Study On Fusion Characteristic And Mineral Change Of Blends Of Sludge And Coal

Slagging properties and selection of slag dischange form of boiler are affected by ash Fusion characteristics. And it's an important factor that affects the normal operation of boilers. Many domestic and foreign scholars who study on combustion of blends of sludge and coal mainly focus on combustion characteristics and pollutant emission characteristics of blends of sludge and coal. While the fusion characteristics of blends of sludge and coal is rarely studied.This thesis selects Lanba coal and sewage sludge ash, and make ash samples according to certain mixing proportion. The ash was analyzed by ash melting point testing, X-ray diffraction, TD-DSC, SEM/EDX means. And fusion characteristics were studied from minerals, microstructure perspective in order to provide relevant repference for the design of the sludge and coal mixed fuel boiler.The main contents of this thesis are as follows:1. Fusion characteristic of mixing fuel ash under different mixing proportion were studied by pyramid metod, and found as the sludge content rising in blends, fusion characteristics temperatures of ash reduce.2. Mixing fuel ash under different mixing proportion and different calcining temperature were studied by XRD. And the influence of minerals in ash to ash fusion characteristic is analysised from mineralogical perspective, and found the relatively high contents of hematite and calcium feldspar in sludge ash caused the characteristic temperatures low, the relatively low contents of mullite coal ash caused the characteristic temperatures high.3. Fusion characteristic of mixing fuel ash under different mixing proportion were studied by TG-DSC. The causes of formation of weightlessness peak on TG curves and characteristic peaks on DSC curves were analyzed. A little carbonate and sulphate were found in coal ash. Carbonate, sulphate, Ca(OH)2 were found in blends ash and sludge ash. And the contents rise as the content of sludge in blends rise.4. Microscopy and element of mixing fuel ash under different mixing proportion were studied by SEM and EDX. And the different morphological features of scanning photo were analyzed by EDX to reflect the element differences, found as the improvement of calcining temperature, but there is no obvious difference of the elements in each ash sample.