COMPREHENSIVE USE OF SUBSTANDARD NEPHRITE

Abstract

The relevance. In recent years, there has been an increased interest in nephrite. Demand for it requires the development of new fields. However, more than 70 % of the extracted nephrite containing raw materials is of poor quality, unclaimed, having a negative impact on different spheres of life. In addition, there is a plunder of substandard nephrite and its involvement in illegal trafficking. In this regard, its use in production is an urgent task not only from the environmental but also from the technological side. The main aim of the research is to establish the possibility of using substandard nephrite containing raw materials in production of building materials. Objects: nephrite-containing rocks of Ulan-Khoda Deposit of Eastern Sayan. Methods: chemical, granulometric, mechanical methods of analysis. Results. The characteristic of Ulan-Khoda Deposit of Eastern Sayan is given. Substandard rocks formed as a result of extraction and separation of valuable fractions from nephrite containing raw materials were studied. It is established that break-stone from them has high quality. It belongs to the First group of gravel, resistant to all kinds of decay and to the environment. The sand from the crushing screenings of substandard nephrite is large sand with grains of angular shape, ensuring the quality of the obtained materials. The acidity modulus of the rock was determined to be 1,59; basicity modulus – 0,63; silicate modulus – 12,66; and quality factor – 0,66. According to its indicators, substandard nephrite is of high quality and can be used in production of building materials. However, it is established that it does not have the ability to harden on its own, but is able to act as a hydraulic additive in composite materials. Cement binding compositions with the addition of substandard nephrite containing raw materials were obtained, their physical and mechanical properties were studied. It is established that the strength of materials depends on the amount of additives and the grinding time of the raw mixture. The technological parameters of obtaining heavy concretes using nephrite were determined. Summary. Thus, substandard nephrite is a promising raw material for production of new types of building materials. Its involvement in production turnover will allow extracting additional profit in processing nephrite-containing raw materials, as well as minimizing the negative impact of mining enterprises on the environment. In addition, the disposal of substandard nephrite prevents its plunder and involvement in the illegal trafficking.

Keywords

• mining waste
• substandard nephrite
• gravel
• building materials
• compressive strength