Studies of the relationship between mineral matter and grinding properties for low-rank coals

An Evaluation of the Impact Strength Index as a Criterion of Grindability

“…These properties are influenced by coal rank, petrography, and the distribution and types of minerals (Ural and Akyildiz, 2004). Hower and Wild (1988) studied the relationship between sulfur, petrography, and vitrinite maximum reflectance with HGI for eastern Kentucky coals and found a correlation of 0.64 for which liptinite, reflectance, and sulfur emerged as significant predictors.…”

Energy-Size Reduction of Coals in the Hardgrove Machine

“…As a standard device, the Hardgrove machine is used to measure the HGI of a coal. Studies about the breakage characteristic of a coal and analyses of a ball-and-race mill, which has the similar grinding mechanism as the Hardgrove machine, have been reported in the literature [4][5][6][7]. Austin, Shan, and Wang [8] used the Hardgrove machine modified by the addition of a torque device to study the basic principles of an industrial ball-race mill.…”

Quantification of crystalline (mineral) matter in some Turkish coals using interactive Rietveld-based X-ray diffractometry

“…As defined by Ward (2002), "mineral matter in a coal" embraces three classes of materials namely: dissolved salts and other inorganic substances present in coal's pore water, inorganic elements incorporated within the organic compounds of the coal macerals, and discrete inorganic particles (crystalline or noncrystalline) representing true mineral components. The first two forms of mineral matter that may be described as non-mineral inorganics are significant in the mineral matter of lower-rank coal seams (Benson and Holm, 1985;Ward, 1991Ward, , 1992Ural and Akyıldız, 2004). Regarding coal as a mixture of minerals and organic matter may be valid for higher-rank coals (Ward, 1978).…”

“…However, no quantification estimation of crystalline phases has been carried out using Rietveld-based computational method (SIROQUANT™), with the exception of Tufanbeyli and Elbistan coals (Ural and Akyıldız, 2004). The purpose of the present paper is to study the crystalline (mineral) matter contents of eight Turkish coal samples from Zonguldak (ZO), Çayırhan (ÇA), Soma (SO), Elbistan (EL), Ermenek (ER), Orhaneli (OR), Tufanbeyli (TU) and Tunçbilek (TU), respectively using interactive Rietveld-based full profile XRD.…”