热脱附污染土壤制备水泥活性混合材的研究

Study on preparation of cement active admixture by thermal desorption of contaminated soil

为了解决热脱附污染土壤离场消纳途径少、消纳量小、附加值低的问题,提高其资源利用价值,本文研究了不同温度下热脱附的污染土壤的pH值、活性指数、矿物组成,并与石灰石粉进行复合,解决标准稠度用水量高的问题。结果表明,随着温度升高,热脱附污染土壤的pH值由7.90增大到12.85,活性指数则先增大后减小,伊利石、方解石和钾长石发生分解;随着复合混合材中石灰石含量的增加,水泥的标准稠度用水量降低,水泥3 d和28 d抗压强度基本不变。

In order to solve the problems of less off-site consumption,small consumption and low added value of thermal desorption contaminated soil,and to improve its resource utilization value,this paper studied the pH value,activity index and mineral composition of thermal desorption contaminated soil at different temperatures,and compounded it with limestone powder to solve the problem of high water consumption of standard consistency.The results showed that as the temperature of thermal desorption rises,the pH value increases from 7.90 to 12.85,the activity index was first increased and then decreased,and the mineral composition such as illite,calcite and potash feldspar were decomposed.With the increase of the limestone content in the composite admixture,the water requirement of normal consistency of the cement was decreased,and the 3 d and 28 d compressive strength of the cement were basically unchanged.