Characterization and Reutilization Study on Crystallized slags from Co-Melting processed incinerator ash/Calcium Fluoride sludge
Date Issued
2007
Date
2007
Author(s)
Chou, Chang-Hua
DOI
zh-TW
Abstract
The purpose of the research was to study the effects of high temperature co-melting slags producted from municipal solid waste incineration bottom ash and industrial calcium fluoride sludge,and to utilize the crystallized slags obtained by cooled by air, re-heated and temperatured controlled to reach the destination of reutilization .Experiments were conducted to (1) determine the lowest pouring temperature of co-melting ash and sludge at various proportions.(2) analyze the physical and chemical characteristics of the pulverized slags,such as specific gravity,particle size,chemical composition,TCLP,XRD patterns and strength activity index (SAI). (3) incorporate the slags as mineral admixtures in the cement-based composites materials in place of a fraction of the cememt,and evaluate the concerned characteristics by compressive strength、MIP、SEM、DSC、NMR,etc.
The results showed that the lowest pouring temperature was 1060。C when the co-melting ash and sludge were blended in the ratio of 7︰3,and the value of basicity was 0.542. It was observed that the crystallized slags was crystallized which was closed to class C fly ash belonged to pozzolan. could be used as pozzolan closed class C fly ash. 3% replacement of cememt,and 40% replacement of aggregate could produce highest compressive strength.The high compressive strength could be obtained through the hydration and pozzolanic reaction in the optimal ratio,but the replacement of aggregate should be lower than 30% due to the workability.
Althought pozzolanic activity is benefitial to compressive strenght,is also limited by the hydration. It was observed that the CH did not decrease apparently with time in the analysis of DSC. It also demonstrated that the length of polysilicate bond increased with the curing time in the concrete by NMR,and the trend is more distinct with higher replacement. Moreover,the specific gravity of crystallized slags could reach 2736 kg/m3 was greater than that of water-cool and air-cool slags which asserted the degree of crystallization.The crystallized slags had the greater compressive strength than that of water-cooled and air-cooled slags,even the outcome compared with the air-cool is not apparently.Comparing to water-cooled slags,it had the better advantage because crystallized slags utilized to replace part of cement would increase the compressive strength in the later curing stage.
Subjects
底渣
污泥
熔融
糝料
卜作嵐性質
bottom ash
sludge
melting
admixture
pozzolan
Type
thesis
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