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采选技术与矿山管理

分层尾砂胶结充填体力学特性及优化试验研究

  • 海龙 ,
  • 鲍荣涛 ,
  • 谭世林 ,
  • 房祥龙
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  • 辽宁工程技术大学力学与工程学院,辽宁 阜新 123032
鲍荣涛(1997-),男,河南信阳人,硕士研究生,从事固废综合利用及矿山充填研究工作。

海龙(1975-),男,辽宁阜新人,副教授,从事固体废弃物综合利用及矿山采空区充填研究工作。

收稿日期: 2023-03-02

  修回日期: 2023-04-08

  网络出版日期: 2023-11-21

基金资助

国家自然科学基金项目“随机扰动下深部软岩渗流—蠕变损伤破裂耦合机理研究”(52274084)

Experimental Study on the Mechanical Properties of Layered Tailing Sand Cemented Backfill and Optimization

  • Long HAI ,
  • Rongtao BAO ,
  • Shilin TAN ,
  • Xianglong FANG
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  • School of Mechanics and Engineering,Liaoning Technical University,Fuxin 123032,Liaoning,China

Received date: 2023-03-02

  Revised date: 2023-04-08

  Online published: 2023-11-21

摘要

在尾砂胶结充填采空区过程中,充填操作的不连续会造成充填体在2次充填的界面处发生分层现象。为研究分层尾砂胶结充填体力学特性,改善分层的劣化影响,引入混凝土学中处理新旧混凝土界面的喷砂法,制作完整不分层、界面自然分层和界面喷砂处理分层3种分层类型的充填体试件,设置灰砂比分别为1∶4、1∶6和1∶8,在养护龄期为3 d、7 d、14 d和28 d条件下对试件进行单轴压缩试验。结果表明:(1)分层现象降低了尾砂胶结充填体的单轴抗压强度,折减率区间为1.41%~19.09%,且随养护龄期和灰砂比的增加折减率呈指数函数增长;界面喷砂处理提高了尾砂胶结充填体的单轴抗压强度,增益率区间为1.92%~16.26%,增益率随着灰砂比的增加而增大,且在养护早期增益更明显。(2)充填体的弹性模量随养护龄期的增加呈指数函数增长,分层充填体弹性模量的折减随养护龄期和灰砂比的增加均呈增大趋势。(3)充填体的峰后强度曲线随灰砂比的降低表现出更优的峰后延性,且随养护龄期的增加愈加明显;不同分层类型充填体的峰后延性优劣顺序为:界面喷砂处理分层>界面自然分层>完整不分层。(4)分层充填体的破坏形式主要表现为拉张破坏和共轭剪切破坏,喷砂处理能够改善力在分层面上的传递方式。

本文引用格式

海龙 , 鲍荣涛 , 谭世林 , 房祥龙 . 分层尾砂胶结充填体力学特性及优化试验研究[J]. 黄金科学技术, 2023 , 31(5) : 763 -772 . DOI: 10.11872/j.issn.1005-2518.2023.05.037

Abstract

In the process of tailing cemented filling goaf,the discontinuity of the filling operation causes delamination of the filling body at the interface of the two fillings.In order to study the mechanical properties of the layered tailing cemented backfill and improve the deterioration effect of stratification,three types of delaminated backfill specimens,namely,intact non-delaminated,interface natural delamination,and interface sandblasted delamination,were produced.Each delamination type contains three material ratios of 1∶4,1∶6,and 1∶8 for ash-sand ratio,and uniaxial compression tests were conducted on specimens at curing ages of 3 d,7 d,14 d and 28 d to compare and analyze the deformation and damage characteristics of specimens with different delamination characteristics,different material ratios,and different curing ages.The results show that:(1) The delamination phenomenon significantly affects the mechanical properties of the tailing sand cemented backfill,considerably reducing the uniaxial compressive strength and the elastic modulus.Comparing the intact unstratified,naturally stratified specimens,the strength reduction rate caused by stratification increase ranged from 1.41% to 19.09% and exponentially with the increase of the curing age and ash-sand ratio.It indicates that the more significant the ash-sand proportion and the longer the maintenance age,the more pronounced the weakening effect of delamination of the backfill.Comparing the naturally delaminated and sandblasted delaminated specimens,the strength gain rate due to sandblasted delamination ranges from 1.92% to 16.26%,which increases with the increase of the ash-sand ratio,decreases firstly with the rise of the curing age and then remains flat and stable,and shows a higher strength gain rate in the early curing period.(2) The modulus of elasticity of the three-layered backfill types increases exponentially with the maintenance age.The discount of the modulus of elasticity of the natural layering relative to the complete layering increases with the rise in the maintenance age and decreases with the decrease of the gray sand ratio.The modulus of elasticity of the sandblasted layering relative to the natural layering only has a relatively apparent increase at 3 d,and the rest of the age is basically at the same level.(3) Using the rate of decrease of the post-peak strength curve as the ductility evaluation criterion,the post-peak strength curves of the three-layered types of backfill show better post-peak ductility with the decrease of ash-sand ratio,and it becomes more and more evident with the increase of maintenance age.The post-peak ductility performance of different layered types of backfill is in the order of interface sandblasted layered>interface natural layered>complete non-layered.(4)The damage of the delami-nated backfill is mainly in the form of tensile damage and conjugate shear damage,and the delamination surface makes part of the vertical compressive stress transformed into horizontal tensile stress,and the cracks inside the specimen are concentrated in the soft delamination surface,which makes the compressive strength of the backfill reduced.Sandblasting treatment can improve force transmission on the delamination surface to a certain extent.In order to reduce the degradation of the material’s mechanical properties by delamination,sandblasting,and other roughening treatment can be carried out on the last filling surface at the interval of the second filling.

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2023年前三季度我国黄金产量271.248 t,黄金消费量835.07 t

中国黄金协会最新统计数据显示:2023年前三季度,国内原料黄金产量为271.248 t,与2022年同期相比增产1.261 t,同比增长0.47%,其中,黄金矿产金完成214.866 t,有色副产金完成56.382 t。另外,2023年前三季度进口原料产金96.277 t,同比增长11.48%,若加上这部分进口原料产金,全国共生产黄金367.525 t,同比增长3.14%。

2023年前三季度,在全国黄金生产平稳运行的基础上,黄金行业在地质找矿、科技创新和整合并购等方面稳步推进:山东莱州西岭金矿在探明的382.58 t金金属量基础上,新增金金属量209.61 t,累计探获金金属量592.19 t;中国黄金集团在生物冶金和尾矿资源化方面的2项成果获第二十四届中国专利优秀奖;山东黄金、紫金矿业和山东招金等通过并购、竞标获甘肃西和大桥金矿、西藏朱诺铜矿和甘肃敦煌北山金矿等多项金、铜矿项目。大型黄金企业(集团)境内矿山矿产金产量为107.058 t,占全国的比重为49.83%。紫金矿业、山东黄金和赤峰黄金等企业境外矿山实现矿产金产量43.067 t,同比增长18.10%。

2023年前三季度,全国黄金消费量为835.07 t,与2022年同期相比增长7.32%。其中:黄金首饰552.04 t,同比增长5.72%;金条及金币222.37 t,同比增长15.98%;工业及其他用金60.66 t,同比下降5.53%。前三季度,国民经济持续恢复向好,市场需求持续扩大,国家统计局数据显示,金银珠宝类商品零售额增幅继续领跑其他品类商品。三季度黄金价格持续处于高位,黄金首饰消费增速有所放缓,特别是9月底临近“双节”黄金价格大幅波动,黄金首饰消费观望情绪加重,但硬足金、古法金等升级类商品仍有较快增长。而黄金价格的高位波动令实物黄金投资获得较高关注度,金条及金币消费继续较快增长。

2023年前三季度,上海黄金交易所全部黄金品种累计成交量双边3.15万t(单边1.58万t),同比增长3.08%,成交额双边13.86万亿元(单边6.93万亿元),同比增长16.52%;上海期货交易所全部黄金品种累计成交量双边9.22万t(单边4.61万t),同比增长40.55%,成交额双边35.27万亿元(单边17.64万亿元),同比增长51.81%。前三季度,国内黄金ETF持仓规模总体呈先抑后扬的趋势,其中三季度,国内黄金ETF持仓规模大增9.53 t。截至9月末,国内黄金ETF持有量约为59.69 t。

2023年前三季度,全球经济下行压力不断积累,地缘冲突持续恶化,国际黄金价格高位震荡。9月底,随着市场对美联储维持高利率预期的升温,国际金价大幅回调至年初水平,但仍保持在历史高位。9月底,伦敦现货黄金定盘价为1 870.50美元/盎司,较年初上涨1.48%;上海黄金交易所Au9999黄金9月底收盘价447.10元/g,较年初上涨8.78%。

2023年前三季度,中国人民银行累计增持黄金181.02 t。自2022年11月至2023年9月,中国人民银行已连续11个月增持黄金,截至9月底,我国黄金储备达到2 191.55 t。

脚注

中国黄金协会)

http://www.goldsci.ac.cn/article/2023/1005-2518/1005-2518-2023-31-5-763.shtml

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