ABSTRACT

Coal refuse slurry impoundments have potential environmental concerns associated with water contamination and impoundment stability. Pressure filtration can be used as an alternative method of handling such coal waste streams as it offers an opportunity to stack the dewatered refuse solids for subsequent disposal, reducing or eliminating the need for the impoundment. A response surface methodology approach was used to evaluate the effects of pH, filtration time, and air-blow time on pressure filtration, whose response was measured in terms of final cake moisture. Cake moistures as low as 19.2% were obtained in this study. Experimental results showed a decrease in cake moisture by 13% with an increase in filtration time from 40 minutes to 50 minutes. One third reduction in cake moisture was achieved for a test with 10 minutes of air-blow after 30 minutes of filtration time compared to a test with 40 minutes of filtration time. The effect of pH was significant on both the residual moisture content and the amount of solids deposited in the cake, with acidic pH increasing the filtration performance. A linear fit was developed to relate the amount of solids deposited in the cake as a function of pH and filtration time. A regression model for the response surface with respect to the predictor variables had an R² value of about 0.99 with almost all the main effects, their square terms, and the interaction effects statistically significant.

摘要

煤矸石浆蓄水池具有与水污染和蓄水稳定性相关的潜在环境问题。压力过滤可用作处理此类煤废料流的替代方法，因为它提供了将脱水的垃圾固体堆积起来以进行后续处理的机会，从而减少或消除了对蓄积的需要。响应面法用于评估 pH 值、过滤时间和吹气时间对压力过滤的影响，其响应是根据最终滤饼水分来测量的。在这项研究中获得了低至 19.2% 的蛋糕水分。实验结果表明，随着过滤时间从 40 分钟增加到 50 分钟，滤饼水分减少了 13%。与过滤时间为 40 分钟的测试相比，过滤 30 分钟后吹气 10 分钟的测试的滤饼水分减少了三分之一。pH 值对残留水分含量和滤饼中沉积的固体量都有显着影响，酸性 pH 值会提高过滤性能。建立了线性拟合，以将沉积在滤饼中的固体量与 pH 值和过滤时间的函数联系起来。相对于预测变量的响应曲面的回归模型具有 R 建立了线性拟合，以将沉积在滤饼中的固体量与 pH 值和过滤时间的函数联系起来。相对于预测变量的响应曲面的回归模型具有 R 建立了线性拟合，以将沉积在滤饼中的固体量与 pH 值和过滤时间的函数联系起来。相对于预测变量的响应曲面的回归模型具有 R²值约为 0.99，几乎所有的主效应、它们的平方项和交互效应都具有统计显着性。