Understanding how fast minerals form and dissolve is of great interest in science. Minerals can be used to clean up waste waters and prevent transport of contaminants, be used as a storage for nutrients in soils, or even used to supply medicine. Sometimes minerals themselves act as a source for contamination, leading to acidity and large concentration of heavy metals. Mineral synthesis is used to make a range of functional materials, and control on the size and shape of particles are especially important. To predict the size distribution of particles, the rates of nucleation and growth of minerals are needed. Unfortunately, data on nucleation rates are more or less unknown for most minerals, and little is also known on the factors that control rate of nucleation-growth.
Barite (BaSO4) is a heavy mineral that have many uses. It occurs naturally in nature and is the primary source for Ba. Barite is for example used in hospitals as a diagnostic tool, as barite particles blocks X-rays and can act to illuminate soft tissue after being digested. Barite forms solid-solutions with different contaminants, and the growth of these solid-solutions is of interest in water management.
In this master thesis, the main objective is obtain nucleation rates of barite on a silicon glass substrate. The nucleation will be done by dispersing glass plates in chemical reactors with a dissolved Ba and SO4 salts. After experiments, microscopes will be used to image the glass plates with visible barite crystals, and image analyses will be done to estimate nucleation rates. In the work the student will learn how to perform chemical experiments carefully controlling temperature, stirring, and chemical composition of reactive solutions. The student will learn how to use reflection or transmission microscopy to obtain images, and how to use image software (ImageJ) to obtain statistical information on the number and size of mineral crystals.
The MSc study will be done at the laboratories at Department of Geosciences, UiO. This will give the student good experience with laboratory methods commonly used in environmental geology and geochemistry.
