Ash properties

Ashing Ashphaltenes Ash properties Ash slagging Asmatane Mst ASN As203... 

Pulverized-Coal Furnaces In designing and sizing PC furnaces, particular attention must be given to the following fuel-ash properties ... 

Ashing, recovery of silver via, 22 653 Ash melting point, coal, 6 727, 781-782 Ash properties, of coals, 12 324t ASHRAE Standard 55 thermal comfort guidelines, 1 818... 

Coal liquefaction, 6 765-766, 832-869 coprossing, 6 856-858 direct, 6 833-858 indirect, 6 858-867 use of steam in, 23 239-240 Coal mining, 6 744-745 Coal-oil coprocessing, 6 833, 856-857 Coal petrography, 6 706-709 Coal petrology, 6 706 Coals, ash properties of, 72 324t Coal slurry pipelines, 6 748 Coal tar... 

Fourier transform infrared (FTIR) spectroscopy of coal low-temperature ashes was applied to the determination of coal mineralogy and the prediction of ash properties during coal combustion. Analytical methods commonly applied to the mineralogy of coal are critically surveyed. Conventional least-squares analysis of spectra was used to determine coal mineralogy on the basis of forty-two reference mineral spectra. The method described showed several limitations. However, partial least-squares and principal component regression calibrations with the FTIR data permitted prediction of all eight ASTM ash fusion temperatures to within 50 to 78 F and four major elemental oxide concentrations to within 0.74 to 1.79 wt % of the ASTM ash (standard errors of prediction). Factor analysis based methods offer considerable potential in mineral-ogical and ash property applications. 

Table V. Principal Component Regression Calibrations For Selected Ash Properties...

Figure 3. PCR Model Results for AI2O3 wt % of Oxidized Ash (Best Model of Ash Properties).

The calibrations obtained are valid over a significant range of each property. It is feasible to predict all these properties from the LTA from a small sample of coal, should that be desired. These results mainly show that the methods employed can model other ash properties which are more closely related to large-scale combustion behavior. This is one area where further study is desirable. 

Clean coal production will undoubtedly help reduce combustion waste, especially if reject material is returned to the coal extraction site. Some ash, especially fly ash, finds useful application, but scope exists for innovative research to improve utilization of coal combustion products. For example, tailoring ash properties to specific applications offers scope for increased utilization, provided tailoring can be done economically. 

Sorensen, L, H., Fjellerup, J., Henriksen, U., Moilanen, A., Kurkela, E. Winthcr, E. (2000). A evaluation of char reactivity and ash properties in biomass gasification. Fundamental processes in biomass gasification. Confidential project report. REAl/3/2000, ReaTech. 91 p. + 3 app. 

The slagging and fouling tendencies of coals largely differ according to the deposit but also differ within the deposit because of widely varying coal composition. Ash properties are so complex that evaluation of coal performance is extremely difficult. The performance of coals in furnaces are further complicated by the processes which control deposition on heat transfer surfaces in boilers. Based on these complications, we must neither deceive ourselves as to the possibility of reliable estimates nor deny the possibility of making a useful estimate of the performance of brown coal in boilers. 

Finding significant parameters for ash properties which predict performance. 

Sulfur forms Ash properties Elemental analysis Mineralogical analysis Trace element analysis Ash fusibility... 

Volcanoes.Usgs.Gov. Ash properties dispersal by wind [Online]. Available http //volcanoes.usgs.gov. 

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