Study on performance optimization of gasification slag based paste filling materials in Ningdong mining area

Authors

CHEN Denghong, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, ChinaFollow
LI Chao, School of Mining Engineering, Anhui University of Science and Technology, Huainan 232001, ChinaFollow
ZHANG Zhiguo, Institute of Energy, Hefei Comprehensive National Science Center, Hefei 230031, China

Abstract

As one of the nine coal bases at hundred million ton level in Yellow River Basin, Ningdong Mining Area has nearly 2×10⁸ t of coal-based solid waste produced annually, and faces to the problems of large stock of gasification slag, difficulty in scaled utilization, and limited space for simple landfill. Filling mining could solve the problem of stockpiling, of which the cost is high and the performance needs to be optimized. According to the response surface method, 17 groups of central composite experiments were designed for the three factors at three levels: the mixing amount of gasification slag in solid (A), the mass ratio of gasification slag to cement (B), and the slurry concentration (C). Meanwhile, comparative optimization research was conducted for the slump, expansion, 7 d and 14 d uniaxial compressive strength and other properties of gasification slag based paste filling materials. Before the experiment, the composition and micromorphology of the raw materials were observed and analyzed by XRD and SEM. Besides, the test block was observed by SEM and had its hydration characteristics analyzed after uniaxial compression, thereby revealing the strength formation mechanism. By integrating the strength and fluidity, the following optimum mixing ratio and performance characteristics of the filling material were obtained: 48% for A, 3 for B and 80% for C. Meanwhile, the desulfurized gypsum, coal gangue and bottom slag should be mixed at the mass ratio of 2∶1∶1 to reach the 7 d and 14 d strengths of 1.15 MPa and 2.41 MPa respectively, the slump of 133 mm, the expansion of 325.5 mm, and the slump to expansion ratio of 0.41. According to the further analysis based on response surface method, the single influencing factors of 7 d and 14 d strength are B>C=A and B>A>C, the interaction influencing factors of 7 d and 14 d strength are BC>AB>AC and AB>AC>BC, and the single influencing factors of slump and expansion are C>B>A and C>A>B respectively according to the significance. On this basis, the proportioning scheme and parameters were optimized for the 3 different functional requirements, including the strict control of surface settlement, rapid filling to reduce pipe plugging, and control of strength and cost. Generally, the research results provide important basic parameters and optimization direction for the ecological protection and low damage coal mining in Yellow River Basin.

Keywords

gasification slag based paste filling material, response surface method, influencing factor, performance optimization, hydration mechanism

DOI

10.12363/issn.1001-1986.22.05.0385

Recommended Citation

CHEN Denghong, LI Chao, ZHANG Zhiguo, et al. (2022) "Study on performance optimization of gasification slag based paste filling materials in Ningdong mining area," Coal Geology & Exploration: Vol. 50: Iss. 12, Article 6.
DOI: 10.12363/issn.1001-1986.22.05.0385
Available at: https://cge.researchcommons.org/journal/vol50/iss12/6

Reference

[1] 杨科,魏祯,赵新元,等. 黄河流域煤电基地固废井下绿色充填开采理论与技术[J]. 煤炭学报,2021,46(增刊2):925−935

YANG Ke,WEI Zhen,ZHAO Xinyuan,et al. Theory and technology of green filling of solid waste in underground mine at coal power base of Yellow River Basin[J]. Journal of China Coal Society,2021,46(Sup.2):925−935

[2] 靳德武,王甜甜,赵宝峰,等. 宁东煤田东北部高矿化度地下水分布特征及形成机制[J]. 煤田地质与勘探,2022,50(7):118−127

JIN Dewu,WANG Tiantian,ZHAO Baofeng,et al. Distribution characteristics and formation mechanism of high salinity groundwater in northeast Ningdong Coalfield[J]. Coal Geology & Exploration,2022,50(7):118−127

[3] 王景升,李佳,陈宝雄,等. 宁夏东部能源化工基地煤炭产业生态风险评估[J]. 资源科学,2013,35(10):2011−2016

WANG Jingsheng,LI Jia,CHEN Baoxiong,et al. Coal mining ecological risk assessment of the energy chemical production base in Eastern Ningxia[J]. Resource Science,2013,35(10):2011−2016

[4] 王璐,于瑶,任会斌,等. 积存超600亿吨工业固废如何走出“埋埋埋”尴尬[J]. 资源再生,2020(6):40−42

WANG Lu,YU Yao,REN Huibin,et al. How to get rid of the embarrassment of“buried and buried”for the accumulation of over 60 billion tons of industrial solid waste[J]. Resource Recycling,2020(6):40−42

[5] 张新国,江宁,张玉江,等. 矸石膏体充填材料力学特性试验[J]. 金属矿山,2012(12):127−131

ZHANG Xinguo,JIANG Ning,ZHANG Yujiang,et al. Study on mechanical properties of coal waste paste filling materials[J]. Metal Mine,2012(12):127−131

[6] 王有志. 煤矸石–粉煤灰用作井下充填材料实验研究[J]. 有色金属工程,2020,10(11):108−113

WANG Youzhi. Experimental study on coal gangue–fly ash as underground filling material[J]. Nonferrous Metals Engineering,2020,10(11):108−113

[7] 唐岳松,张令非,吕华永,等. 煤基固废制备充填材料配比优化试验研究[J]. 矿业科学学报,2019,4(4):327−336

TANG Yuesong,ZHANG Lingfei,LYU Huayong,et al. Study on proportion optimization of coal–based solid wastes filling materials[J]. Journal of Mining Science and Technology,2019,4(4):327−336

[8] 崔增娣,孙恒虎. 煤矸石凝石似膏体充填材料的制备及其性能[J]. 煤炭学报,2010,35(6):896−899

CUI Zengdi,SUN Henghu. The preparation and properties of coal gangue based sialite paste–like backfill material[J]. Journal of China Coal Society,2010,35(6):896−899

[9] 程海勇,吴爱祥,王贻明,等. 粉煤灰–水泥基膏体微观结构分形表征及动力学特征[J]. 岩石力学与工程学报,2016,35(增刊2):4241−4248

CHENG Haiyong,WU Aixiang,WANG Yiming,et al. Fractal features and dynamical characters of the microstructure of paste backfill prepared from fly ash based binder[J]. Chinese Journal of Rock Mechanics and Engineering,2016,35(Sup.2):4241−4248

[10] 李茂辉,杨志强,王有团,等. 粉煤灰复合胶凝材料充填体强度与水化机理研究[J]. 中国矿业大学学报,2015,44(4):650−655

LI Maohui,YANG Zhiqiang,WANG Youtuan,et al. Experiment study of compressive strength and mechanical property of filling body for fly ash composite cementitious materials[J]. Journal of China University of Mining & Technology,2015,44(4):650−655

[11] 杨宝贵,杨捷,于跃,等. 煤矿新型胶凝充填材料配比试验及水化机理研究[J]. 矿业科学学报,2017,2(5):475−481

YANG Baogui,YANG Jie,YU Yue,et al. Study on proportioning test of a new cementing filling material and hydration mechanism[J]. Journal of Mining Science and Technology,2017,2(5):475−481

[12] 赵康,黄明,严雅静,等. 不同灰砂比尾砂胶结充填材料组合体力学特性及协同变形研究[J]. 岩石力学与工程学报,2021,40(增刊1):2781−2789

ZHAO Kang,HUANG Ming,YAN Yajing,et al. Mechanical properties and synergistic deformation characteristics of tailings cemented filling assembled material body with different cement−tailings ratios[J]. Chinese Journal of Rock Mechanics and Engineering,2021,40(Sup.1):2781−2789

[13] 温亮,阎长虹,张政,等. 水泥–粉煤灰–煤渣–吹填粉细砂混合料强度试验[J]. 煤田地质与勘探,2019,47(1):149−154

WEN Liang,YAN Changhong,ZHANG Zheng,et al. Test on the strength of the backfill fine sand mixture composed of cement−fly ash−cinder[J]. Coal Geology & Exploration,2019,47(1):149−154

[14] 李磊. 颚式破碎机能耗和齿板结构参数研究[D]. 长沙：中南大学，2009.

LI Lei. Study on energy consumption and toothed plate structural parameters of jaw crusher[D]. Changsha：Central South University，2009.

[15] 刘智勇. 粉煤灰的经济价值和利用探讨[J]. 现代经济信息,2017(13):335

LIU Zhiyong. Discussion on economic value and utilization of fly ash[J]. Modern Economic Information,2017(13):335

[16] 张明，院晓丽. 砼拌合物的坍落度和坍落扩展度之关系[J]. 建筑与发展，2012.

ZHANG Ming，YUAN Xiaoli. The relationship between slump and slump expansion of concrete mixture[J]. Architecture and Development，2012.

[17] 李典,冯国瑞,郭育霞,等. 基于响应面法的充填体强度增长规律分析[J]. 煤炭学报,2016,41(2):392−398

LI Dian,FENG Guorui,GUO Yuxia,et al. Analysis on the strength increase law of filling material based on response surface method[J]. Journal of China Coal Society,2016,41(2):392−398

[18] 张超,王星龙,李树刚,等. 基于响应面法治理煤矿硫化氢的改性碱液配比优化[J]. 煤炭学报,2020,45(8):2926−2932

ZHANG Chao,WANG Xinglong,LI Shugang,et al. Optimization of the ratio of modified alkaline solution for hydrogen sulfide treatment in coal mine based on response surface method[J]. Journal of China Coal Society,2020,45(8):2926−2932

[19] 唐海,赵海龙,黄靖龙,等. 煤矿膏体充填材料配比试验研究[J]. 华北科技学院学报,2015,12(4):43−47

TANG Hai,ZHAO Hailong,HUANG Jinglong,et al. Study on proportion experiment of paste filling material in coal mine[J]. Journal of North China Institute of Science and Technology,2015,12(4):43−47

[20] 徐文彬,潘卫东,丁明龙. 胶结充填体内部微观结构演化及其长期强度模型试验[J]. 中南大学学报(自然科学版),2015,46(6):2333−2341

XU Wenbin,PAN Weidong,DING Minglong. Experiment on evolution of microstructures and long–term strength model of cemented backfill mass[J]. Journal of Central South University (Science and Technology),2015,46(6):2333−2341

[21] 冯国瑞,任亚峰,张绪言,等. 塔山矿充填开采的粉煤灰活性激发实验研究[J]. 煤炭学报,2011,36(5):732−737

FENG Guorui,REN Yafeng,ZHANG Xuyan,et al. The activating experimental research of fly ash for mining fillingmaterial in Tashan Mine[J]. Journal of China Coal Society,2011,36(5):732−737

[22] 屈慧升,索永录,刘浪,等. 改性煤气化渣基矿用充填材料制备与性能[J]. 煤炭学报,2022,47(5):1958−1973

QU Huisheng,SUO Yonglu,LIU Lang,et al. Preparation and properties of modified coal gasification slag–based filling materials for mines[J]. Journal of China Coal Society,2022,47(5):1958−1973