Dry Industrial Technology for Reducing Quartz Toxicity

The inclusion of “work involving exposure to respirable crystalline silica dust generated by a work process” in Annex I of Directive 2004/37/EC, which regulates worker exposure to carcinogenic agents, requires companies where this pollutant is present to take extra precautions to protect worker health. Replacing quartz is usually unfeasible. Two research projects were conducted in which technologies were developed that allow crystalline silica particle toxicity to be reduced by coating the particle surface with organosilanes. In the first project (SILICOAT), the effectiveness of adding these coating agents in wet production processes for traditional ceramics was verified. In the second project (SILIFE), a dry coating process was developed that enables quartz powders with low or zero toxicity to be obtained, ready for use as raw material in industrial processes without wet production stages, such as those of frits, glazes, and ceramic pigments. The technology developed in the SILIFE project is protected by European patent application reference EP19382177.4, date of application 11.03.2019. In every case, coating the quartz particles was verified to lower crystalline silica toxicity, and the technical feasibility of the treatment was confirmed by industrial trials.