Augmenting the Stability of OB Dump by Using Fly Ash: A Geo Technical Approach to Sustainably Manage OB Dump at Jharia Coalfield, India

Abstract

This paper is mainly focused over the possible utilization of fly ash along with OB dump to enhance the stability of OB dump and thus provide a sustainable approach for better waste management of both these materials simultaneously. Instability of coal mine overburden (OB) dumps is an important problem in most of the coal mines like Jharia coalfields in India. This is mainly occurring due to sliding nature of the rock material, lack of vegetation etc. Numbers of Environmental and health issues are associated with these unstable OB dumps. As it may easily flow with running water can contaminate the nearby water resource as well as carbonaceous content of the dump causes air pollution due to simultaneous combustion. On the other hand management of coal ash that is produced from thermal plants is also an important task. Dumping of fly ash in open may cause number of environmental problems. Various geotechnical and physical parameters such as particle size analysis, specific gravity, density, and friction angle/cohesion test have been performed to check the stability of OB dump and to analyze impacts of fly ash utilization to stabilize the OB dump.

Effect of fly ash on geotechnical properties and stability of coal mine overburden dump: an overview

“…Rajak et al [56] identified the surface characterization of materials of fly ash (Class F) and OB material using scanning electron microscope (SEM) test and found that OB material has irregular shape however, fly ash has spherical shape. The addition of fly ash in OB material provides the good packaging and bonding which improves the stability of the dump [57].…”

“…Stability analysis of the fly ash mixed mine OB dump materials revealed that 20-25% fly ash can be utilized for stabilizing the dump [58]. Gupta and Paul [57] suggested that 10-20% fly ash can be used to enhance the strength of the OB dump. Rajak et al [56] have evaluate the shear strength parameters of OB material mixed with fly ash (Class F) with and without addition of Ground Granulated Blast Furnace Slag (GGBS) and found that addition of 20% fly ash with OB material causes improvement in cohesion value by 45%.…”

Evaluation of the mechanical properties and critical slope parameters of mine tailings at Enyigba, South eastern, Nigeria

“…It has been noted by Gupta and Paul [23] that slope geometry and the strength of materials on it ultimately determines the stability of a slope. Table 2 shows that the range of the angle of internal resistance and cohesion of the slope materials are 8°-37° and 13-34kN/ m 2 respectively.…”

Fly Ash Mixing With Mine Ob Dumps: An Enviro-Friendly, Clean and Green Method of Disposal

“…The addition of fly ash in the OB dump material changes its shear strength behaviour thereby affecting the stability of dumps. Limited research has been carried out to assess the effect of mixing the fly ash with OB dump material on its slope stability (Singh 2011, Jayanthu et al 2012, Pradhan et al 2014, Gupta and Paul 2016, Dewangan et al 2016. Singh (2011) studied the effect of mixing 30% fly ash on factor of safety for OB dump slope of a height of 120 m under dry and wet conditions using numerical simulation.…”

“…Pradhan et al (2014) also analyzed the stability of dump slope of 60 m height having an overall slope angle of 32° made up of OB dump material randomly mixed with 20% fly ash by weight and found the slope stable. Gupta and Paul (2016) conducted direct shear tests on OB dump material mixed with 10%, 20% and 30% fly ash by weight and concluded that mixing of fly ash in the range of 10% to 20% by weight improves the shear strength of the mixture. The limitations of all the above studies were the inclusion of only sand and silty fractions of …”