Sodium Silicate Research Articles

Enhancing low-rank coal beneficiation: optimization of aggloflotation process for Sivas/Gemerek lignite

ABSTRACT This study investigated the performance of aggloflotation, a novel hybrid process that combines oil agglomeration and flotation, for the beneficiation of lignite coal from Sivas/Gemerek, Türkiye. The effects of critical process parameters, including depressant (sodium silicate) dosage, collector (kerosene) dosage, frother (methyl isobutyl carbinol) dosage, pulp pH, and solid-liquid ratio, were systematically evaluated. The optimum conditions were determined to be 250 g/t sodium silicate, 250 g/t kerosene, 200 g/t methyl isobutyl carbinol, pH 4, and a solid-liquid ratio of 10%. Under these conditions, the aggloflotation process achieved a yield of 80.92%, a combustible recovery of 91.35% and an ash content of 8.65%. Compared to conventional flotation and oil agglomeration, aggloflotation significantly outperformed both, particularly in reducing ash content while maintaining high recoveries. The process demonstrated efficiency in treating fine and ultrafine coal particles, addressing a significant challenge in the beneficiation of low-rank coals. These results suggest that aggloflotation offers a promising, efficient, and environmentally friendly solution for the cleaning of low-rank coals, with potential implications for enhancing coal utilization in energy production.

Utilizing municipal solid waste incineration fly ash for mine goaf filling: Preparation, optimization, and heavy metal leaching study.

Municipal solid waste incineration fly ash (MSWI FA) contains many harmful substances, such as heavy metals, which pose a great threat to the ecological environment. Its proper disposal is an urgent environmental problem that needs to be addressed. The large number of goaf areas in China's mines provides a new approach for MSWI FA treatment. Scientifically processed MSWI FA can be used for goaf filling; this reduces the stockpile of MSWI FA and improves the safety of mine goaf areas. In this study, paste backfill was prepared using MSWI FA and slag as cementitious materials and coal gangue as aggregates under the composite excitation of sodium hydroxide and water glass. The optimal mix ratio was determined using response surface methodology, and the leaching trend of the heavy metal ions inside the material and the micro mechanism of strength formation were studied. Molecular dynamics simulations were used to further examine the leaching pathways of the heavy metal ions. The experimental research showed that the optimal mix proportions of the backfill were 81.65%, 3.67% and 52.27% for the mass concentration, aggregate-to-cement ratio and fine gangue ratio, respectively. The main polymerization products were C-(A)-S-H and N-A-S-H silicate gel, and small amounts of ettringite (AFt), calcium aluminate chloride (3CaO • Al2O3 • 3CaCl2 • 30H2O) and CaCO3 were generated. Through Materials Studio (MS) software, the leaching pathway of the heavy metal ions in the backfill and the adsorption performance between the ions were examined, and the influence of the C-A-S-H gel on the leaching rates of the heavy metal ions of Pb2+, Cr3+, and Cd2+ was explored. The leaching rate was ranked as Pb2+>Cr3+>Cd2+. In this study, a pollution-free and structurally stable mine paste backfill material was prepared using MSWI FA solid waste.

Strength, durability and microscopic analysis of geopolymer mortar composed of gold tailings: Effects of sodium silicate

Strength, durability and microscopic analysis of geopolymer mortar composed of gold tailings: Effects of sodium silicate

Formamide as novel catalyst for the gelation of water glass to synthesize silica aerogel monolith

Formamide as novel catalyst for the gelation of water glass to synthesize silica aerogel monolith

Modernization of the drive of the hopper gate of the blast furnace autoclave for preparation of liquid glass

Modernization of the drive of the hopper gate of the blast furnace autoclave for preparation of liquid glass

Studies of Corrosion Inhibition Performance of Inorganic Inhibitors for Aluminum Alloy

In this study, the behavior of sodium silicate (Na2SiO3), manganese sulfate monohydrate (MnSO4·H2O), and ammonium metavanadate (NH4VO3) as corrosion inhibitors for AA6061 aluminum alloy (Al) was investigated. The polarization resistance (Rp) of the Al substrate immersed in 0.1 M NaCl solution was found to be 13 kΩ·cm2. In comparison, the Rp of the Al substrate immersed in 0.1 M NaCl in the presence of Na2SiO3, Na2SiO3/MnSO4·H2O, and Na2SiO3/NH4VO3 inhibitors was found to be 100, 133, and 679 kΩ·cm2, respectively. The best inhibition result was obtained when the mixture of the inhibitors was used with Rp of 722 kΩ·cm2. The maximum percentage of the corroded area calculated from the scanning electron microscopy (SEM) images was found to be 5.7% for Al substrate immersed in 0.1 M NaCl, which decreased to 0.06% when the mixture of the inhibitors was used. The synergetic effects between the three inhibitors were studied, and the results illustrated that the combination of Na2SiO3, MnSO4·H2O, and NH4VO3 provided the best corrosion inhibition properties for Al in aqueous NaCl environments.

Design of Perlite Based Thermal Insulation Plate and Determination of its Physical, Mechanical and Thermal Properties

According to the current fire regulations in Turkey, the use of insulation materials such as EPS, which are commonly employed in building insulation, is limited to buildings up to 28.5 m in height. The regulations mandate the use of Class A fire-resistant thermal insulation materials in high-rise buildings. However, these materials may present challenges in terms of application and sustainability. This study aims to develop a perlite-based thermal insulation board that is Class A fire-resistant, competitive with traditional insulation materials, and possesses optimal physical, mechanical, and thermal properties. In the production of the specimens, expanded perlite, liquid sodium silicate, and silicon powder were used, and tests for apparent density, compressive-flexural strength, capillary water absorption, and thermal conductivity were conducted in accordance with EN standards. In the first stage, the produced specimens were subjected to four different activation temperatures to determine the optimal process temperature. In the second stage, the ratios of perlite, sodium silicate, and water were varied to achieve the mixture design that yielded the highest mechanical properties from the specimens. In the final stage, water-repellent admixtures were incorporated into the batches at mass ratios of 1.5 %, 3 %, 4.5 %, and 6 %. The perlite-based thermal insulation board, which offers optimal properties in the most cost-effective manner, has an apparent density of 127 kg·m−3, compressive strength of 266 kPa, flexural strength of 156 kPa, capillary water absorption value of 0.0197 kg·m−2·min−0.5, thermal conductivity of 0.0475 Wm−1·K−1, and a unit cost of 97 $ m−3. Consequently, the insulation board developed in this study presents a viable alternative to conventional insulation materials, offering Class A fire resistance.

Study on the Macroscopic Properties and Microstructure of High Fly Ash Content Alkali-Activated Fly Ash Slag Concrete Cured at Room Temperature

Fly ash and granulated blast furnace slag are both bulk industrial solid wastes. Using these two raw materials to completely replace cement and prepare alkali-activated fly ash slag concrete (AAFSC) at room temperature can not only efficiently utilize industrial solid waste and reduce the carbon footprint, but also reduce the economic cost and technical difficulty of construction, which is of great significance for promoting the sustainable development of the concrete industry. In this article, the content of fly ash accounted for 80% of the total precursor (fly ash + slag), and a mixed solution of sodium silicate and sodium hydroxide was used as alkali activator to prepare AAFSC by curing at room temperature. The effects of alkali equivalent and activator modulus on compressive strength, impermeability, water absorption, and microstructure were systematically studied and compared with ordinary Portland cement concrete. The conclusions drawn were as follows. The 7-day compressive strength of AAFSC was lower than that of cement concrete, while its 28-day compressive strength was 104.86% to 131.94% of that of cement concrete. AAFSC exhibited excellent impermeability protection performance. The water absorption rate of AAFSC was lower, with A8M1 having a water absorption rate of 2.13%, which was only 60.86% of cement concrete. Through microscopic analysis, it was found that the alkali-activated fly ash slag cementitious matrix had good bonding with the aggregate, and there existed fly ash particles with different degrees of reaction. The Ca/Si value of AAFSC was smaller than that of cement concrete.

An Experimental and Predictive Models for Compressive Strength of Geopolymer Concrete Made with GGBFS and Fly ash

This work investigated the potential synergy between Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) as binder solids in the manufacturing of Geopolymer Concrete (GPC), a concrete that does not contain Ordinary Portland Cement (OPC). At a ratio of 1:1, the ideal mixture of binder solids was attained. Based on absolute volume, the mix design was created using techniques akin to those found in ACI 211.1. In order to investigate the impact on the evolution of strengths, the alkaline activator content (AAC) to binder solid ratio—which is comparable to the water/binder ratio in OPC concrete—was varied in the ratios of 0.25, 0.3, 0.35, 0.4, and 0.5. For every mixture, the ratio of sodium hydroxide to sodium silicate was maintained at 1.5. To evaluate the functional relationships between the response variable (strength) and the independent variables (GPC constituents), a nonlinear regression analysis was conducted. Experimental results on workability for all mixes are in agreement with ACI 211.1 criteria. In all mixes, GPC specimens exhibited higher compressive strengths than OPC specimens; with a maximum value of 73.67 Mpa and 72.67 Mpa respectively. Nonlinear regression results provide equations that predict the strengths with excellent correlation. In addition to F-statistics that are statistically significant within acceptable probabilities.

Characterization of Clay Shock Slurry and Its Safety Risk Control in Shield Crossing Project

To investigate the mechanism by which clay shock slurry fills excavation gaps and reduces ground layer deformation during shield tunneling, we conducted a study using the project example of Beijing Metro Line 19 from Youanmenwai Station to Niujie Station, which passes through Guang’anmennei Station to CaiShiKou Station of Beijing Metro Line 7 at a close distance. We employed physical and mechanical testing, numerical simulation calculations, and other methods to examine the deformation law and mechanism of the clay shock method in shield tunneling construction. Our results indicate that (1) as the mass concentration of clay shock slurry increases, its permeability decreases significantly; at a mass concentration of 400 kg/m3, clay shock slurry can prevent synchronous grouting slurry from flowing forward, providing optimal filling and support for excavation gaps. (2) Clay shock slurry can reduce friction between the shield shell and soil body by 50%, avoiding super-consolidation, shear damage, and volumetric expansion of the surrounding soil body. (3) Radial grouting with a two-fluid slurry of cement–water glass at a 1:1 ratio within 15 rings after shield tail removal effectively reduces settlement of the existing tunnel. (4) Numerical simulations demonstrate that using clay shock slurry to fill shield tunnel gaps not only significantly reduces construction settlement but also effectively inhibits strata displacement along the tunnel axis.

Hábitos alimenticios e hipertensión en pacientes ambulatorios de un Hospital en Honduras

Eating habits play an important role in the prevention and management of high blood pressure. The World Health Organization demonstrated that poor eating habits trigger arterial hypertension, which is a chronic increase in blood pressure with values ​​equal to or greater than 140 millimeters of mercury (MmHg) systolic pressure and 90 mmHg. diastolic pressure. The general objective of this study was to identify the eating habits of patients with high blood pressure who attended the outpatient clinic at the Gabriela Alvarado Hospital in Danlí, Honduras, in the period January-March 2024. It was a descriptive, cross-sectional study; The study data was obtained through a structured questionnaire addressed to each of the participants. Among the results found, the eating habits of the 81 participating patients reflect that 86.4% eat 3 times a day, with lunch being the most substantial with 88.9%, in which they mainly consume more fruits and vegetables, 35.8% consume 4 to 6 glasses of water a day, have eating habits that include healthy aspects according to their health status.

Voice Based Hot Cold- Water Dispenser Using Arduino

Technology is a never-ending process. To be able to design a product using the current technology that will be valuable to the lives of others is a huge contribution to the neighbourhood. Voice Based Water Dispenser Automation method using controller is the plan will be very useful for old age people and disabled people, basically one’s who cannot achieve basic actions efficiently. It is the idea Corresponds to the new area of automation and technology. This presents the design and implementation of a low cost but flexible Secure voice based hot and cold-water dispenser system. The Between the cell phone and the controller board is wireless. Voice Command sends from mobile to the micro controller, to understand whether the water required by the person should be hot or cold. The Micro controller processes the information to the IR sensor to Determine where the glass is placed below the pipe or not. The method uses IR sensors to detect the presence of stream beaker and then the IR sensor sends the signal to the micro controller about the presence of the glass, accordingly the motor starts and the Water flows though the pipes from the particular jar (hot/cold). Key Words: IR sensor, Water glass, Micro controller, Blue-tooth.

Exploration of Key Factors in the Preparation of Highly Hydrophobic Silica Aerogel from Rice Husk Ash Assisted by Machine Learning.

To expand the applications of hydrophobic silica aerogels derived from rice husk ash (HSA) through simple traditional methods (without adding special materials or processes), this paper employs machine learning to establish mathematical models to identify optimal conditions for extracting water glass and investigates how preparation conditions and heat treatment temperatures affect properties such as the porosity and hydrophobicity of HSA. The results indicate that the decision tree regression model provides the most accurate predictions for the extraction rate and modulus of water glass. Notably, the water contact angle of HSA produced using nitric acid as a catalyst can reach as high as 159.5°, classifying it as a superhydrophobic material. Additionally, while moderately increasing the concentration of the hydrophobic modifier enhances HSA's hydrophobicity, it concurrently reduces its porosity. The HSA maintained hydrophobicity until 500 °C. The pore structure of HSA collapsed gradually with the increase in heat temperature. After treatment at 700 °C, HSA lost its hydrophobicity and the porous structure was severely damaged. Compared with silica aerogel using traditional silicon sources, the damage to pore structure and the crystallization occurred at lower temperatures, but the hydrophobicity remained at higher temperatures.

Effects of Sodium Silicate on Flotation Separation of Sphalerite and Dolomite and Its Mechanism

Sphalerite often co-exists with dolomite, a carbonate mineral containing calcium and magnesium. In the flotation process of sphalerite, dolomite entering into the concentrate will have a considerable negative impact on the subsequent smelting. Therefore, the effects of sodium silicate on the flotation separation of sphalerite and dolomite and its mechanism were investigated in this study. It was found that alkaline conditions and the addition of sodium silicate were conducive to the flotation separation of sphalerite and dolomite. Under alkaline conditions, sodium silicate improved the hydrophobicity of sphalerite and the slurry turbidity. The yield stress and apparent viscosity were significantly reduced when dolomite was present in slurry. In addition, the surface electrical properties of dolomite shifted from positive to negative with an increase in the dosage of sodium silicate at pH 11, leading to electrostatic repulsion between sphalerite and dolomite. EDLVO results indicated that the total interaction energy between dolomite and sphalerite particles was repulsive when sodium silicate was present. This study provided a theoretical basis for the flotation separation of sphalerite and dolomite.

Mechanical and microstructural properties of fiber-reinforced basalt rock cutting waste-based geopolymer composites exposed to high temperatures.

Managing basalt rock cutting waste in an environmentally responsible manner is crucial to mitigate its negative impacts and protect both the environment and human health. Recycling basalt rock cutting waste in geopolymer applications offers multiple environmental, economic, and performance benefits, making it a promising approach for sustainable construction practices. For this purpose, this study concerns about the performance of fiber-reinforced basalt rock-cutting waste-based geopolymer composites at high temperatures up to 1000°C. Geopolymer composites were manufactured by activating basalt rock cutting waste with sodium silicate. Alongside the fiber-free mixtures, fiber-reinforced geopolymer composites incorporating 0.5% and 1.0% basalt or polypropylene fibers by volume were synthesized. These composites underwent thermal curing at 100°C for two distinct durations: 8h and 24h. In addition, the geopolymer composites were subjected to thermal exposure at three different temperatures: 600°C, 800°C, and 1000°C. Changes in the strength and weights of the composites were determined after high-temperature exposure. In addition, XRD and SEM/EDX analyses were performed on the selected composites to investigate the changes in the microstructure of the composites. Thermal curing time and fiber content had significant influence on the high-temperature performance of the geopolymer composites. In this study, geopolymer mortars based on basalt rock cutting waste were successfully developed, demonstrating resistance to elevated temperatures up to 1000°C. No reduction in compressive strength was observed in any of the composites when exposed to 600°C, 800°C, and 1000°C. In fact, an increase in strength was recorded at varying rates, compared to the pre-exposure values.

Operational properties of cement-free concrete with porous aggregate

The article presents the results of technology development and research on the operational properties of porous aggregate and cement-free concretes based on it. The purpose of the work is to study lightweight concretes containing a liquid–glass porous aggregate for resistance to various aggressive influences. The porous granular aggregate was obtained by firing a mixture of liquid glass with the ash of thermal power plants and an ash aluminosilicate microsphere. Binders based on caustic magnesite and liquid glass with the addition of thermal energy waste were used to produce coarse-pored concretes. The choice of cement-free binders is due to the high adhesion to the filler. The behavior of the developed concretes in various aggressive environments, under the influence of low and elevated temperatures, has been studied. The resistance of magnesia concrete to the effects of water and salt solutions has been revealed. The technological and operational advantages of liquid-glazed concrete are shown, featuring increased thermal insulation ability, satisfactory resistance to aggressive media and resistance to low and high-temperature fluctuations. The developed concretes can be used in the enclosing structures of objects for various purposes.

In Situ Synthesis of Zr-Doped Mesoporous Silica Based on Zr-Containing Silica Residue and Its High Adsorption Efficiency for Methylene Blue

Zr-containing silica residue (ZSR) is an industrial by-product of ZrOCl2 production obtained through an alkali fusion process using zircon sand. In this study, low-cost and efficient Zr-doped mesoporous silica adsorption materials (Zr-MCM-41 and Zr-SBA-15) were prepared in one step via the hydrothermal synthesis method using ZSR as the silicon source for the removal of methylene blue (MB) from dye-contaminated wastewater. The samples were characterized using X-ray fluorescence (XRF) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetry (TG), and N2 adsorption–desorption measurements. The findings indicate that the synthesized Zr-MCM-41 and Zr-SBA-15 possess highly ordered mesoscopic structures with high specific surface areas of 910 and 846 m2/g, large pore volumes of 1.098 and 1.154 cm3/g, and average pore diameters of 4.18 and 5.35 nm, respectively. The results of the adsorption experiments show that the adsorbent has better adsorption properties under alkaline conditions. The adsorption process obeys the pseudo-quadratic kinetic model and the Freundlich adsorption isotherm model, indicating the coexistence of physical and chemisorption processes. The maximum adsorption capacities of Zr-MCM-41 and Zr-SBA-15 are 618.43 and 516.58 mg/g, respectively, as calculated by the Langmuir model (pH = 9, temperature of 25 °C). Compared with mesoporous silica prepared with sodium silicate as the silicon source, Zr-MCM-41 and Zr-SBA-15 have different structural properties and better adsorption properties due to Zr doping. These findings indicate that ZSR is the preferred silicon source for preparing mesoporous silica, and the mesoporous silica prepared using Zr silicon slag is a promising adsorbent and has great application potential in wastewater treatment.

Study on the Improvement Effect of Polypropylene Fiber on the Mechanical Properties and Freeze-Thaw Degradation Performance of High Fly Ash Content Alkali-Activated Fly Ash Slag Concrete.

This article systematically investigated the improvement effect of polypropylene fiber (PPF) on the mechanical and freeze-thaw properties of alkali-activated fly ash slag concrete (AAFSC) with high fly ash content and cured at room temperature. Fly ash and slag were used as precursors, with fly ash accounting for 80% of the total mass. A mixed solution of sodium hydroxide and sodium silicate was used as alkali activator, and short-cut PPF was added to improve the performance of AAFSC. Firstly, the strength characteristics of AAFSC at different curing ages were studied. Then, key indicators such as morphology, residual compressive strength, weight loss, relative dynamic modulus of elasticity (RDME), and pore characteristics of AAFSC after different freeze-thaw cycles were tested and analyzed. The strength performance analysis showed that the optimal dosage of PPF was 0.90%. When the alkali equivalent of the alkali activator was increased from 4% to 6%, the frost resistance of AAFSC could be improved. Furthermore, adding 0.90% PPF could increase the freeze-thaw cycle number of AAFSC by about 50 times (measured by RDME). With the increase in freeze-thaw cycles, the porosity of AAFSC increased, the fractal dimension decreased, and the proportion of harmless and less harmful pores decreased, while the proportion of harmful and multiple harmful pores increased. The relationship model between the porosity and compressive strength of AAFSC after freeze-thaw cycles was established.

Effects of Real-Life Motor Complexity on Walking and Mobility in Trained and Sedentary Adolescents With Intellectual Disabilities: A Motor Dual-Task Investigation.

Adolescents with intellectual disabilities (ID) often encounter challenges in walking and mobility due to cognitive and motor impairments. This study aimed to investigate the impact of real-life motor complexity on walking and mobility in this population, particularly focusing on dual-task scenarios. Twenty-four adolescents with ID, divided into trained and sedentary groups, participated in the study. Participants completed the Timed Up and Go Test and the 10-m walk test under various conditions, including holding a water glass, carrying a tray with 2 glasses of water, introducing background noise, and encountering unexpected obstacles. Both groups significantly exhibited increased completion times (P < .001) in the Timed Up and Go Test and 10-m walk test with each added level of difficulty. The trained group demonstrated significantly superior performance (P < .05), only in the single task and holding a water glass. However, the difference between groups diminished as the challenges increased. In conclusion, real-life motor dual-tasking scenarios significantly impact walking and mobility in adolescents with ID. Physical activity may improve mobility and walking, particularly under less challenging conditions. Incorporating real-life challenges into motor dual-task training programs can enhance adaptability and reduce the risk of falls and injuries, ultimately improving the quality of life for individuals with ID.

Effect of curing temperature on the soil physical and mechanical properties on clay shale geopolymer fly ash stabilization

Clay shale is an easily degraded mudrock when exposed to weathering. The reduced strength due to degradation can be mitigated through soil stabilization. In recent years, soil stabilization using geopolymers has become one of the latest popular methods due to its economic benefits and lower carbon footprint. A widely used cementitious material for this method is fly ash-based geopolymer. The relationship between curing temperatures and the performance of clay shale stabilized with fly ash-based geopolymer has yet to be studied for the purpose of identifying a more effective stabilization method. In this study, clay shale was stabilized using geopolymer. The geopolymer was made of fly ash and an activator. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as activators. The activator is diluted with water to create a 12 M mixture. Before the unconfined compressive strength test, the specimens were subjected to various curing temperatures from 26oC to 60oC. The test result shows that, in general, higher curing temperatures increased the dry density from 1.66 g/cm3 to 1.84 g/cm3. Meanwhile, the unconfined compressive strength multiplies about 3.5 times. Furthermore, the moisture content decreased after the curing process from 19% to 2.5%. This led to the specimen volume experiencing decrement due to the shrinkage during the curing period. The volume reduces from 67.7 cm3 to 63.5 cm3. In general, temperature plays a significant role in enhancing the strength of clay shale stabilized using fly ash-based geopolymer.