Browsing by Author "Durr, Johan Frederik Wilhelm"

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    A feasibility study for titanium recycling in South Africa
    (Stellenbosch : Stellenbosch University, 2016-12) Durr, Johan Frederik Wilhelm; Oosthuizen, Gert Adriaan; Bam, Wouter; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: In this study, the possibility of titanium recycling in South Africa is explored. Inspired by recent beneficiation processes for the production of titanium from South Africa's vast mineral resources, this study identified the opportunity to create sustainable value from the inevitable influx of scrap, once these beneficiation strategies have been implemented. The objectives were to research all methods capable of recycling titanium, map their process chains, and model them financially. Furthermore, a feasibility framework was to be created, which serves the purpose of showing when each recycling method becomes financially feasible. Finally, a business case was to be created after choosing the best recycling alternative in South Africa at the time of the study. A background study was done at Hansens Engineering in Port Elizabeth, to gain insight into a state-of-the-art waste-to-resource process through their in-house aluminium recycling operations. Eight methods of recycling titanium are identified in the literature review, namely washing and briquetting swarf, precision casting, thermal degreasing, ferrotitanium production, vacuum-arc remelting (VAR), electron beam cold hearth melting (EB CHM), plasma arc cold hearth melting (PA CHM) and mill product production. Each process is modelled financially, by use of a factorial method, which utilises equipment, operating labour, waste treatment, utilities and raw material costs as input variables to estimate total fixed capital investment and total manufacturing costs. A ten-year NPV analysis on each process is done, which is used to conduct the feasibility study, which consists of break-even analysis, scenario analysis, and the creation of the feasibility framework. The break-even analysis determines the yearly volume of scrap required to make each recycling method financially feasible. By use of this, the feasibility framework is created. The break-even volumes are contextualised by use of benchmark components. This is used to represent the break-even points of each recycling method in terms of an amount of components, as opposed to a volume of titanium scrap. The financial feasibility models are also used to perform scenario analysis using pessimistic and optimistic hypothetical swarf availabilities, based on South African titanium trade statistics. Based on the collective feasibility study results, it is found that only two of the eight recycling processes are financially feasible at present, namely washing and briquetting swarf, and precision casting. The best option for recycling titanium at present is identified as precision casting, which shows a positive NPV of R650.55 million and R81.96 million in the optimistic and pessimistic hypothetical scrap availabilities, respectively. Uncertainty analysis is performed on this process through the use of Monte-Carlo simulation. Input variables are varied over probable ranges, or by fitting distributions on historical data, to predict the probability of having a positive NPV after the analysis period. The results showed that when recycling titanium through precision casting, one can be almost 99% certain of having a positive NPV after ten years, when implementing either a 150% fixed profit margin or a selling price of R1000 per casting. By this, a business case for titanium recycling in South Africa is created.