Natural stone waste generation from the perspective of natural stone processing plants: An industrial-scale case study in the province of Bilecik, Turkey

Abstract

Natural stone has been used for various purposes, such as for building stone, megaliths, ornamental stone, hunting, and grinding, throughout history. Upon the advent of industrial-scale production for natural stone, both quarries and stone processing plants began to generate a high quantity of waste in large bulk. Natural stone waste is a current worldwide environmental problem. It is imperative to use natural stone waste in other industries and to declare the amount of waste generated by users. This study presents an on-site industrial analysis of the natural stone production process for natural stone waste which has not previously been quantitatively and qualitatively examined on an industrial scale. The study was conducted in nineteen natural stone processing plants, generating almost 98% of the marble produced in the province of Bilecik and 11% of that produced in Turkey. The resulting daily amount of waste generated was calculated on a monthly basis based on current production capacity. Following an analysis, the industrial waste was quantified, with the waste generation mechanism being analyzed and the types of waste being classified by size and quality. The results suggest that a natural stone processing plant generates nearly 1044 tons (solid and sludge) of natural stone waste a day. The waste generated was divided in two parts as sludge waste and large-size solid waste, and then analyzed under three categories. In addition, the samples collected from the plants were evaluated via physical-mechanical tests and XRD analyses. According to the figures of the marble processing plants, it can be said that a mid-scale marble processing plant with a monthly production capacity of 10.000 m2, on average generates a total of 50 tons of waste, comprising 25 tons of solid waste and 25 tons of sludge. It was also observed that natural stone waste was 28% in block cutting and 20% in gangsawing, as a result of cutting operations performed to turn one cubic meter of natural stone into a block. This translates into 756 kg and 540 kg of waste, respectively. Additionally, the storage of natural stone waste dispatched from various plants should be revised, and new categorized landfill areas and storage models should be introduced to individually store solid waste and sludge.