Volatility of arsenic in contaminated clay at high temperatures

Experiments were conducted in a tube furnace on the volatility of arsenic f rom contaminated kaolin clay. The experimental temperatures ranged from 522 to 1125 degreesC. The gas compositions used were nitrogen, oxygen and nitr ogen, carbon monoxide and nitrogen, and hydrogen chloride and nitrogen. At 522 degreesC, 10 to 22% or less of the arsenic volatilized in all experimen ts. At 1125 degreesC under inert and oxidizing atmospheres, about 40% of th e arsenic volatilized. Arsenic volatility was higher for the reducing and t he hydrogen chloride-containing atmospheres. At 950 degreesC and residence times of I h or longer, 80% or more of the arsenic was lost for both the re ducing and the hydrogen-chloride containing atmospheres. At 1125 degreesC, arsenic volatilization ranged from 82 to 92% for the reducing atmosphere an d 91 to 98% for the hydrogen chloride-containing atmosphere. The low arseni c volatility in the oxidizing experiments is similar to results in pilot- a nd full-scale incinerator tests.