垃圾焚烧炉渣特性分析及制备免烧砖技术研究

炉渣制备免烧砖的技术作为固废建材化利用的手段之一，具有广阔的应用前景.基于炉渣基本性质，本文探讨了炉渣预处理、原料配比及养护方式等工艺条件对炉渣免烧砖的抗压强度和环保性能的影响，并提出了优化的工艺条件和参数.结果表明:炉渣的热灼减率为1.2%，物相组成与天然骨料相似，但水溶性氯离子含量为GB 50010-2010《混凝土结构设计规范》标准限值的8倍，且存在重金属超标风险，需要在固液比1:3的条件下水洗3次，使得水溶性氯离子含量削减87.5%；免烧砖原料配比较养护方式对抗压强度的影响更大，不添加炉渣的普通免烧砖的最终强度为全炉渣免烧砖的2.23倍；养护方式的影响体现在高温养护初期抗压强度增长速度较自然养护更快，但最终差异在±3%以内；选取全炉渣的免烧砖进行高温养护或者炉渣河砂配比1:1的免烧砖进行自然养护可使产品最终强度达到10 MPa或20 MPa的要求，且水溶性氯离子含量最终削减90%，重金属浸出浓度削减50%~60%，可满足不同用途对砖的标准要求.研究显示，在不同抗压强度的要求下选取适当的配比与养护条件，可以达到炉渣消纳量大且能源耗费少的目的，并削减水溶性氯离子含量与重金属浸出浓度，具有环保效益. 

Characteristics of Incineration Slag and Production Technology of Baking-Free Bricks

As one of the methods of utilizing solid waste to develop building materials, the technology of using incineration slag to produce baking-free bricks has a promising future. Based on the study of basic properties of slag, this paper discusses the influences of technological conditions such as pretreatment, raw material composition and curing methods on the compressive strength and environmental performance of bricks. The results show that the ignition loss is 1.2%, and the phase composition of slag is similar to natural aggregate. However, the water-soluble chloride content is 8 times the limit of Code for Design of Concrete Structures (GB 50010-2010), and there is a risk of exceeding the heavy metal standards. It is necessary to wash 3 times under the condition of solid-to-liquid ratio of 1:3 to reduce the water-soluble chloride content by 87.5%. For baking-free bricks, the impact of raw material composition on the compressive strength is greater than curing methods, and the final strength of common bricks without slag is 2.23 times that of the bricks without sand. The impact of curing methods is reflected in the great increase of compressive strength in the early stage of high temperature curing than natural maintenance, but the final difference is within ±3%. Bricks without sand can reach 10 MPa under high temperature curing, and bricks of slag-to-sand ratio of 1:1 can reach 20 MPa under natural maintenance. Finally, the water-soluble chloride can be reduced by 90%, and the leaching concentration of heavy metals can be reduced by 50% to 60%, which can meet the standard requirements of bricks for different usages. Obviously, selecting appropriate material composition and curing methods under different requirements can consume large amounts of slag and less energy. It can also reduce water-soluble chloride content and heavy metal leaching concentration, which has environmental benefits.