2016-12-23T18:44:59

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In 1996, Georgian mining and extractive industry moved to a new stage as a result of the adoption of a new law on subsoil, which prepared grounds for the development of a legislative framework regarding the use of country’s subsoil and created new economic settings for the industry. Mining and extractive industry play a significant role in Georgia’s sustainable economic development. From 1999 through 2020, the output value of the industry (excluding non-renewable energy resources: coal, natural gas and oil products)is estimated at of 5,6 billion Lari (GEL). The majority of deposits of mineral resources in Georgia are mainly small and medium in size. Considering the current rate of their exploitation, within 15-20 years their majority will be exhausted. Over time, the country’s economy will face a serious problem as it will need to import raw materials. It is therefore important to look for feasible technologies for the application of unconventional raw materials, namely secondary raw materials that come with essential mineral resources. This will allow to maintain the potential of mineral resources of the country. The work presents the outcomes of the Mining Institute’s current studies on qualitative, quantitative and assimilative technologies and possibilities of the application of mining waste as secondary natural resources. Research methodology is based on the principles of Green Economy that implies linking mining and extractive industry to circular economy, aiming at rational assimilation of natural resources by applying the 3R (reduce, reuse and recycle) approach. Within the frames of the study, technologies were developed for obtaining construction, glass and porcelain raw materials (from spoiled rock layers stored and extracted from operating open pit mines of the Chiatura manganese and Bolnisi ore deposits/queries), along with those for manufacturing products with such materials.

Abstract. Explosion protection technologies are based on the formation of a shock wave mitigation barrier between the protection site and the explosion site. Contemporary protective systems use water mist as an extinguishing barrier. To achieve high effectiveness of the protective system, proper selection of water mist characteristics is important. The main factors defining shock wave attenuation in water mist include droplet size distribution, water concentration in the mist, droplet velocity and geometric properties of mist. This paper examines the process of attenuation of shock waves in mist with droplets ranging from 25 to 400 microns under different conditions of water mist location. Experiments were conducted at the Mining Institute with the use of a shock tube to study the processes of explosion suppression by a water mist barrier. The shock tube consists of a blast chamber, a tube, a system for the dosed supply of water, sensors, data recording equipment, and a process control module. Shock wave overpressure reduction coefficient was studied in the shock tube under two different locations of water mist: a) when water mist is created in direct contact with blast chamber and b) the blast chamber and the mist are separated by air space. It is established that in conditions when the air space distance between the blast chamber and the mist is 1 meter, overpressure reduction coefficient is 1.5-1.6 times higher than in conditions when water mist is created in direct contact with blast chamber. IntroductionBlast suppression mechanisms using water mist have been addressed by G. Thomas, Van Winderden, K. Kailasanath, and R. Ananth et al [1][2][3][4]. It has been noted that water mist with fine sprays is efficient for the mitigation of explosions. Research has shown that shock energy attenuation in water mist takes place during the process of aerodynamic droplet break-up and vaporization of child droplets. The main purpose of the existing studies is to determine the effect of droplet size distribution and concentration of water on blast overpressure attenuation in water mist. Significant knowledge has been accumulated in this area, however there still are some gaps that need to be addressed in order to improve the design of protective devices. More specifically, the effect of the water barrier location on the suppression impact remains understudied. A. Resnyansky and T. Delaney have compared mitigation curves for an explosion of a charge in direct contact with water and for an explosion of a charge surrounded by airwater [5]. The comparison has shown that the location of mist in relation to the explosion source influenced phase transformation and water breakdown mechanisms and is a factor affecting overall mitigation performance.