XRD (X-Ray Diffraction) Analysis of the Stabilized Ash

2013 ◽  
Vol 459 ◽  
pp. 7-10
Author(s):  
Hai Ying Zhang ◽  
Shu Zhen Li

MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

2012 ◽  
Vol 531 ◽  
pp. 292-295
Author(s):  
Hai Ying Zhang ◽  
Guo Liang Yuan ◽  
Guo Xian Ma

The characteristics and leaching behavior of heavy metals in fly ash, sampled from one MSWI (municipal solid waste incineration) plant in Shanghai China, were investigated. The results indicated that the main elements of fly ash were Fe, K, Na, Cl, Si, Ca, Al, and the total fraction of heavy metals was in the range of 0.8 % - 2.0%. Hence, MSWI fly ash was considered to be one kind of hazardous waste due to its potential environmental risk. Leaching toxicity was performed on fly ash samples from the MSWI plant in Shanghai China. Leaching toxicity of the heavy metals by the ALT (available leaching toxicity) procedure exceeded that by the HVEP (horizontal vibration extraction procedure) standard. Leaching concentrations of Ni, Zn, Cd and Pb exceeded the limit of hazardous waste identification standard. Hence, fly ash is a hazardous waste.


2012 ◽  
Vol 531 ◽  
pp. 272-275 ◽  
Author(s):  
Hai Ying Zhang ◽  
Guo Xian Ma ◽  
Guo Liang Yuan

The presence of heavy metals in municipal solid waste incineration (MSWI) fly ash is of environmental concern due to their leaching potential in landfill environments. Heavy metal content was performed on fly ash samples from a large-scale municipal solid waste incineration plant in Shanghai China. Content of heavy metals followed the decreasing sequence of Ni > Zn > Pb > Cu > Cd. As pollution of heavy metals is related to not only the content but also their leaching toxicity, further experiment of leaching concentrations of the metals is required to determine the seriousness of pollution caused by the heavy metals.


2021 ◽  
Vol 121 ◽  
pp. 33-41
Author(s):  
Yanjun Hu ◽  
Lingqin Zhao ◽  
Yonghao Zhu ◽  
Bennong Zhang ◽  
Guixiang Hu ◽  
...  

2021 ◽  
Vol 13 (2) ◽  
pp. 535
Author(s):  
Jing Gao ◽  
Tao Wang ◽  
Jie Zhao ◽  
Xiaoying Hu ◽  
Changqing Dong

Melting solidification experiments of municipal solid waste incineration (MSWI) fly ash were carried out in a high-temperature tube furnace device. An ash fusion temperature (AFT) test, atomic absorption spectroscopy (AAS), scanning electron microscope (SEM), and X-ray diffraction (XRD) were applied in order to gain insight into the ash fusibility, the transformation during the melting process, and the leaching behavior of heavy metals in slag. The results showed that oxide minerals transformed into gehlenite as temperature increased. When the temperature increased to 1300 °C, 89 °C higher than the flow temperature (FT), all of the crystals transformed into molten slag. When the heating temperatures were higher than the FT, the volatilization of the Pb, Cd, Zn, and Cu decreased, which may have been influenced by the formation of liquid slag. In addition, the formation of liquid slag at a high temperature also improved the stability of heavy metals in heated slag.


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