カルシウム系廃棄物からの炭酸化抽出液の生成と脱硫特性

抄録

For the purpose of recovering calcium resource, an attempt was made to extract Ca²⁺ by carbonation reaction from the calcium-based wastes such as limestone slurry, concrete waste and steel slag, and then the desulfurization characteristics of the Ca²⁺ extracts obtained from these calcium-based wastes were investigated. The Ca²⁺ extraction experiment was carried out in a hermetic vessel under the CO₂ pressure range of 0.10-2.00 MPa at the temperature range of 280-333 K.
As a result, it was found that Ca²⁺ extraction behaviors of limestone sludge and concrete waste were similar to that of limestone. However, the rate of Ca²⁺ extraction from steel slag was about one-third of those from the other calcium-based wastes. By introducing SO₂ gas (1000 cm³·m^-3) into the Ca²⁺ extract, it was found that SO₂ absorption performance of the Ca²⁺ extract of the calcium-based waste employed was almost the same to that of limestone slurry.