Fluorine-fixing efficiency on calcium-based briquette: pilot experiment, demonstration and promotion.
BACKGROUND
The fluorosis derived from coal burning is a very serious problem in China. By using fluorine-fixing technology during coal burning we are able to reduce the release of fluorides in coal at the source in order to reduce pollution to the surrounding environment by coal burning pollutants as well as decrease the intake and accumulating amounts of fluorine in the human body. The aim of this study was to conduct a pilot experiment on calcium-based fluorine-fixing material efficiency during coal burning to demonstrate and promote the technology based on laboratory research.


METHODS
A proper amount of calcium-based fluorine sorbent was added into high-fluorine coal to form briquettes so that the fluorine in high-fluorine coal can be fixed in coal slag and its release into atmosphere reduced. We determined figures on various components in briquettes and fluorine in coal slag as well as the concentrations of indoor air pollutants, including fluoride, sulfur dioxide and respirable particulate matter (RPM), and evaluated the fluorine-fixing efficiency of calcium-based fluorine sorbents and the levels of indoor air pollutants.


RESULTS
Pilot experiments on fluorine-fixing efficiency during coal burning as well as its demonstration and promotion were carried out separately in Guiding and Longli Counties of Guizhou Province, two areas with coal burning fluorosis problems. If the calcium-based fluorine sorbent mixed coal was made into honeycomb briquettes the average fluorine-fixing ratio in the pilot experiment was 71.8%. If the burning calcium-based fluorine-fixing bitumite was made into a coalball, the average of fluorine-fixing ratio was 77.3%. The concentration of fluoride, sulfur dioxide and PM10 of indoor air were decreased significantly. There was a 10% increase in the cost of briquettes due to the addition of calcium-based fluorine sorbent.


CONCLUSIONS
The preparation process of calcium-based fluorine-fixing briquette is simple yet highly flammable and it is applicable to regions with abundant bitumite coal. As a small scale application, villagers may make fluorine-fixing coalballs or briquettes by themselves, achieving the optimum fluorine-fixing efficiency and reducing indoor air pollutants providing environmental and social benefits.
Yang
Jiao-lan
JL
Department of Quality Control, Institute for Environmental Health and Related Product Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Chen
Dong-qing
DQ
Li
Shu-min
SM
Yue
Yin-ling
YL
Jin
Xin
X
Zhao
Bing-cheng
BC
Ying
Bo
B
D000397:Air Pollution / Q000517:prevention & control*; D002118:Calcium / Q000737:chemistry*; D002681:China; D003031:Coal / Q000032:analysis*; D005461:Fluorine / Q000737:chemistry*; D006801:Humans
D003031:Coal; D005461:Fluorine; D002118:Calcium