This paper presents the results of experimental studies on desulfurization of high sulfur Indian coal by oil agglomeration using linseed oil. During experimental studies, various operating parameters like effect of pH, particle size, pulp density, agglomeration time, agitation rate and linseed oil dose were studied to find their impact on clean coal properties like sulfur reduction ratio (S/So), ash reduction ratio (A/Ao) and gross calorific value (GCV) ratio (GCV/GCVO). Experimental results showed that raw coal with 5.52% sulfur, 13.47% ash and GCV of 7038 kcal/kg can be beneficiated to produce clean coal with 2.18% sulfur along with 5.32% ash and 7769 kcal/kg GCV. Physico-chemical characterizations of raw and clean coal samples were carried out by using Field Emission Scanning Electron Microscope (FESEM), Fourier Transformation Infrared (FTIR) and Petrographic analysis to appraise the product quality. Microscopic analysis using FESEM confirmed the formation of agglomerates and reduction of mineral matters from coal structure. Petrographic analysis further confirms the increases in vitrinite, inertinite and liptinite from 68.62 to 73.61%, 12.45 to 14.07% and 3.25 to 4.27% respectively in the clean coal along with reduction of pyritic sulfur (from 937 to 3.87%) and mineral matter (from 6.31 to 4.18%). FTIR results infers the reduction of sulfur, oxygen rich hydrocarbons and minerals along with increase of carbon, hydrogen rich hydrocarbons in the clean coal. (C) 2018 Elsevier B.V. All rights reserved.