Related Experiment Videos
Study on fluoride emission from soils at high temperature related to brick-making process
1College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029, PR China. zhmxie@zju.edu.cn
Chemosphere
|April 12, 2003
Summary
Fluoride emissions from soils during brick-making increase significantly with firing temperatures above 700°C. Calcium carbonate addition effectively reduces fluoride release, particularly at higher temperatures.
Area of Science:
- Environmental Science
- Geochemistry
- Materials Science
Background:
- Brick-making processes can release fluoride into the atmosphere.
- Understanding fluoride emission characteristics is crucial for environmental protection.
Purpose of the Study:
- To investigate fluoride emission from soils during simulated brick-making at high temperatures.
- To identify factors influencing fluoride release and evaluate mitigation strategies.
Main Methods:
- Heating 12 soil samples from 400-1,100°C.
- Analyzing fluoride emission as gaseous HF and SiF4.
- Correlating emissions with soil composition and added calcium compounds.
Main Results:
- Fluoride release initiated between 500-700°C, with significant increases (57.2% to 85.4%) from 700-1,100°C.
- Peak fluoride emission occurred around 800°C.
- Soil composition influenced emissions below 900°C, while calcium compounds, especially CaCO3, reduced overall release.
Conclusions:
- Firing temperature, soil fluoride content, and soil composition are key factors in fluoride emission.
- Calcium carbonate is an effective additive for mitigating fluoride release during high-temperature processes.