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South African titanium : techno-economic evaluation of the alternatives to the Kroll processVan Tonder, Willem 03 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: the potential to serve as a strategic economic driver for the country if a local processing and
production industry could be successfully established. According to the US Geological
Survey, conducted in January 2009, South Africa has approximately 14% of the world’s
reserves in ilmenite and rutile, the two most important titanium-containing minerals, but
no metal producing abilities. The only role players, Exxaro and Richards Bay Minerals, have
smelting operations and produce an enriched titania slag, but all the slag is exported.
The processing steps between titanium-containing minerals and the metal represent a
significant portion of the total production costs and this study is chiefly concerned with
recommending a more cost-effective alternative for these steps. The existing industrial
process is archaic, cost and energy intensive, batch operated with unfavourable economics.
A large number of internationally research initiatives are actively trying to address the
problem of high production costs by searching for and developing alternative, more costeffective,
processes.
It was the purpose of this study to provide the decision making authorities with a ranking
and evaluation of these alternatives to produce titanium metal. A 2-Phase Filtering System,
based on both qualitative and quantitative techniques, was designed to assess, evaluate
and formulate a final ranking. This evaluation was followed by a detailed sensitivity analysis
of both local and global parameters.
A total of 26 process alternatives were selected to be evaluated in this techno-economic
evaluation. The complete ranking is given in Table 8.8, and the four leading process
alternatives, based on this evaluation and the findings of the sensitivity analysis, are as
follows:
1. CardQIT: The Canadian affiliate of Rio Tinto, QIT, developed a high-temperature
titanium extraction process based on an electrolysis reaction, where molten titania
slag is the cathode.
2. ArmITP: The Armstrong process is a continuous process that produces titanium in a
very similar fashion as with the Hunter process, by the reduction of TiCl4 with sodium. TiCl4 vapour is injected into a stream of molten sodium to form titanium
powder as the reaction product.
3. Kroll: This process was developed in the 1950s and the reduction step remains
very much similar to the original process used by the USBM (United States Bureau
of Mines). Two criteria played a big part in the unexpected high ranking of the Kroll
process, and that were academic coverage, with almost 60 years of research, and
the commercial readiness of an industrial process.
4. FFC: Solid pre-forms are pressed and sintered from pigment grade TiO2, to be
directly electrochemically reduced to metallic titanium in a molten electrolyte of
CaCl2.
For future work, it is recommended that an additional filtering stage, a detailed profitability
analysis, be added to the decision model. The top 4 alternatives, as mentioned above,
should be used to estimate the cost-reduction potential as well as the capital investment
and production costs based on process, industrial and economic engineering fundamentals. / AFRIKAANSE OPSOMMING: Titaan is deur die Suid Afrikaanse regering geidentifiseer as 'n mineraalhulpbron met die
potensiaal om te dien as 'n strategiese ekonomiese drywer, indien 'n plaaslike verwerkingen
verwaardingsbedryf suksesvol op die been gebring kan word. Volgens die US Geological
Survey, wat in Januarie 2009 gedoen is, het Suid Afrika ongeveer 14% van die wêreld se
reserwes in ilmeniet en rutiel, die twee belangrikste titaanhoudende minerale. Suid Afrika
het egter geen metaal-vervaardigingsaanlegte nie. Die enigste twee rolspelers, Exxaro en
Richards Bay Minerals, het smelteraanlegte en vervaardig 'n verrykte
titaandioksiedkonsentraat, wat alles uitgevoer word.
Die waardetoevoegingsaktiwiteite tussen die titaanhoudende minerale en die metaal
verteenwoordig ‘n groot gedeelte van die produksiekoste van titaanmetaal en hierdie
studie is hoofsaaklik daarmee gemoeid om ‘n meer koste-effektiewe aanbeveling te maak,
m.b.t. dié stappe. Die bestaande bedryfsproses is argaïes, koste- en energieintensief, en is
ontwerp as ‘n lot proses met ongunstige ekonomiese eienskappe. 'n Groot aantal
internasionale navorsingsinstansies is aktief besig om oplossings te soek vir die probleem
van hoë verwerking- en vervaardigingkostes, deur alternatiewe opsies te ondersoek en te
ontwikkel.
Die doel van hierdie studie was om vir die besluitnemingsgesag 'n rangorde en vergelyking
van die alternatiewe opsies om titaniummetaal te vervaardig, te gee. 'n Tweeledige Filter
Stelsel, gebaseer op beide kwalitatiewe- en kwantitatiewe tegnieke, is ontwerp om die
rangorde te vorm, te bereken en te formuleer. 'n Sensitiwiteitsanalise is gedoen om die
besluitnemingsparameters se invloed op die finale rangorde en uitslag te toets.
'n Totaal van 26 prosesse is geidentifiseer en gekies om aan hierdie tegno-ekonomiese
evaluasie, te onderwerp. Die volledige rangorde word in Table 8.8 getoon, en die vier
leidende prosesalternatiewe, gebaseer op die uitkomste van dié evaluering en die
bevindinge van die sensitiwiteitsanaliese, is as volg:
1. CardQIT: Die Kanadese filiaal van Rio Tinto, QIT, het ‘n hoë-temperatuur titaan
ontginningsproses ontwikkel, gebaseer op ‘n elektrolitiese reaksie, waarin gesmelte
titaandioksiedkonsentraat die katode vorm. 2. ArmITP: Die Armstrong proses is ‘n kontinue opsie wat titaan produseer op ‘n baie
soortgelyke wyse as die Hunter proses, deur die reduksie van TiCl4 met natrium, Na.
TiCl4 damp word in ‘n gesmelte stroom natrium ingespuit om titaanmetaalpoeier te
vorm as die reaksie produk.
3. Kroll: Die proses is ontwikkel in die 1950s en die reduksie stap wat vandag gebruik
word is steeds soortgelyk soos die oorspronklike proses, aan gebruik deur die
USBM. Veral twee besluitnemingskriteria het ‘n belangrike rol gespeel om tot die
onverwagte hoë plasing van die Kroll proses te lei. Eerstens, akademiese dekking
en die feit dat omtrent 60 jaar se navorsing in hierdie opsie ingepomp is en
tweedens, die kommersiële gereedheid van hierdie prosesalternatief as ‘n
volskaalse bedryfsproses.
4. FFC: Gegoe vorms van pigmentgehalte TiO2, word gepers en gesinter om die
katodes te vorm wat dan direk elektrochemies gereduseer word tot titaanmetaal in
‘n gesmelte bad van CaCl2, as die elektroliet.
Vir toekomstige werk word aanbeveel dat ‘n addisionele filtervlak, ‘n
winsgewendheidsanalise, by die besluitnemingsmodel gevoeg word. Die vier
prosesalternatiewe, soos hierbo genoem, kan gebruik word en vir elk moet die kostebesparingspotensiaal,
die kapitaal insetkoste en die produksiekostes bereken word. Hierdie
berekeninge kan gebaseer word op proses-, bedryfs- en ekonomiese ingenieurswese
beginsels.
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Формирование лексической компетенции у студентов непрофильных специальностей средствами иностранного языка : магистерская диссертация / Developing of lexical competence among students of non-linguistic majors by means of a foreign languageКораблёв, В. С., Korablev, V. S. January 2024 (has links)
The developing of lexical competence is one of the goals of teaching a foreign language. The lexical competence is the student's ability to determine the meaning of a word in context, the ability to use it in speech and in writing. It is worth noting that lexical competence also includes knowledge of the system and norms of the language being studied, which are subsequently applied in practice. In the modern methodology of teaching foreign languages, there are a large number of methods and technologies that contribute to the achievement and realization of the set learning goal. One such approach is the lexical approach, which emphasizes the importance of actively using vocabulary in the context of real communication situations, which allows students to learn a foreign language faster and more effectively. The relevance of the study is determined by the necessity for further development of effective approaches to the development of lexical competence. In the theoretical chapter, the components of the foreign language learning process were analyzed, the structure, approaches and methods of developing lexical competence were analyzed, the principles of teaching a foreign language to students of non-linguistic majors were considered, the principles of implementing a lexical approach in teaching English to students of non-linguistic majors were formed. In the practical chapter, lesson plans based on the lexical approach, exercises that form lexical competence were developed, their practical application was described, the results of their testing were analyzed, proving the effectiveness of the lexical approach in the process of teaching a foreign language. / Формирование лексической компетенции является одной из целей обучения иностранному языку, то есть способность учащегося определять значение слова в контексте, возможность использовать его в устной и письменной форме. Стоит отметить, что лексическая компетенция также включает в себя знание системы и норм изучаемого зыка, которые в последующем применяются на практике. В современной методике преподавания иностранных языков существует большое количество методов и технологий, способствующих достижению и реализации поставленной цели обучения. Один из таких подходов – это лексический подход, который подчёркивает важность активного использования лексики в контексте реальных ситуаций общения, что позволяет обучающимся быстрее и эффективнее овладевать иностранным языком. Актуальность исследования обусловлена необходимостью дальнейшей разработки эффективных подходов к формированию лексической компетенции. В теоретической главе были проанализированы составляющие процесса обучения иностранному языку, проанализированы структура, способы формирования, подходы и методы формирования лексической компетенции, рассмотрены принципы обучения иностранному языку студентам неязыковых специальностей, сформированы принципы реализации лексического подхода при преподавании английского языка студентам непрофильных специальностей. В практической главе были разработаны планы занятий, основанные на лексическом подходе, упражнения, формирующие лексическую компетенцию, описано их практическое применение, проанализированы итоги их апробации, доказывающие эффективность применения лексического подхода в процессе обучения иностранному языку.
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