611 |
A project health check for coal mining caompanies : case of Douglas Middelburg optimisation projectDe Wet, G.F. 30 November 2007 (has links)
The purpose of the study is to develop a project health check model to evaluate
the status of projects within the coal mining industry. The model will be based on
the Buttrick (2000) project health check model as described in his book “The
Interactive Project Workout”.
The model assesses the current “health” or status of a project. It looks at the full
project environment and uses a set of question results in an assessment of the
overall risk associated with the project. The model evaluates seven key project
success factors which include:
1. Project Plan 5. Expertise
2. Resources 6. Clear Specification
3. Ownership 7. Top Level Support
4. Justifiable Case
The model fulfils two roles:
• As a checklist, and
• As a tool to indicate where a project manager’s efforts should be directed.
This study will give an overview of the coal mining industry and the way projects
are being evaluated and prioritised. The Buttrick (2000) project health check
model will be assessed and adapted to evaluate projects within the coal mining
industry. The “new / adapted” model will be applied to the Douglas / Middelburg
Optimisation (DMO) to evaluate the health status of the project which is currently
at the end of definition (feasibility) stage within BHP Billiton Energy Coal South
Africa.
The results obtained from the new health check model showed that the DMO
project was in a healthy state with a project health check score of 47.33. It could
4
thus be concluded that the DMO project is ready to move in to the execution
phase of the BHP Billiton capital investment process.
The results obtained from the project team member participants were split into
management perception and team members’ perception. The overall health of
the DMO project between the two parties gave similar results with the team
members score of 43.76 being slightly lower than the management health score
of 45.42. The only major difference was observed on the “Communication”
project evaluation criteria where the management perspective on the
communication effectiveness was higher than that of the project team members.
|
612 |
The causes and effects of project delays in the coal mining industry in South AfricaLee, Clinton 20 August 2012 (has links)
This research is addressing the causes and effects of project delays in the coal mining industry in South Africa. A literature review was conducted and it was found that the causes of delays are extensively researched in the construction industry with only limited reference to delays in the mining industry which are mainly risk based. The effects of delays are predominantly listed as timing and cost effects.
|
613 |
Crosshole seismic processing of physical model and coal measures dataLeggett, Miles January 1992 (has links)
Crosshole seismic techniques can be used to gain a large amount of information about the properties of the rock mass between two or more boreholes. The bulk of this thesis is concerned with two crosshole seismic processing techniques and their application to real data. The first part of this thesis describes the application of traveltime and amplitude tomographic processing in the monitoring of a simulated EOR project. Two physical models were made, designed to simulate 'pre-flood' and 'post-flood' stages in an EOR project. The results of the tomography work indicate that it is beneficial to perform amplitude tomographic processing of cross-well data, as a complement to traveltime inversion, because of the different response of velocity and absorption to changes in liquid/gas saturations for real reservoir rocks. The velocity tomograms image the flood zone quite accurately. Amplitude tomography shows the flood zone as an area of higher absorption but does not image its boundaries as precisely, because multi-pathing and diffraction effects are not accounted for by the ray-based techniques used. Part two is concerned with the crosshole seismic reflection technique, using data acquired from a site in northern England. The processing of these data is complex and includes deconvolution, wavefield separation and migration to a depth section. The two surveys fail to pin-point accurately the position of a large fault; the disappointing results, compared to earlier work in Yorkshire, are attributed to poorer generation of compressional body waves in harder Coal Measures strata. The final part of this thesis describes the results from a pilot seismic reflection test over the Tertiary igneous centre on the Isle of Skye, Scotland. The results indicate that the base of a large granite body consists of interlayered granites and basic rocks between 2.1 and 2.4km below mean sea level.
|
614 |
The history of English coal mining, 1500-1700Moller, Asta Winifred Russell January 1933 (has links)
No description available.
|
615 |
Agricultural residue as a renewable energy resourcePotgieter, Johannes George 03 1900 (has links)
Thesis (MScEng (Mechanical and Mechatronic Engineering)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: In the Greater Gariep agricultural area adjacent to the Orange River between Prieska and
the Vanderkloof dam alone an estimated 311 000 ton/yr of maize and wheat straw is
available. These agricultural residues have an energy equivalent of 196 000 ton of coal per
year and should be utilised as a renewable energy resource.
A technical and financial evaluation on the collection and transport of agricultural residue
showed that the Hopetown area has the highest concentration of agricultural residue in the
Greater Gariep agricultural area with approximately 68 000 ton/yr that is spread out over 76 kmª. Briquetting, combustion, pyrolysis and gasification were identified as the technologies with
the highest potential to convert agricultural residue into a higher grade energy product in this area. The expected overall energy conversion efficiency for a plant capacity between 5 000 to 100 000 ton/yr is 98.9%, 10-25%, 25-30% and 28-36% for the briquetting,
combustion, pyrolysis and gasification plants respectively. A financial evaluation based on the internal rate of return and the net present value of investment showed that the briquetting plant is financially feasible and the most profitable for capacities between 25 000 and 60 000 ton/yr while the pyrolysis plant was financially feasible and the most profitable technology for capacities greater than 60 000 ton/yr. A sensitivity and risk analysis done on the proposed briquetting and pyrolysis plants to
evaluate the impact of market fluctuations on the profitability of the power plants exposed the briquetting plant as a very high risk investment, mainly because of the sensitivity to the selling price of fuel briquettes and the high maintenance cost associated with the briquetting
equipment. Although the proposed pyrolysis plant is sensitive to variation in the electricity price, the risks associated with the market conditions for the pyrolysis plant is very low and an internal rate of return of 15% is still projected at the minimum expected electricity price.
From the study it is clear that the utilisation of agricultural residue available in the Greater Gariep agricultural area is technically and financially viable. / AFRIKAANSE OPSOMMING: In die Groter Gariep landbougebied langs die Oranjerivier, tussen Prieska en die Van Der Kloof Dam is daar jaarliks ’n beraamde 311 000 ton mielie- en koringstrooi beskikbaar. Hierdie landbou-reste het die energie-ekwivalent van 196 000 ton steenkool per jaar en behoort as hernubare energiebron benut te word.
’n Tegniese en finansiële evaluasie van die versamel en vervoer van landbou-reste het
getoon dat die Hopetown-area die hoogste konsentrasie landbou-reste in die Groter Gariep landbougebied het met ongeveer 68 000 ton/jaar wat versprei is oor 76 kmª. Brikettering, verbranding, pirolise en vergassing is geïdentifiseer as die tegnologieë met die hoogste potensiaal om landbou-reste te omskep in ’n hoër graad energieproduk vir hierdie gebied. Die verwagte totale energie-omsettingseffektiwiteit vir ’n aanlegkapasiteit van tussen 5 000 tot 10 000 ton/jaar is onderskeidelik 98.9%, 10-25%, 25-30% en 28-36% vir die brikettering, verbranding, pirolise en vergassingsaanlegte. ’n Finansiële evaluasie gebaseer op die opbrengs op aanvangskoste en die netto huidige
waarde van die belegging het getoon dat die briketteringsaanleg finansieel lewensvatbaar is en die winsgewendste is vir ’n aanlegkapasiteit tussen 25 000 en 60 000 ton/jaar terwyl die pirolise-aanleg finansieel lewensvatbaar is en die winsgewendste tegnologie is vir
kapasiteite van groter as 60 000 ton/jaar.
’n Sensitiwiteits- en risiko-analise is op die voorgestelde brikettings- en pirolise-aanlegte
gedoen om die impak van markskommelings op die winsgewendheid van die aanlegte te
evalueer. Die resultate het getoon dat die briketteringsaanleg ’n baie hoë-risiko belegging is as gevolg van die sensitiwiteit op die verkoopprys van brikette en die hoë onderhoudskoste van briketteringstoerusting. Alhoewel die voorgenome pirolise-aanleg sensitief is vir skommelings in die elektrisiteitsprys, is die risiko’s wat met die marktoestande vir die
pirolise-aanleg gepaardgaan, baie laag en ’n opbrengs op aanvangskoste van 15% word
steeds voorspel teen die minimum verwagte verkoopsprys van elektrisiteit. Vanuit die studie blyk dit duidelik dat die gebruik van landbou-reste wat beskikbaar is in die
Groter Gariep landbougebied, tegnies en finansieel lewensvatbaar is as hernubare
energiebron. / Sponsored by the Centre for Renewable and Sustainable Energy Studies
|
616 |
Regenerating Dixie: Electric Energy and the Making of the Modern SouthCater, Casey P. 12 August 2016 (has links)
The emergence and spread of electricity profoundly shaped the “long New South.” This dissertation traces the electrification of the US South from the 1880s to the 1970s. Focusing primarily on the Atlanta-based Georgia Power Company, it emphasizes that electricity’s rise was not simply the result of technological innovation. It was a multifaceted process that deeply influenced, and was influenced by, environmental alterations, political machinations, business practices, and social and cultural matters. Although it hewed to national and global patterns in many respects, southern electrification charted a distinctive and instructive path. Its story speaks to the ways the South’s experiences with electrification shaped larger American models of energy transitions and economic development, but also the ways it wrought dramatic changes in the fabric of everyday life.
|
617 |
The stability of development tunnels sited adjacent to previous excavationsSharpe, Leigh January 1999 (has links)
No description available.
|
618 |
COLLOID MEDIATED TRANSPORT OF HEAVY METALS IN SOILS FOLLOWING RECLAMATION WITH AND WITHOUT BIOSOLID APPLICATIONMiller, Jarrod O. 01 January 2008 (has links)
Soils disturbed by strip mining practices may have increased colloid loads moving to groundwater resources, also enhancing the transport of contaminants into our water resources. We hypothesize that contaminant transport within soils following mining is enhanced by colloid mobility. Two sites were chosen for this study, a 30-year old reclaimed strip mine in southwest Virginia and a recently mined area from eastern Kentucky. Intact reclaimed soil monoliths were retrieved from sandstone derived soils in southwestern Virginia. Reclaimed monoliths from eastern Kentucky were recreated in the lab. Intact undisturbed (native) soil monoliths representing the soils before mining were also sampled for comparison. Biosolids were added to an additional reclaimed monolith at a rate of 20 T/acre. Leaching experiments with deionized water at a rate of 1.0 cm/h involved 6 cycles of 8 hours each, giving each monolith at least 2 pore volumes of leaching. Native soil monoliths from Virginia had an average colloid elution of 857 mg over all cycles, reclaimed soil monoliths had an elution of 1460 mg, reclaimed soil monoliths with spoil material had a colloid elution of 76 mg, and when biosolids were amended to reclaimed soil and spoil monoliths, 870 mg colloids were eluted. Native soil monoliths from eastern Kentucky eluted 7269 mg colloids, reclaimed monoliths from eastern Kentucky eluted 10,935 mg colloids, and reclaimed soils with spoil material eluted no colloids. Lime stabilized biosolids enhanced colloid elution due to high pH dispersing material within the monoliths, while spoil materials with high density and salt content reduced colloid elution. Metal loads in solution were mobilized by DOC, particularly in low sulfate environments, while colloid bound metals increased the total metal loads in the order of Pb > Ni > Cu > Cd > Zn > Cr.
|
619 |
An Experimental Study of Catalytic Effects on Reaction Kinetics and Producer Gas in Gasification of Coal-Biomass Blend Chars with SteamZhang, Ziyin January 2011 (has links)
The objective of this thesis is to experimentally investigate the performance of steam gasification of chars of pure coal (lignite, sub-bituminous), pure biomass (radiata pine, eucalyptus nitens) and their blends. The influences of gasification temperature, types of coal and biomass, coal-biomass blending ratio, alkali and alkaline earth metal (AAEM) in lignite, on specific gasification characteristics (producer gas composition and yield, char reactivity) were studied. In addition, synergistic effects in co-gasification of coal-biomass blend char were also investigated. This project is in accordance with objectives of the BISGAS Consortium.
In this study, experiments were performed in a bench-scale gasifier at gasification temperatures of 850°C, 900°C and 950°C, respectively. Two types of coals (lignite and sub-bituminous) and two kinds of biomass (radiata pine and eucalyptus nitens) from New Zealand were selected as sample fuels. From these raw materials, the chars with coal-to-biomass blending ratios of 0:100 (pure coal), 20:80, 50:50, 80:20 and 100:0 (pure biomass), which were derived through the devolatilization at temperature of 900°C for 7 minutes, were gasified with steam as gasification agent. During the gasification tests, the producer gas composition and gas production were continuously analysed using a Micro gas chromatograph. When the gas production was undetectable, the gasification process was assumed to be completed and the gasification time was recorded. The gasification producer gas consisted of three main gas components: hydrogen (H2), carbon monoxide (CO) and carbon dioxide (CO2).
The results from gasification of chars of individual solid fuels (coal or biomass) confirmed that biomass char gasification was faster than coal char gasification. The influences of gasification temperatures were shown as: when gasification temperature increased, the H2 yield increased in coal char gasification but decreased in biomass char gasification. In the meantime, CO yields increased while CO2 yields decreased in both coal char and biomass char gasification. In addition, the char reactivity of all the pure fuel samples increased with elevated gasification temperatures.
The results from co-gasification of coal-biomass blend char exhibited that the syngas production rate, which is defined as the total gas production divided by the gasification completion time, was enhanced by an increase in gasification temperatures as well as an increase in the biomass proportion in the blend. The AAEM species played a significant catalytic role in both gasification of pure coal chars and co-gasification of coal-biomass blend chars. The presence of AAEM increased the producer gas yield and enhanced the char reactivity.
The positive synergistic effects of the coal-biomass blending char on syngas production rate only existed in the co-gasification of lignite-eucalyptus nitens blend chars. The other blend chars showed either insignificant synergistic effects or negative effects on the syngas production rate.
|
620 |
Identification of minor components of oil refinery productsSmith, R. W. January 1982 (has links)
No description available.
|
Page generated in 0.0667 seconds