Influence of Iron Tailings Powder-Silica Fume Mineral Admixture on Concrete Performance
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摘要:
将研磨后的铁尾矿粉末和硅粉分别按照3∶2和4∶1的比例制备了两种复合矿物掺合料替代水泥进行浆体和混凝土试样的制备。通过微观结构分析、强度和耐久性分析对铁尾矿-硅粉复合矿物掺合料浆体和混凝土的基本性能进行了研究，结果表明：随着复合矿物掺合料掺量的增加，试样的水化反应放热量、抗压强度、劈裂抗拉强度和冻融耐久性均逐渐降低；且加入铁尾矿粉可使的硬化浆体试块孔隙结构变大，导致混凝土的抗压强度和冻融耐久性降低；但增加硅粉的掺量可以提高试样的水化反应强度，降低Ca(OH)2的含量，且硅粉水化反应生产的C-S-H凝胶也可以细化孔结构，从而改善混凝土的微观特性、抗压强度、劈裂抗拉强度和冻融耐久性；弥补铁尾矿粉对混凝土性能的负面影响。整体上，改性混凝土的抗压强度在普通混凝土抗压强的85%以上，能满足工程要求。
Abstract:Two kinds of composite mineral admixtures were prepared by grinding iron tailings powder and silicon powder in the ratios of 3∶2 and 4∶1, respectively to substitute cement for the preparation of mortar and concrete samples. The basic properties of iron tailings-silica fume composite mineral admixture mortar and concrete have been studied through microstructure analysis, strength and durability analysis. Results show that: as the content of the composite mineral admixture increases, the heat of hydration reaction, compressive strength, split tensile strength and freeze-thaw durability of the sample gradually decrease; and adding iron tailings powder can increase the pore structure of the hardened mortar test block, which reduces the compressive strength and freeze-thaw durability of the concrete. However, increasing the amount of silica fume can increase the strength of the hydration reaction of the sample, and increasing the silica fume can reduce the content of Ca(OH)2. The CSH gel produced by the hydration reaction of silica fume can also refine the pore structure, thereby improve the microscopic properties, compressive strength, split tensile strength and freeze-thaw durability of concrete; make up for the negative impact of iron tailings powder on concrete performance. On the whole, the compressive strength of modified concrete is more than 85% of that of ordinary concrete, which can meet engineering requirements.
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Key words:
- Iron tailings powder /
- Silica fume /
- Concrete /
- Hydration characteristics /
- Microstructure /
- Strength /
- Freeze-thaw durability
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表 1 水泥、铁尾矿粉和硅粉的化学成分/%
Table 1. Chemical composition of cement, iron tailings powder and silica fume
材料 SiO2 Al2O3 Fe2O3 CaO MgO SO3 Na2O 烧失量 水泥 21.55 4.59 3.27 62.5 2.61 2.93 0.53 2.02 铁尾矿粉 62.46 8.68 11.98 9.84 3.78 0.45 1.69 1.12 硅粉 92.91 1.35 1.45 1.22 0.48 0.19 0.85 1.55 
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表 2 浆体的配合比/%
Table 2. Mixing ratio of paste
水泥 MG1 MG2 水 CP 100 0 0 40 GP1-15 15 40 GP1-30 30 40 GP2-15 15 40 GP2-30 30 40
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表 3 混凝土的配合比
Table 3. Mix ratio of concrete
水泥/kg MG1/kg MG2/kg 水/kg 细骨料/kg 粗骨料/kg C 370 0 0 142 820 1070 G1-15 314.5 55.5 142 820 1070 G1-30 259 111 142 820 1070 G2-15 314.5 55.5 142 820 1070 G2-30 259 111 142 820 1070
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[1] 李军卫, 刘长明, 单雪峰. 水泥改良铁尾矿砂路基填料的力学特性[J]. 矿产综合利用, 2021(3):193-199. LI J W, LIU C M, SHAN X F. Research on mechanical properties of cement-improved iron tailings sand roadbed filler[J]. Multipurpose Utilization of Mineral Resources, 2021(3):193-199.
[2] 邹锋, 殷志刚, 陈思竹. 攀枝花白马选铁尾矿综合回收利用研究[J]. 矿产综合利用, 2020(6):19-25. ZOU F, YIN Z G, CHEN S Z. Research on comprehensive utilization of iron tailings from Baima Panzhihua[J]. Multipurpose Utilization of Mineral Resources, 2020(6):19-25. doi: 10.3969/j.issn.1000-6532.2020.06.004
[3] 李日文, 蔡海立, 宁寻安, 等. CaCl2氯化焙烧分离铁尾矿中的重金属铅铜镉[J]. 环境工程学报, 2021, 15(3):1083-1091. LI R W, CAI H L, NING X A, et al. Separation of heavy metals, lead, copper and cadmium from iron tailings by chlorination roasting with CaCl2[J]. Techniques and Equipment for Environmental Pollution Control, 2021, 15(3):1083-1091.
[4] 祁磊, 席欣月, 蔡鑫, 等. 北衙硫化矿选厂尾矿中金银铁综合回收实验研究[J]. 矿产综合利用, 2021(4):182-187. QI L, XI X Y, CAI X, et al. Experimental study on comprehensive recovery of gold, silver and iron from tailings of beiya sulfide ore concentrator[J]. Multipurpose Utilization of Mineral Resources, 2021(4):182-187. doi: 10.3969/j.issn.1000-6532.2021.04.029
[5] 李萌, 周庆立, 白丽梅, 等. 机械力化学效应提高铁尾矿活性研究[J]. 矿产综合利用, 2021(1):179-185. LI M, ZHOU Q L, BAI L M, et al. Experimental study on improving the activity of iron tailings by mechanochemical effect[J]. Multipurpose Utilization of Mineral Resources, 2021(1):179-185. doi: 10.3969/j.issn.1000-6532.2021.01.030
[6] 林敏, 王瑞, 彭亮. 龙桥铁矿全尾砂料浆流动阻力及流变参数试验研究[J]. 矿业研究与开发, 2021, 41(9):46-51. LIN M, WANG R, PENG L. Experimental research on flow resistance and rheological parameters of the whole tailings slurry in Longqiao iron mine[J]. Mining Research and Development, 2021, 41(9):46-51. doi: 10.13827/j.cnki.kyyk.2021.09.009
[7] 张伟, 刘梁友, 李莉丽, 等. 铁尾矿粉-粉煤灰-矿渣粉复合掺合料对混凝土性能的影响[J]. 硅酸盐通报, 2016, 35(11):3826-3831. ZHANG W, LIU L Y, LI L L, et al. Iron tailings powder-fly ash-slag powder composite admixture affects the performance of concrete[J]. Bulletin of the Chinese Ceramic Society, 2016, 35(11):3826-3831.
[8] 宋少民, 张乐义, 李紫翼. 铁尾矿微粉对水泥混凝土后期性能的影响[J]. 混凝土, 2019(1):128-131+145. SONG S M, ZHANG L Y, LI Z Y. The influence of fine iron tailings on the later performance of cement concrete[J]. Concrete, 2019(1):128-131+145.
[9] 姚雷, 李晓芝, 鲁明星. 铁尾矿砂掺量对混凝土性能的影响[J]. 混凝土与水泥制品, 2019(10):97-100. YAO L, LI X Z, LU M X. The influence of iron tailing sand content on the performance of concrete[J]. Concrete and Cement Products, 2019(10):97-100.
[10] 宁波, 闫艳, 左夏伟, 等. 铁尾矿砂混凝土力学特性实验研究[J]. 矿产综合利用, 2021(4):159-164. NING B, YAN Y, ZUO X W, et al. Experimental study on mechanical properties of iron tailings concrete[J]. Multipurpose Utilization of Mineral Resources, 2021(4):159-164. doi: 10.3969/j.issn.1000-6532.2021.04.025
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