Study On The Performance Of Semi-dry Flue Gas Sulfur Fixation Of Calcium Carbonate/copper Slag Sulfur Fixer

As the national environmental requirements gradually improve,efficient coal-fired flue gas pollutant control technology and solid waste utilization has get more and more attention.By the combination of copper slag and conventional desulfurizing agent,a new calcium/copper slag compound desulfurizer is made.The comprehensive evaluation of this compound desulfurizer is made through pyrolysis performance analysis and thermodynamic calculations,as well as the desulfurization experiment.The main work in this paper are as follow from the perspective of the analysis of the solid waste utilization.Firstly.the analysis from physical properties of CaCO3/TZ compound desulfurizer.The result showed that the copper slag contained mainly the Fe2O3,CaO,MgO and other substances.Secondly,with the help of X-ray diffraction(XRD),TG-DSC simultaneous thermal analyzer,the specific surface area(BET)measurement instrument,scanning electron microscopy,the physical properties,the pyrolysis properties of copper slag and CaCO3/TZ composite desulfurizing agent has been explored.The result showed that the CaCO3/TZ as composite desulfurizer has great feasibility.When the copper slag adding amount was 10%and the temperature is 900?,CaCO3/TZ compound desulfurizer was most favorable to desulfurization.Thirdly,MgO,Fe-based oxides,Ca-based oxide,CuO,Al2O3 and other substances are generated by CaCO3/TZ complex desulfurizer pyrolysis under high temperature.Gibbs free energy calculations and chemical reaction equilibrium constant K calculations of these substances by chemical reaction with SO2 in the flue gas calculation analysis.Gibbs free energy calculation results showed that the function of MgO during the reaction in which SO2 involved is mainly catalyzed oxidation-absorption.Only a small part of Fe2O3,Fe3O4 and other iron oxides produced in the desulfurization reaction can react with SO2 to removal SO2 while most of them are indirectly involved in the catalytic effect of SO2 removal.In the temperature range of 0?1000? CaO can absorb SO2 spontaneously in two ways.The process of CuO,Al2O3 absorb SO2 in the flue gas absorption is similar to the decomposition process.The chemical equilibrium constant K calculation analysis shows that with the increase of reaction temperature,the chemical equilibrium constant is leveling off,its value at about 0.Finally,simulation of flue gas desulfurization experiment has been done.Experimental results showed that the efficiency of desulfurization can be improved by adding copper slag as additive in CaCO3.Desulfurization efficiency reached the maximum at the temperature of 900?,adding copper slag reached 10%.The conclusion is same as the pyrolysis analysis results of desulfurization agent,and also with the same conclusion of desulfurization agent thermodynamic analysis.This illustrates that copper slag has both catalytic and desulfurizing action in desulfurization process.Through the above analysis and research of CaCO3/TZ composite desulfurizer,we know that copper slag to as additive in calcium base desulfurizer is very good.Copper slag has both desulfurizing and catalytic role.Adding copper slag makes CaCO3/TZ composite desulfurizer to increase desulfurization efficiency and reduce desulfurization costs.At same time,copper slag resource can be utilized.In addition,a good use of copper slag can be found.