论文部分内容阅读
为评价AOD(氩氧脱碳炉)渣的淋溶毒性,采用连续20 d的静态淋溶试验,研究了中性和酸性淋溶液对AOD炉渣中Cr(铬)淋溶特性的影响,以累积溶出率构建了Cr淋溶动力学模型.结果表明:在连续淋溶过程中,淋溶液p H(9.6~11.5)始终保持碱性,DO(溶解氧)基本处于饱和状态,淋溶液还原性呈降低趋势;随着淋溶时间的延长,淋溶液中Cr6+、TCr和Cr3+的累积溶出率呈增加趋势,不同初始淋溶液p H(2.0、3.0、4.0、5.0、6.0、7.0)下,连续淋溶20 d时Cr6+、TCr和Cr3+的累积溶出率分别是淋溶2 d时的10.1~22.2、7.5~15.6、6.3~17.1倍;与中性和弱酸性淋溶液相比,连续淋溶20 d,酸性较强的淋溶液中Cr6+、TCr和Cr3+的累积溶出率分别为其3.1~6.6、1.6~3.2和1.8~2.1倍;与短期静态淋溶相比,连续淋溶增加了淋溶液总量,尽管ρ(Cr)变化较小,但TCr累积溶出率显著增加;双常数速率、抛物线和指数模型均可拟合淋溶液中Cr6+、TCr和Cr3+的累积溶出率,其中,抛物线模型的相关系数均在0.99以上,是最佳模型.AOD渣中Cr的连续淋溶动力学模型的构建可为不锈钢渣中Cr的淋溶毒性及其生态风险评价奠定试验和理论基础.
In order to evaluate the leaching toxicity of AOD slag, the effect of neutral and acidic leachate on the leaching characteristics of Cr (Cr) in AOD slag was investigated by static leaching test for 20 days. The dissolution kinetics model was used to establish Cr leaching kinetics model. The results showed that pH (9.6-11.5) was always alkaline and DO (dissolved oxygen) was almost saturated in the leaching process. The reduction of leaching solution (P <0.05). The cumulative dissolution rates of Cr6 +, TCr and Cr3 + in leaching solution tended to increase with the leaching time prolonging. Under the initial pH of 2.0, 3.0, 4.0, 5.0, 6.0 and 7.0, The cumulative dissolution rates of Cr6 +, TCr and Cr3 + at 20 d were 10.1 ~ 22.2, 7.5 ~ 15.6 and 6.3 ~ 17.1 folds, respectively, at 2 days of leaching. Compared with neutral and weak acid leaching solution, the cumulative leaching rates of Cr6 +, TCr and Cr3 + , And the cumulative dissolution rates of Cr6 +, TCr and Cr3 + in leachate with strong acidity were 3.1 ~ 6.6, 1.6 ~ 3.2 and 1.8 ~ 2.1 times respectively. Compared with short-term static leaching, the continuous leaching increased the total amount of leaching solution , Although the change of ρ (Cr) was small, the cumulative dissolution rate of TCr increased significantly. The double constant rate, parabola and exponential model fitted the Cr6 +, TCr and Cr3 + Cumulative dissolution rate, of which the correlation coefficient of the parabola model is above 0.99, is the best model.The construction of continuous leaching kinetic model of Cr in AOD slag can lay the foundation for the leaching toxicity of Cr in stainless steel slag and its ecological risk assessment Experimental and theoretical basis.