Inorganic Chemicals Industry ›› 2024, Vol. 56 ›› Issue (10): 118-126.doi: 10.19964/j.issn.1006-4990.2024-0140

• Environment·Health·Safety • Previous Articles     Next Articles

Study on pyrolysis behavior and mechanism of calcium carbide slag/magnesium carbonate system

QI Xingzhao1,3(), WANG Feng1(), WU Jie1,2(), ZHANG Qi1,3, TANG Zhongfeng3   

  1. 1.School of Energy and Power Engineering,Inner Mongolia University of Technology,Hohhot 010051,China
    2.Inner Mongolia Power Research Institute Branch,Inner Mongolia Power(Group) Co. ,Ltd. ,Hohhot 010020,China
    3.Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201204,China
  • Received:2024-03-11 Online:2024-10-10 Published:2024-11-05
  • Contact: WANG Feng, WU Jie E-mail:q15147159224@163.com;wangfeng@imut.edu.cn;wujiegongda@126.com

Abstract:

A carbide slag/magnesium carbonate system was synthesized by mechanical mixing method.Thermal decomposition behavior and mechanism under high temperature conditions were studied from three aspects of component ratio,heating rate,and pyrolysis atmosphere.The results indicated that the thermal decomposition of this carbide slag/MgCO3 system with different ratios could be divided into three stages and displayed similar trends.As the amount of magnesium in the samples increased,the decomposition temperature of the samples in the first stage was dropped from 387 ℃ to 361 ℃,while the weight loss rate was increased from 16.0% to 18.0%.The decomposition temperature of the samples in the second stage maintained steady with the weight loss rate increasing from 13.2% to 17.1%.The changes in the third stage of the decomposition temperature and weight loss rate of the samples were minimal which could attribute to the formation of stable metal oxides.The thermogravimetric curve of the carbide slag/MgCO3 system gradually shifted towards higher temperatures with the increasing heating rate,and its apparent activation energy was increased with the magnitude of magnesium.The weight of the carbide slag/MgCO3 system displayed the tendency of firstly increased and then decreased under CO2 atmosphere.CO2 released from the decomposition of MgCO3 was absorbed by Ca(OH)2 within the same reaction temperature range.The prepared carbide slag/magnesium carbonate agent system exhibited a more abundant porous structure with Ca and Mg elements dispersed uniformly on the adsorbent surface,which effectively enhanced the anti⁃sintering properties of the carbide slag/MgCO3 system.The reaction mechanism during the thermal decomposition process of the carbide slag/MgCO3 system was revealed that provided theoretical support for the preparation of calcium carbide slag adsorbents with strong CO2 capture capacity and cycling stability.

Key words: carbide slag, magnesium carbonate, thermal decomposition, high temperature, crystalline structure

CLC Number: