Introduction
Luminescence is a general term for many physical phenomena that emit light from an object or material, usually as a result of an internal energy source or when exposed to external energy sources such as an electric current or light. Luminescence of minerals refers to the emission of light from mineral substances under certain stimulation forms. Different types of luminescence have been observed in minerals including photoluminescence, fluorescence and triboluminescence. The luminescence of minerals can provide important information about its physical and chemical properties by investigating its characteristics. This report examines the luminescence properties of metallurgical ore minerals, and the application of their luminescence in metallurgical ore mineral exploration.
Types of Metallurgical Ore Mineral Luminescence
Photoluminescence is one of the most common luminescence exhibited by metallurgical ore minerals and refers to light emission initiated by a prior exposure to electromagnetic radiation such as ultraviolet (UV) or visible light. In some cases, this happens spontaneously, however, often it requires external stimulus and the mineral will still continue glowing for some period of time, usually only minutes, even after the radiation ceases. The luminescence intensity depends on the spectrum and energy of radiation, the intensity of light and its duration. Fluorescence and phosphorescence are two types of photoluminescence. Fluorescence is light emission under UV and visible radiation, while phosphorescence is light emission under UV and infrared radiation. They are all related to the presence of organic matter in minerals.
Triboluminescence refers to the light emission when a mineral breaks or a material is scratched. This phenomenon is caused by the separation and reuniting of electron-hole pairs in the crystal lattice. Most of the metallurgical ore minerals have triboluminescence and some have very strong luminescence. The light emission intensity is related to the mineral grain size and its components.
Application of Metallurgical Ore Mineral Luminescence in Exploration
Metallurgical ore mineral luminescence is a useful tool for the exploration of metallurgical ore deposits. There are several applications of luminescence in metallurgical ore mineral exploration.
1. Identification of metallurgical ore minerals: luminescence can help to identify certain types of ore minerals. For example, fluorescence of magnetite has been used to distinguish it from other similar minerals such as hematite. This is because magnetite fluoresces strongly when stimulated by UV light, whereas hematite does not.
2. Detection of Ore Bodies: Metallurgical ore minerals can be detected through the glow of luminescence. This is especially useful for shallow mineral deposits that are not clearly visible by other methods.
3. Analysis of Mineral Composition: Different ore minerals have different luminescence spectra and can therefore be used to infer information on the mineral composition of ore samples.
Conclusion
Metallurgical ore mineral luminescence is a useful tool in metallurgical ore mineral exploration. It can be used to identify, detect and analyse ore deposits. It is also relatively inexpensive, making it a cost-effective method of exploration. Despite its advantages, luminescence is not always reliable and should only be used in conjunction with other exploration methods.
