多维度调控策略:钢渣体积稳定性优化方法综述

Multidimensional control strategy: a review of optimization methods for the volume stability of steel slag

  • 摘要: 钢渣是冶金企业产生的主要固体废弃物,产量大,有效利用率低,对生态环境造成了严重危害。钢渣体积稳定性差是阻碍其大规模应用的主要原因。如何有效提升钢渣体积稳定性是其大规模应用的关键。本文着眼于钢渣体积膨胀风险,多维度分析了钢渣体积稳定性调控的研究进展。分析结果表明:对于熔融态钢渣,调质法和工艺法均能显著降低熔融态钢渣中的活性物质含量,实现对钢渣体积稳定性的调控,空气淬火通过优化活性物质的粒度能降低钢渣膨胀风险。对于冷却后的固态钢渣:陈化处理为目前钢渣体积稳定性处理的主要手段,自然陈化处理周期长且均匀性差,通过施加温度、压力、湿度等外部条件后,可大幅度缩短处理周期,但也存在废水处理量大、能耗高、钢渣质量下降等缺点;碳化处理主要分为直接碳化法和间接碳化法,直接碳化法通过施加温度、压力、CO2浓度等提高钢渣碳化效率,从而降低钢渣的膨胀风险,间接碳化法不依赖传统的碳化设备,通过调节pH值或者使用微生物,诱导钢渣中的碱金属离子沉淀,碳化效率更高,虽然步骤繁琐,但不需要严格的外部条件;表面改性主要分为无机改性和有机改性,改性处理后显著降低钢渣体积膨胀风险,但酸处理产生难以处理的废液,有机材料处理存在成膜效果差,弹性高,易脆性损伤等缺点;联合多种方法对钢渣进行预处理效果更好,其中,碳化处理联合其他方法,无论与酸处理,碱活化,还是通过碳化制备人工钢渣骨料,相较于单一处理,进一步提高了钢渣体积稳定性。以人工钢渣骨料制备的的混凝土表现出优异的性能,缓解了天然骨料匮乏的局面,研究及应用前景广阔。

     

    Abstract: Steel slag is the main solid waste produced by metallurgical enterprises, which has large output and low effective utilization rate, and has caused serious harm to ecological environment. The poor volume stability of steel slag is the main reason that hinders its large-scale application. How to effectively improve the volume stability of steel slag is the key to its large-scale application. This paper focuses on the volume expansion risk of steel slag and analyzes the research progress of volume stability control of steel slag in multiple dimensions. The analysis results show that: for molten steel slag, both tempering method and process method can significantly reduce the content of active substances in molten steel slag, and achieve the regulation of the volume stability of steel slag. Air quenching can reduce the expansion risk of steel slag by optimizing the particle size of active substances. For cooled solid steel slag: aging treatment is the main means of volume stability treatment of steel slag at present, natural aging treatment period is long and the uniformity is poor, by applying external conditions such as temperature, pressure and humidity, the treatment period can be greatly shortened, but there are also shortcomings such as large wastewater treatment volume, high energy consumption, and the quality of steel slag decline. The carbonization treatment is mainly divided into direct carbonization method and indirect carbonization method. The direct carbonization method improves the carbonization efficiency of steel slag by applying temperature, pressure, CO2 concentration, etc., thus reducing the expansion risk of steel slag. The indirect carbonization method does not rely on traditional carbonization equipment, and induces the precipitation of alkali metal ions in steel slag by adjusting pH value or using microorganisms, thus achieving higher carbonization efficiency. Although the procedure is cumbersome, it does not require strict external conditions; Surface modification can be divided into inorganic modification and organic modification. After modification, the volume expansion risk of steel slag can be significantly reduced. However, acid treatment can produce waste liquid that is difficult to be treated. The combination of various methods for pretreatment of steel slag is better, among which carbonization treatment combined with other methods, whether with acid treatment, alkali activation, or by carbonization to produce artificial steel slag aggregate, further improves the volume stability of steel slag compared with a single treatment. The concrete made of artificial steel slag aggregate shows excellent performance, alleviates the shortage of natural aggregate, and has broad research and application prospects.

     

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