Physical disintegration of the rocks is promoted by the closely spaced blast-hole grid used in the mining operation. Wet-dryfreeze-thaw forces are effective in causing disarticulation of the weakened rocks in 6 months or less. The silty spoils cause excessive dust, are crusted and support ponds. Application of organic amendments promotes infiltration. Some of the spoils contain enough salts to seriously retard growth of non-tolerant plant species. Exchangeable bases are overestimated, but the salts are a nutrient source. K is low, but adsorption isotherms indicate that, unlike the naturally occurring soils of the locality, there is no serious problem of K-fixation in the spoils. NaHCO₃ gives the most accurate measure of spoil P. A response to fertilization is likely. Adsorption isotherms suggest a problem with P-fixation by the goethite rocks. There was no measurable pedogenic activity in the spoils after two years of weathering other than physical disintegration of rock fragments and weakly developed structure in some spoil surface layers. There was no evidence of leaching of salts during this period. When regrading the spoils on the benches, maintenance of adequate drainage is essential to prevent nutrient depletion, Fe-generated toxicity and acidity and toxic accumulations of salts. A mixture of 70% sandstone, 20% siltstone and 10% shale should yield a well-drained sandy loam spoil upon weathering. The ferruginous and silty rocks should be regraded well below the surface. / Master of Science

Many coal mines in southwestern Virginia and West Virginia are plagued with excessive deterioration of roof shales. Shale flakes and sheets spall off the roofs at unpredictable intervals and create hazards in many coal mines (P1.1). The failures are more frequent during the summer months when the incoming air is at a higher temperature than the roofs and walls of the mine. This differences in temperature causes the moisture of the air to condense on the cooler parts of the mine. Prof. C.T. Holland, Department of Mining Engineering, Virginia Polytechnic Institute, has suggested that this type of roof failure may depend upon some mineralogical or chemical change caused by the increase in moisture on the rooms of the mine. In addition to the weathering process, some roof shales are notoriously susceptible to failure in those places where ground-water seepage is prevalent. The failures caused by this type of situation at the entry of a mine are usually more predictable than those caused by weathering. The purpose of this investigation was to determine if there were any significant differences in the mineral, chemical, or textural compositions of roof rocks which have failed and those which have not. / Master of Science

As a consequence of new coal mining practices, coal preparation plants have been inundated with increased loads of coal and clay particles in their wastewaters. Traditionally, the industry has employed primary sedimentation as the fundamental treatment scheme for these sediment-laden blackwaters. This study was undertaken to determine the effects of a combination of coagulant addition and rapid mixing on the settleability of these particles. After initial testing, aluminum sulfate and two low molecular weight cationic polymers, Cyanamid Magnifloc 513C and Cyanamid 515C, were chosen as primary coagulants for use in this work. An artificial wastewater was prepared from finely powdered (62 to <38 microns) raw coal samples and tap water, after initial tests indicated that typical frothing and/or collector agents had no demonstrable effect on coagulant function. Initially determined optimum coagulant dosages, as well as flocculation and sedimentation times, were kept constant while rapid mix intensities were varied at G values of 330 sec⁻¹, 700 sec⁻¹, 2000 sec⁻¹ and 7000 sec⁻¹ for each sample. Using a combination of residual turbidity and particle size analyses to determine the effectiveness of each rapid mix intensity, it was discovered that only the highest mixing intensities and durations (G(t) values) caused floe disintegration due to overmixing. At the lower G(t) matrices floe formation and settleability was consistently good. When aluminum sulfate was used as a coagulant, the wastewater was tested at a high pH of 8.1 to 8.3 and a low pH of 5.5 to observe floe behavior under different conditions of coagulant mechanism. The test results were similar for both pH values except at the lowest mixing intensities where the high pH samples settled well, resulting in low residual turbidities, but the low pH samples had relatively high turbidities. / Master of Science

The increased impact on mine subsidence during the recent years led to the development of two semi-empirical prediction methods for the eastern United States coalfields. The methods are based on an extensive data bank, which includes a total of twenty three panels, from nine case studies, which were instrumented during this research effort. An extensive field monitoring program, utilizing a digital computer tacheometer, was developed and implemented for this purpose. The first prediction method using a profile function, provides a fast and convenient method for prediction of vertical movements above mine panels of uniform geometry. More specifically the hyperbolic tangent function is utilized, as adapted to regional data. The developed model is capable of accurate general predictions for the Eastem U.S. coalfields. The second method is based on the Budryk-Knothe influence function. The parameters used in this method were mainly determined from the monitored case studies. The use of such a method requires primarily a computer, however, it can negotiate mine sections of complex conditions and can calculate subsidence as well as any other mode of deformation on the surface. For the prediction of the parameters required for the application of both methods a number of relationships between mining and subsidence factors were established through the analysis of the collected data. Computer software were developed for the analysis of the data as well as for the application of the prediction methods. / Ph. D.

Recently, competition has increased in the surface coal mining industry, which has necessitated the development of more efficient methods for coal removal. Despite this trend, very little emphasis has been placed on the development of optimization techniques applicable to the surface coal industry. The available methods are inadequate in that they recognize neither the complex equipment interactions present in a surface mining operation nor the interdependence of overburden removal and spoil placement. The lack of available techniques prompted the development of a mixed integer model to optimize the scheduling of equipment and the distribution of overburden in a typical mountaintop removal operation. Using this format, a (0-1) integer model and transportation model were constructed to determine the optimal equipment schedule and optimal overburden distribution, respectively. To solve this mixed integer program, the model was partitioned into its binary and real-valued components. Each problem was successively solved and their values added to form estimates of the value of the mixed integer program. Optimal convergence was indicated when the difference between two successive estimates satisfied some pre-specified accuracy value. The performance of the mixed integer model was tested against actual field data to determine its practical applications. To provide the necessary input information, production data was obtained from a single seam, mountaintop removal operation located in the Appalachian coalfield. As a means of analyzing the resultant equipment schedule, the total idle time was calculated for each machine type and each lift location. Also, the final overburden assignments were analyzed by determining the distribution of spoil material for various overburden removal productivities. Subsequent validation of the mixed integer model was conducted in two distinct areas. The first dealt with changes in algorithmic data and their effects on the optimality of the model. The second area concerned variations in problem structure, specifically those dealing with changes in problem size and other user-inputted values, such as equipment productivities or required reclamation. For each of these optimal schedules and assignments obtained from the model, analyses were conducted in manner similar to that discussed above. / Ph. D.

Recognizing the complexity of coal mining management, e.g., the scarcity of financial resources and the high level of uncertainty, a mixed binary programming model has been developed as an aid for generating production schedules which maximize the associated net present value. Defining the mine layout as a precedence network, with the nodes representing mining blocks, a solution procedure is developed, based on Benders' partitioning scheme. That is, the procedure iterates between two problems, namely, the master (primal) problem, solved by a combination of heuristic and exact methods, and the subproblem (dual problem), solved partly by inspection and partly as a minimal cost network flow problem. The heuristic methods are based on improvements of existing algorithms for scheduling precedence-related jobs on m processors. Computational experiences are presented and the procedure is demonstrated on a mining case. / Ph. D.

Most research on surface subsidence pertains to domestic as well as foreign experiences with longwall mining. Investigations into room-and-pillar subsidence have often been neglected, despite the fact that this is the predominant mining system in this country. However, the recent economic incentives which have caused the need for higher secondary extractions in room-and-pillar mines and the severe subsidence occurrences over certain abandoned mines have placed added emphasis into the subsidence phenomenon above such panels. In this research, a comprehensive subsidence data bank for cases of partial extraction was compiled through both literature sources and unpublished data. Emphasis on Appalachian data was sought in order to minimize geologic variation. The data was then used to validate various published empirical models for subsidence prediction within the U.S. From this analysis, and from the longwall information used in previous research, a more comprehensive prediction method for partial subsidence was obtained. The modeling represents a relationship between various geometric and characteristics. geologic parameters with subsidence profile In addition to the empirical methods, the zone area technique was investigated for a predictive computer model of room-and-pillar subsidence. Alteration of a previous VPI & SU, longwall subsidence, zone area program allowed the formulation of the room-and-pillar model. The resulting zone area program for predicting room-and-pillar subsidence is not only more applicable to partial mining techniques, but also more flexible, allowing for more complex mine geometries and variable mine parameters. / M.S.

Climate change adaptation has received limited attention compared to mitigation across all spatial levels. This is besides the documented adverse impacts of climate change in different sectors of societies including mining in general and coal mining specifically. Against this background, the study set three objectives. The first objective was to identify current and possible future climate change impacts that may affect selected coal mines in South Africa. The second objective was to establish the nature and extent to which these mines were ready to address and implement adaptation measures. The last objective was to determine and document existing climate change adaptation practices in selected mines. Employing the mixed methods approach, the research engaged five coal mines located in Mpumalanga, Free State and Kwa Zulu-Natal, gathering both the qualitative and quantitative data. This data was analysed thematically. The research made three major findings. The first finding was that the climatic conditions in the research areas have been changing over the observed period. In general, rainfall has been declining and temperatures have been increasing, leading to increased cases of extreme fog, mist and heatwaves. The second finding was that there has been an increase in frequency and intensity of extreme weather events, most notably, floods and droughts. These changes in the climate and associated weather events have frequently affected mine operations particularly at the production sub-chain of the coal mining value chain. The third major finding was that despite this evidence of adverse impact of climate change on the production sub-chain of the South African coal mining value chain, adaption responses in all the studied mines showed reactive adaptation to extreme events instead of proactive adaptation planning and implementation. South Africa depends on coal-derived energy, electricity in particular and the coal mines are implicitly exposed and vulnerable to the adverse impacts of climate change. Reducing this exposure and vulnerability dictates the urgent need to implement anticipatory adaptation measures in all the sub-chains of the coal mining value chain. / Environmental Sciences / D. Litt. et Phil (Environmental management)

PhD (Environmental Management) / Mining and mining-related activities remain the world’s most intensive, primary industrial activity undertaken with severe environmental impact. Coal mining falls within these primary undertakings, while coal burning for energy use further adds to environmental degradation. Coal burning is by far the least expensive and thus the most affordable means of energy supply to the South Africa low-income communities. It is likely that this status quo will continue indefinitely. The use of coal as an energy source in South African communities has been inherited with its resultant environmental (physical), social and economic implications. The physical implications are the actual hazards associated with coal during and after mining activities. “Physical hazards” include processes generating coal dust, coal ash and gaseous emissions, and hazards that manifest themselves from the existence of coal mining at a particular site, such as spontaneous combustion, surface instability and acid mine-water drainage. “Social hazards” are mostly the social and economic effects that are related to health. Social hazards associated with coal mining, coal processing and coal usage include dilution of cultural values, ethics, norms and the growth of informal sectors, for example, settlements and trade. Some of these hazards are immediate, while others are long-term and cumulative. Emphasis was placed on the cumulative effects of mining activities and the need to address issues relating to communities that live close to mining operations. This process of addressing community concerns is known as “creating a sustainable mining community”. South Africa hosted the 2002 World Summit on Sustainable Development and is a signatory of the working plan of action known as the Johannesburg Plan of Implementation. Therefore, one would expect to see that mining communities in South Africa are acting on and benefiting from this plan of action. The aim of this research is to assess the effectiveness of the 2002 World Summit on Sustainable Development and the Johannesburg Plan of Implementation in promoting sustainable mining and sustainable communities through changes in practices, perceptions and community participation in decision making. The research, undertaken during February to June 2007, examines the role of stakeholders and local authorities in basic environmental decisions. Environmental decisions examined were the provision of education and information to the community, uplifting community welfare through corporate social investment and corporate social responsibility. The surrounding communities of eMalahleni (formerly Witbank) in the Mpumalanga (Highveld) coal-mining region – were identified as a suitable area for this case study. Social research tools, comprising multiple-choice and open-ended questions administered to 6 790 respondents (3 930 learners and 2 860 general adult population), 650 voluntary comments, six individual interviews, and a 20 member focus group discussion, were used. Photographic images and personal observation provided meaning to results by presenting the quantitative and qualitative data visually. A blended methodological approach was used to analyse the data using descriptive statistics and a t-test for variance. Tables, bar graphs and pie charts were the various representative techniques deployed during the analysis. Data were analysed comparing statistical input and responses of the learners and the general population. Results presented show that the studied community is aware of some hazards associated with coal from the mining process to indoor combustion. The community studied is aware of the need for pro-active measures to protect their community. Members of the community are not aware of company decisions affecting the community with regard to coal hazards. They are also unaware of the existence and application of environmental legislation. Awareness was not linked to education or information obtained from a reliable source, such as a mining company or a local authority. It was based on personal experience, longevity of dwelling in the community and observation of the health conditions of relatives and friends. Some voluntary comments from the respondents and photographic images are included to support the community’s outlook. The research concluded that there are more unidentified hazards in the community than were covered in the structured questionnaires. The responses received to the questionnaires exposed the mining industry as being dismissive when it came to applying the law. This evasive behaviour emanates from the laxity of the enforcement departments and responsible authorities. More needs to be done to attain the requirements of the Johannesburg Plan of Implementation as agreed upon at the 2002 World Summit on Sustainable Development.

Thesis (MBA (Business Management))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: The South African Mining industry has had a poor safety performance over the past couple of years, which led to a lot of questions being asked about how effective mining operations are managed. Numerous concerns and opinions have been raised on the reasons why no improvement is seen in organisations’ safety trends. The general concern in the mining industry is that safety and operations are managed as separate entities and not as an integrated unit. Besides the perception of operational issues that are managed more diligently than safety issues, the associated competency levels of line personnel are also questioned. Safety management systems in mining organisations are also under the spotlight in respect of quality, effective application and a positive contribution in preventing accidents and incidents. A more intensified focus on safety is required by the respective mining houses. The main contributing factors that lead to accidents and incidents need to be determined. The possible reasons for the unsatisfactory safety results can be divided into controllable and uncontrollable elements when seen from a safety perspective. The controllable elements are all possible reasons for why a safety management system is not working. There might also be different contributors to poor safety performance but these are definitely underlying to the main reasons identified. The influence of human behaviour on accidents as well as the considered organisation safety system is essential in safety management. Human behaviour is a function of the characteristics of both the person and the environment. Individuals bring elements to the organisational setting, including abilities, personal beliefs, expectations and past experiences. The environment provided by an organisation has a number of features: jobs, relationships between people, work that needs to be done, rewards available to individuals, and so on. Behaviour results from the interaction of individual and organisational characteristics. The behaviour of humans and the understanding thereof will be a science in its own right. To prevent incidents, one should know their causes. As Louis Pasteur put it, over 100 years ago: “All things are hidden obscure and debatable if the cause of the phenomena be unknown, but everything is clear if the cause be known.” / AFRIKAANSE OPSOMMING: Die Suid-Afrikaanse mynboubedryf presteer die afgelope aantal jaar swak wat betref veiligheidsbestuur en ʼn hele aantal vrae word gevra oor hoe effektief mynbouoperasies bestuur word. Verskeie besorgdhede en opinies is gelug oor die moontlike redes waarom daar geen verbetering in ondernemings se veiligheidsindekse ervaar word nie. Die algemene bekommernis in die mynboubedryf is dat veiligheid en operasionele verantwoordelikhede afsonderlik bestuur word en nie as ʼn geïntegreerde eenheid nie. Afgesien van die persepsie dat operasionele uitdagings meer doelgerig bestuur word as veiligheid, word die gepaardgaande bevoegdheidsvlakke van lynpersoneel ook bevraagteken. Veiligheidsbestuurstelsels in mynbouondernemings is ook onder verdenking wat betref gehalte, effektiewe toepassing en ’n positiewe bydrae ten opsigte van ondersteuning en voorkoming van insidente en ongelukke. ʼn Meer intense fokus op veiligheid word benodig by die onderskeie mynhuise. Die belangrikste bydraende faktore wat tot ongelukke en insidente lei, moet bepaal word. Die moontlike redes vir onbevredigende veiligheidsresultate kan verdeel word in beheerbare en onbeheerbare elemente wanneer gesien vanuit ʼn veiligheidsperspektief. Die beheerbare elemente is moontlike redes waarom ʼn veiligheidbestuurstelsel nie werk nie. Daar kan moontlik ook ander bydraende faktore wees tot ʼn swak veiligheidsprestasie maar dit is definitief onderliggend tot die hoofredes soos geïdentifiseer. Die invloed van menslike gedrag op ongelukke sowel as die inaggenome veiligheidstelsel van die organisasie is essensieel by veiligheidsbestuur. Menslike gedrag is ʼn funksie van die eienskappe van beide die persoon en die omgewing. Individue bring sekere elemente na die organisatoriese opset wat vermoëns, persoonlike oortuigings, verwagtings en ondervinding insluit. Die omgewing geskep deur organisasies behels ʼn aantal elemente: werksomskrywing, verhoudings tussen mense, werk wat gedoen moet word, vergoeding van individue, ens. Gedrag is die resultaat van die interaksie tussen individue en die kenmerke van die organisasie. Die gedrag van mense en begrip daarvan sal ʼn wetenskap in eie reg bly. Om insidente te verhoed, moet die oorsake bekend wees. Soos Louis Pasteur dit meer as 100 jaar gelede gestel het: “All things are hidden obscure and debatable if the cause of the phenomena be unknown, but everything is clear if the cause be known.”