Study of thermogravimetric curves of LD Slag size fractions in oxygen and nitrogen atmosphere and effect of FeO and free lime on weight loss at different temperatures

2018 ◽  
Vol 115 (4) ◽  
pp. 417
Author(s):  
Shrenivas Ashrit ◽  
Ravikrishna V. Chatti ◽  
Udayabhanu G. Nair ◽  
Venugopal Rayasam
Keyword(s):  
Weight Loss ◽  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Nitrogen Atmosphere ◽  
Oxygen Atmosphere ◽  
Free Lime ◽  
Size Fractions ◽  
Steel Making ◽  
Different Temperatures ◽  
Ld Slag

The thermogravimetric (TG) method offers a new approach to the study of the thermal degradation of LD Slag fines, which is a by-product produced in the Tata Steel plant, Jamshedpur during the steel making process. TG curves for LD Slag fines of different particle sizes in oxygen and nitrogen atmosphere from 100 to 900 °C were compared to each other to find the variation in the weight loss. Effect of FeO and free lime on weight loss of LD Slag fines was also discussed. Weight loss in the temperature range of 450–550 °C and then up to 700 °C confirmed the presence of calcium hydroxide, magnesium hydroxide, calcium silicate hydrate and calcite in LD Slag fines. Except −6.0 + 2.0 mm LD Slag fines, the weight loss in oxygen atmosphere is more than nitrogen atmosphere for other size fractions. The higher weight loss in nitrogen atmosphere than the oxygen atmosphere was attributed to the decomposition of calcium silicate hydrate and hydrated aluminate phases. Higher free lime values in finer LD Slag fractions than the coarser LD Slag fractions confirmed more volumetric stability of coarser LD Slag size fractions than the finer fractions due to powdering in the cooling process.

An infrared spectroscopic study of non-metallic portion of Linz-Donawitz slag fines generated at Tata Steel, Jamshedpur

2018 ◽  
Vol 115 (6) ◽  
pp. 608 ◽  
Author(s):  
Shrenivas Ashrit ◽  
Ravikrishna V. Chatti ◽  
S. Sarkar ◽  
Rayasam Venugopal ◽  
Udayabhanu G. Nair
Keyword(s):  
Chemical Constituents ◽  
Value Added ◽  
Xrd Analysis ◽  
Waste Recycling ◽  
Parent Material ◽  
Infrared Spectroscopic Study ◽  
Free Lime ◽  
Size Fractions ◽  
Agricultural Applications ◽  
Ld Slag

The main constituents of LD Slag fines in the size range of 0–6 mm after recovering the metallic iron in a waste recycling plant (WRP) mainly contains calcium bearing mineral phases such as mono, di and tricalcium silicates along with free lime. The chemical constituents are CaO, SiO2, FeO and Al2O3 with traces of chromium, manganese, etc., as oxides. The WRP waste, i.e., LD Slag fines of 0–6 mm is further subjected to sieving mainly into three different size fractions viz. + 10 mesh (−6.0 + 2.0 mm), + 60 mesh (−2.0 + 0.25 mm), −60 mesh (−0.25 mm) for studying its possible application economically in different sectors such as agriculture, construction and chemical industries. Chemical and XRD analysis indicate high lime content along with some compounds like calcite, silicates of calcium, brownmillerite and dicalcium diferrate, etc., in these slag samples. FTIR analysis of these size fractions also indicates the presence of hydrated silicates, calcite and anhydrous calcium silicate. In this study, the authors have attempted to correlate the chemical analysis and XRD studies with FTIR technique of characterisation for better understanding of the parent material. This was done to get a deeper insight of the fines which can be useful for development of suitable calcium-based value added materials for different industrial, chemical and agricultural applications.

scholarly journals Torrefaction Thermogravimetric Analysis and Kinetics of Sorghum Distilled Residue for Sustainable Fuel Production

2021 ◽  
Vol 13 (8) ◽  
pp. 4246
Author(s):  
Shih-Wei Yen ◽  
Wei-Hsin Chen ◽  
Jo-Shu Chang ◽  
Chun-Fong Eng ◽  
Salman Raza Naqvi ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Pso Algorithm ◽  
Nitrogen Atmosphere ◽  
Computational Method ◽  
Weight Changes ◽  
Design And Optimization ◽  
Thermogravimetric Analyzer ◽  
Model Free ◽  
Different Temperatures ◽  
Kinetics Of

This study investigated the kinetics of isothermal torrefaction of sorghum distilled residue (SDR), the main byproduct of the sorghum liquor-making process. The samples chosen were torrefied isothermally at five different temperatures under a nitrogen atmosphere in a thermogravimetric analyzer. Afterward, two different kinetic methods, the traditional model-free approach, and a two-step parallel reaction (TPR) kinetic model, were used to obtain the torrefaction kinetics of SDR. With the acquired 92–97% fit quality, which is the degree of similarity between calculated and real torrefaction curves, the traditional method approached using the Arrhenius equation showed a poor ability on kinetics prediction, whereas the TPR kinetic model optimized by the particle swarm optimization (PSO) algorithm showed that all the fit qualities are as high as 99%. The results suggest that PSO can simulate the actual torrefaction kinetics more accurately than the traditional kinetics approach. Moreover, the PSO method can be further employed for simulating the weight changes of reaction intermediates throughout the process. This computational method could be used as a powerful tool for industrial design and optimization in the biochar manufacturing process.

Multiple ions transport and interaction in calcium silicate hydrate gel nanopores: Effects of saturation and tortuosity

2021 ◽  
Vol 283 ◽  
pp. 122638
Author(s):  
Zhiyong Liu ◽  
Yuncheng Wang ◽  
Dong Xu ◽  
Chuyue Zang ◽  
Yunsheng Zhang ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Calcium Silicate Hydrate ◽  
Ions Transport

Polyvinyl fibers as outperform candidature in the solid polymer electrolytes

2020 ◽  
pp. 152808372097062
Author(s):  
Muhammad Yameen Solangi ◽  
Umair Aftab ◽  
Muhammad Ishaque ◽  
Aqeel Bhutto ◽  
Ayman Nafady ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Weight Loss ◽  
Ionic Conductivity ◽  
Polymer Electrolytes ◽  
Vital Role ◽  
Solid Polymer Electrolytes ◽  
Solid Polymer ◽  
Main Challenge ◽  
Different Temperatures ◽  
Solution Cast

Solid polymer electrolytes (SPEs) are the best choice to replace liquid electrolytes in supercapacitors, fuel cells, solar cells and batteries. The main challenge in this filed is the ionic conductivity and thermal stability of SPEs which is still not up to mark, therefore more investigations are needed to address these issues. In this study, PVA/salt based SPEs was fabricated using both solution cast and electro-spinning methods to probe the effect of different salts such as (NaCl, KCl and KI) and their concentrations on the ionic conductivity. Scanning electron microscopy (SEM) x and Fourier Transform Infra-Red (FTIR) have been employed to study the morphology as well as the different functional groups of SPEs, respectively. It was noted that small addition of NaCl, KCl and KI salts in SPEs dramatically increased the ionic conductivity to 5.95×10−6, 5.31×10−6 and 4.83×10−6 S/cm, respectively. Importantly, the SPEs obtained with NaCl via electro-spinning have higher ionic conductivity (5.95×10−6 S/cm) than their casted SPEs (1.87×10−6 S/cm). Thermal stability was also studied at two different temperatures i.e. 80 °C and 100 °C. The weight loss percentage of electrospun SPEs have zero percent weight loss than the solution based SPEs. The combined results clearly indicated that the nature of salt, concentration and fabrication process play a vital role in the ionic conductivity. Also, the NaCl salt with low molecular weight at low concentrations shows an enhanced ionic conductivity.

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