scholarly journals Influence of slag particle size on performance of ceramic bricks containing red clay and steel-making slag

2019 ◽  
Vol 127 (2) ◽  
pp. 105-110 ◽  
Author(s):  
Yan-bing ZONG ◽  
Wen-hui CHEN ◽  
Yi-xuan LIU ◽  
Xiao-xiong XU ◽  
Zhao-bo LIU ◽  
...  
Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 487 ◽  
Author(s):  
Jianli Li ◽  
Qiqiang Mou ◽  
Qiang Zeng ◽  
Yue Yu

The stability of chromium in stainless steel slag has a positive correlation with spinel particle size and a negative correlation with the calcium content of the spinel. The effect of heating time on the precipitation of spinel crystals in the CaO-SiO2-MgO-Al2O3-Cr2O3-FeO system was investigated in the laboratory. Scanning electron microscopy with energy-dispersive and X-ray diffraction were adopted to observe the microstructure, test the chemical composition, and determine the mineral phases of synthetic slags, and FactSage7.1 was applied to calculate the crystallization process of the molten slag. The results showed that the particle size of the spinel crystals increased from 9.42 to 10.73 μm, the calcium content in the spinel crystals decreased from 1.38 at% to 0.78 at%, and the content of chromium in the spinel crystal increased from 16.55 at% to 22.78 at% with an increase in the heating time from 0 min to 120 min at 1450 °C. Furthermore, the species of spinel minerals remained constant. Therefore, an extension in the heating time is beneficial for improving the stability of chromium in stainless steel slag.


2019 ◽  
Vol 37 (5) ◽  
pp. 469-477 ◽  
Author(s):  
Krishna R. Reddy ◽  
Archana Gopakumar ◽  
Raksha K. Rai ◽  
Girish Kumar ◽  
Jyoti K. Chetri ◽  
...  

The mineral carbon sequestration capacity of basic oxygen furnace (BOF) slag offers great potential to absorb carbon dioxide (CO2) from landfill emissions. The BOF slag is highly alkaline and rich in calcium (Ca) containing minerals that can react with the CO2 to form stable carbonates. This property of BOF slag makes it appealing for use in CO2 sequestration from landfill gas. In a previous study, CO2 and CH4 removal from the landfill gas was investigated by performing batch and column experiments with BOF slag under different moisture and synthetic landfill gas exposure conditions. The study showed two stage CO2 removal mechanism: (1) initial rapid CO2 removal, which was attributed to the carbonation of free lime (CaO) and portlandite [(Ca(OH)2)], and (2) long-term relatively slower CO2 removal, which was attributed to be the gradual leaching of Ca2+ from minerals (calcium-silicates) present in the BOF slag. Realising that the particle size could be an important factor affecting total CO2 sequestration capacity, this study investigates the effect of gradation on the CO2 sequestration capacity of the BOF slag under simulated landfill gas conditions. Batch and column experiments were performed with BOF slag using three gradations: (1) coarse (D50 = 3.05 mm), (2) original (D50 = 0.47 mm), and (3) fine (D50 = 0.094 mm). The respective CO2 sequestration potentials attained were 255 mg g−1, 155 mg g−1, and 66 mg g−1. The highest CO2 sequestration capacity of fine BOF slag was attributed to the availability of calcium containing minerals on the slag particle surface owing to the highest surface area and shortest leaching path for the Ca2+ from the inner core of the slag particles.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kaisheng Chen ◽  
Qinqin Wang ◽  
Dipu Luo ◽  
Bo Zhou ◽  
Kun Zhang

Rubber powder formed from discarded tire rubber is mixed with red clay to form a rubber-red clay mixture. The dynamic triaxial test was carried out on the mixtures under different conditions. The effects of rubber content, rubber particle size, moisture content of mixed soil, compactness, confining pressure, and vibration frequency on shear strain relation, dynamic shear modulus, and damping ratio of the mixture were investigated. The results show that under the same dynamic strain, the dynamic shear stress-strain curve of rubber mixed soil decreases with the increase in rubber particle content and moisture content and decrease in rubber particle size. On the other hand, it increases with the increase in compactness, confining pressure, and vibration frequency, and as the dynamic strain increases, the τd-γd curve becomes more nonlinear. In addition, with the increase in the rubber particle content, the dynamic shear modulus decreased while the damping ratio increased. When the content was 2%, the change was fastest. After continued addition, it gradually became stable, and when the decrease in rubber particle size also shows the same pattern, 2.00 mm rubber-red clay mixture shows better structure. The water content has great influence on dynamic shear modulus and damping ratio of rubber-red clay mixtures. With the increase in compactness, confining pressure, and vibration frequency, the interaction between mixed soil particles was enhanced, the dynamic shear modulus increased, and the damping ratio decreased.


2014 ◽  
Vol 798-799 ◽  
pp. 343-346
Author(s):  
Jonas Alexandre ◽  
Caio Lobato de Assis Paula e Silva ◽  
Afonso Rangel Garcez de Azevedo ◽  
Gustavo de Castro Xavier ◽  
Veronica Scarpini Candido ◽  
...  

Soil-cement blocks are worldwide used in civil construction competing with ceramic blocks like the red clay ceramic bricks. In the southeast of Brazil, particularly in the states of Espirito Santo and Rio de Janeiro, clay ceramic blocks predominate owing to lower processing costs. The incorporation of inexpensive raw materials into soil-cement blocks could improve their margin of competition. Therefore the present work investigated the processing and properties of soil-cement blocks incorporated with a relatively high amount, 81 wt%, of natural grit in substitution for the conventionally used gravel and sand. The grit had a convenient particle size. The results of compression and water absorption tests indicated that the grit incorporated soil-cement blocks attend the norms for civil construction.


2018 ◽  
Vol 44 (5) ◽  
pp. 5226-5232 ◽  
Author(s):  
E. Furlani ◽  
S. Maschio ◽  
M. Magnan ◽  
E. Aneggi ◽  
F. Andreatta ◽  
...  

2014 ◽  
Vol 52 ◽  
pp. 488-493 ◽  
Author(s):  
Zhijun Tan ◽  
Geert De Schutter ◽  
Guang Ye ◽  
Yun Gao ◽  
Lieven Machiels

2014 ◽  
Vol 775-776 ◽  
pp. 642-647
Author(s):  
Carolina Nascimento de Oliveira ◽  
Michelle Pereira Babisk ◽  
Fernando Vernilli ◽  
Veronica Scarpini Candido ◽  
Sergio Neves Monteiro ◽  
...  

The addition of industrial residues into common red clay ceramic has been, from many decades, an alternative of using other low cost raw materials and, more recently, as an environmentally correct destination for polluting substances. An important residue, known as yellow sludge, is that generated at the water clearing stage (WCS) of a treatment plant by some heavy industries such as an integrated steel making. Since this yellow sludge residue is normally disposed in ways that pollutes water bodies, the objective of the present work was to characterize a WCS yellow sludge and investigate its addition into clay ceramics. The residue was characterized by X-ray fluorescence, particle size distribution and scanning electron microscopy. The addition was carried out up to 7.5 wt% followed by firing at 800oC. The added ceramics were evaluated in terms of water absorption, linear shrinkage, dry apparent density and flexural rupture strength. It was found that the residue addition does not practically alter the ceramic technical properties.


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