Abstract
South Africa is a country that is very rich in mineral resources but the use of
Mössbauer spectroscopy to solve operational industrial problems is however very limited.
In the Bushveld Igneous Complex the main minerals extracted from the ore are the platinum
group metals and chromium, but secondary recovery of base metals such as nickel, copper
and cobalt forms an integral part of the process. Losses of nickel in the slag can amount to
about 4%and subsequent a slag cleaning furnace is used to reduce the loss to less than 0.5%
nickel oxide. The Fe2+/Fe3+ ratio and mineralogy was used to determine the partial oxygen
pressure in the furnaces and also the efficiency of the nickel recovery. From the Mössbauer
results, augmented with XRD, SEM, EMP-WDX and MLA analyses, optimum conditions
were determined to ensure minimum metal losses. The use of Mössbauer spectroscopy in the
coal industry, to investigate mineral changes that occur during its use, is also of importance.
The main minerals present in coal were determined with the aid of various techniques, such
as Mössbauer, XRD, SEM and HR-TEM, with the major iron minerals found to be pyrite,
illite, ankerite and jarosite. A large quantity of coal is used to produce syngas via gasification
plants for the production of synthetic fuels. The change of the mineral matter during
gasification was studied and the changes occurring during the gasification process were followed.
The syngas produced, is further treated by means of the Fischer–Tropsch process
where an iron catalyst is incorporated in the process. The usefulness and fouling of the catalyst
is being studied with the aid of Mössbauer spectroscopy.