Detection of mineral impurities in diatomite ores

Diatomaceous Earth (DE) is commonly used in the industry for the manufacturing of filters, where diatomite is preferred due to its low chemical reactivity and high porosity. Diatomite deposits with major amounts of mineral impurities, such as carbonates, present a problem in the production DE. In this study, samples from a diatomite deposit with known presence of carbonate were analysed. With the aim of estimating the carbonate content, the samples were analysed with infrared (IR) spectroscopy. The association between the carbonate and diatomite was characterised using thin sections and Environmental Scanning Electron Microscopy (ESEM). Based on the infrared spectra, the diatomite ore was classified according to the carbonate content. The microscopy images showed laminae, cement and coating of carbonate around the diatomite. These findings indicate that the IR classification along with the type of carbonate association can optimise the production of DE.