废石尾砂混合料浆充填启动方式与管输阻力

针对金川矿山充填法采矿,研究了废石尾砂混合充填料浆配比设计与充填工艺,解决混合粗骨料料浆充填在启动阶段存在的沉淀离析难题,为废弃物在充填采矿中应用奠定基础.分别进行细砂引流、分级尾砂引流和直接放流三种启动方式的工业试验以及管道输送阻力损失试验.结果表明,直接放流启动方式可用于混合粗骨料充填料浆在起始阶段的管道输送.根据混合粗骨料的料浆管输阻力试验,建立充填料浆管道输送阻力与管径、料浆流速和料浆浓度的关系,确定废石与尾砂配合质量比为6∶4的混合粗骨料料浆可输送上限浓度为78%.在此条件下,混合粗骨料料浆管输阻力最小.     

金川镍矿混合充填集料胶结充填体强度试验研究

针对金川矿山棒磨砂充填集料存在的成本高和供不应求的矛盾,开展了棒磨砂、戈壁砂和尾砂3种充填集料不同配比的混合集料胶结充填体强度试验研究。通过9组混合充填集料的胶结充填体强度试验和数据分析,揭示了影响胶结充填体强度的因素与规律。研究结果表明:合理添加尾砂的棒磨砂和戈壁砂混合充填料,不仅可以提高充填体强度,而且还能够减小充填料浆的分层和离析,有利于提高充填体整体质量。通过建立神经网络模型,进行不同配比的混合集料胶结充填体强度预测和回归分析,获得了满足金川矿山充填法采矿安全高效生产的充填材料配比:灰砂比为1∶4、料浆浓度大于80.8%、混合集料平均粒径不大于1.692 mm和非均匀系数不小于38.4,由此对应的3 d充填体试块密度不小于2.24 g/cm3。该研究成果为混合集料在金川镍矿充填采矿奠定了基础。     

云南某铅锌矿全尾砂膏体室内实验研究

对云南某铅锌矿采用全尾砂膏体充填方案开展了室内实验研究,分析了全尾砂基本物理化学性质（粒级组成、化学成分）,并进行了全尾砂自然沉降试验、坍落度试验、全尾砂试块单轴强度试验,获得了全尾砂及全尾砂胶结料的自然沉降特性、流动性能、析水性能及强度特性.试验结果显示：全尾砂自然沉降2~3 h后,重量浓度达到72%~76%,需要添加絮凝剂加快沉降;全尾砂胶结料的重量浓度为78%~79%时,坍落度为24~17 cm,基本无析水（1%~0.6%）,充填料呈膏体状态,适合长距离输送;全尾砂膏体配合比在1∶4~1∶12时,28 d单轴抗压强度达到1~4 MPa.室内实验初步表明该矿山可以采用全尾砂膏体充填方案.     

多目标条件下矿山充填材料配比优化实验

为准确确定某铁矿尾砂胶结充填材料最优配比,分别选择制浆水性、砂灰质量比和料浆质量浓度与充填体强度、料浆坍落度和料浆泌水率作为尾砂胶结充填材料配比优化的影响因素和充填性能评价指标.基于响应面–满意度函数耦合理论,采用Box-Behnken实验设计方法开展13组不同充填配比实验,构建充填性能评价指标的响应面函数,研究各影响因素与目标响应量的相关关系及多目标条件下的最优充填材料配比.结果表明,制浆水性对响应量影响不显著;砂灰质量比对充填体强度影响极显著;坍落度受料浆质量浓度、砂灰质量比影响较显著;砂灰质量比和料浆质量浓度对料浆泌水率的影响均极为显著,且二者之间存在极显著的交互作用.该矿尾砂胶结充填材料最优配比为:制浆水性为海水,砂灰质量比为8.44:1,料浆质量浓度为72%,该配比条件下对应的响应量预测结果为:充填体28 d龄期单轴抗压强度为2.00 MPa,料浆塌落度为27.15 cm,料浆泌水率为7.35%,与验证实验结果基本吻合,为现场工业实验提供强有力的理论支撑.     

基于磁化水的建筑垃圾深井充填新技术

为解决建筑垃圾与煤矸石混合骨料浆体管道输送性能差,后期强度不足的问题,将磁化水和活化搅拌技术引入建筑垃圾充填配浆试验中.试验探究了不同磁化条件下,磁化水-建筑垃圾浆体主要流变参数和抗压强度的变化规律;基于Fluent的充填管道输送流速和压力变化模拟,对磁化水-建筑垃圾浆体的管道输送性能进行分析.试验结果表明:在磁感应强度B=200mT,水循环流速v=0.3m/s时,经活化搅拌后的磁化水-建筑垃圾浆体的坍落度、稠度提升15%~20%,抗压强度提升20%~30%,管道沿程阻力损失减少27%.磁化水在提高建筑垃圾充填体强度,改善其流变性能,提升管道输送效率方面具有显著的优越性.     

高硫尾砂胶结充填体强度影响因素实验研究及应用

全尾砂用于井下充填在环保、安全、经济方面均具有显著优势,但有色矿山尾砂普遍含硫,过多的硫会劣化充填体长期强度.用新疆某铜矿高硫尾砂与戈壁料混合作充填骨料,通过全面实验法研究骨料硫含量、灰砂比、料浆浓度、养护龄期对充填体强度的影响,通过灰关联法分析各影响因素的主次排序.结果表明,硫含量低于11.72%时,充填体强度随硫含量、灰砂比、浓度增加呈线性增长,随养护龄期增加呈多项式函数增长,确定骨料中尾砂占比为30%.充填体强度影响因素的主次排序为灰砂比养护龄期浓度硫含量(尾砂含量),建议矿山优化进路开采顺序以延长充填体养护时间,灰砂比由1∶4降为1∶6,可在满足强度和采充周期的同时降低充填成本.     

金矿尾矿胶结充填用胶凝材料的制备及其性能表征

以矿渣微粉、水泥(P.O 42.5)、粉煤灰、氧化钙和硫酸钙为原料制备早强型尾矿胶结胶凝材料(尾矿胶结料),将尾矿胶结料用于胶结充填中位直径D_(50)为11.3μm的金矿细粒尾矿,表征分析充填试样的力学性能与流动性能。结果表明:相同胶砂质量比和尾矿浆固含量下,用尾矿胶结料胶结固化尾矿的效果优于P.O 42.5水泥;胶砂质量比1∶12时,充填试样28 d抗压强度为P.O 42.5水泥的4.9倍,尾矿胶结料的水化产物量高于P.O 42.5水泥;尾矿胶结料的胶砂质量比为1∶6、尾矿浆固质量分数为70%时,加入0.15%(质量分数)聚羧酸减水剂的充填料浆坍落度为278 mm,其力学性能和充填流动性能均可满足矿山充填要求。     

废石-尾砂高浓度料浆的流变特性及输送参数优化

料浆的流变特性是实现料浆管道输送的基础,影响着管路设计与阻力计算等技术问题.废石-尾砂料浆的水灰比或骨料性质都不同于混凝土及全尾砂浆,料浆结构更加复杂,确定最佳管输料浆组合变得更加困难.通过对某矿山废石和尾砂的级配分析,选用废石和尾砂优化后的配合比(6∶4,7∶3,8∶2)制成高浓度料浆进行流变实验,首先回归流变曲线获取流变参数,其次应用灰色关联理论对屈服应力及粘度的影响因素进行排序与分析,最后应用Deport Expert软件确定优化后的料浆组合.结果表明水泥添加量和质量浓度是屈服应力的决定因素;废石-尾砂比是粘度的主要影响因素,水泥量、质量浓度次之;料浆的优化组合为废尾比取1.40,质量浓度取82%,水泥添加量取275.29 kg/m3.此研究为矿山自流充填管道输送提供了理论依据.     

复合坯体增强剂的制备及对Al_2O_3料浆性能和生坯强度的影响

以玉米淀粉为主要原料,采用交联-醚化改性法,通过干法球磨制备性能优良的改性淀粉。将改性淀粉与适量无机化合物进行复合优化制得复合陶瓷坯体增强剂,并加入到Al_2O_3料浆中进行料浆流动性和干燥后的生坯抗折强度测试评价其效果。结果表明,当改性淀粉∶焦磷酸钠=1∶1时,复合增强剂的性能最好。复合增强剂在Al_2O_3陶瓷中的最佳质量添加量为0.6%~0.8%,能很好地满足生产工艺要求。自制复合增强剂增强效果明显,同时不影响料浆流动性,成本低廉且制备工艺简单。     

大红山铜矿粗骨料充填料浆的高浓度判定

高浓度充填是目前主要的充填方式,粗骨料高浓度充填料浆性质复杂、影响因素多,而且某些参数的变化又不易控制,所以粗骨料充填料浆的高浓度判定仍是一大难题.本文结合目前国内外的研究现状给出了粗骨料高浓度充填料浆判定式.采用大红山铜矿废石与分级尾砂为材料进行验证,首先通过级配分析,选用最优配合比(废石∶分级尾砂为7∶3)配置料浆,进行抗离析性、泌水性观察以及坍落度试验,同时计算出高浓度充填料浆判定式对应值,最终选出符合要求的实验组,确定判定式的上下限.实验结果表明本文提出的粗骨料高浓度充填料浆判定式合理,且准确度很高,具有实际应用价值.     

Hydraulic calculation of gravity transportation pipeline system for backfill slurry

Taking cemented coal gangue pipeline transportation system in Suncun Coal Mine, Xinwen Mining Group, Shandong Province, China, as an example, the hydraulic calculation approaches and process about gravity pipeline transportation of backfill slurry were investigated. The results show that the backfill capability of the backfill system should be higher than 74.4 m^3/h according to the mining production and backfill times in the mine; the minimum velocity （critical velocity） and practical working velocity of the backfill slurry are 1.44 and 3.82 m/s, respectively. Various formulae give the maximum ratio of total length to vertical height of pipeline （L/H ratio） of the backfill system of 5.4, and then the reliability and capability of the system can be evaluated.     

Experimental Study on the Mechanical Properties of Paste-like Fill Material

The experiments, which include the complete stress-strain curves, triaxial compressive loading history and the main factors affecting the compressive strength of the material, were made to research the mechanical properties of paste-like fill material. The results show that the material still has a relatively high load-bearing capacity after yielding. From the view of the backfill strength, the suitable content of the fine particles in the aggregates is 20%, the curing temperature of backfill slurry is about 20 centigrade degrees or higher. The backfill strength can reach 2.5-3.6 MPa when the binder dosage is 5%-8%. It can meet the needs for mining with backfill.     

A New Mode of Coal Mining Under Buildings with Paste-Like Backfill Technology

The formation of the paste-like backfill technology was introduced briefly in this paper. From the actual cases of coal mines, a new mode of coal mining under buildings with the technology was proposed. And its specificity was analyzed, and a further introduction to the full-sand-soil solidifying material was given. The main parts of the backfill system, such as the backfill preparation system, the pipeline transportation system,the backfill systems in fully-mechanized mining faces and the backfill process, were presented emphatically.     

Performance of cemented coal gangue backfill

Possibility of cemented gangue backfill was studied with gangue of Suncun Coal Mine, Xinwen Coal Group, Shandong, and fly ash of nearby thermal power plant, in order to treat enormous coal gangue on a large scale and to recovery safety coal pillars. The results indicate that coal gangue is not an ideal aggregate for pipeline gravity flow backfill, but such disadvantages of gangue as bad fluidity and serious pipe wear can be overcome by addition of fly ash. It is approved that quality indexes such as strength and dewatering ratio and piping feature of slurry can satisfy requirement of cemented backfill if mass ratio of cement to fly ash to gangue is 1：4：15 and mass fraction of solid materials reaches 72%-75%. Harden mechanism suggests that the cemented gangue fill has a higher middle and long term comprehensive strength.     

预填集料高强混凝土抗压强度影响因素研究

当前工程应用的预填集料混凝土其集料粒径大且组成单一,混凝土强度偏低,应用范围受限.为提高预填集料混凝土抗压强度,本文试验研究制备方式、浆体材料类型、粗集料级配组成等对预填集料混凝土抗压强度的影响.结果表明:分层填筑、振动灌浆比自填充灌浆更有利于提高预填集料混凝土抗压强度;粗集料堆积程度越紧密、空隙率越小,预填集料混凝土...     

Cemented backfill technology based on phosphorous gypsum

Physical-chemical properties of phosphorous gypsum, proportion and cemented mechanism of slurry with gypsum as aggregate were studied to remove the harms of gypsum pile, combining with difficult problems of excessive mined-out gobs, enormous ore body under roadway and low recovery ratio of Yongshaba Mine, Kaiyang Phosphor Mine Group, Guizhou Province, China. An appropriate backfill system and craftwork were designed, using shattering milling method to crush gypsum, double-axles mixing and strong activation mixing way to mix slurry, cemented slurry and mullock backfill alternately process. The results show that gypsum is fit for backfilling afterwards by adding fly ash, though it is not an ideal aggregate for fine granule and coagulate retardation. The suggested dosage (the mass ratio of cement to fly ash to gypsum) is 1:1:6–1:1:8 with mass fraction of solid materials 60%–63%. Slurry is transported in suspend state with non-plastic strength, and then in concretion state after backfilling. The application to mine shows the technology is feasible, and gypsum utilization ratio is up to 100%. Transportation and backfill effect is very good for paste-like slurry and drenching cemented slurry into mullock, and the compressive strength and recovery ratio are 2.0 MPa and 82.6%, respectively, with the maximum subsidence of surface only 1.307 mm. Furthermore, the investment of system is about 7×10⁶ yuan (RMB), only 1/10 of that of traditional paste backfill system. Foundation item: Project (2006BAB02A03) supported by the National Key Technology Research and Development Program; Project (08MX16) supported by Mittal Scientific and Technological Innovation Projects of Central South University during 2008     

Paste-like self-flowing transportation backfilling technology based on coal gangue

A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recovering high quality safety coal pillars and deep mining of the Suncun Coal Mine (SCM), Xinwen Coal Group, Shandong are resolved. The physical-chemical properties of coal gangue, optimized proportion of materials, backfilling system and craft in the SCM were studied in the laboratory and then an industrial test was carried out on high quality coal pillars under a town. The results show that finely crushed kaolinized and fresh gangue with granularity less than 5 mm can be used as aggregate with fly ash to replace part of the cement and a compos-ite water reducer as an additive, accounting for 1.0%-1.5% of the total amount of cement and fly ash. The recommended proportion is I(cement):4(fly ash): 15(coal gangue), with a mass fraction of 72%-75%, theological paste-like properties and a strength of more than 0.7 MPa at 7 d. The sequence of adding cement, fly ash, water reducer and then coal gangue ensures that the suspended state of the slurry, reducing the wear and jam of pipelines. The working face is advancing continuously by the alternating craft of building block walls with coal gangue and backfilling mined-out gobs with paste-like slurry. The recovery rate is as high as 90% with a backfilling cost of 36.9 Yuan/t, good utilization of coal gangue and no subsidence on the surface. This technology provides a good theoretical basis and application experience for coal mines, cement backfilling with paste-like slurry.     

生活垃圾填埋场渗滤液防渗浆材的实验研究

通过正交实验研制出了一种低渗透系数并对污染物有一定吸附阻滞作用的黏土基浆材,用于城市生活垃圾填埋场渗滤液防渗工程。该浆材配方为:膨润土20%～30%、水泥15%～25%、粉煤灰20%～25%、纯碱1.0%～1.4%、稀释剂FCLS加量0.35%～0.75%,余之为水。该浆材结石率大于99.6%,固结体28d渗透系数小于0.8×10-7cm/s,无侧限抗压强度小于2.0MPa,浆材固结体对CODCr、BOD5、铵态氮和磷的吸附阻滞率达到了82%以上,对Hg、Pb等重金属离子阻滞率在99%以上。     

Numerical investigation into the effect of backfilling on coal pillar strength in highwall mining

This paper attempts to quantify the effect of backfilling on pillar strength in highwall mining using numerical modelling. Calibration against the new empirical strength formula for highwall mining was conducted to obtain the material parameters used in the numerical modelling. With the obtained coal strength parameters, three sets of backfill properties were investigated. The results reveal that the behavior of pillars varies with the type and amount of backfill as well as the pillar width to mining height ratio(w/h). In case of cohesive backfill, generally 75% backfill shows a significant increase in peak strength, and the increase in peak strength is more pronounced for the pillars having lower w/h ratios. In case of noncohesive backfill, the changes in both the peak and residual strengths with up to 92% backfill are negligible while the residual strength constantly increases after reaching the peak strength only when 100%backfill is placed. Based on the modelling results, different backfilling strategies should be considered on a case by case basis depending on the type of backfill available and desired pillar dimension.     

定向钻穿越孤东辛输气管线黄河段的应用

针对孤东辛输气管道穿越黄河段更新工程的需要,根据输气管线穿越黄河段特殊的地质条件,提出管道穿越段的曲率半径、穿越强度以及回拖力轨迹的计算方法,通过计算结果确定了输气管道穿越过程中采取的技术方案和技术措施,解决了定向钻导向孔难、预扩孔难的问题,使管线回拖一次性成功,更新工程顺利完成。