An Investigation into the Short Scale Spatial Variability of Sulfur Content in Coal Part II: Analysis of Sulfur in Washed Samples

Abstract

Analysis of longwall channel sample data discussed in the earlier paper by the authors revealed negligible spatial correlation in sulfur content over short distances. As most coal is washed prior to use in power plants, it was decided to investigate the spatial behavior of sulfur in washed samples. This paper discusses the results of the analysis of spatial variability of sulfur in homogeneous size-gravity fractions. Procedures used for data transformations, detection of outliers and estimation of robust and nonergodic variograms are also discussed.

Keywords:

• Key words: Coal washability
• sulfur content
• spatial variability
• geostatistics