La Première Guerre mondiale prive la France d’une partie des mines du Nord et du Pas-de-Calais, d’un grand nombre de mineurs et des importations de combustible allemandes et belges. En dépit des principes libéraux de la Troisième République, l’État, pour résoudre la pénurie, est conduit à intervenir de plus en plus dans la production, le transport et la commercialisation du charbon. À partir de l’été 1917, le ministre de l’Armement Louis Loucheur organise une administration spécifique, le Bureau national des Charbons, qui exerce la mainmise sur ce marché en regroupant les producteurs et les consommateurs, en fixant les prix et en réglementant la répartition. Après l’armistice, l’augmentation des prix anglais et la faible exécution des livraisons de charbon allemand rendent nécessaires le maintien du contrôle de l’administration. L’objectif du Bureau national des Charbons est alors d’unifier le marché national en essayant d’instaurer des prix de vente uniques sur tout le territoire. Mais en avantageant certaines catégories de consommateurs, il devient également un instrument de politique économique. Ce régime de guerre est supprimé brutalement au début de 1921. La France fait alors face à une crise industrielle de surproduction qui met fin à la pénurie et remet en cause l’intervention de l’État dans le marché. / During the First World War, France loses some coalmines in Nord and Pas-de-Calais, a large number of miners and German and Belgian imports. Despite the liberal principles of the Third Republic, the French State intervenes more and more into the production, the transport and the commercialization of coal to fix the shortage. From summer 1917, the Minister of Armament Louis Loucheur settles a specific administration, the Bureau national des Charbons, which controls the whole market: it gathers producers and consumers, fixes prices and rules the repartition. After the Armistice, increased English prices and insufficient German deliveries impose on the administration to keep controlling the market. The Bureau national des Charbons aims to unify the national market with single sales price for the whole country. It also becomes an instrument of economic policy since it can give some advantages to specific categories of consumer. At the beginning of 1921, this war system is suddenly dismantled. France faces then an industrial overproduction crisis which gives an end to the shortage and questions the State’s market intervention.

Waste rocks (WRs) from coal mining and fly ash (FA) from coal combustion were studied to determine the potential of the WRs to generate AMD, FAs to neutralise it and estimate their impacts on environment. The ultimate goal was to develop a methodology based on co-disposal to mitigate the environmental problems associated to both wastes. Two methods for co-disposal were tested: i) Mixing WRs and FAs and ii) covering WRs with FAs. WRs were sampled from the Lakhra coal mines in Pakistan (PK), which has an estimated coal reserves of 1.3 Btonne, varying from lignite to sub-bituminous quality. The FA was sampled from a power plant utilising coal from Lakhra coal mines and is situated in close vicinity (15km) of the mine site. For comparative purposes a bituminous FA from Finland (FI) and biomass FA from Sweden (SE) were also characterised. The WRs and FA samples were characterised by mineralogical and geochemical methods. Besides organic material (coal traces), quartz, pyrite, kaolinite, hematite, gypsum and traces of calcite, lime, malladerite, spangolite, franklinite and birnessite were identified in WRs by XRD. The major elements Si, Al, Ca and Fe were in the range (wt. %) of 8 – 12, 6 – 9, 0.3 – 3 and 1 – 10, respectively, with high S concentrations (1.94 – 11.33 wt. %) in WRs. The AMD potential of WRs ranged from -70 to -492 kg CaCO3 tonne-1. All FAs contained quartz, with iron oxide, anhydrite and magnesioferrite in PK, mullite and lime in FI and calcite and anorthite in SE. The Ca content in SE was 6 and 8 times higher compared to PK and FI, respectively. FAs were enriched in As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn compared to continental crust. The acid neutralising potential of PK was equivalent to 20 kg CaCO3 tonne-1 compared to 275 kg CaCO3 tonne-1 (SE) and 25 kg CaCO3 tonne-1 (FI). During the period of 192 days in weathering cell experiments (WCE), the pH of leachates from most acidic WRs was maintained from 1 to 2.5, whereas, the less acidic WRs produced leachates of mildly acidic (2.7) to neutral (7.3) pH. The leachates from very acidic WRs ranged in the concentrations of Fe, SO24− and Al from mg L-1 to g L-1. The samples were subjected to column leaching experiments (CLE) in which mixture (FA:WR; 1:3) and cover (FA:WR; 1:5) cases were mimicked (with 10mm particle size) and effects of particle size (2, 5 and 10mm) on element leaching were studied. Despite having the lowest acid-neutralisation potential compared to FI and SE, co-disposal of PKFA as mixture readily provides acid buffering minerals, resulting in better start-up pH conditions and leachate quality. However, acidity produced by secondary mineralisation contributes towards the acidification of the system, causing stabilisation of pH at around 4.5−5. Secondary mineralisation (especially Fe- and Al-mineral precipitation) also removes toxic elements such as As, Pb, Cu, Zn, Cd, Co, Ni and Mn, and these secondary minerals can also buffer acidity when the pH tends to be acidic. In contrast, the pH of the leachates from the PKFA cover scenario gradually increased from strongly acidic to mildly acidic and circumneutral along with decrease in EC and elemental leaching in different WRs. Gradually increasing pH can be attributed to the cover effect, which reduces oxygen ingress, thus sulphide oxidation, causing pH to elevate. Due to the fact that pH~4–5 is sufficient for secondary Fe- and Al-mineral precipitation which also removes toxic elements (such as Cd, Co, Cu, Zn and Ni) by adsorption and/or co-precipitation, the FA cover performs well enough to achieve that pH until the conclusion of the CLE. However, due to the slower reactivity of the buffering system (additional to the initial flush-out), leaching in the beginning could not be restricted. The co-disposal of FA as cover and/or mixture possesses potential for neutralisation of AMD and improving leachate quality significantly. Particle size of the WRs affected the leaching of the sulphide related elements (such as Fe, S, Zn, Co, Cr, Cu, Mn and Ni) in CLE and WCE. Experiments with ≤1mm particle size constantly produced acidic and metal laden leachates. Co-disposal of FA and WRs as cover and mixture need to be investigated on pilot-scales before full-scale application.

This research investigates cases of learning pathways for improving rehabilitation practices for key occupations in the mining industry. The study is set up as a partnership research programme between Rhodes University Environmental Learning Research Centre in South Africa, and the South African Qualification Authority, focussing on workplace learning and sustainability practices. This research programme seeks to understand the implications of the move to a knowledge society, with its emphasis on knowledge building over time, particularly in and for the environmental sector. The research was conducted as a qualitative case study that made use of semi-structured interviews, document analysis, visual photographs and observations as instruments of data gathering. Participants were sampled from two case studies, one in Limpopo province and the other one in Mpumalanga Province, who are directly involved in rehabilitation practices and related education and training programmes. The study makes use of career stories from the key occupations to provide insight into workplace learning pathways to inform education and training in the mining industry. A series of analytical statements captures some of the main findings on early education histories, career choices, learning pathway decisions and experiences related to sustainable practices and some complexities related to learning pathways. Environment and sustainability education is a cross-cutting issue in the NQF; and it pertains to the mining sector, especially to rehabilitation practices, which form the focus of this study as little is known about learning pathways associated with these sustainability practices. Insights from the study should enable the sector to enhance rehabilitation training for key occupations and at the same time encourage lifelong learning contributing towards sustainable development.

Incineration is an attractive solution to the problems of disposing of municipal solid wastes and supplying energy. Because up to 25 percent of the waste in refuse-derived-fuel systems is ash, the physical and chemical characteristics of ash become more and more important for its potential impacts and methods suitable for their disposal. Trace elements concentration in ash is of great interest because of its relationship to regulatory criteria under the Resource Conservation and Recovery Act (RCRA) regarding toxicity and hazards. The applications of a microwave oven sample dissolution method has been tested on a variety of standard reference materials, with reproducible and accurate results. Fourteen trace elements, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, V, and Zn, from the dissolved ash samples were determined by inductively coupled plasma atomic emission spectrometry.

Master thesis deals with current trends on coal market, relationships between prices of coal and prices of other commodities, forecasting of coal prices in fifteen years horizon utilizing statistical tools and business valuation of a company from coal mining industry. Master thesis further analyzes a sensitivity of the company value on changes in projected prices of coal and other commodities.

This master‘s thesis deals with denitrification of brown coal-fired boiler of electric power plant. First chapters describe technical characteristics of the boiler and possible measurements which would lead to lowering NOx emissions. In order for boiler to meet emission standards valid from 1.1.2016 flue gas treatment by selective catalytic reduction is proposed. Main part of the thesis is thermal calculation of the boiler with modifications necessary in order to apply SCR. The aim of calculation is to determine flue gas exit temperature and temperature at catalyst area in order to assess the suitability of proposed modifications.

The aim of this thesis is the proposal of a coal mill system and a combustion chamber for the boiler PK 4S situated in Košice CHP station with regard to transition to the new fuel. This proposal is focused on the elimination of NOx emissions. The calculation is based on required parameters of the boiler and declared characteristic of the new fuel. The proposal of the coal mill system includes three roller mills working in closed circuit with direct blowing. One of the mills serves as a reserve in case of failure. Dimensions of the dry bottom combustion chamber are proposed considering the applied primary measures to reduce NOx emissions so that the temperature at the end of the furnace would not be higher than maximal allowed temperature 1200 °C.

MENVSC / Department of Ecology and Resource Management

Die Arbeit fängt mit einer Beschreibung des Zustands der Kohlenbergbauindustrie weltweit und des zukünftigen Bedarfes für Kohle an. Danach folgt eine allgemeine Beschreibung des Restrukturierungsprozesses des Kohlenbergbaus in Rumänien und eine vertiefende Untersuchung der Situation im Schiltal infolge des Umstrukturierungsprozesses. Die schwierige sozioökonomische Lage im Schiltal braucht konkrete Lösungen; das Potenzial der Region bietet die Möglichkeit für zukünftige Entwicklungen. Eine vollständige, umfangreiche Analyse und ein Entwicklungskonzept wurden durchgeführt bzw. entwickelt. Es werden sowohl die Entwicklung von alternativen Wirtschaftstätigkeiten, als auch die Modernisierung und Rentabilisierung des traditionellen Bergbaus begründet.

A thesis submitted to the Faculty of Humanities, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the Degree of Doctor of Philosophy. Johannesburg, March 2017. / This thesis follows the development of a particular set of large technical systems in South Africa from the late apartheid era into the age of democracy. During apartheid technological prowess, upheld by the network of state corporations or parastatals, bolstered the authoritarian rule of the white minority government in South Africa. The economic and political liberalisation of the late 1980s challenged the power of the parastatals and altered the underlying rationale of infrastructure development. In particular I describe the transformation of Iscor and Eskom, two of the country’s major parastatals, and their activities in the Waterberg coalfields, an isolated region on the country’s north-western border. While Eskom’s activities in the region began in the 1980s they gained public notoriety with the construction of the Medupi power station two decades later. The obstacles that Eskom faced at Medupi represent the main challenge of developing large technological infrastructures in the democratic, post-colonial order, where the fruits of infrastructure development demand to be spread beyond the bounds of an elite minority. But the eventual completion of some power generating units in 2015 at Medupi demonstrates that failure is not inevitable. I argue that this success is due to the fact that the autonomous parastatal network negotiated the political and economic liberalisation of the early 1990 by incorporating the changing socio-political conditions into its operations. The parastatal network retained a momentum, in the sense first described by the historian of technology Thomas Hughes, which was also a product of the “locked-in” nature of investment in the infrastructure project. Because of the large capital investment required for the infrastructure development, proceeding tenaciously against the odds to see the project to completion was cheaper than retreat for those involved. / MT2018