|
Of boiler slagging problems caused by migration and transformation of coal-fired minerals have long plagued the safe operation of the power station, transformed by coal minerals and boiler slagging research priorities, expectations can have a further understanding of the mechanism of slagging. Select nine kinds of typical coal-fired low-temperature ash flotation experiments, the system analyzes the chemical light and heavy mineral flotation, mineral microscopic characteristics; from the mineralogical point of the Zhuzhou plant slagging sample study their slagging mechanism analysis; concluded that the heavy gray mineral coal combustion and conversion slagging. Heavy gray mineral flotation results show that: the nine kinds of coal low-temperature the basic gray mineral phase constituted by quartz, kaolinite, pyrite, calcium mineral; basically the same light gray mineral ingredients with low-temperature ash mineral content of a slight change; secondary mineral phase composition and distinct from the low-temperature ash, based on mineral composition is divided into iron-bearing minerals, calcium, minerals and impurities minerals, iron minerals the heavy ash principal mineral, calcium mineral, quartz class, mineral kaolinite and other impurities in the heavy ash content is small; heavy ash FSEM-EDX analysis of the five kinds of coal samples to identify a variety of pyrite mineral, according to its morphology is divided into nine categories: Flake the massive, raspberry globular, spherical, fine dust particles, cylindrical, Crystal, pentagonal dodecahedron, and fluff polymerization Yellow iron ore; anhydrite is also common in heavy ash minerals, its microstructure is more consistent, cylindrical crystalline The often tiny crystals enrichment in its smooth surface; occasionally fluorite, potassium feldspar, anatase, magnesium cordierite mineral. 6 Zhuzhou plant boiler parts slag-like system analysis results show that: the chemical composition of the slag layer, mineral composition different from each other; residue samples mainly composed of amorphous phase silicate constitute the main minerals include: mullite cristobalite, hydrothermal quartz, hematite, quartz, iron spinel and calcium feldspar; slag silicon-rich glass phase is mainly derived from the reaction between the volatilization of SiO vapor condensation and aluminosilicates and other minerals; Samples mineral crystals comprising: a long strip, clastic, granular, diamond, druse and cube ore; melting and decomposition of the minerals in the formation of slag-like porous; viscous SiO vapor formed in the high temperature and ash between small mineral reaction and low temperature eutectic is the main reason of the the Zhuzhou plant boiler slagging. Typical of iron, calcium minerals, quartz and clay minerals in the combustion process of the conversion process were analyzed. The pyrite slagging contribution mainly due to partial oxidation of molten intermediate formed in the reducing atmosphere the wustite SiO2 reaction series of low-temperature co-melt; the calcium mineral decomposition products party calcium stone will reduce ash melting point and gray sticky, causing the slagging; quartz formation of the amorphous phase in the slag, easy restore for viscous SiO vapor at high temperatures and steam for the rest of the deposition of particles in the wall surface condensation facilitate; combustion clay minerals not amorphous silica-alumina oxide is easy with the calcium iron mineral reaction generates ternary, the four yuan low temperature melt, thus speeding up the integration of the remaining mineral.
|