水泥-BPSF改良尾矿型植生基材强度与微观机理  

Strength and Micro-Mechanism of Tailings-Type Vegetation Substrate Improved by Cement-BPSF

作　　者：成词峰 赵海燕 曾家鹏 安家金 戴仕鹏 CHENG Cifeng;ZHAO Haiyan;ZENG Jiapeng;AN Jiajin;DAI Shipeng(Kunming Prospecting Design Institute of China Nonferrous Metals Industry Co.,Ltd.,Kunming,Yunnan 650051,China;Yunnan Key Laboratory of Geotechnical Engineering and Geohazards,Kunming,Yunnan 650051,China)

机构地区：[1]中国有色金属工业昆明勘察设计研究院有限公司,云南昆明650051 [2]云南省岩土工程与地质灾害重点实验室,云南昆明650051

出　　处：《矿业研究与开发》2024年第6期248-257,共10页Mining Research and Development

基　　金：中国铝业集团青年科技人才启明星计划项目(2019MXJH31);云南省岩土工程与地质灾害重点实验室科技计划项目(2021YN01A3)。

摘　　要：为解决矿山边坡生态修复所需天然土壤匮乏的问题,采用低碱水泥和甘蔗渣-聚丙烯酰胺-吸水树脂-酸性肥料(Bagasse-PAM-SAP-Fertilizer,BPSF)作为改良剂对尾矿性质进行改良,制成了可用于矿山边坡生态修复的植生基材。通过L9(34)正交试验,对不同配比植生基材初期的试样进行剪切试验,以初期(3 d)抗剪强度为考核指标,通过极差分析确定基材的最优配比;对最优配比基材不同龄期的试样进行剪切试验,研究了养护龄期对基材抗剪强度的影响;通过薄片鉴定、扫描电镜(SEM)和X射线衍射(XRD)试验,分析了水泥-BPSF协同改良尾矿型植生基材的抗剪强度特征与微观机理。结果表明,水泥和甘蔗渣掺量是影响基材强度最为显著的因素,基材初期的抗剪强度随着水泥和甘蔗渣掺量的增加而增大;随着龄期的增长,基材的内摩擦角达到峰值后开始降低,基材的破坏模式从初期的韧性破坏转变为脆性破坏;水泥-BPSF协同改良的尾矿型植生基材具备植物生长所需的类土壤结构和强度。最优的基材配比为水泥12%、甘蔗渣4%、聚丙烯酰胺0.6%、吸水树脂0.15%、酸性化肥1.2%。In order to solve the problem of lack of natural soil required for ecological restoration of mine slope,low-alkali cement and bagasse-polyacrylamide-super absorbent polymer-acid fertilizer(Bagasse-PAM-SAP-Fertilizer,BPSF)were used as modifiers to improve the properties of tailings.The vegetation substrate which can be used for ecological restoration of mine slope was prepared.Through the L9(34)orthogonal design,the shear tests were carried out on the initial samples of vegetation substrate with different ratios.Taking the initial(3d)shear strength as the evaluation index,the optimal ratio of the substrate was determined by range analysis.The effect of curing age on the shear strength of the substrate was studied by the shear tests on the samples with the optimal ratio of the substrate at different ages.The shear strength characteristics and micro-mechanism of cement-BPSF synergistically improved tailings-type vegetation substrate were analyzed by thin section identification,scanning electron microscopy(SEM)and X-ray diffraction(XRD)tests.The results show that the contents of cement and bagasse is the most significant factor affecting the strength of the substrate.The initial shear strength of the substrate increases with the increase of the content of cement and bagasse.With the increase of age,the internal friction angle of the substrate begins to decrease after reaching the peak,and the failure mode of the substrate changes from the initial ductile failure to brittle failure.The tailings-type vegetation substrate improved by cement-BPSF has the soil-like structure and strength required for the growth of each plant.The optimal substrate ratio is 12%of cement,4%of bagasse,0.6%of PAM,0.15%of SAP and 1.2%of acid fertilizer.

关 键 词：尾矿 水泥-BPSF 植生基材 抗剪强度 微观机理 

分 类 号：TD854.6[矿业工程—金属矿开采] TD926.4[矿业工程—矿山开采]