A feasibility study for titanium recycling in South Africa

[摘要] ENGLISH ABSTRACT: In this study, the possibility of titanium recycling in South Africa is explored. Inspiredby recent beneficiation processes for the production of titanium from South Africa's vastmineral resources, this study identified the opportunity to create sustainable value fromthe inevitable influx of scrap, once these beneficiation strategies have been implemented.The objectives were to research all methods capable of recycling titanium, map theirprocess chains, and model them financially. Furthermore, a feasibility framework was tobe created, which serves the purpose of showing when each recycling method becomesfinancially feasible. Finally, a business case was to be created after choosing the bestrecycling alternative in South Africa at the time of the study. A background study wasdone at Hansens Engineering in Port Elizabeth, to gain insight into a state-of-the-artwaste-to-resource process through their in-house aluminium recycling operations. Eightmethods of recycling titanium are identified in the literature review, namely washingand briquetting swarf, precision casting, thermal degreasing, ferrotitanium production,vacuum-arc remelting (VAR), electron beam cold hearth melting (EB CHM), plasma arccold hearth melting (PA CHM) and mill product production. Each process is modelledfinancially, by use of a factorial method, which utilises equipment, operating labour,waste treatment, utilities and raw material costs as input variables to estimate totalfixed capital investment and total manufacturing costs. A ten-year NPV analysis on eachprocess is done, which is used to conduct the feasibility study, which consists of break-evenanalysis, scenario analysis, and the creation of the feasibility framework. The break-evenanalysis determines the yearly volume of scrap required to make each recycling methodfinancially feasible. By use of this, the feasibility framework is created. The break-evenvolumes are contextualised by use of benchmark components. This is used to representthe break-even points of each recycling method in terms of an amount of components, asopposed 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 studyresults, it is found that only two of the eight recycling processes are financially feasibleat present, namely washing and briquetting swarf, and precision casting. The best optionfor 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 hypotheticalscrap availabilities, respectively. Uncertainty analysis is performed on this process throughthe use of Monte-Carlo simulation. Input variables are varied over probable ranges, orby fitting distributions on historical data, to predict the probability of having a positiveNPV after the analysis period. The results showed that when recycling titanium throughprecision casting, one can be almost 99% certain of having a positive NPV after tenyears, when implementing either a 150% fixed profit margin or a selling price of R1000per casting. By this, a business case for titanium recycling in South Africa is created.

[发布机构] Stellenbosch University