El-Nakheil Oil Shale: Material Characterization and Effect of Acid Leaching

Abstract

The ever increasing demand for energy and the progressive depletion of crude oil resources, have renewed interest in oil shale as an alternative fuel resource. Weathered oil shale samples were assembled from El-Nakheil phosphate mine in Quseir area, Eastern desert, Egypt. The oil shale samples were prepared and analyzed by XRD (X-ray diffraction), XRF (X-ray flourescence spectrometry), and optical microscopic techniques. Rock-Eval pyrolysis and total organic carbon were used to study shale hydrocarbon potential. A leaching procedure using inorganic and organic acids was used to selectively dissolve the oil shale associated ash forming minerals.XRD results showed that calcite is the dominant carbonate mineral, whereas primary silicate minerals are quartz and montmorillonite. SEM (Scanning Electron Microscopy) observations indicated that the organic matter is dispersed throughout the rock matrix. The acid soluble fraction upon leaching was determined to be 37.59 and 42.74 wt% by using 5% HCl and 10% HCl, respectively. The TOC has been increased from 20.78 to 29.88 and 34.09 wt% by using 5% HCl and 10% HCl, respectively.

The structure and reactivity of a low-sulfur lacustrine oil shale (Colorado U.S.A.) compared with those of a high-sulfur marine oil shale (Julia Creek, Queensland, Australia)

“…Representative samples of shales were washed with 0.5 M HCl as described by Redlich et al [14] primarily to remove the carbonates and other acid soluble minerals and permit the organic C, N and S contents of the shales to be determined and the H content to be estimated by elemental analysis of the acid-washed shale. It has been shown that HCl of this strength will dissolve all of the carbonates in oil shales [25]. The acid-washed oil shales were also used for solid state 13 C NMR to improve the signal-tonoise ratio and reduce the concentration of paramagnetic materials.…”

Type I kerogen-rich oil shale from the Democratic Republic of the Congo: mineralogical description and pyrolysis kinetics

“…The S1 parameter which was equal to 2.7 mgHC/g rock showed a low content of organic volatiles like bitumen. From these results, we can conclude that the shale rock studied presents a very promising petroleum potential and could be of significant commercial interest by comparing with other reported oil shales (Tissot and Welte 1984;Muhammad et al 2011).…”

Characterization and separation of pyrite from Abu Tartur black shale

“…By measuring the particle size distribution of the overflow hydrocyclone product, it was found that its D90 was about 15 lm. This suggests that the majority of pyrite particle that were found below 15 lm could not being cached as heavies by the Falcon separator.…”

“…Moreover, the speciation of the heavy metals and uranium in the Egyptian oil shale is not yet studied. Pyrite was detected in many of mineralogical studies applied on many of these deposits; in Dakhla Formation west Quseir area [13], in El-Nakheil oil shale in Quseir area [14,15], and in Duwi black shale in Abu Tartur phosphate mine and reached about 6% [16,17].…”