the fabrication of porous MOF materials within resistant structures is a key challenge impeding their wide commercial use for processes such as adsorptive separation. In fact, the integration of nano-scale MOF crystallic structures into bulk components that can maintain the desired characteristics, i.e., size, shape, and mechanical stability, is a prerequisite for their wide practical use in many applications. At the same time, it requires sophisticated shaping techniques that can structure nano/micro-crystalline fine powders of MOFs into diverse types of macroscopic bodies such as monoliths. Under this framework, this review aims to bridge the gap between research advances and industrial necessities for fostering MOF applications into real life. Therefore, it critically explores recent advances in the shaping and production of MOF macro structures with regard to the binding materials that have received little attention to date, but have the potential to give new perspectives in the industrial applicability of MOFs. Moreover, it proposes future paths that can be adopted from both academy and industry and can further boost MOF exploitation.

Since recycled technologies usage is mandatory for environmental safety, and in this regard, it is important to examine new materials that can be used in construction and are primarily produced from fly ash. In addition to characteristics such as hardness and compressive strength, the given materials must also be radiologically and environmentally safe. The main concept of engineered geopolymer gel composites based on fly ash residues is focused on developing binder materials via gel formation processes that can replace ordinary cement materials. This study is unique in researching the potential use of fly ash from the Nikola Tesla thermal power plant in Serbia, where the hybrid geopolymeric materials synthesized from fly ash are experimentally examined with the addition 1 wt% and 2 wt% of polyvinyl alcohol (PVA). This paper aims to investigate the structural, morphological, mechanical, and radiological properties of hybrid materials with the addition of PVA and without additive in the period of ageing for 28 days at room temperature. The phase composition was investigated using X-ray powder diffraction (XRPD) analysis, while morphological characteristics of these materials were examined using scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDS). Vibrational spectra of obtained samples are investigated using diffuse reflectance infrared Fourier transform (DRIFT) and Fourier transform infrared (FTIR) techniques. The hardness and compressive strength are also examined, indicating that the 1 wt% addition in geopolymeric matrix results in the best mechanical properties. Radiological measurements of investigated all geopolymer samples show decreasing activity concentrations of radionuclides for 50% compared to fly ash.

The production of cores for the pre-casting of holes in castings places high demands on the quality of the molding mixtures used. For this reason, organic binders are still used to a large extent, which, although they meet the technological requirements, are a source of pollutant emissions during the production of castings. The current trend towards greening production is therefore looking for a suitable alternative in ‘green’ inorganic binders. Although for many decades standard inorganic binders could not be compared with organic resins in terms of technological properties, new inorganic binder systems are currently being developed that can largely eliminate these disadvantages, which include, in particular, significantly lower collapsibility and reclaimability, and lower mechanical strength values. Last but not least, the use of these binder systems may be limited by the technological parameter of shelf-life, which is the main focus of this study. The aim of this paper is to evaluate the influence of technological parameters of core production using a new generation of inorganic binder systems on their shelf-life. Shelf-life, defined as the change in mechanical strength and wear resistance as a function of exposure time in a given environment, is evaluated under different climatic conditions.

This study shows the results of the investigation of the strength performance, and residual strength of a single component inorganic binder system Cast Clean S27®. The study was conducted using three different foundry sand sources in South Africa. Sample A is an alluvial coastal sample, sample B is an alluvial riverbed sample and Sample C is a blasted sample from a consolidated quartzite rock. The binder was also cured using three different curing mechanisms. The aim of the investigation was to determine the variation of strength performance and residual strength between the different South African sand sources based upon the physical and chemical properties of the sand sources. The moulding sand was prepared using three possible curing mechanisms which are carbon dioxide curing, ester curing and heat curing. The strength measurements were determined by bending strength. Sample A and sample C sand had good strength development. Sample B sand had inferior strength development and excellent high temperature residual strength. The study showed that the single component inorganic binders have good strength development and low residual strength. The silica sand properties have major contributing factors on both strength development and residual strength. The degree of influence of silica sand properties on strength performance and residual strength is dependent on the time of curing and method of curing.

The authors consider some aspects of production of inorganic heat-resistant composite materials in which new classes of inorganic binders - the basic salts of various metals – are applied. The possibility to use hydroxochlorides and hydroxonitrates of aluminum, zirconium, chromium and a number of other metals as the binder has been shown. The main products of the thermal decomposition of all types of binders discussed in this paper are nano-dispersed highly refractory oxides. Increased pressure in the manufacture of these materials shifts the position of the minimum of the dependence «production strength – production temperature» in the direction of low temperatures. This effect is caused by decreased film thickness of the binder located between filler particles and hence by increased rate of transfer of the matter to the interface and by facilitated sintering process. Materials based on the systems containing chromium and some other elements in transitional oxidation states are colour. For this reason, they have the worst thermal conductivity under the same heat resistance compared to colorless materials.

Methods are determined for the production of noncombustible reinforced materials of general purpose based on the use of oligomeric inorganic polyoxides and reinforcing fillers, as well as the molding of products under mild conditions. By the example of a chemically modified potassium salt of polysilicic acid ("liquid glass") and technical fabrics of various nature, the possibility of obtaining thin-walled noncombustible composite materials is considered. A technology for molding the composites is developed, and their mechanical and thermal properties, including resistance to atmospheric moisture and combustibility, are studied. [ABSTRACT FROM AUTHOR]

Infiltration is an important issue for unidirectional carbon fiber-reinforced aluminum matrix (CF/Al) composites. In the present study, aluminum dihydrogen phosphate (ADP) and silica sol were used to prepare CF preforms, then CF/Al composites were prepared by simulated horizontal continuous casting. The results showed that silica sol significantly affects the curing process of ADP. When the content of silica sol is 50 % and heated at 500 °C, the product transformed from Al(PO 3) 3 (cubic system) to an amorphous phase with good thermostability. The mixture binder can fully fill the gaps between CFs, leading to a dense CF preform. The obtained CF/Al composite has a good bonding interface between Al and CFs, without pores or crack defects, and thus shows an obvious enhancement in tensile strength of 64.9 MPa, which is 34.6 % improved compared with that of CPAl. The CF/Al composites also maintained a good electrical conductivity of 56.9 % IACS, similar to that of CPAl. [Display omitted] • The CF/Al composite by inorganic binder has an 34.6 % improvement in UTS without degradation in conductivity compared to CPAl. • Inorganic binder pretreatment has a simplified process with less chemicals. • The curing product has good thermostability. [ABSTRACT FROM AUTHOR]

Ductile cast iron (GS) has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

This paper discusses methods for producing of heat-resistant inorganic composite materials, using new classes of inorganic binders, which are the basic salts of various metals. There is demonstrated the possibility of using hydroxo-chlorides and hydroxo-nitrates of aluminum, zirconium, chromium and other metals as binder. The main products of the thermal decomposition of all types of binders discussed in this paper are nanodispersed high-refractory oxides. [ABSTRACT FROM AUTHOR]

• Previous research on the strengthening of RC beam with FRCM is analyzed. • Failure modes of strengthened beams are highlighted. • The performances of strengthened elements with FRCM at high temperatures are reviewed. Strengthening and rehabilitation of structural element are inevitable and the strengthened concrete structural elements are primarily used to increase the life span of deteriorated structures by complying with the updated design code and regulation. Fiber Reinforced Polymer (FRP) technique is used for repairing and strengthening concrete structures, due to the properties of FRP such as light weight, high strength, corrosion refusal and easy to oversee. The organic binder resins used along with FRP have their own shortcomings due to which inorganic binders like cementitious mortars are used along with FRP as replacement for strengthening the structural members. They are commonly denoted as Fabric Reinforced Cementitious Matrix (FRCM). Inorganic binders consist of cement mortar added with any of the industrial by-products such as fly ash, ground blast-furnace slag, silica fume etc., and relevant polymers are added to increase the bond strength virtues. The FRCM can withstand high thermal conditions and exhibits better compatibility with the concrete surface. This paper aims to provide comprehensive details about the structural strengthening using inorganic bonding agent along with FRP under common practical conditions. [ABSTRACT FROM AUTHOR]

Abstract: In the production of zeolite-based adsorbents the inorganic binders such as bentonite and kaolin are normally used to extrude the solid in different shapes such as Raschig ring. In this investigation, statistical combinations of a three-component mixture were designed to achieve synergetic values of mechanical characteristics and lead removal efficiency. The adsorbents in the form of Raschig ring were shaped by a single screw extruder and calcined at different temperatures after drying in laboratory oven. The adsorbent properties such as porosity, compressive strength and removal efficiency were measured. The response surface algorithm was applied to analyze the obtained data. The feasibility of Weibull statistical theory was examined to determine the reliability of adsorbents. The results were very satisfactory for characterizing and predicting the reliability and manufacturing technical factors. The best calcination temperature was determined to simultaneously optimize removal efficiency and mechanical characteristics. However, the Weibull modulus should be considered for fabricating reliable adsorbent. According the laboratory experiments and statistical algorithms used in this study, the suitable combination region in which the ring acts as a good adsorbent were determined. It is concluded that the use of these procedures can be important tools to manufacture reliable adsorbent. The obtained results were confirmed by scanning electron microscopy observations. [Copyright &y& Elsevier]

Abstract: The article presents the structural, technological and ecological features of the new type of silicate binders. The binders are used in foundry practice to produce moulds and cores, especially for castings made from non-ferrous metal alloys. The nanostructure of binders was described, i.e. the size and decay of nanoparticles of the diffuse binder phase. The technological research showed the beneficial mechanical properties of moulding sands prepared with these binders at both ambient temperature and at temperatures of up to 900oC (the residual strength), compared to the moulding sands with traditional silicate binders. The residual strength of moulding sands with the new binder decreased by about 50% at 800oC. The results of comparative chromatography of the thermal emission rate of harmful gases and odours were examined for moulding sands with new silicate binders and with organic binders. [Copyright &y& Elsevier]

Metal–organic frameworks (MOFs) could be utilized for a wide range of applications such as sorption, catalysis, chromatography, energy storage, sensors, drug delivery, and nonlinear optics. However, to date, there are very few examples of MOFs exploited on a commercial scale. Nevertheless, progress in MOF-related research is currently paving the way to new industrial opportunities, fostering applications and processes interconnecting fundamental chemistry with engineering and relevant sectors. Yet, the fabrication of porous MOF materials within resistant structures is a key challenge impeding their wide commercial use for processes such as adsorptive separation. In fact, the integration of nano-scale MOF crystallic structures into bulk components that can maintain the desired characteristics, i.e., size, shape, and mechanical stability, is a prerequisite for their wide practical use in many applications. At the same time, it requires sophisticated shaping techniques that can structure nano/micro-crystalline fine powders of MOFs into diverse types of macroscopic bodies such as monoliths. Under this framework, this review aims to bridge the gap between research advances and industrial necessities for fostering MOF applications into real life. Therefore, it critically explores recent advances in the shaping and production of MOF macro structures with regard to the binding materials that have received little attention to date, but have the potential to give new perspectives in the industrial applicability of MOFs. Moreover, it proposes future paths that can be adopted from both academy and industry and can further boost MOF exploitation. [ABSTRACT FROM AUTHOR]

The production of cores for the pre-casting of holes in castings places high demands on the quality of the molding mixtures used. For this reason, organic binders are still used to a large extent, which, although they meet the technological requirements, are a source of pollutant emissions during the production of castings. The current trend towards greening production is therefore looking for a suitable alternative in 'green' inorganic binders. Although for many decades standard inorganic binders could not be compared with organic resins in terms of technological properties, new inorganic binder systems are currently being developed that can largely eliminate these disadvantages, which include, in particular, significantly lower collapsibility and reclaimability, and lower mechanical strength values. Last but not least, the use of these binder systems may be limited by the technological parameter of shelf-life, which is the main focus of this study. The aim of this paper is to evaluate the influence of technological parameters of core production using a new generation of inorganic binder systems on their shelf-life. Shelf-life, defined as the change in mechanical strength and wear resistance as a function of exposure time in a given environment, is evaluated under different climatic conditions. [ABSTRACT FROM AUTHOR]

• Multi-step reaction of potassium silicate solutions with aluminum metaphosphates. • Binder performance in correlation to alkali modulus and metaphosphate modification. • Improved mechanical strength with decreasing alkali modulus. • Improved acid resistance with increasing alkali modulus. In this study the interaction of the chemically initiated setting of potassium silicate solutions with aluminum metaphosphates was investigated in terms of the structural analysis. The mechanism occurs in a multi-step reaction involving the depolymerization of the cyclic phosphate structure yielding to different phosphates and hydrogen phosphate structures which mainly are formed with potassium ions of the silicate solution. The setting of the potassium silicate solutions is activated by the loss of potassium ions which drop of pH value which initiates the cross connection of the silicate framework. At the same time aluminum ions are incorporated into the setting of the amorphous alumosilicate silicate network. Correlating the phase composition in respect to the alkali modulus of the potassium silicate solution and the ring size of the aluminum metaphosphate gives an insight into the performance of the binder system. [ABSTRACT FROM AUTHOR]