Explosives Engineering Commons^™

Compressibility Behavior Of Conditioned Sandy Clay Considering The Physical Degradation Of Foam: Tunneling Issue, Mœz Selmi, Yahya Alassaf, Mariem Kacem, Mehrez Jamei

Journal of Sustainable Mining

Surfactants in the form of liquid foam are commonly used for ensuring the fluidity of conditioned soil during shield tunneling in mining zone. The compressibility can be significantly affected, depending on the percentage of fine soil. Thus, this paper investigates the compressibility of foam-conditioned fine soil. Oedometric tests as a function of the percentage of foam have been performed. Foam’s stability was analyzed, considering a laboratory soil made from 40% kaolinite and 60% of sand and mixed with a foaming agent based on an anionic surfactant. Experimental results showed that the foam stability was manifested through a reduction of the …

Geophysical Imprint Of Mining-Induced Rock Mass Deformation In The Area Of Construction Disaster In Bytom (Poland), Andrzej Kotyrba, Łukasz Kortas

Journal of Sustainable Mining

The paper presents the analysis of the results of geophysical surveys conducted in the mining area located in Bytom – Karb (USCB, Poland) in the aspect of identifying the causes of significant damage to the complex of inhabited tenement houses which occurred in 2011. The surveys were carried out by microgravimetric and GPR methods. The construction disaster was caused by the exploitation of one of the hard coal seams at a depth of about 800 m along the mining longwall running underneath the settlement. The terrain deformation parameters exceeded the forecasted values, and in several places discontinuities took linear forms …

Prospects For Thiourea As A Leaching Agent In Colombian Gold Small-Scale Mining: A Comprehensive Review, Johana Borda, Robinson Torres

Journal of Sustainable Mining

Thiourea, as an alternative medium, is one of the most promising leaching agents for gold recovery by its commercial benefits and research challenges associated with performance and environmental impacts. This review article describes the operational conditions for the use of Thiourea vs cyanide, its chemistry, limitations, toxicity factors, environment, and recovery processes. Although thiourea gold extraction processes have not been applied on a large scale due to the instability of the reagent, its potential to overcome the limitations of cyanide is attractive to the process; with pH, potential, oxidant dosage, and temperature control, solubilized gold thiourea species are achieved. These …

Analysis Of The Application Of Methane-Bearing Capacity Test Methods In The Conditions Of Polish Mining, Marcin Karbownik

Journal of Sustainable Mining

The methane hazard is one of the natural hazards occurring in hard coal mining. The content of natural methane in hard coal seams, the so-called methane-bearing capacity, is one of the key parameters that allow for proper assessment of the methane hazard and the state of the threat of gas and rock outbursts. For safety purposes, there is a constant need to improve the methods for the determination of this parameter. In the conditions of Polish mining, the method used for methane-bearing capacity determination is the direct drill cuttings method. This paper contains a comparative study presenting three different methods …

Gravity Field Changes During Deep Exploitation Of The Coal Longwall And Their Relation To Stress Distribution And Seismic Activity, Łukasz Kortas

Journal of Sustainable Mining

Mining operations cause volumetric deformations within the rock mass and changes in its density, to which the gravimetric method is sensitive. These changes are particularly well seen in periodic measurements of the local gravity field. The paper analyses the relationship between the movement of a longwall in a coal seam and the change in the distribution of the gravity field in time and space observed on the ground surface. Relative gravimetric measurements were carried out in six series between 2018 and 2020; before the start of coal extraction, with the progress of the longwall and after the cessation of mining. …

The Mechanics Of Precision Presplitting, Anthony Joseph Konya

Doctoral Dissertations

"Precision Presplitting is a widely used method of presplit blasting for the mining and construction industries. In recent years considerable effort has gone into the development of empirical equations based on field data to be able to better design the Precision Presplit for various rock types and structural environments. However, the most widely discussed theory about the mechanics of the presplit formation, that of shockwave collisions, does not appear to be applicable for this method of presplitting.

This research has disproven this theory based on insufficient magnitude of the shockwave from modeling with basic wave mechanics. Other authors have suggested …