Fluxing Agent Research Articles

Application of the container waste glass in foamed glass production

We report on foamed glass production from container glass cullet, foaming couple carbon/Mn3O4, and crystallization inhibitors (fluxing agents, aluminum oxide and phosphates) under an oxygen-free atmosphere. We study the influence of the content of the inhibitors on the density, porosity, crystallinity, and thermal conductivity of the foamed samples. We observe that the amounts of fluxing agents determined to effectively decrease the crystallization (5 wt%) prevent effective foaming and were thus decreased. By decreasing the content of the fluxing agent to 2 wt%, the densities of the foamed samples are decreased. With the addition of phosphates to the mixtures, crystalline content, open porosity and thermal conductivity are decreased. However, the obtained foamed samples remain mainly open porous with density and thermal conductivity in the ranges 140–168 kg m−3 and 57–66 mW m−1K−1, respectively.

Transformation of Physical Characteristics in Fired Clay Bricks by Adopting Waste-based Fluxing Agent

The current practices in the recent development of fired clay brick (FCB) by adopting waste materials have tremendously reduced the usage of the primary source of FCB, which is clay soil (CS). In this study, the main objective is to reduce the utilisation of CS as the main component in the FCB-making process. Other waste materials such as soda lime silica (SLS) glass bottles, and sea shells (SS) were also added into the precursor admixtures. The admixtures containing CS, SLS and SS were mixed according to the empirical formula of (1-x)[40SLS - 60CS]: x[SS] = 0, 10, 20, 30, 40 wt.%. A batch of 40 g mixture was prepared, and 21% water was added. The admixtures were mixed, moulded into a rectangular brick shape, and dried before the sintering process at 850 °C. The physical properties of the FCB were investigated as a function of the SS content in the form of apparent density, linear shrinkage, loss of ignition and plasticity. As a result, the apparent density and loss of ignition of the FCB increased from 1.91 gcm-3 to 2.31 gcm-3 and 10.60 % to 20.81%, respectively. The linear shrinkage and plasticity percentage decreased from 2.50% to 2.27% and 11.01% to 8.70% with an increase of SS content. This study has uncovered the above findings, and has demonstrated a promising discovery of the SS as a possible substitute in FCB.

Study on recycling Si from silicon diamond-wire saw cutting waste by a slag refining process in industrial scale

Silicon cutting waste (SCW) produced during silicon wafer producing process mainly consists of Si (80–85 wt%), SiO2 (13–16 wt%) and other impurities (2–4 wt%). In this paper, a slag refining process was proposed to recycle Si from SCW for producing high-quality silicon. CaO was used as fluxing agent to react with SiO2 for forming compounds with low melting point and viscosity during recycling process. The influences of CaO addition amount and refining time on recovery ratio of SCW and purity of Si products were investigated. Under the optimized conditions of a CaO addition amount of 8 wt% and a refining time of 50 min, the recovery ratio of SCW and the purity of Si products can achieve 59.59% and 99.56%, respectively, in laboratory-scale experiments. The separation mechanism of Si from SCW is that the external SiO2 film is digested by CaO, and then the internal Si is exposed and melted into liquid Si. This method was successfully applied for recycling Si from SCW in industrial-scale and the recovery ratio of SCW can reach 60%. Economical evaluation shows that this method can bring enormous economic benefit ($0.98/kg SCW).

Application of factorial model for an optimization of partial replacement of feldspar by talc on the sintering process

AbstractThis research used a factorial model containing two levels and three variables to evaluate the partial substitution of sodium feldspar (albite) by a talc ore found in abundance in the region of Itaiacoca—Brazil. The model can also be used to verify the influence of initial talc particle size, proportion, and sintering threshold temperature on the following physical properties, such as linear shrinkage, water absorption, bulk density, total porosity, and firing color. In this study, the mechanical strength of the compositions was evaluated by the flexural strength test. The factorial model indicated the sintering temperature as the variable that most affects the samples’ densification and the proportion of talc as the variable that changes the firing color. The experiment that used a higher sintering temperature combined with a coarser talc granulometry presented the highest mechanical strength. When more refined granulometry was used, there was the beginning of an overfire process. Water absorption values in the range of .04% and modulus of rupture of 49 MPa were obtained, confirming the talc's effectiveness as a secondary flux agent suitable for the formulation of ceramic bodies.

Optimization of metals degradation and vitrification from fly ash using Taguchi design combined with plasma pyrolysis and recycling in cement construction

Fly ash has been widely recognized as the hazardous waste due to its toxicity to environment. It should be treated properly for preventing the high contamination to the environment and generate volatile organic compounds (VOCs) from the pyrolysis treatment. The aim of this study is to investigate the most influenced parameters in elimination of elements, vitrification and destruction of volatile organic compounds (VOCs) from the fly ash via a plasma pyrolysis with the combination of Taguchi method and recycling it into the cement construction, which potentially applied in the real application. The combination of fly ash treatment with CaCO3, SiO2, Al2O3 and glass gives the high removal efficiency of VOCs at 4.653 ppm under the nitrogen plasma. Furthermore, the gas flow rate has the most significant impact on the destruction of elements based on the Taguchi analysis. The best removals of element are known as follows: Hg>Cd>Se>As>Cr>Pb>Cu. Lastly, compressive test of the cement at age 28 days with the substitution of 10% fly ash confirmed greater result on cement quality. The most influenced parameter, namely gas flow rates with the combination of flux agents are thus suggested for degrading harmful elements and VOCs. Fly ash from plasma post-treatment has the potential for replacing the cement material when used in the construction material to implemented the recycling concept.

Rejuvenating Agents vs. Fluxing Agents: Their Respective Mechanisms of Action on Bitumen Subjected to Multiple Aging Cycles

During the service life of road pavements, the asphalt, more specifically the surface layer, is susceptible to aging due to the oxidation phenomenon and the loss of the volatile compounds of bitumen, which functions as the binder in the asphalt conglomerate. Road pavements that undergo a significant level of oxidation become rigid and susceptible to cracking, and new paving operations will need to be carried out in order to make the road ideal for continued use. However, due to recent eco-friendly initiatives that have been put in place to promote a circular economy and also mitigate the problem of environmental pollution, the asphalt industry is currently devising means of safeguarding the environment while also minimizing the cost of the production of road pavements without compromising their quality. As a general solution to this issue, old asphalt pavements are removed and recycled as reclaimed asphalt (RA), with the aim of restoring the original properties of the binder in such a way that RA can be re-used in combination with virgin materials to produce new road pavements. In this research study, virgin bitumen is subjected to a cycle of aging, after which two recycling agents are used to modify the aged bitumen samples. These samples containing the different recycling agents were subjected to a second aging cycle, a second recycling agent treatment, and then again subjected to a final aging cycle. The two recycling agents have different compositions, and each one of them could be either a rejuvenating agent or a fluxing agent. This study investigates the effect of these recycling agents on aged bitumen, and how the addition of these recycling agents influences the changes observed between virgin, aged and recycled bitumen. This would enable an understanding of rejuvenation and fluxing mechanisms, which will help in the classification of the asphalt recycling agents as either rejuvenating or fluxing agents. Dynamic shear rheology, atomic force microscopy, and light microscopy to determine asphaltene melting point were the techniques used in this investigation. The results obtained demonstrate that rejuvenating agents are more effective in reversing the effects of oxidative aging on the bitumen binder than fluxing agents.

Management of Repeated Denture Fracture Through Direct Metal Laser Sintering Metal Reinforced Denture

Direct Metal Laser Sintering (DMLS) is a type of additive metal production that is simpler, more precise, and healthier than traditional manufacturing, while being highly cost-effective. In this process, the metal powder which is free of binder or fluxing agent, is completely melted by the scanning of a high-power laser beam. The resulting part has properties like the original material. In removable prosthodontics, the fracture of heat cure acrylic resin dentures is an unsolved problem. The most common issue is a midline fracture of the maxillary denture. Among midline fractures, 71% were reported in maxillary complete dentures and 29% in mandibular dentures. Patients with heavy masticatory loads and those with parafunctional habits are more likely to experience this. In such circumstances, a metal framework base improves a prosthesis’s fracture resistance, stability, and retention. A 45- year-old female patient reported with a chief complaint of repeated fracture of maxillary complete denture and gave the history of midline fracture of upper denture three times in last 2 years. Intraoral examination revealed v shaped deep hard palate and severely resorbed mandibular ridge. DMLS metal reinforced maxillary denture and metal mesh reinforced mandibular denture was planned to prevent fracture of the denture in future. Metal framework reinforcement of complete denture is a simple, quick, and cost-effective technique to decrease the chances of denture fracture in future, thus beneficial for both patient and the dentist. One year follow-up has been done and patient is comfortable with the denture.

Preparation and Study of Borosilicate Foam Glass with High Thermal Insulation and Mechanical Strength

Foam glass is a kind of green building material that is widely used because of its excellent thermal insulation and mechanical properties. In this study, the borosilicate foam glass was fabricated by powder sintering method using recycled soda lime waste glass, quartz, and borax as the primary raw materials. CaCO3 was used as a foaming agent and Na2CO3 as a flux agent. Results showed that as the quartz content decreases from 30 to 17.5 wt.% and borax content increases from 5 to 17.5 wt.%, the pore size, porosity, and thermal insulation of borosilicate foam glass increase significantly, while the compressive strength decreases slightly. When the content of quartz and borax are both 17.5 wt.%, borosilicate foam glass with outstanding performance can be prepared, whose pore distribution is uniform, mean pore size is 1.93 mm, total porosity is 83.44%, thermal conductivity is 0.0711 W/(m⋅K), and compressive strength is 2.37 MPa. Finally, the influences of foaming agent content, flux agent content, foaming temperature, and holding time on the pore structure and various properties of borosilicate foam glass were investigated by orthogonal test. According to the results, the foaming temperature has a significant effect, and appropriate foaming agent content, flux agent content, and holding time help to form a uniform pore structure, thereby improving the thermal insulation and mechanical strength of the borosilicate foam glass.

Glass from Islamic Sicily: typology and composition from an urban and a rural site

As part of the Sicily in Transition and GlassRoutes projects glass, artefacts from various medieval Sicilian sites have been analysed by LA-ICP-MS. This made it possible to collect data on the circulation of glass on the island in the Middle Ages. The comparison of the data from the coastal town of Mazara with those from the rural area of Castronovo di Sicilia allowed us to establish a continuity in the supply of fresh Levantine glass to the island as late as the end of the 7th century. The results also point to a possible role of urban centres in the redistribution of goods to the hinterland in the 8th century. During this period, the Castronovo area was supplied by imports of fresh glass from the Levant and Egypt, from regions that were part of the Umayyad caliphate. The 10th- to 11th-century glass assemblages from both sites shows a considerable Islamisation of Sicilian material culture, with typologies reminiscent of what is known from Egypt, Ifrīqiya and the Iberian Peninsula. The discovery of a compositional group at both Mazara and Castronovo, which differs from published data from other areas of the Mediterranean basin, also suggests a Sicilian origin of these objects. Islamisation is thus also evident in the adoption of production technologies typical of the Islamic world, such as the use of soda-rich plant ash as a fluxing agent.

Pulse High Temperature Sintering to Prepare Single‐Crystal High Nickel Oxide Cathodes with Enhanced Electrochemical Performance (Adv. Energy Mater. 3/2023)

Metal-Oxide Cathodes In article number 2203188, Hong Li, Jieshan Qiu, Weidong Zhou and co-workers develop a pulse high temperature sintering strategy for the preparation of single crystal high nickel NCM(LiNixCoyMn1−x−yO2), without using a fluxing agent or changing the current production line. With the help of the single crystal NCM, tap density is increased by a third and the internal micro-cracks are effectively suppressed, improving cycling life and safety performance.

Biomass Hierarchical Porous Carbonized Typha angustifolia Prepared by Green Pore-Making Technology for Energy Storage.

The cost-effective biomass-derived carbon with high electrochemical performance is highly desirable for the sustainable development of advanced energy storage devices. In this manuscript, Typha angustifolia with a large output and loose porous characteristics was selected as the raw material of biomass. In the synthesis process, KHCO3, which is more environmentally friendly, is used as a pore-forming agent, and the low-cost, easy-to-clean fluxing agent NaCl is used to assist the pore-forming process. Based on the analysis of thermogravimetric-infrared test results, the calcination procedure of porous carbon was designed reasonably, so that the functions of the pore-forming agent and fluxing agent could be fully exerted. Its high electrochemical performance is attributed to combined contributions from high surface area and hierarchical porous structures. The as-prepared carbon also showed an outstanding capacitance of 317.2 F/g at a current density of 1 A g-1 and a high capacitance retention of over 97.83% after 5000 cycles at a current density of 4 A g-1. This work provides an outstanding renewable candidate and a feasible route design strategy for the fabrication of high-performance electrodes.

Metal tools of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol: chemical and metallurgical characteristics

In this paper, the chemical composition of tools and ingots of the Petrovka Culture of the Southern Trans-Urals and Middle Tobol region is characterized with identification of main recipes of the alloys using several analytical methods (spectral, X-ray fluorescence, and atomic emission spectrometry analyses carried out in the laboratories of the Institute of Archaeology of the Russian Academy of Sciences and the Institute of Inorganic Chemistry of the Si-berian Branch of the Russian Academy of Sciences). The complexes of the Petrovka Culture of the Sou-thern Trans-Urals have been dated by a set of AMS 14C dates to 19th–18th centuries BCE. Recently introduced in the scientific discourse 27 AMS 14C dates (settlement of Stepnoe and burial grounds of Stepnoe 1, 7 and 25) established an ear-lier interval of the Petrovka series — 2133–1631 BCE and point to the synchroneity of the cultures at the northern periphery of the Sintashta area in the local micro-region of the Southern Trans-Urals. The results of the analytical study of 106 metal tools and 70 ingots of the Petrovka Culture of the Southern Trans-Urals and south of Western Siberia are reported. The statistical processing of the analytical results with plotting correlation diagrams of Sn–As, Sn–Pb, As–Ag, As–Sb, and a frequency distribution histogram for the proportions of Sn allowed casting the metal into 4 metallurgical groups — pure copper and tin, arsenic-tin and arsenic bronzes. The first group subdivided into oxide and sulfidic samples. According to the geochemical peculiarity of the metal from the metal industry centers of Ustie 1, Kulevchi 3 and Shibaevo 1, several sources of oxide-carbonated ores were utilized for copper smelting — malachite and azurite-malachite deposits, while sulfidic chalcocite-covelline ores, and sometimes chalcopyrite-pyrite depositions, were added to the melt as a flux agent. The admixture of sulfides was carried out as an experiment and was not purposeful. Petrovka metallurgists supplied copper to the workshops of the Middle Tobol region — the sites of Ubagan 1, 2, 3 and Kamyshnoe 1, 2. The centers of the Petrovka Culture of the Southern Trans-Urals were domi-nated by the production of pure copper implements, including the metal smelted from the oxidized ore. To a lesser extent, low-alloyed bronze was used — Cu+Sn, Cu+Sn+As and Cu+As, whose feedstock was supplied by the kin-dred tribes of Central and Eastern Kazakhstan in the form of ingots and finished products along the eastern part of the Trans-Eurasian transport corridor of metal trade — over the Turgay trough and further along the extensive river system of the Tobol River and its tributaries. The highest concentration of tools of alloyed bronzes was recorded in the burial grounds of the Middle Tobol, which can be explained from the point of view of the prestige value of such goods and observance of special ceremonial practices.

Warm Mix Asphalt Binder Utilizing Water Foaming and Fluxing Using Bio-Derived Agent.

The present paper investigates the effects of simultaneous mechanical foaming using water and fluxing with a bio-derived agent on the properties of three distinct asphalt binders: 50/70 paving-grade bitumen, 45/80-55 polymer-modified bitumen, and 45/80-80 highly modified asphalt binder. The testing involved classical tests for assessing binder consistency (penetration at 25 °C, ring and ball softening point, Fraass breaking point, and dynamic viscosity) as well as performance tests (high and low Superpave critical temperatures and multiple stress creep recovery). The tests included assessment directly after asphalt binder foaming and were repeated after a 14-day period. It was shown that bitumen foaming had only short-term effects on the asphalt binders, which did not persist in the repeated tests after 14 days. The fluxing agent that was utilized caused significant changes in the consistency of all asphalt binders. The changes in the performance characteristics of the 50/70 and 45/80-55 binders were severe and amounted to a significant decrease in high-temperature performance of these binders. On the other hand, an improvement in all performance characteristics in the case of the 45/80-80 asphalt binder was observed as a result of the applied processes, particularly when measured 14 days after foaming. This study shows that the simultaneous use of foaming and the fluxing additive decreased the dynamic viscosity of the 45/80-80 binder, while improving its properties relating the pavement performance.

The effect of fluxing agents and heat treatment on the leucite crystallization in bio glass–ceramic composites

The effect of fluxing agents and heat treatment on the leucite crystallization in bio glass–ceramic composites

Reclaimed asphalt recycling agents: Looking into the blueprint of their mechanisms of action

As the global environmental crisis is reaching an irreversible point, within the roadway industry, the demand for eco-friendly products such as recycled asphalt pavement is at an all-time high. As a result, and thanks to the promising advancements made in the past decades, doubts no longer exist about the benefits of asphalt recycling. However, the current issue is how to increase the proportion of reclaimed asphalt in new road paving operations. This research study deals with one of the key factors of a successful asphalt pavement recycling; the recycling agents. Several techniques were applied to investigate the mechanism of action of two recycling agents speculated to be rejuvenators and/or flux oils using two different paving grade bitumens. In order to perform a comprehensive study, the testing scheme involved rheological, microscopic, chemical, and physicochemical analyses. Although the physical changes of the aged bitumen containing the studied recycling agents were similar, the chemical impacts were quite different as suggested by the results obtained from the tests performed in this study. The results demonstrate the rejuvenator having an edge over mere fluxing agents in the reversal of the aging phenomenon in bitumen. In fact, this could be determinant in the durability and quality of recycled asphalt pavement.

The use of boron based materials on efficiency of environmentally friendly porous ceramics

In this study, the use of boron-based materials on efficiency of environmentally friendly porous ceramics was investigated. In this context, a glaze formulation was created that uses high amounts of frit and sintered at low temperatures. Boric acid and colemanite were added to glaze formulations and different alternative formulations were created by reducing the frit percentage. These materials were added to these glaze formulations in two different ways, calcined and raw. The glaze mixtures obtained from the formulations were applied on the ceramic body and fired at 950-1000-1020-1100-1200 °C in the laboratory oven. Crystal phase structures of glaze samples containing boric acid and colemanite were analyzed by X-Ray Crystallography (XRD) method. The surface properties and characterizations of the obtained samples were examined by scanning electron microscopy (SEM). Differential Thermal Analysis and Thermogravimetric analysis (DTA/TG) were performed to determine their thermal behavior and mass loss. As a result of the analysis, it was observed that boron derivatives are a good flux agent and do not have a negative effect on the surface and other technical properties of the glaze. In the formulations of glazes with high frit content and processed at low temperatures, the percentage of frit has been reduced and costs have been improved. Also, energy costs were improved with the reduction in firing temperatures. Considering the energy and raw material costs of this study, it is predicted that high efficiency will be achieved in the process.

Low-temperature sintering of CaZnSi2O6 glass ceramics with machinable precursor based on silicone rubber and enhanced mechanical strength by Bi2O3

Machinable precursors were prepared using methyl vinyl silicone rubber, kilchoanite, fluxing agents, and nano silica. CaZnSi2O6 glass ceramics were sintered using machinable precursors at temperatures ranging from 600 to 1000 ℃. The microstructure and crystal phase during the heating process were analyzed by SEM and XRD. The flexural strength and linear contraction of the ceramics were measured. The results showed that Bi2O3 improved the flexural strength above 800 ℃. When the sintering temperature was 1000 ℃, Bi2O3 improved the flexural strength by 22%, from 90.54 to 110.48 MPa. Furthermore, the linear contraction increased by 1.88%, from 15% to 16.88%. Bi2O3 provided more liquid phase above 800 ℃, which connected the grains more tightly and caused the ceramics to shrink further, so that the ceramics with Bi2O3 had a denser microstructure and higher flexural strength.

Upcycling Discarded Shoe Polish into High Value-Added Asphalt Fluxing Agent for Use in Hot Mix Paving Applications.

This research effort is geared towards revealing the latent potential of discarded shoe polish that might be repurposed as an asphalt fluxing agent for the construction of durable and sustainable road surfaces. To drive this creative invention, the effect of various proportions of waste shoe polish (e.g., 5, 10 and 15 wt. % WSP) on the performance of base AP-5 bitumen was inspected in great detail. A meticulous investigation of the chemical, physical, and rheological properties of the resultant combinations was carried out using a variety of state-of-the-art laboratory techniques, specifically: thin-layer chromatography-flame ionization detection (TLC-FID), Fourier transform-infrared spectroscopy (FT-IR), needle penetration, ring-and-ball softening point, Brookfield viscometer, ductility, flash/fire points, dynamic shear rheometer (DSR), multiple stress-creep recovery (MSCR), and bending beam rheometer (BBR) tests. The Iatroscan data disclosed that the continuous feeding of binder with WSP had a minor impact on SARA fractional distribution, regardless of aging. According to the FT-IR scan, the stepwise addition of WSP to the binder did not result in any significant chemical alterations in the blends. The combined outcomes of the DSR/BBR/empirical test methods forecasted that the partly bio-sourced additive would greatly improve the mixing–compaction temperatures, workability, and coating–adhesion properties of bituminous mixtures while imparting them with outstanding anti-aging/cracking attributes. In short, the utilization of waste shoe polish as a fluxing agent for hot asphalt mix production and application is not only safe, feasible, and affordable, but it has the potential to abate the pollution caused by the shoe-care market while simultaneously enhancing the overall performance of the pavement and extending its service lifespan.

Investigations on the preparation of ceramsite from petrochemical excess sludge.

Petrochemical excess sludge, as hazardous solid waste, poses a great threat to the environment and is difficult to dispose of in an economic and environmentally friendly way. A new alternative of using the petrochemical excess sludge to prepare ceramsite is proposed. The relationship between the sintering behavior of dried excess sludge, including the composition, temperature, fluxing agent, and pore-forming agent addition, and the properties of ceramsite is investigated. The properties of ceramsite are primarily affected by the sintering temperature and the addition of a fluxing agent. Ceramsite with a sintering-expanded surface is prepared. Also, its water absorption is quite low, indicating an improvement in densification due to sintering. Moreover, the leaching toxicity of the heavy metals in the dried excess sludge and prepared ceramsite is also investigated. It reveals the feasibility of ceramsite preparation by sintering petrochemical excess sludge.

Sawdust Recycling in the Development of Permeable Clay Paving Bricks: Optimizing Mixing Ratio and Particle Size

The permeable pavement system (PPS) has effectively contributed to stormwater management as a low-impact development (LID) technology. The suitability of clay bricks, consolidated with waste materials, for sustainable PPS applications in urban infrastructure needs further attention. In this study, several series of permeable clay paving bricks samples were prepared by mixing different ratios and particle sizes of sawdust (SD) with clay soil and firing at 900 °C. The raw soil and SD samples were characterized through sieve analysis, X-ray Fluorescence (XRF), X-ray diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FTIR). The bricks were tested for their compressive strength, bulk density, apparent porosity, water adsorption, permeability coefficient, and stormwater treatment efficiency. The clay soil comprised 17.5% clay/silt with appropriate amounts of SiO2 (50.47%), Al2O3 (19.14%), and fluxing agents (15.34%) and was suitable for brick manufacturing. XRD and FTIR analysis revealed that the soil predominantly comprises quartz, dolomite calcite, feldspar, kaolinite, illite, and chlorites. The SD samples were enriched with amorphous and crystalline cellulose. The compressive strength of the bricks decreased, while the permeability of the bricks increased with an increasing percentage of SD. An optimal percentage of 10% SD achieved a 21.2 MPa compressive strength and a 0.0556 m/s permeability coefficient, meeting the ASTM specifications for PPS. The optimal size of SD, between 0.5 and 1.0 mm, achieved the desired compressive strength of the bricks. The permeable bricks effectively removed the total suspended solids (TSS), turbidity, and BOD5 from the stormwater, which complies with the guidelines for wastewater reuse applications.