Sustainable growth of Indian coal industry: policy perspectives and recommendations.


Abstract: Coal is the most abundant fossil fuel resource in India, and the country’s industrial and economic heritage has been built upon indigenous coal. India is the world’s 3rd largest energy consumer after China and USA. However, as the country goes through profound economic and societal
transformations, such as economic and population growth, urbanization and industrialization, energy demand is expected to increase substantially. Looking into the significance of coal not only in the energy-mix but also in the economic development of India, the paper is aimed at an assessment of
coal sector in India which shall also help contextualize the place of coal in India’s contemporary energy, industrial and social sectors amidst a range of developments – both national and international – related to coal sector. The authors looked into various aspects of Indian coal sector from a policy
perspective and suggested subsequent course of action so the same can be used by Indian coal mining stakeholders towards the larger goal of sustainable growth of coal sector including coal mining. The analysis produced important policy recommendations for coal industry stakeholders including the
Indian Government, who is the sovereign owner of coal mine acreage in India.

Keywords: Coal; dry fuel; coal mining; coal regulations; sustainable growth; decarbonization; Industry 4.0

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Rheological Behaviour Of Water Based Mud Formulated With Sodium Hydroxide (Naoh) Plant Extracts


The rheological behaviour of drilling mud formulated with sodium hydroxide extracts of Bitter-leaf (BL), Pawpaw (PL), Almond (AL) and Moringa (ML) leaves applied as surfactant (emulsifiers) was studied. The rheological properties (plastic viscosity (PV), yield point (YP), and gel strength) of the mud
were measured using standard procedures. The mud specific gravity for BLEM and PLEM was observed to give same value (1.08) as that of the C1 mud. pH of the formulated mud were all alkaline and in the order BLEM (8.6) > PLEM (8.3) > ALEM (8.3) > C1(8.3) > MLEM (8.2) > C2 (8.2). The highest PV (19cP)
was recorded by PLEM at 30ºC, while the least value (6cP) was by C2 at 60ºC temperatures. Highest YP (70 1b/100ft2) was recorded by C2 while the lowest YP value (22 1b/100ft2) by C1 both at 30ºC. Gel strength at 10 seconds showed reduction in value as the temperature increased for MLEM, ALEM,
C2 and C1 formulated mud and recorded maximum of 45 1b/100 ft2 at 30ºC for C2 while the lowest gel strength was reported by C1 at 60ºC. The results obtained from the study showed that the various alkaline plant extracts used as emulsifying agent have no negative effect on the rheological properties
of the formulated mud, rather it enhances the rheological properties even after aging of the mud at 65oC. These results therefore, show the need to use the various plant extracts as alternative additive (emulsifying agent) in the formulation of water based drilling mud.

Keywords: NaOH-plant extracts, rheological properties, surfactant, drilling mud, emulsifying agent

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Design Of Remnant Pillar In Mechanized Depillaring Using Continuous Miner


Abstract: Ribs and snooks are the critical natural support at the goaf edge in the mechanized depillaring operation of the bord and pillar mining system. The pillar extraction has been carried out by taking the slices and leaving ribs and snooks during the depillaring operation. Remnants are the remaining portion of the extracted pillar. The depillaring operation leads to an unsupported roof, and the immediate unsupported roof imposes its weight on the pillar (remnant) under extraction. The remnant’s purpose is to provide a necessary reaction to the overhang to restrict roof failure until the pillar’s final slice. The remnant’s stability during depillaring operation has been accessed in the study
using three-dimensional numerical simulations. A scheme has also been proposed in the study to evaluate the factor of safety (FOS*) of the remnant pillar in the residual phase at different stages of slicing operation. A case of an Indian coal mine using the fish-bone method has been chosen for the
study. A typical depillaring stage has been selected for the extraction of the pillar using the fish-bone method. The numerical simulation of the considered panel provides the vertical stress and yielding profile on the pillars at different stages of depillaring. The simulation results show the influence zone
up to one pillar from the goaf edge. The immediate intact pillar shows considerable yielding of about 60% of the pillar area. The remnants have completely yielded during the slicing operation but provide a reaction to the immediate strata. The remnant should provide the reaction to the immediate roof till taking the final slice from the pillar. The remnant’s FOS* is calculated by taking the ratio of reaction offered by the remnant (numerical simulations) and the weight of the overhang (estimation). The area’s borehole section shows two layers of medium to coarse-grained sandstone as an immediate
stratum. The weight of the immediate strata has been estimated in the study considering the immediate strata’s thickness. Two different scenarios of immediate strata thickness (i.e., 4.75 m and 9 m) have been considered in the study to evaluate the remnant’s FOS at different depillaring stages.

Keyword: Remnant, ribs/snooks, fish-bone pattern, continuous miner, mechanized depillaring, numerical simulation.

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A Review On Underground Mine Ventilation System


Abstract: In the field of mines, there are dozens of methods concerned with the optimization of ventilation system in underground mines and how bad ventilation system is playing a major effect on miners and mine’s activities. The ventilation system is considered very important because it consumed
high energy of mines of total power consumption. This paper is a review of previous studies, which have been done before on design of ventilation system and its optimization methods like, using of software tools to simulate the numerical equations based on the pressure, temperature, flow rate,
and other effected parameters, which are recorded by various ways of surveying. It has observed that Ventsim software is widely used because of its flexibility in dynamic simulation based on various parameters included deep, fan position and flow rate.

Keywords: Ventilation, underground mine, software, atkinson, hardy cross method, Kirchhoff’s.

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Surface subsidence monitoring in mining area of SBAS-InSAR based on Sentinel-1A


Abstract: In this study, the surface subsidence caused by underground mining is monitored by the technique of SBAS-InSAR. The second west mining area of Longshou mine, Jinchang Jinchuan Cu-Ni sulfide mine, Gansu province, is selected as the research area for the experiment. The 29 scene elevation rail Sentinel-1A image data from 2019.03-2020.3 are analyzed for the sequence analysis of the SBAS-InSAR. The vertical subsidence rate and cumulative subsidence results of the surface sequence of the mining area are obtained. According to the study, the minimum error of cumulative sedimentation between SBAS-InSAR and D-InSAR is 0.1mm, the maximum error is 21.37mm, and the median error is ±6.65mm. The minimum error of cumulative settlement between SBAS-InSAR and levelling is 0.66mm, the maximum is 23.74mm, and the median error is ±10.79mm. The results show that the application of the SBAS-InSAR technique in the monitoring of surface subsidence in the mining area is reliable, which provides an important basis for the subsequent safe mining in the mining area.

Keywords: SBAS-InSAR; D-InSAR; surface subsidence; levelling; time series analysis.

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Strengthening of oil exporters’ position within OPEC+ in the world oil market


Abstract: The current petrodollar system has become a key factor in US economic power by creating external demand for US dollars and treasury bonds, which has allowed accumulation of the state debt without any change in actual credit solvency. The mechanism of this interaction is based on the
conclusion of an agreement between the United States and Saudi Arabia, to which joined other OPEC countries subsequently. As a result, OPEC countries pledged to sell oil on the world market exclusively for US dollars. In exchange, the United States granted preferential loans and technology to petroleum
exporting countries. An increase in oil production in the United States alongside growth in exports has neutralized US dependence on oil supplies from OPEC countries, resulting in the transformation of the petrodollar system and a shift in the balance of power in the world oil market. The US had no need to interact with OPEC countries, and the strengthening of sanctions imposed by Western countries against third countries has contributed to the establishment of a new balance of power in the oil market, through coordination between OPEC+ exporters. A key feature of the change in the position on the world oil market was the new status of the United States, turning from one of the leading oil importers to a world-class exporter. This situation led to a reorientation of OPEC to other markets and to competition with the United States for a share of the world oil market. As a response, the OPEC+ format was created, which led to an increased influence of exporting countries on the oil market, which is confirmed by the conclusions of the built mathematical model based on the analysis of correlation dependencies of dependent and independent variables used to construct regression
equations. The dynamics of world oil market prices and the median values of OPEC countries’ currencies against the US dollar were selected as dependent variables. Variables that impact the formation of dependent values are the US dollar index, the level of oil production by OPEC countries and the interest rate on federal funds of the US Federal Reserve. The equations and correlation
analysis were based on monthly data from January 2007 to October 2020. To assess the changed nature of the influence of OPEC countries on the global dynamics of oil prices, the time interval was divided into two intervals. The first selected time interval covers the period before the creation of the OPEC+ format: January 2007 – November 2016. Accordingly, the second selected time interval includes the duration of the OPEC+ agreement: December 2016-October 2020. To determine the effective influence of the considering variables on the results obtained at the initial stage, the correlation value
was set within – 0.5 d” R e” 0.5, which allowed us to filter out variables with insignificant correlation. After obtaining the correlation dependencies, all pairs of dependent and independent variables were analyzed for approximating functions, which allowed us to study the nature of the dependence in more detail and more accurately construct the regression equations.

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Shale oil and ecology in Australia – the search for balance


Abstract: Today Australia is one of the main mineral resources exporters in Asia. Besides, the country possesses huge reserves of shale oil and gas. The estimation of these resources extraction potential without any harm to country’s ecology and society is one of the key aims of this article. The authors
research an export and import dynamic of hydrocarbon by Australia with the aim to identify an economic effect from the beginning of shale oil extraction in 2011. Besides, according to expert community’s opinion, there is the emission dynamic of carbon dioxide, which is one of the key factors, determining the environment pollution after the beginning of shale oil extraction in Australia. The major challenge of the article is to estimate the difficulty in real correlation between the ecology and the financial benefits for the economy, as these two factors are loosely connected and the index of additional harm to wildlife and people cannot be directly calculated in financial losses. The major
contribution of the article is the development and comparison of the two scenarios of oil extraction and exports with or without frocking bans in Australia. The authors come to the conclusion that positive effects from shale oil and gas extraction for country’s economy do not surpass negative effects
for ecology; thus, the authors suggest to use the shale oil reserves only as the strategic resource for economic recovery after crises and at the present moment it should be to realize the shale oil extraction in test mode.

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Planned redesign of beehive coke ovens for pollution control and power generation


Fossil fuel based thermal power or ovens not only exude greenhouse gases and pollutants but transfer enormous amount of waste heat up in air. Heat gets enveloped in the stratosphere and circulate around the earth; escalating global warming. France, Czech Republic, Slovakia, Austria, Andorra,
Luxembourg, Poland and Germany made it the hottest June on record in 2019. Around 50 coke ovens around Dhanbad are losing and facing closure, with fate of employees doomed. Jharkhand State Pollution Control Board, Dhanbad had been issuing letters to the small-scale refractory and beehive hard coke-ovens to bring down stack gas emissions to below 150mg/Nm3 of suspended particulate matter (SPM), equivalent to the standards of large thermal power plants, deploying electrostatic precipitators (ESP). Some locally made pollution control devices were deployed, but these reduced the chimney draft and coking time increased. Installation of wet scrubbing methods would not be
economic and slow down production. With experience as the Manager of a by-product coke oven, the chimney detour method with mechanical exhauster suggested for beehive coke oven. Proposed design not only can generate power, but also trap pollutants by a kind of wet scrubbing and produce
by products like coal tar. Various associations of small-scale hard coke ovens and refractory industries had approached The Institution of Engineers (India), Dhanbad Local Centre. In this paper, the authors briefly present how waste heat can be converted to power, while absorbing pollutants in hydraulic
main in the unique chimney detour method and producing coal tar, exuding clean gas.

Keywords: Flue
gases; coke ovens; hydraulic main; chimney detour method; thermodynamics; converting pollutants.

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