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A study of flexible supercapacitors : design, manufacture and testingZhang, Ruirong January 2016 (has links)
Supercapacitors have attracted great attention because of their high power density, long life cycle and high efficiency. They can be generally classified into two types: electrical double-layer capacitors (EDLCs) and pseudocapacitors. Compared with pseudocapacitors, EDLCs have a very fast charge/discharge rate, higher power density, higher coulombic efficiency and longer cycle life. Recently, in order to meet the requirements of portable and wearable electronics, supercapacitor development is moving towards flexible and stretchable solutions. This thesis presents the design, fabrication, performance testing and optimisation of flexible strip and fibre EDLCs. In this research, a sandwich structured strip EDLC was designed and manufactured. Experimental design was utilised to optimise the operation parameters of the EDLC in order to improve its capacity for energy storage. The flexibility of the strip EDLCs was studied extensively by mechanical tests under static and dynamic loading conditions, and the correlation between the electrochemical performance of the EDLCs and the mechanical testing process was investigated. Novel coaxial fibre EDLCs have also been studied and developed in this study. Fibre supercapacitors showed a good flexibility and weavability. The activated carbon produced by ball-milling method with optimum specific capacitance was mixed with commercial ink to produce active material to optimise the electrochemical performance of fibre EDLCs. The flexible EDLCs were applied into different appliances to demonstrate the stability of performance and the usability of EDLCs developed in this study. The electrical current and potential range can be altered by connecting multiple strip or fibre EDLCs in parallel or in series to meet the power and energy requirements. It has been proved that the flexible EDLCs developed have a great potential to be used as energy storage devices for smart electronics. This thesis makes original contributions to knowledge, including using an advanced test method to study the electrochemical performance of flexible supercapacitors under static and dynamic mechanical testing, investigation of the effect of key parameters in the manufacturing process on the performance of strip supercapacitors using experimental design method to optimise the supercapacitors’ performance, and optimisation of the performance of fibre supercapacitors by improving the structure and using a new active material with higher specific capacitance.
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Sistemas de cultivo e métodos de implantação de cebola no verãoVan der Vinne, Jhony [UNESP] 18 December 2006 (has links) (PDF)
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vandervinne_j_me_jabo.pdf: 347258 bytes, checksum: b5423484849f6fdd515cedd6cecc561c (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O trabalho teve como objetivos avaliar os efeitos de sistemas de cultivo e métodos de implantação no sistema radicular da cebola e nas propriedades fisicas do solo (Experimentos I e 11), bem como na produtividade de cultivares no verão, visando à colheita de bulbos na entressafra (Experimentos 111 e IV). Os experimentos foram conduzidos em um Latossolo Vermelho, em São José do Rio Pardo-SP, entre dezembro de 2004 e setembro de 2005. No Experimento I, instalado em dezembro, foram avaliados os sistemas de cultivo na palha e convencional (aração/gradagem) e pontos de coleta de amostras do solo: linha e entrelinha. No Experimento 11, instalado em fevereiro, foram avaliados os sistemas de cultivo na palha e convencional, implantados por semeadura direta, transplantio de mudas de bandejas e de raizes nuas. No Experimento 11I, instalado em dezembro, foi avaliada a produtividade de Alfa Tropical, Alfa São Francisco e Mercedes, implantadas por transplantio de mudas de bandejas e de raizes nuas, no cultivo na palha e convencional. No Experimento IV, instalado em fevereiro, foram avaliados os mesmos tratamentos do Experimento 111 e foi adicionado o método da semeadura direta. O sistema radicular concentrou-se entre O e 20 cm de profundidade. A densidade de raizes foi maior no sistema de cultivo na palha do que no convencional, entre O e 10 cm. Os atributos físicos do solo não alteraram o desenvolvimento radicular. A semeadura direta propiciou maior densidade de raizes que mudas de bandejas e de raizes nuas. Altas produtividades foram obtidas com Alfa Tropical e Alfa São Francisco em dezembro, e em fevereiro com Mercedes. O transplantio de mudas de bandejas e a semeadura direta proporcionaram produtividades de até 50 t ha-1, quase o dobro da constatada no método de mudas de raizes nuas. Maiores produtividades ou precocidade de colheita foram obtidas no cultivo na palha em relação ao sistema convencional. / The aim of the study was to determine the effects of til/age system and method of crop implementation on the root system of onions and on the physical properties of the soil (Experiment I and 11), as well as on the productivity of the cultivars in the summer, for the purpose of collecting bulbs in the period of low onion yield (Experiments 111 and IV). The experiments were conducted in red latosol soil, in São José do Rio Pardo-SP, between Oecember, 2004 and September, 2005. Experiment I, started in Oecember, compared tillage systems, conventional (plowing/harrowing) versus no-tillage, and collection areas of soil samples, row versus interrow. Experiment 11, started in February, examined the two tillage systems, where crops were implemented by direct seeding (DS) and transplanting seedlings produced in trays (TST) or in raised beds (TSR). Experiment 11I, started in Oecember, studied the productivity of Alfa Tropical, Alfa São Francisco and Mercedes, implemented by TST and TSR, cultivated with no tillage and with conventional soil preparation. Experiment IV, started in February, examined the same treatments as in Oecember but also the OS method. The root system was concentrated at a depth of O to 20 cm. The density of the roots was greater between O and 10 cm with no tillage compared to conventional soi! preparation. The physical attributes of the soil had no influence on root development. OS favored a greater root density compared to TST and TSR. High productivity was obtained with Alfa Tropical and Alfa São Francisco in Oecember, and in February with Mercedes. TST and OS resulted in productivities of up to 50 t ha-1, almost double that with TSR. Greater yield was obtained with no tillage versus the conventional system.
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Implementation of a wideband microstrip phased array antenna for X-band radar applicationsDavids, Vernon Pete January 2009 (has links)
Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2009 / This thesis presents the design, analysis and implementation of an eight-element phased array
antenna for wideband X-band applications. The microstrip phased array antenna is designed
using eight quasi-Yagi antennas in a linear configuration and is printed on RT/Duroid
6010LM substrate made by Rogers Corporation. The feeding network entails a uniform
beamforming network as well as a non-uniform -25 dB Dolph-Tschebyscheff beamforming
network, each with and without 45° delay lines, generating a squinted beam 14° from
boresight. Antenna parameters such as gain, radiation patterns and impedance bandwidth
(BW) are investigated in the single element as well as the array environment. Mutual coupling
between the elements in the array is also predicted.
The quasi-Yagi radiator employed as radiating element in the array measured an exceptional
impedance bandwidth (BW) of 50% for a S11 < -10 dB from 6 GHz to 14 GHz, with 3 dB to
5 dB of absolute gain in the frequency range from 8 GHz to 11.5 GHz. The uniform broadside
array measured an impedance BW of 20% over the frequency band and a gain between 9 dB
to 11 dB, whereas the non-uniform broadside array measured a gain of 9 dB to 11 dB and an
impedance BW of 14.5%. Radiation patterns are stable across the X-band. Beam scanning is
illustrated in the E-plane for the uniform array as well as for the non-uniform array.
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Narrativas em Libras: análise de processos cognitivos / Narratives in Libras: analysis of cognitive processesValeria Fernandes Nunes 10 January 2014 (has links)
Palavras ou expressões produzidas em línguas de sinais são conhecidas como sinais. Línguas de sinais são produzidas especificamente em forma visual e o significado dos sinais pode ser compreendido por meio da relação com recursos visuais, do usuário com o mundo e com o corpo. Este estudo, com base na Linguística Cognitiva, propõe-se a analisar essas relações em sinais da Língua Brasileira de Sinais (Libras), produzidos por dez surdos ao narrarem a história em quadrinhos Não chora que eu dou um jeito da Turma da Mônica. Os processos cognitivos foram analisados à luz da gramática cognitiva (LANGACKER, 2008), da corporificação (LAKOFF; JOHNSON, 1980), da metonímia conceptual (LAKOFF; JOHNSON, 2003; EVANS; GREEN, 2006; KÖVECSES, 2010), da categorização (CROFT; CRUSE, 2004; Rosch apud FERRARI, 2011), da iconicidade cognitiva (WILCOX, 2000; QUADROS, 2004; WILCOX, 2004) e da mescla em espaço real (FAUCONNIER; TURNER, 1996, 2003; LIDDELL, 2003; SHAFFER, 2012; DUDIS apud SHAFFER, 2012). Constatou-se que alguns sinais produzidos apresentaram conceptualização de base icônica. A partir dessa fundamentação, postulou-se que esses sinais poderiam receber a seguinte categorização: icônicos (BOLA e CAIXA); icônico metonímicos (INES e CASA); icônico metonímico corporificados (MONICA e CHORAR). Por meio dessa classificação, propôs-se também a categorização de nomes e verbos pessoais. Outro processo cognitivo investigado foi a mescla em espaço real, constatada em seis das dez narrativas, como um recurso cognitivo acionado para expor ao interlocutor a troca de turnos dos participantes da narração. Tendo em vista que esses sinais foram encontrados em narrativas, analisam-se etapas da narrativa (LABOV apud FIGUEIREDO, 2009) e a estrutura das histórias em quadrinhos (SILVA, 2001; SOUZA, 2013). Verificou-se que não houve narrativa com todas as etapas de Labov. Assim, por meio de uma investigação inicial, esta pesquisa fornece questionamentos acerca dos processos cognitivos acionados na produção de sinais da Libras nas narrativas pesquisadas / Words or expressions produced in sign languages are known as signs . Sign languages are produced specifically in visual form and signs meaning can be understood through the relationship with visual space, the signers relationship with the world and with the body. This study, based on Cognitive Linguistics, proposes to examine these relationships in signs of Brazilian Sign Language Libras, which were produced by ten deaf when narrating Turma da Mônica comic strip Não chora que eu dou um jeito. Cognitive processes were analyzed according to cognitive grammar (LANGACKER, 2008) , embodiment (LAKOFF; JOHNSON, 1980) , conceptual metonymy (LAKOFF; JOHNSON, 2003; EVANS; GREEN, 2006; KÖVECSES, 2010), categorization (CROFT; CRUSE, 2004; ROSCH apud FERRARI, 2011) , cognitive iconicity (WILCOX, 2000; QUADROS, 2004; WILCOX, 2004) and real space blend (FAUCONNIER; TURNER, 1996, 2003; LIDDELL, 2003; SHAFFER, 2012; DUDIS apud SHAFFER, 2012). It was found that some signs produced had an iconic relationship. From this reasoning, it was postulated that these signs could receive the following categorization: iconic signs (BOLA and CAIXA); iconic metonymic signs (CASA and INES); iconic metonymic embodied signs (MONICA e CHORAR). Through this classification, it was also proposed the categorization of personal nouns and verbs. Another cognitive process investigated was real space blend, found in six of the ten narratives, as a cognitive resource used to expose the receiver the differences between participants narration. These signs were removed from narratives, therefore stages of the narrative (LABOV apud FIGUEIREDO, 2009) and structure of comics ( SILVA, 2001; SOUZA, 2013 ) were analyzed. It was found that there wasnt a narrative with all Labovs stages, but narrations with some of those stages. Thus, by an initial investigation, this research provides questions about the cognitive processes used to produce signs of Libras in narratives
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Trazendo a noite para o dia : apontamentos sobre erotismo, strip tease masculino, pedagogias de gênero e sexualidadeNunes, Claudio Ricardo Freitas January 2012 (has links)
Esta pesquisa de doutorado em Educação, realizada com recorte etnográfico, analisa um determinado lugar na cidade de Porto Alegre, reconhecido como um lugar de sociabilidades e práticas homossexuais, mas que se diferencia ao acolher qualquer público adulto (homens heterossexuais, travestis, mulheres). Mesmo se tratando de lugar reconhecidamente gay, paradoxalmente se percebem indicações eróticas e hierarquizações a partir de comportamentos e práticas heterossexuais. Inspirado na obra do Marques de Sade, Os 120 dias de Sodoma ou a Escola de Libertinagem, penso nesse local com a ajuda da metáfora do Castelo de Silling, que sofreu inúmeras adaptações para comportar tantas atuações a partir de manifestações eróticas e das próprias práticas sexuais. O ‘castelo’ pesquisado também possibilitou a análise de uma específica prática corporal, o strip tease masculino, a partir de variados investimentos no substrato corporal de homens jovens, masculinos, que diariamente exibem-se para uma plateia predominantemente homossexual. Nesses shows foram percebidos elementos pedagógicos relacionados a gênero e sexualidade, pautados em uma possível supremacia da heterossexualidade que se apresenta no palco, ao mesmo tempo em que se desvalorizam as próprias homossexualidades dos clientes, o gênero feminino e a condição travesti. Portanto, tal ‘castelo’ pode ser também analisado a partir de referenciais heteronormativos percebidos em alguns espaços e nesses shows com o rechaço das homossexualidades e feminilidades ali representadas. / This qualitative doctoral research in education, conducted with ethnographic inspiration, examines a particular place in the city of Porto Alegre, recognised as a place of homosexual sociabilities and practices, but that also excepts any adult audience (heterosexual men, transvestites, women). Even if it came to be recognized as a gay place, paradoxically it is possible to notice some hierarchies based upon heterosexual practices and behaviors. Inspired by the work of Marquis de Sade, The 120 days of Sodom, or the School of Licentiouness, I see this particular research field as he metaphor of the Silling castle, which suffered numerous adaptations to accommodate several performances and erotic practices. The ' Castle ' that was researched also enabled the analysis of a specific bodily practice, the male strip tease. The analysis problematized the various investments in the body young masculine men who, daily entertain an audience that is predominantly homosexual. In these shows pedagogical elements related to gender and sexuality were perceived. These elements presented on stage were mosty based on a possible supremacy of heterosexuality, which at the same time that devalues the homosexuality of the customers, the feminine and transvestite conditions. Therefore, though being mostly dedicated to gay customers the shows presented in this “castle” also have heteronormative referentials like the rejection of feminine traits and homosexuality.
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Trazendo a noite para o dia : apontamentos sobre erotismo, strip tease masculino, pedagogias de gênero e sexualidadeNunes, Claudio Ricardo Freitas January 2012 (has links)
Esta pesquisa de doutorado em Educação, realizada com recorte etnográfico, analisa um determinado lugar na cidade de Porto Alegre, reconhecido como um lugar de sociabilidades e práticas homossexuais, mas que se diferencia ao acolher qualquer público adulto (homens heterossexuais, travestis, mulheres). Mesmo se tratando de lugar reconhecidamente gay, paradoxalmente se percebem indicações eróticas e hierarquizações a partir de comportamentos e práticas heterossexuais. Inspirado na obra do Marques de Sade, Os 120 dias de Sodoma ou a Escola de Libertinagem, penso nesse local com a ajuda da metáfora do Castelo de Silling, que sofreu inúmeras adaptações para comportar tantas atuações a partir de manifestações eróticas e das próprias práticas sexuais. O ‘castelo’ pesquisado também possibilitou a análise de uma específica prática corporal, o strip tease masculino, a partir de variados investimentos no substrato corporal de homens jovens, masculinos, que diariamente exibem-se para uma plateia predominantemente homossexual. Nesses shows foram percebidos elementos pedagógicos relacionados a gênero e sexualidade, pautados em uma possível supremacia da heterossexualidade que se apresenta no palco, ao mesmo tempo em que se desvalorizam as próprias homossexualidades dos clientes, o gênero feminino e a condição travesti. Portanto, tal ‘castelo’ pode ser também analisado a partir de referenciais heteronormativos percebidos em alguns espaços e nesses shows com o rechaço das homossexualidades e feminilidades ali representadas. / This qualitative doctoral research in education, conducted with ethnographic inspiration, examines a particular place in the city of Porto Alegre, recognised as a place of homosexual sociabilities and practices, but that also excepts any adult audience (heterosexual men, transvestites, women). Even if it came to be recognized as a gay place, paradoxically it is possible to notice some hierarchies based upon heterosexual practices and behaviors. Inspired by the work of Marquis de Sade, The 120 days of Sodom, or the School of Licentiouness, I see this particular research field as he metaphor of the Silling castle, which suffered numerous adaptations to accommodate several performances and erotic practices. The ' Castle ' that was researched also enabled the analysis of a specific bodily practice, the male strip tease. The analysis problematized the various investments in the body young masculine men who, daily entertain an audience that is predominantly homosexual. In these shows pedagogical elements related to gender and sexuality were perceived. These elements presented on stage were mosty based on a possible supremacy of heterosexuality, which at the same time that devalues the homosexuality of the customers, the feminine and transvestite conditions. Therefore, though being mostly dedicated to gay customers the shows presented in this “castle” also have heteronormative referentials like the rejection of feminine traits and homosexuality.
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An evaluation of small scale open cast mining of UG2 in the Bushveld complexMooney, David G January 1997 (has links)
The current weak state of the platinum market, as well as the large inventory of platinum group metals held by Russia, necessitates that the South African platinum mining industry must carefully evaluate the benefits and disadvantage of small-scale mining of shallow, open castable ore resources. Until the late 1980's, these resources were ignored due to the metallurgical complexities of treating oxidized ore, as well as the mind set that existed within the South African mining industry which militated against open cast mining in the Bushveld. During the latter part of the 1980's and early 1990's, advances in the metallurgical treatment of oxidized ore, specifically the UG2, as well as operational problems, created the impetus to begin the exploitation of these resources. Small-scale open cast mining has become viable due to the development of suitable mining methods that facilitate mining practices acceptable to the Department of Mineral and Energy Affairs, in terms of environmental legislation. Metallurgical advances and growing experience, especially with respect to the UG2, enables reasonable platinum group metals recovery from oxidized ore. The problems experienced in doing this can, and are being overcome. With growing public awareness of environmental issues, particularly related to the mining industry, the requirement to ensure that the small-scale open cast mine site is well managed is paramount. A methodology for the evaluation is presented along with a case study of a small-scale UG2 open cast pit. Evidence is presented that shows that these small-scale open cast mining operations are extremely profitable and require minimal capital expenditure. However, caution is advised when evaluating Merensky Reef open cast operations because of the problems that they present.
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The design of feed networks for enhanced bandwidth operation of microstrip patch antennasDe Haaij, David Martin 22 September 2005 (has links)
This dissertation investigates a simple LC-matching network for the impedance bandwidth enhancement of microstrip patch antennas. Wideband impedance matching is a standard practice for active circuits. Simple impedance matching of antennas is also quite common, but data on wideband impedance matching of antennas is not found very much in the open literature. The matching circuit presented consists out of a resonant LC-circuit with a quarterwave matching line as part of the design. Results for a number or experimental antennas, on which the new technique was applied, are included in the report. A well-defined design procedure is also presented, and results in a relatively small circuit to implement. It is shown that the antenna VSWR bandwidth could be improved to more than double the original size in most of the antennas investigated. / Dissertation (M Eng (Electronic Engineering))--University of Pretoria, 2006. / Electrical, Electronic and Computer Engineering / unrestricted
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Riparian Graminoid Species Responses and Productivity in Compromised Environmental and Soil ConditionsWallace, Casey Ruth January 2019 (has links)
Riparian buffers have been created as a sustainable and effective way to combat the harmful effects of excess nitrogen and soil salinity in riparian settings. The goal of this research was to determine what species will I) germinate in saline environments and II) establish and produce sufficient biomass while being exposed to increased nitrogen. Incubation of eight native riparian graminoid species were evaluated for their ability to germinate in MgSO4-induced salinity. In a greenhouse study, seven riparian graminoid species were evaluated to quantify their ability to survive and take up nitrogen, mimicking buffer strips exposed to high inputs of runoff nitrogen. Slender wheatgrass and green needlegrass were able to germinate successfully when exposed to MgSO4 with EC levels up to 16 dS m-1 and 8 dS m-1, respectively. Of the graminoid species tested, smooth brome yielded sufficient biomass and nitrogen uptake percentages in a controlled setting.
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Evaluation of two different mechanized earth moving technologies truck and shovel and IPCC for handling material from a large open pit mine using requesite design and operational conditions, efficiency, cost , skills and safety as criteria using sishen iron ore mine as a case studyBanda, Nelson January 2016 (has links)
An advanced coursework and a project submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements of MSc. Engineering
(Mining), November 2015 / General
For mining operations, both underground and open cast, there are generally
accepted criteria used to arrive at the optimum mining method with which to exploit
the ore body economically. Having selected the optimum mining method, mining
companies should then make the decision to also select the optimum technology to
apply given the various options that are now available.
In the case of a shallow massive ore body where open-pit mining has been selected
as the optimum mining method, the use of conventional trucks and shovels has been
the popular choice but over the years, as pit become deeper, and stripping ratios
increase, growing interest and adoption of in-pit crushing and conveying for both ore
and waste has been gaining ground with several mining sites currently now
operating, testing the systems or conducting studies at various stages for In-pit
Crushing and Conveying (IPCC) in its different configurations (Chadwick, 2010).
Open pit mining general involves the movement of pre-blasted or loose waste ahead
of underlying ore out of the pit or to a previously mined part of the pit. This is then
followed by the drilling and blasting or loosening of the ore and transportation to the
processing plant or stockpiles.
The conventional Truck and Shovel open pit operation involves the use of shovels –
electric rope shovels, diesel or electric hydraulic shovels or excavators or front-end
loaders to load the blasted, or loose waste and ore material in the pit onto mining
trucks which haul the material to crushers or stockpiles if it is ore or to waste dumps
in the case of waste.
In a Fully Mobile IPCC (FMIPCC) system, the broken or loose material in the pit is
loaded into a crusher or sizer by a shovel, continuous miner or dozer, crushed to a
manageable size and transported by conveyor belts to the waste dump where it is
deposited in place using spreaders if it is waste or onto stockpiles if it is ore.
A combination of the two systems is where trucks dump material loaded at the face
into a semi mobile crusher or sizer located in the pit close to the loading points
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before conveying to destination thereby reducing truck haulage distance. In the
semi-mobile configuration, the crusher is relocated closer to the loading points to
minimise the hauling distance. Other various configurations are also employed
depending on the various considerations. Although the Truck and Shovel system is
considered as the convention in open pit mining, the IPCC system is not a new
concept and has been operational on a number of mines worldwide for quite a
number of years (Szalanski, 2010). Loading and hauling receive great attention
especially in a high volume open pit mines due to the high cost contribution to the
overall operation and therefore, if optimised, good cost savings can be realised
(Lamb, 2010).
Figure 1: Sishen Mining Cost Breakdown
In the case of Sishen Loading and Hauling costs constituted 67% of the mining costs
including labour mining support services in 2013 (Kumba Iron Ore, 2013). This
picture remains unchanged to a large extent. In some cases the hauling cost alone
can make up as much as 60% of the mining operating cost (Meredith May, 2012)
Selection of a materials handling system between Truck and Shovel (T/S) and In-pit
Crushing and Conveying (IPCC) has proven to be difficult due to limited
understanding of the IPCC system especially its advantages and disadvantages
relative to the Truck and Shovel system. The aim of this research was to unpack
these two systems in terms of their applicability using studies conducted at Sishen
6,5%
8,8%
29,1%
22,7%
9,7%
0,6%
1,3%
0,4% 7,0%
4,2%
3,7% 5,9%
Sishen Mining Cost 2013
Blasting Drilling Hauling
L&H Contractors Loading Maintenance Other
Mining Manangement Mining Engineering Mining Other
Resource Management SHEQ Mining Support
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Mine as well as develop some scorecard that could be used to select one over the
other one.
Sishen Case Study
Sishen Mine is an iron ore open pit mine located in the Northern Cape province of
South Africa and is part of Kumba Iron Ore Company which is
Anglo American PLC. The mine has been in operation since 1953 with the current
life of mine going up to 2030. It produces 44Mt tonnes of product from a 56Mt
mine ore at a life of mine strip ratio of 4. One of the planned expansion
the north part of the mine known as the GR80 and GR50 areas. Mining in these
areas will require pre-stripping of
290Mt of clay material over the life of mine to expose the ore in pre
volume phases.
Figure2: Sishen Pit –Sishen Mine 2014.
Sishen mine is constantly evaluating various technologies in its mining operations
aimed at improving its bottom line by way of increasing productivity and efficiency,
reducing costs and improving safety, however, the last time that the mine considered
evaluating a technology that significantly could have resulted in a totally different
operational philosophy was i
contracted to institute a study to evaluate technology options for mining and moving
majority owned by
a minimum of 437Mt of calcrete and the underlying
pre-
g in 2007 when Snowden Mining Consultants
run-ofmine
areas is in
-planned time and
were
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55 Mt of the calcrete/clay material per year from the waste pushback area in the
GR80/GR50 area of the mine from 2009 till 2030. Snowden completed the
Prefeasibility study in early 2008 in which they evaluated a conventional Truck and
Shovel operation as well as IPCC. Economic viability of both systems in various
configurations was demonstrated with the use of larger trucks and shovels ranked as
the most economic option in terms of Net Present Cost (NPC), unit owning and
operating cost per mined tonne and, to a less extent, in terms of risk and other
considerations. In this case, the Truck and Shovel option was more economic than
both IPCC configurations. However the small difference in the cost figures gave rise
to interest in further evaluations.
Following the Snowden study, Sishen engaged Sandvik Mining and Construction in
2008, to review the work done by Snowden and provide more detail and practical
input to the IPCC system at scoping level. In the review, the IPCC system was
shown to be the economic approach for the waste removal from the target area in
terms of owning and operating cost. Practicality was also demonstrated and the case
for the consideration of the IPCC system was put forward to Sishen.
A further consultant, Sinclair Knight Merz (SKM) of Australia, was engaged, in the
later part of 2008, to further evaluate and optimise the IPCC option to further
demonstrate practically in detail at a feasible study level and strengthen its case by
mitigating perceived risk. This included equipment specifications, mine and
equipment layout per period per bench and risk assessment on the IPCC options.
The mine, however, implemented the conventional truck and shovel option using
larger equipment. The final decision was to stick with the current set up of Truck and
Shovel system and gradually replace the current fleet of 730E Komatsu (190 tonne
payload) trucks with the 930E or equivalent ( 320 tonne payload) and the current
XPB 2300 P& H electric rope shovels and CAT 994/Komatsu WA1200 front end
loaders with XPC 4100 P&H electric rope shovels, Komatsu PC8000/Liebherr 996
diesel hydraulic shovels and LeTournea L-2350 front end loaders to reduce the
number of equipment and manage the operational cost.
This decision was based on issues around initial capital investment, flexibility of the
system to suit changing mining plans, ability of current personnel to run the system
and general low risk appetite for change. The adopted option has its own challenges
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such as supporting infrastructure requirements, labour intensity and associated low
productivity and high cost, fleet management challenges to achieve required
productivity constantly, supplies such as fuel and tyres and safety issues due to
traffic density.
A high level recalculation of the costs using current information was done as part of
this research. For simplicity, no escalations or discounting were applied on future
expenditure. The estimated unit owning and operating costs in 2014 terms for the
study area were as follows:-
Fully Mobile IPCC (FMIPCC) option ZAR 10.38/t,
Semi Mobile IPCC (SMIPCC) option ZAR 13.12/t,
Truck and Shovel option ZAR 15.80/t.
The objective of this research is to use lessons from the Sishen case as well as
other operations and gather expert views with the aim of establishing criteria that
could be applied in a preliminary evaluation that would determine the suitability of
either of the materials handling options.
General Approach
The costs were recalculated using as much current information as possible. Other
considerations including advantages and disadvantages of either of the systems
were examined in more detail, with real life examples examined where possible. This
resulted in the establishment of generalized criteria for the selection of mining and
transport technology for a large open pit mine with focus on conventional Truck and
Shovel systems on one hand and IPCC systems, in their various formats, on the
other. These criteria which identify conditions necessary for the successful adoption
and implementation of either of the systems could then be used as input into the
decision to carry out any further detailed studies of the options. The previous study
reports on the Sishen mine case were examined, input parameters to the
calculations checked and the general approached analyzed for practicality. The
relative costs were also viewed for comparative purposes.
Literature on these two main systems was reviewed including that from conferences.
Other large operations running either one or both systems were looked at to gain
N BANDA 392438
further insight. Original Equipment suppliers’ views on these systems were also
looked at through many articles in the public domain. Sishen mine has previously
had the IPCC system running in the same part of the mine in a semi mobile
configuration, crushing and conveying waste. It was then changed to become a
supplementary system for the ore handling system and the in pit crusher has never
been relocated. The Truck and Shovel system took over the movement of all the
waste and most of the ore at the mine. Lessons from these experiences were
incorporated in this study.
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