Applications of the Dry Disposal Process in the Arsenic Contaminated Soil Treatment

The wet washing method using solvent like water has been widely used in the contaminated soil cleaning process, however the wet process tends to be complicated and expensive by solvent handling requirements.

In previous tests, the arsenic concentration shows sharp variations with soil diameters, and the dry disposal process is proposed as an alternative or complementary process.

Computer simulations are carried out to determine the proper air classifier type, and the operation conditions are optimized according to the cut-size. The rotating plate type disintegration device is adopted to increase the whole system recovery ratio.

The air classification can recover more than 60% arsenic contaminated soils, based on the national standard, and, with the additional feed-back and disintegration unit, the total recovery ratio of larger than 95 % is achieved. The proposed method is proven to reduce wet by-products and be advantageous in economic and environmental aspects.