Ecological and Economic Substantiation of the Modified Borehole Charges Stemming for Gaseous Waste Reduction

A modified borehole charge stemming, consisting of a suspension of clay material (CM) (> 30% mass) and a surfactant complex (up to 2.5% mass) is proposed. It is justified not only to pursue the goal of increasing blasting efficiency by reducing the borehole charge stemming departure velocity, but also to mitigate the environmental impact of blasting by altering the densitometric and rheological properties of the stemming material. For modifying the composition of the stemming, a densitometric study of CM suspensions in the concentration range of 20–70% mass has been carried out. The deviation of such systems from the additivity law and the behavior of these systems as non-Newtonian fluids due to structure formation processes have been proven; the relative deviations of experimental density values from their additive values have been calculated. Based on densitometric studies of clay suspensions, an approximate polynomial model of the second degree has been developed, that makes it possible to determine the density of suspensions almost up to the critical concentration of structure formation. An important aspect of the proposed technological solution is the availability of the stemming material, its relative cheapness and ease of preparation, and significant adsorption properties. All components of the stemming are eco-friendly; surfactants decompose easily and are permitted in Ukraine and the EU. To substantiate the technological, environmental, economic and legal feasibility of modifying the borehole charge stemming, the authors’ methodology, system of criteria, and computer program have been developed based on Thomas L. Saaty’s analytic hierarchy process using RStudio; the proposed solution is feasible with a probability of 83.4%. The developed methodology also investigates the compliance with the concepts of a circular green economy and sustainable development, and environmental, social, and governance (ESG) principles