利用垃圾焚烧渣制备陶瓷透水路面砖的试验研究

Experimental study on preparation of ceramic permeable pavement brick from waste incineration slag

垃圾焚烧渣是一种危险的固体废弃物,无害化利用垃圾焚烧渣具有重要意义。以垃圾焚烧渣为主要原料,通过高温烧结工艺制备了一种综合性能较佳的透水砖,研究了垃圾焚烧渣的添加量与烧成温度对样品结构与性能的影响规律。结果表明:添加适量的废玻璃及适当提高烧成温度能够改善试样的强度及环境安全性;当垃圾焚烧渣、废玻璃与煤粉(外加)的添加量分别为60%、40%、20%(质量分数)时,在1 200℃下烧成制品的透水系数、抗折强度与抗压强度分别为0.58 mm/s、6.23 MPa和18.58 MPa,其强度和透水系数分别达到了R_(f)4.5与B等级,且制品的Cu^(2+)、Pb^(3+)和Zn^(2+)浸出浓度满足GB 5085.3—2007《危险废物鉴别标准浸出毒性鉴别》要求。XRD与SEM-EDS分析结果表明,由废玻璃熔融而成的高温液相溶解了三氧化二铅、氧化锌和氧化铜,抑制了Cu^(2+)、Pb^(3+)和Zn^(2+)的浸出。提高烧成温度能够降低样品的气孔率,促进三氧化二铅、氧化锌与氧化铜的溶解,进而协同改善制品的环境安全性。莫来石与玻璃相相互胶结,连通气孔均匀分布,赋予了透水砖较高的强度与优良的透水性能。

Waste incineration slag is considered as a kind of dangerous solid waste,harmless utilization of waste incinera-tion slag is of great significance.In this study,permeable brick with satisfactory comprehensive performances was prepared by high-temperature sintering process using waste incineration slag as raw material,and the effects of waste incineration slag addition and firing temperature on the properties of samples were explored.The results showed that the strength and safety of the samples could be improved by introducing suitable amount of waste glass and properly increasing sintering tem-perature.When the amounts of waste incineration slag,waste glass and pulverized coal(additional)were 60%,40%,and 20%respectively,the water permeability coefficient,flexural strength and compressive strength of permeable brick fired at 1200℃reached 0.58 mm/s,6.23 MPa and 18.58 MPa,respectively.The flexural strength and permeability coefficient had respectively reached the R_(f)4.5 and B levels,meanwhile,the leaching concentration of Cu^(2+),Pb^(3+) and Zn^(2+) in the product met the GB 5085.3—2007《Identification standard for hazardous waste leaching toxicity identification》standard.The XRD and SEM-EDS analysis results showed that the high-temperature liquid phase derived from melting waste glass dissolved Pb_(2)O_(3),ZnO and CuO,thus inhibiting the leaching of Cu^(2+),Pb^(3+) and Zn^(2+).It was also found that raising the firing temperature re-duced the porosity of the sample and promoted the dissolution of lead oxide,zinc oxide,and copper oxide,thereby synergis-tically improving the environmental safety of the product.Additionally,it was concluded that the high strength and excellent water permeability of the permeable brick was resulted from the mutual cementation of mullite and glass as well as even dis-tribution of connecting pores.