Block Extraction of Himalayan Rock Salt by Applying Conventional Dimension Stone Quarrying Techniques

A salt block is a regular prism of rock salt containing least undesirable cracks which is mainly used for carving artifacts especially salt lamps, tiles and other products. This research work is focused on the comparison of three common and simple dimension stone quarrying techniques including wedges and feathers, expansive cement, and controlled blasting methods for the extraction of rock salt block. The selected techniques were applied at the underground working face of Khewra Salt Mines (Punjab, Pakistan) to extract representative blocks in accordance with a predefined field experimental program. In order to find out the most suitable block extraction technique in terms of the quality of excavated salt blocks, physical and mechanical rock property tests were performed comprising of core recovery, uniaxial compressive strength, Brazilian tensile strength, dynamic Young’s modulus, quality and P-wave velocity. This paper statistically confirms that the rock salt blocks excavated by using wedges and feathers method have higher quality in comparison to the blocks obtained by expansive cement and controlled blasting techniques. Further the results of overall technique wise comparison are also discussed.