EFFECTS OF FLY ASH INCORPORATION ON HYDRAULIC CHARACTERISTICS AND AIR PERMEABILITY OF COAL GANGUE
-
摘要: 为研究粉煤灰掺入量对煤矸石水力学性质和导气率的影响,设计9种矸灰比的粉煤灰-煤矸石混合物,运用室内一维定水头法和压力膜仪(DIK-3423)以及一维瞬态法测试了混合物饱和含水量、饱和导水率、水分特征曲线和导气率等指标,并与土壤、粉煤灰和煤矸石进行对比分析。结果表明:1)粉煤灰的掺入可以提高煤矸石的饱和含水量,矸灰比3∶7~2∶8的混合物的饱和含水量为36.9%~41.4%,数值上最接近土壤;2)混合物的饱和导水率受粉煤灰掺入量和容重影响,相同粉煤灰掺入量下提高容重会降低饱和导水率,而饱和导水率变化的整体趋势随粉煤灰掺入量的增大而减小;3)混合物的持水性能随粉煤灰掺入量的增大而增大;4)混合物的导气率随粉煤灰掺入量的增大而减小,粉煤灰掺入量<40%的混合物导气率对含水量的敏感度呈先减小后增大的趋势,其余比例混合物导气率变化较均匀;5)矸灰比(煤矸石与粉煤灰体积比)在3∶7~2∶8混合物的植物有效水含量为17.3%~17.6%,数值上最接近土壤,选用粉煤灰-煤矸石混合物充填塌陷土地时可控制矸灰比在3∶7,此时渗透性小,且可以保证有良好的土壤有效水供给。研究结果可为塌陷区土地复垦质量的改良提供数据参考。Abstract: In order to study the effect of fly ash incorporation on the hydraulic characteristics of coal gangue, nine kinds of mixtures with different mixing ratio of fly ash and coal gangue were analyzed. The indoor one-dimensional fixed head method, a multi-fold pF Meter (DIK-3423) and a falling-pressure method was used to measure the volume of saturated water content, saturated hydraulic conductivity, the soil water characteristic curve(SWCC) and air permeability. The results indicated that:1) adding fly ash could increase the saturated water content of the mixtures, and the saturated water content of the mixture with mixing ratio of 3:7 was 36.9%~41.4%, the closest to the soil; 2) the saturated hydraulic conductivity of the mixture was affected by mixing ratio and bulk density. The saturated hydraulic conductivity decreased with the increase of bulk density, and also with the increase of fly ash's dosage in general. 3) the water retention capability of the mixture decreased with the increase of fly ash dosage. 4) the air permeability of the mixture decreased with the increase of fly ash's dosage. The air permeability of the mixture with fly ash incorporated below 40% had a changing tendency of small to large in sensitivity to water content, and mixture with other composition changed more uniformly. 5) the available water content of the mixture with the mixing ratio of 3:7~2:8 was 17.3%~17.6%, the closest to the soil; when the mixture was used to fill the collapsed land, the mixing ratio could be controlled at 3:7 to ensure suitable available water supply while the permeability was at a lower level. This study could provide data reference for improvement of land reclamation model in the subsidence areas.
-
[1] 肖武,李素萃,王铮,等.高潜水位煤矿区生态风险识别与评价[J].生态学报,2016,36(17):5611-5619. [2] 于亚军,贺泽好.三种复垦类型煤矸山土壤重金属有效态含量及其影响因素分析[J].环境工程,2018,36(5):189-192. [3] 宗燕兵,李飞,刘召波,等.造块焙烧对于酸碱联合法提取粉煤灰中氧化铝工艺的改进[J].环境工程,2020,38(6):208-213,258. [4] WANG J M,QIN Q,HU S J,et al.A concrete material with waste coal gangue and fly ash used for farmland drainage in high groundwater level areas[J].Journal of Cleaner Production,2016,112(JAN.20PT.1):631-638. [5] 宗燕兵,张学东,李飞.粉煤灰陶瓷的制备及致密化过程探讨[J].环境工程,2019,37(4):148-152. [6] 陈敏,陈孝杨,王芳,等.容重对煤矸石水力特性的影响[J].煤炭技术,2017,36(3):52-54. [7] 王顺,陈敏,陈孝杨,等.煤矸石充填重构土壤水分再分布与剖面气热变化试验研究[J].水土保持学报,2017,31(4):93-98,126. [8] 宁松瑞,韩霁昌,张扬,等.粉煤灰在土地整治工程中的研究及应用现状[J].环境工程,2016,34(增刊1):1025-1028,1033. [9] 刘曙光,徐良骥,余礼仁.煤矸石充填复垦地土壤理化性质的时空变化特征[J].环境工程,2018,36(2):173-177. [10] ZETTL J D,BARBOUR S L,HUANG M,et al.Influence of textural layering on field capacity of coarse soils[J].Canadian Journal of Soil Science.2011,91(2):133-147. [11] 张世文,葛畅,赵辉,等.粉煤灰充填复垦土壤理化性质分布特征及其对覆土厚度响应[J].安徽农业大学学报,2019,46(1):43-50. [12] WANG J M,LI X F,BAI Z H,et al.The effects of coal gangue and fly ash on the hydraulic properties and water content distribution in reconstructed soil profiles of coal-mined land with a high groundwater table[J].Hydrological Processes,2017,31(3):687-697. [13] CHEN M,CHEN X Y,HE H,et al.Effects of fly ash,silty clay loam and loamy sand on the hydraulic conductivity and air permeability of coal gangue[J].Fresenius Environmental Bulletin,2018,27(4):2035-2042. [14] GENUCHTEN M T V.A closed-form equation for predicting the hydraulic conductivity of unsaturated soils[J].Soil Science Society of America Journal,1980,44(5):892-898. [15] QIN Y D.Soil Physics[M].Beijing:High Education Press,2003:237-240. [16] LI H L,JIAO J J,LUK M.A falling-pressure method for measuring air permeability of asphalt in laboratory[J].Journal of Hydrology,2004,286(1/2/3/4):69-77. [17] 宋杨睿,王金满,李新凤,等.高潜水位采煤塌陷区重构土壤水分运移规律模拟研究[J].水土保持学报,2016,30(2):143-148,154. [18] 胡振华,王君,李长生.粉煤灰不同掺土比例下入渗模拟试验[J].中国水土保持科学,2010,8(2):52-58. [19] ZHANG Z H,XU Z G,LI H Y,et al.Effects of Cu2+ concentration and confining pressure on the hydraulic conductivity of saturated clay soils[J].Fresenius Environmental Bulletin,2015,24:755-763. [20] YU Y B,TANG M G,ZHONG Z S,et al.The influence of coal-mining waste piles on hydro-environment in Shandong province[J].Earth Science Frontiers,2001,8(1):163-169. [21] 胡振琪,张明亮,马保国,等.粉煤灰防治煤矸石酸性与重金属复合污染[J].煤炭学报2009,34(1):79-83. [22] LI X P,CAI G J,LIU S Y,et al.Consolidation and hydraulic conductivity of soil-bentonite cutoff wall (SBCW) from CPTU investigations[J].Fresenius Environmental Bulletin,2016,25(12):6069-6077. [23] ZHOU B B,SHAO M A,WEN M X,et al.Effects of coal gangue content on water movement and solute transport in a china loess plateau soil[J].Clean-Soil Air Water,2010,38(11):1031-1038. [24] 王卫华,王全九,王铄.土石混合介质导气率变化特征试验[J].农业工程学报,2012,28(4):82-88. [25] KUNCRO P H,KOGA K,SATTA N,et al.A study on the effect of compaction on transport properties of soil gas and water I:relative gas diffusivity,air permeability,and saturated hydraulic conductivity[J].Soil & Tillage Research,2014,143:172-179. [26] CHENG W,BIAN Z F,DONG J H,et al.Soil properties in reclaimed farmland by filling subsidence basin due to underground coal mining with mineral wastes in China[J].Transactions of Nonferrous Metals Society of China,2014,24(8):2627-2635.
点击查看大图
计量
- 文章访问数: 122
- HTML全文浏览量: 10
- PDF下载量: 2
- 被引次数: 0