Describing the Diffusion and Distribution of Airborne Nanoparticulates (NPs) and Ultrafine Particulates (UFPs) - Investigation of Size, Composition and Concentration in a Metallurgy and Smelting Plant by Scanning Electron Microscopy (SEM)

Abstract

     Airborne nanoparticles have long been a human health concern, with epidemiological studies linking increased mortality and health problems. This study investigates the nature and evolution of dust particles within a unit for mining and mineral recycling, focusing on a metallurgical plant producing iron and aluminum ingots. It characterizes the particles in the air and investigates the significance of their chemical composition and size. Samples have been collected from different areas of a mining plant and have been analyzed by means of scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS).

The results show a high concentration of metallic particles near the thermal mining area and a decrease in concentration towards other areas. The SEM shows particles of irregular size and distribution. The diameter of spherical particles ranges from 12 nm to more than 5500 nm. Microanalysis (EDX) data indicate the presence of iron oxide (Fe2O3) nanoparticles with oxygen and iron as major components. The larger nanoparticles show compounds adhering to their surface, indicating that they are composed of a core of iron and oxygen. It is likely that other chemical elements such as copper, aluminum, and carbon are incorporated to form many large nanoparticles.

This research provides valuable insight into occupational health and safety measures to mitigate potential health risks associated with exposure to these nanoparticles by shedding light on the formation and distribution of airborne nanoparticles in a foundry environment.