| 摘要 |
<p>PURPOSE:To make waste soil with sand harmless by decreasing its sulfate ion concentration by a method in which the composition of the soil is analyzed to confirm whether it contains waste clay and/or sulfated pitch or not, the soil is classified, and the soil containing sulfated pitch is neutralized by adding a lime neutralizer. CONSTITUTION:In a composition analysis step 1, the composition of waste soil mixed with sand and oil is analyzed to confirm whether the soil contains waste clay and/or sulfated pitch or not, and the soil is classified. In a neutralization step 2, the soil containing sulfated pitch is mixed with a lime neutralizer to decrease its sulfate ion concentration to make it harmless. In a sand separation step 3, the soil containing waste clay and the neutralized soil are sieved respectively to separate into sand and waste soil. In a dewatering step 4, the waste soil separated is heated and dewatered to make its water content below a specified value. In a kneading step 5, the dewatered soil is mixed with the separated sand, a solidification agent, and an additive, and the mixture is kneaded into a stable mixture. In a pulverization step 6, the mixture is pulverized into aggregate.</p> |
