A Novel Application of Egyptian Oil Shale as a Filler in the Production of Lithium Lubricating Grease

This article reports on the preparation and characterization of six formulations of grease based on soybean soapstock and aromatic extracts using oil shale as a filler. The oil shale that occurs within the Quseir–Safaga district is subjected to a detailed petrography, size distribution, mineralogy, and chemical studies. The total extracted hydrocarbon content, using an organic solvent, is analyzed for molecular weight by gel permeation chromatography (GPC). The physicochemical properties of the aromatic extracts are determined. The processing conditions following the blending are optimized to produce the appropriate lithium soap structure, as well as dispersion of the filler. The work also includes a study of the competitive effectiveness of different grades of aromatic extracts and also various percentages of oil shale, along with an evaluation of their effects on the properties of formulated lubricating greases. The prepared greases are assessed in accordance with National Lubricating Grease Institute (NLGI) and Egyptian Standard (ES). It is concluded that the above-mentioned ingredients can be used for the preparation of lithium greases.