Dolomite type nephrite processing wastes and their application

The demand for ornamental stone material has led to an increase in the amount of rock mass being processed. However, the production of lapidary works and jewelry result in a significant amount of waste. This study aims to investigate the material composition and physical and mechanical properties of the solid wastes generated during the processing of dolomite type nephrite in the Vitim region. The accumulation of such waste leads to increased costs of transportation, storage, security, and negative environmental impact. The majority of dolomite type nephrite deposits are located in the Northwest, Northeast, and South of China, in South Korea, Australia, Italy, and Poland, with a large deposit in the Vitim region of Russia. In this study, the waste from the Kavoktinsky deposit, the most productive in Russian, was used. A visual and petrographic examination of nephrite, skarn and amphibolite which are components of the solid waste, was conducted. The macro- and microchemical composition of nephrite of different colors was studied, and X-ray phase analysis was performed. The decorative properties of the waste were determined. A radiation and hygienic certificate was obtained. The waste has a crushability grade of 1200, abrasion grade of I1, and frost resistance of F400. The study has shown that the waste does not contain grains of incompetent rocks, clay, dust, and clay particles. The solid waste form the Vitim nephrite processing is of high quality and meets the requirements of GOST 8267-93, except for an increased content of flagstone (flattened) and large size fragments. It can be used for the production of ordinary, decorative, and mosaic concrete, decorative plates, interior decoration of premises, bathrooms, and saunas, and the manufacture of souvenir products. However, further research is needed to investigate the application of the waste as a raw material for stone casting and a slow-release fertilizer. The utilization of this waste not only solves the problem of waste disposal but also improves economic performance of mineral extraction.