Emplacement of Mine Rejects in Underground Voids: Research Report

This report explores the research methods for engineers, focusing on the emplacement of mine rejects in underground voids. It addresses the environmental challenges posed by mining waste, particularly the rejects produced during coal washing, which can amount to 300,000 tonnes annually. The literature review highlights the problems of storage space exhaustion and the environmental impact of transporting rejects. Various emplacement techniques, including backfilling methods and the use of high-density slurry, are discussed in terms of their effectiveness in preventing underground void creation and mitigating environmental damage. The report also raises questions about waste management practices, the utilization of waste materials, and the regulation of waste disposal, emphasizing the need for eco-friendly and economically viable solutions to minimize the adverse effects of mining activities.

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Running head: RESEARCH METHODS FOR ENGINEERS
Title: Emplacement of mine rejects in underground voids- technologies and challenges
Name of the Student:
Name of the University:
Word Count: 3000
Referencing: Harvard
Date: 11.10.2018

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Running head: RESEARCH METHODS FOR ENGINEERS
Abstract
This paper throws light upon the research designs and methodology on the basis of research
methods for engineers and lays stress upon mining. The various problems relating to mining and
the waste and rejects which emitted out of it are given importance to. These rejects can be a
threat to the environment and poses great difficulties when they are left neglected. The research
question beneath deals with the various doubts that has come across in the modern society while
dealing with management and regulation of rejects.

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Running head: RESEARCH METHODS FOR ENGINEERS
Table of Contents
Introduction......................................................................................................................................5
Literature Review............................................................................................................................5
Design Plan......................................................................................................................................9
a) Research Question:...................................................................................................................9
b) Related Work:...........................................................................................................................9
c) Design:.......................................................................................................................................10
Literature Planner..........................................................................................................................11
Reference: 1...............................................................................................................................11
Reference: 2...............................................................................................................................11
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Reference.......................................................................................................................................16

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Running head: RESEARCH METHODS FOR ENGINEERS

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Running head: RESEARCH METHODS FOR ENGINEERS
Introduction
Mining is a process in which different minerals are being extracted from inside the earth, there
are many problems which are created. The soil is eroded, the surface water is polluted, the soil
gets contaminated, the biodiversity is lost, sinkholes are created, contamination due to release of
chemical effluents, and many other forms of environmental degradation take place (Crankshaw,
2017). During the process of mining the mined coal at the site is washed. This is done in order to
produce the coking coal of high quality. At this time of washing this coal is separated from the
waste rock. The siltstone and the shales are a part of the entire mined material comprising almost
17 per cent of it. Due to this entire mining process every year at an average rejects amounting to
around 300,000 tonnes are generated. The way or the place of disposal of this mining reject is a
major concern as it leads to many environmental hazards. The rejects from these coal mines are
also utilized for the building the infrastructure of the townships surrounding the mining area. The
sports fields or other areas can be constructed using these rejects from the mines. In the different
sites of mining the rejects are also stored.
Literature Review
According to Smoliński, (2014) the storage space for the rejects from the mining activities is
getting exhausted since the 1990s. There are different emplacements facilities out of which some
are underground and some rejects are transported to a different area for emplacement. The
transportation of the rejects through the roadways creates a lot of noise pollution as well as emits
a lot of dust. According to Duarte, et.al, (2015) the various mining activities create air pollution
as well. The visual amenity is also affected by the mine rejects and their emplacement. Besides,
the road safety is also hampered as such heavy rejects are being carried. The first thing that

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Running head: RESEARCH METHODS FOR ENGINEERS
should be abolished about emplacement of mine rejects is that through the townships these
rejects should not be transported to other sites for storage. This is important because trucking the
mine rejects creates a lot of environmental problem. The future development of the mining firms
can be enhanced through the better storage and emplacement of the mine rejects. Much of these
rejects are dumped into the underground voids for emplacement of the mine rejects. For finding
the main problems in the emplacement of mine rejects, the investigations are made for surface
field impact of these rejects. Moreover, the high density slurry is also abandoned in many
underground sites. The emplacement method can be further developed with the help of pilot
underground plant. The various application techniques are available for emplacement of rejects
from mines among them the best and least environment damaging techniques must be applied.
According to Prusek, Rajwa, Wrana and Krzemień, (2017) the emplacements of the rejects from
the mines can cause problems like cavity, over hanging goof, roof caving, etc. These can be
prevented by proper method of backfilling. The burden which is present above the main mineral
for which one is mining has to be removed. In order to remove this over burdening material
before extracting the needed mineral much reject is generated. The different overlying strata’s
roofs can be backfilled using these rejects. For the emplacement of all the mine reject the major
concern is the safety of the roads and townships and the earning of economic profits through this
process. The material used in backfilling comes from various sites which need to be transported
to the required area. This transportation of the material is costly and also consumes a lot of
valuable time (Wills and Finch, 2015). The creation of underground voids can be prevented with
the use of the over burdening materials. These materials are originating from the underground
mines and implemented in the process of preventing such underground void creation. The
disposal of the various types of mine wastes can help in making this mining a profitable venture

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Running head: RESEARCH METHODS FOR ENGINEERS
for the organizations. The economic effectiveness of the mining activity is dependent of its
waste management and disposal. All the techniques available for backfilling are not effective in
case of preventing the creation of underground voids. Some of these are very effective methods
implemented in the operations of backfilling and help to stop the underground voids. Among
these backfilling methods the mill tailing is used in the void filling in case of the metal mining
activities as stated by Ma, Sun, Yang and Wang, (2015). In metal mining related void filling,
there are various mixtures used. The high density slurry does not consume much time and they
are also economically fruitful. The underground voids in many cases can be stopped or prevented
with the use of the fly ash mixed with water. In this case the process of close packing is also
implemented which helps in the usage of the Aeolian sand as a material for backfilling. Britton,
Dunne and Wilkinson, (2015) stated that this process of close packing is very optimal in use and
sourceful at the same time. The managements of the different organizations should try not to
dump their wastes without a proper method of disposal. For making production faster, the
different managements of the mines try to dispose their rejects as soon as they complete their
mining activity. But the mining organizations should not dispose their wastes after removal of
their over burdening materials. There are many construction projects which are taken up for the
welfare of the civilians in the society. In these projects the over burden materials are needed
along with a lot of soil. These materials are available in the huge mines. According to Wang,
et.al, (2014), there are good results of emplacement shown by the hydraulic method of
backfilling. In this method the underground void creation is also stopped. According to Guo,
et.al, (2014) the other method is that of solid filling in which the natural roof is made out of the
canopy which is facilitated by supportive systems. In stopping or preventing the process of
underground void, the supports must be provided systematically. The safety of the people and the

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Running head: RESEARCH METHODS FOR ENGINEERS
miners can be ensured with the help of this support system. The requirements of the systematic
support works is that they need the machines for mining, the proper infrastructure, etc. so that the
miners can work comfortably and complete their work within time. In some mines, even today
the old techniques of reject disposal are being used. However, they are not giving very
disappointing results. The mines’ waste is collected in an effective manner. The usefulness of the
mine wastes also increase with better disposal of the rejects. The removed over burden from the
mining activities is also used for the purpose of making roads. The entire process of mining
reject disposal can help in stopping the void in underground. As stated by Eyal, (2015) the
profitable use of the mining rejects is possible when it is implemented in the stopping of the
process of underground void creation. Due to the mining activities a lot of noise pollution is
created which leads to environmental degradation as well as health problems among the people
working in them mines as well as those who live in the town areas near the mines. Wang, Li and
Wang, ( 2016) states that in case of the voids in the underground created due to the coal mining
activities’ over burden materials lead to the transfer of many things like oxygen, groundwater,
methane, heat, exhausts like gases and materials of fire - fighting which impact the underground
environment. This has been suggested in most cases that the gob vent boreholes’ inlets are to be
arranged in such a way so that they are placed near the middle of the zone for bed separation.
This is done in the long wall mining’s early stages. They can also be arranged near the perimeter
at the center during the later mining stages. It is suggested that the inlets of gob vent boreholes
should be arranged near the center of the bed separation zone in the early stages of long wall
mining, and around the perimeter in middle to late stages of mining.

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Running head: RESEARCH METHODS FOR ENGINEERS
Design Plan
a) Research Question:
After a close perusal of the above information, the questions that arise are as follows: what are
the various problems that come forth while dealing with the rejects of the mining works? How
far is the storage area is getting hampered due to the reckless displacement of waste materials
discharged from the mining process? Other questions that crop up are, what are the diverse ways
in which the management is taking steps to regulate the disposition and disposal of wastes
coming out from the mines? What are the different ways in which these waste materials could be
utilized for the betterment of the society?
b) Related Work:
Mining is an important process in the contemporary era and hence it cannot be done away with.
The wise way to deal with it is to deal with all the problems relating to it. The rejects and wastes
that come out from the mining process can be disastrous for the environment. Since it leads to
occupation of lot of space, a wise way would be to create sanitary landfills out of the emitted
wastes. Recycling of wastes is also a good option. These stated methods in the research design
are both eco friendly and pollution free as well. Another problem from it is the health condition
of the miners. They are exposed to great threats and often suffer from respiratory and heart
diseases. Extensive and unscrupulous mining however is a resultant factor for creating an
imbalance beneath the surface of the crust of the earth. The hunger for receiving more and more
minerals often lead to disastrous effects and other natural disasters like earthquakes,
displacement of tectonic plates etc.

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Running head: RESEARCH METHODS FOR ENGINEERS
Upon answering the question relating to the utilization of rejects from mines, the wastes pose a
threat to the environment. It hampers the health conditions of all the living beings. When the
wastes cannot decompose themselves on time, they become a burden on earth. Since the
population is increasing around the world, the immediate requirement for it is more space. But
due to the dumping of rejects, the space remains occupied. It becomes very important to deal
with these problems and find the right solutions.
c) Design:
In order to curb the serious threats rising from the rejects and wastes from the mining process,
the first design would be to recycle the wastes for the betterment of the society. Improved
techniques of accumulation, separation and disposal of rejects has to be made out and also in the
most scientific ways best suited for the society. Creation f sanitary landfills is a smart measure
where the wastes would be dumped and covered. The three Rs would be an effective measure
whereby the rejects would be reduced, reused and recycled. The reusing of the products helps in
saving other methods. The wastes which could be decomposed by themselves should be left
with. In this process of decomposition, energy would be created. Another process is by the
incineration of wastes whereby thermal energy could be produced easily and if it is done in the
right way, it would not be polluting. Other designs include composting whereby the rejects are
transformed into useful manure and natural fertilizer. The process of worm farming and
gasification are efficient means of reducing the waste products that come out from the mining.
These designs could prove to be effective methods while dealing with the waste and rejects
coming out of mines. They can be very useful for the society as well as for every people living in
the environment when they are correctly used.

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Running head: RESEARCH METHODS FOR ENGINEERS
Literature Planner
Reference: 1
Authors: Britton, T.B., Dunne, F.P.E. and Wilkinson, A.J
Year of Publication: 2015
Title of Article: On the mechanistic basis of deformation at the microscale in hexagonal close-
packed metals. Proc. R. Soc. A, 471(2178), p.20140881.
This enumerates and throws light upon the micromechanics and distortion of procedures in a
hexagon shaped closed and compactly processed metals. A vivid description of the solo crystal
behavior relating to the crystallographic slip and plastic anisotropy, which involves the
differentiation between an specific items physical characteristics. It also deals with the distortion
similarities.
Reference: 2
Author: Crankshaw, P.,
Year of publication: 2017.
Title of Article: Mining and minerals. In Geography and economy in South Africa and its
neighbours (pp. 63-80). Routledge.
This chiefly deals with the extracting of minerals from the mines of the huge continent of south
Africa. The mines under the South African government are too incorporated while the impacts of
mining are dealt with. The laws which were framed for the mining purpose are discussed and its
link with the environmental factors are also dealt with. The british model of shifting the balance
is emphasized and put importance to.

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Running head: RESEARCH METHODS FOR ENGINEERS
Reference: 3
Authors: Duarte, M.H.L., Sousa-Lima, R.S., Young, R.J., Farina, A., Vasconcelos, M.,
Rodrigues, M. and Pieretti, N.,
Year of publication: 2015.
Title of Article: The impact of noise from open-cast mining on Atlantic forest
biophony. Biological Conservation, 191, pp.623-631.
Technophony deals with the noises and sounds emitted naturally from the activities of human
beings while they are engaged in work. It mainly indicates a negative effect as it disrupts the
smooth communication amongst animals. Being an important activity in Brazil, mining often is
done in the forests and jungles. The various sounds are examined and compared with the natural
sounds during the mining process in these forested areas.
Reference: 4
Author: Eyal, I.,
Year of Publication: 2015, May.
Title of Article: The miner's dilemma. In Security and Privacy (SP), 2015 IEEE Symposium
on (pp. 89-103). IEEE.
The enthusiastic involvement of the volunteers are given importance to in this article. Their
involvement is in the process of mining while dealing with the advanced computerized currency.
This agenda is widely accepted in the modern era. Bit coin is one such digitalized currency
which serves this purpose. A miner can achieve various useful tactics from this.

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Running head: RESEARCH METHODS FOR ENGINEERS
Reference: 5
Authors: Guo, G.L., Zhu, X.J., Zha, J.F. and Wang, Q.,
Year of Publication: 2014.
Title of Article: Subsidence prediction method based on equivalent mining height theory for
solid backfilling mining. Trans Nonferrous Metals Soc China, 24(10), pp.3302-3308.
This articles lays importance upon the technology of backfilling mining method. This is at equal
foot with the height theory of mining. The description and their modes of election are also
described as a guideline. When the different mining processes are differentiated, the
measurement in relation to the heights, quantities, the subsidence factors are laid stress. Solid
backfilling, the dealing with the dilapidated zones and also accompanying the brittle zones are
laid upon.
Reference: 6
Authors: Prusek, S., Rajwa, S., Wrana, A. and Krzemień, A.,
Year of Publication: 2017.
Title of Article: Assessment of roof fall risk in longwall coal mines. International Journal of
Mining, Reclamation and Environment, 31(8), pp.558-574.
When below the earth dimensions are measured and viable inferences can be drawn from the
above depending upon the ceiling, long walls of the coal mines are determined efficiently. This
article incorporates a practicable outlook towards the advanced and desired techniques which
pushes the examiners to understand the actual capacity of the roof falls. It comprises of various
techniques relating to roof falls.

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Running head: RESEARCH METHODS FOR ENGINEERS
Reference: 7
Author: Smoliński, A.,
Year of Publication: 2014.
Title of Article: Analysis of the impact of physicochemical parameters characterizing coal mine
waste on the initialization of self-ignition process with application of Cluster Analysis. Journal
of Sustainable Mining, 13(3), pp.36-40.
The basic aim of this article is to understand and examine the physical and chemical parameters
which distinguish coalmines rejects with other wastes. This is a self starting procedure and the
system of cluster analysis is also applied. It also brings about the same specimens of coalmine
rejects amongst the physical and chemical parameters. This mechanism also affects hierarchical
method of cluster analysis.
Reference: 8
Authors: Wang, S., Li, X. and Wang, D.,
Year of Publication: 2016.
Title of Article: Void fraction distribution in overburden disturbed by longwall mining of
coal. Environmental Earth Sciences, 75(2), p.151.
The gaps in overburden separated by coal mining gives various ways leading to the transmission
of the necessities of life like water, heat, oxygen, groundwater. It also includes methane, exhaust
gas from the biodiversity. The caved areas and the brittle areas are divided into the bed
separation zone and fissure areas. The Antaibao coalmine located in China are compared with

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and further calculations and theories drawn from it. This article also lays stress upon the gaps
based on the fraction distribution models as it was termed to be.
Reference: 9
Authors: Wang, T., Zhou, W., Chen, J., Xiao, X., Li, Y. and Zhao, X.,
Year of Publication: 2014.
Title of Article: Simulation of hydraulic fracturing using particle flow method and application in
a coal mine. International Journal of Coal Geology, 121, pp.1-13.
This article familiarizes with the process of hydraulic breaking or the phenomenan of fracturing
the gas absorption of coal under extreme conditions. Examples of high pressure is given while its
transportation in the fluid form to the crevices. The simulation of hydraulic breaking determines
the link among the macroscopic and mechanical levels which is dependant upon the scientific
particle flow code.
Reference: 10
Authors: Wills, B.A. and Finch, J.,
Year of Publication: 2015.
Title of Article: Wills' mineral processing technology: an introduction to the practical aspects of
ore treatment and mineral recovery. Butterworth-Heinemann.
This article throws light upon the various shades of treatment of ore as an introductory
explanation. The mineral processing and mechanism are referred to while explaining this
concept. This processing is referred to because it has been prevalent over the past thirty years
providing the actual methods of practice for reviving minerals from mines.

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Running head: RESEARCH METHODS FOR ENGINEERS
Reference
Britton, T.B., Dunne, F.P.E. and Wilkinson, A.J., 2015. On the mechanistic basis of deformation
at the microscale in hexagonal close-packed metals. Proc. R. Soc. A. 471(2178), p.20140881.
Crankshaw, P., 2017. Mining and minerals. In Geography and economy in South Africa and its
neighbours. 35(5), pp. 63-80.
Duarte, M.H.L., Sousa-Lima, R.S., Young, R.J., Farina, A., Vasconcelos, M., Rodrigues, M. and
Pieretti, N., 2015. The impact of noise from open-cast mining on Atlantic forest
biophony. Biological Conservation. 191, pp.623-631.
Eyal, I., 2015. The miner's dilemma. 7th ed. Abingdon: Routledge.
Guo, G.L., Zhu, X.J., Zha, J.F. and Wang, Q., 2014. Subsidence prediction method based on
equivalent mining height theory for solid backfilling mining. Trans Nonferrous Metals Soc
China. 24(10), pp.3302-3308.
Prusek, S., Rajwa, S., Wrana, A. and Krzemień, A., 2017. Assessment of roof fall risk in
longwall coal mines. International Journal of Mining, Reclamation and Environment. 31(8),
pp.558-574.
Smoliński, A., 2014. Analysis of the impact of physicochemical parameters characterizing coal
mine waste on the initialization of self-ignition process with application of Cluster
Analysis. Journal of Sustainable Mining. 13(3), pp.36-40.
Wang, S., Li, X. and Wang, D., 2016. Void fraction distribution in overburden disturbed by
longwall mining of coal. Environmental Earth Sciences. 75(2), p.151.

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Running head: RESEARCH METHODS FOR ENGINEERS
Wang, T., Zhou, W., Chen, J., Xiao, X., Li, Y. and Zhao, X., 2014. Simulation of hydraulic
fracturing using particle flow method and application in a coal mine. International Journal of
Coal Geology. 121, pp.1-13.
Wills, B.A. and Finch, J., 2015. Wills' mineral processing technology: an introduction to the
practical aspects of ore treatment and mineral recovery. Butterworth-Heinemann.