利用燃烧煤矸石渣配制混凝土路面砖的试验研究

利用燃烧后的煤矸石渣作骨料 ,配制混凝土路面砖。通过正交试验确定出影响路面砖强度的主要因素及路面砖的最佳配比。     

Creep properties and resistivity-ultrasonic-AE responses of cemented gangue backfill column under high-stress area

To investigate the creep and instability properties of a cemented gangue backfill column under a highstress area, the uniaxial compression creep tests were conducted by single-step and multi-step loading of prismatic samples made of cemented gangue backfill material(CGBM) under the high stressstrength ratio. The creep damage was monitored using an electrical resistivity device, ultrasonic testing device, and acoustic emission(AE) instrument. The results showed that the CGBM sample has a creep hardening property. The creep failure strength(CFS) is slightly larger than the uniaxial compressive strength(UCS), ranging in ratio from 108.9% to 116.5%. The instantaneous strain, creep strain, and creep rate increase with increasing stress-strength ratio in the single-step loading creep tests. The instantaneous strain and creep strain decrease first and then increase during the multi-step loading creep process. The axial creep strain of the CGBM column can be expressed by the viscoelastic-plastic creep model. Creep instability is caused by the accumulation of strain energy under multi-step loading and the continuous lateral expansion at the unconstrained middle position during the creep process. The creep stability of a CGBM column in a high-stress area can be monitored based on the variation of electrical resistivity, ultrasonic pulse velocity(UPV), and AE signals.     

Effects of surface-activated coal gangue aggregates on properties of cement-based materials

Effects of calcined coal gangue （CG） aggregates treated by the surface thermal activation on the flowability and strength, and paste-CG aggregate interfaces of the cement-based material were investigated. The experimental results show that the compressive and flexural strength of the cement-based material with the calcined CG aggregates is much higher than that of the material with the natural CG aggregates, but the flowability of the material with calcined CG is significantly reduced with the calcined time. The strength of the material with the calcined CG aggregates only increases little with the calcined time at the same w/c ratio, but is reduced with the calcined time at the same flowability. The CG aggregates calcined by the surface thermal activation obviously overcomes the disadvantages of fully calcined CG.     

Activity and Structure of Calcined Coal Gangue

Coal gangue was activated by means of calcination in seven temperature ranges. Systematic research was made about activation mechanism and structural evolution. Glycerin-ethanol method, SEM, M1P and XRD were used to determine the variation of structure and activation of coal gangue during the calcination. The experimental results show that because of heat treatment in the range of calcination temperature, mineral composition and microstructure of coal gangue are changed. In addition, its activity is improved evidently. The amount of lime absorbed by the sample calcined at 700 ℃ is 2-4 times that by uncalcined coal gangue in the course of hydration. When NaOH is added to coal gangue-lime system, hydration reaction of the system is sped up and the microstructure of hydrating samples of coal gangue is improved.     

煤矸石砼中钢筋粘结锚固的试验研究

在文献[2]的基础上，对煤矸石砼的粘结应力分布，箍筋及煤矸石砼保护层对粘结应力的影响进行了与普通砼的对比试验，进一步研究砼保护层厚度及钢筋锚固长度对粘结强度的影响，给出了保护层与粘结应力、砼强度与临界锚长的经验公式。     

Pozzolanic Activity of Burned Coal Gangue and Its Effects on Structure of Cement Mortar

The pozzolanic activity of coal gangue burned at different burning temperatures was investigated. The burned coal gangue was mixed with portland cement in different proportions （ 20% - 60% ）. The pozzolanic activity of coal gangue burned and the hydration products were examined, the compressive strengths of the pastes of the mixtures were tested, and the mechanism of the reaction was discussed. The experimental results slum, that the coal gangue burned at 750 ℃ has the optimum pozzolanic activity, and the burned coal ganguc with SiO2 and Al2 O3 is in an active form. When the coal gangue burned at 750℃ is mixed into portland cement, the content of calcium hydroxide in paste is significantly reduced, while the contents of hydrated calcium silk.ate and hydrated calcium aluminate are increased accordingly, hence resulting in the improvement of the microstructure of mortar. The compressive strength of cement paste decreases with increasing the content of burncd coal gangue. The decease in strength is small in the range of 20% - 30% coal gangue substitution and significant in 30%- 60% substitution.     

煤矸石在公路工程中的应用试验研究

煤矸石是一种原煤废料 ,对环境污染严重 ,用于公路建设是一种有利的尝试。本文通过煤矸石填料在公路工程路基、底基层的应用试验与实践 ,阐述了煤矸石施工工艺和质量控制要点 ,并讨论了特殊路基和桥头路基的处理工艺 ,以期为我国公路工程施工提供一种新的建筑材料。     

自燃煤矸石山爆炸的危害及治理技术

自燃煤矸石山濒发爆炸事故,会造成大量的人员伤亡和经济损失,从而极大地影响煤炭企业的快速发展.结合某矸石山爆炸的实际情况,分析诱发自燃煤矸石山爆炸的主要因素,指出其爆炸所产生高压、高温热浪、粉尘、冲击波等对周围环境的危害,提出自燃煤矸石山爆炸的防治措施,对促使煤炭企业意识到矸石山爆炸的危害并主动预防矸石山爆炸具有重要的现实意义.     

Direct-impact of sieving coal and gangue

Gangue from underground separation of coal can directly be used for filling mined out areas, saving transport capacity and reducing the amount of waste polluting the environment above the ground. We introduced a structure and operating principle of an underground direct-impact sieving device by which a separation experiment was carried out. By means of high speed conveyer belts, coal and gangue impacted the breaking board at high speeds ranging from 6 to 14 m/s. Given the differences of hardness between coal and gangue, after selective crushing, the gangue with the higher hardness was crushed less and coal with lower hardness crushed more, which could be separated by a 50 mm sieving plate. The material above the sieving plate was disposed of as gangue and the material below as coal. The results indicate that the crush ratio below the 50 mm sieving plate increases linearly with an increase in impact velocity and decays exponentially with an increase in hardness. Employing this equipment to separate coal and gangue, the hardness of coal f should be <2. This separation device provides relatively good effect in separating coal and gangue with a relatively wide difference of hardness.     

发展煤矸石制砖推进墙体材料改革

煤矸石大量堆存占用土地,污染环境;生产实心粘土砖毁田惊人、耗能巨人、污染环境.倡导并大力发展以煤矸石为原料生产煤矸石砖,取代部分传统的粘土砖,可以做到变废为宝、节约能源、保护耕地、保护环境,对促进我国墙体材料改革和实施可持续发展战略具有重要意义.     

利用煤矸石制取高纯度超微细钛白粉的试验研究

本文对利用煤矸石制取高纯度超微细钛白粉的可行性进行了研究,对焙烧温度、反应温度、pH值、水解、水洗操作、盐处理及煅烧等影响因素进行了分析,通过对所制钛白粉产品质量检验得出:利用煤矸石制取钛白粉是一种切实可行的方法。     

Effect of coal gangue with different kaolin contents on compressive strength and pore size of blended cement paste

The effects of activated coal gangue on compressive strength, porosity and pore size distribution of hardened cement pastes were investigated. Activated coal gangue with two different kaolin contents, one higher and one lower, were used to partially replace Portland cement at 0%, 10%, and 30% by weight. The water to binder ratio（w/b） of 0.5 was used for all the blended cement paste mixes. Experimental results indicate that the blended cement of activated coal gangue mortar with higher kaolin mineral content has a higher compressive strength than that with lower kaolin mineral content. The porosity and pore size of blended cement mortar were significantly affected by the replacement of activated coal gangue.     

煤矸石堆放及其利用中产生的污染

介绍由于风化、淋滤、自燃等作用,煤矸石在堆放时对水、土壤、空气等的污染,以及由于技术水平限制,煤矸石在现阶段的利用过程中产生的污染;分析了污染产生的内部和外部原因,并对无污染的煤矸石综合利用和新技术开发进行了探讨和展望.     

锌改性煤矸石的制备及其对废水中磷酸盐的吸附去除

煤矸石作为吸附剂在废水处理领域广泛应用,但天然煤矸石内部含有大量结晶水和黏土矿物杂质,直接利用天然煤矸石处理废水存在效率低、时间长、投加量大等问题.采用ZnCl2对天然煤矸石进行改性,减少了煤矸石内部的结晶水和黏土矿物杂质,增加了煤矸石的比表面积,提高了处理效率,降低了处理成本.通过不同条件下的改性试验得到改性煤矸石,...     

酸浸法从煤矸石中浸取氧化铝的最佳因素

研究了酸浸法对煤矸石组分的浸取效果,利用正交试验确定了酸浸法从煤矸石中浸取氧化铝的最佳因子,并讨论了各因子对氧化铝浸出率的影响,确定了矸石粒度0.15 mm,煅烧温度780℃,煅烧时间2 h,盐酸质量分数15%,液固比6∶1,浸取温度50℃,浸取时间3 h为最佳浸出条件,并得到在此条件下氧化铝的浸取率为67.4%.     

煅烧煤矸石胶凝活性评价方法分析

为了研究煅烧煤矸石不同活性评价方法之间的关系,利用NMR、XPS、ICP等分析手段,分别采用强度评价法、聚合度评价法、活性硅铝溶出评价法以及XPS评价法,对不同温度煅烧煤矸石的火山灰活性进行了评价,并分析了不同评价方法之间的关系.结果表明不同活性评价方法均可以在一定程度上反映煤矸石胶凝活性的变化规律.其中,强度评价法、聚合度评价法对煅烧煤矸石的火山灰活性变化更为敏感,而XPS评价法、活性硅铝溶出法相对较差.其中就煅烧煤矸石而言,强度评价法和聚合度评价法更适合于煤矸石火山灰活性评价,并且二者者之间存在较好的相关性.     

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.     

淮北矿区煤矸石与煤混合燃烧特性的研究

本文利用STA-409PC热重分析仪,研究了淮北矿区不同质量比的煤矸石与煤混配样品的燃烧性能与动力学特性。结果表明：随着混配样品中的煤比例的增加,其着火温度和燃尽温度都有所降低,综合燃烧特性指数都有所增大,着火和燃烧特性都得到改善。本文还利用Coats--Redfern积分法对上述样品燃烧过程进行了动力学分析,得出淮北矿区煤矸石与煤混煤的燃烧反应历程服从1．5级的化学反应,对优化超临界流化床（简称CFB）锅炉混配燃料的运行具有重要意义。     

煤矸石代替黏土生产水泥可行性分析

为了研究煤矸石代黏土生产水泥的可行性,对10个省份28个矿点进行取样,开展煤矸石特性分析.分析结果表明,煤矸石具有高灰分、高硫分和低热值等特点,化学成分与黏土相近,还含有较丰富的微量元素和矿物组成.对煤矸石、中钙石灰石和硫酸渣等配料进行煅烧试验,试验表明,煤矸石在煅烧时,微量元素和矿物释放其储存的地质能量,加速促进硅氧键的断裂,比黏土配料更早生成硅酸三钙、硅酸二钙和铝酸三钙等水泥熟料矿物.煅烧过程中放出的二氧化硫与钙铝氧化物反应形成早强硫铝酸盐水泥熟料矿物,从而减少硫化物对环境的污染.     

破碎煤矸石粒度与热值分布研究

通过研究不同方式破碎煤矸石中存在的热值随粒度减小而增大的现象,分析了破碎煤矸石粒度与热值分布间的相互关系。结果表明,煤矸石破碎后,不同粒级发热量随粒度变化而重新分布,呈负相关关系,且细粒级比粗粒级发热量提高1倍以上,为煤矸石的破碎分选提供了依据。