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1.
在焦家金矿使用全尾砂代替分级粗尾砂进行胶结充填,可以满足矿石回采时对胶结充填体强度的要来.影响充填作强度的主要因素是灰砂比和料浆浓度.试验研究获得了胶结试块28天单轴抗压强度对灰砂比和料浆重量浓度的回归方程.  相似文献   

2.
针对某矿山采用全尾砂和胶凝材料作为充填材料进行自流胶结充填存在的充填料浆浓度低、井下采场泌水量大及充填体强度达不到要求等问题,开展了充填材料优选和配比优化试验研究。通过进行充填尾砂的物化性质分析和充填材料优化对比试验,优选出适合该矿山的胶结充填材料。在优选试验的基础上,采用正交试验方法进行配比优化试验,以标准水泥为胶结材料,全尾砂和矿渣微粉为骨料,研究矿渣微粉掺量、灰砂比和料浆浓度对充填体和料浆性能指标的影响规律,通过极差分析和方差分析确定因素的主次顺序和影响程度,并最终确定胶结充填材料最佳配比为料浆浓度68%,矿渣微粉掺量18%,灰砂比1∶14。  相似文献   

3.
以某铅锌矿全尾砂为充填骨料、水泥为胶凝剂制作胶结充填体,测定了全尾砂物理化学特性,并用三因素四水平正交试验设计进行单轴抗压强度试验,研究了全尾砂胶结充填体抗压强度与灰砂比、质量浓度和养护时间的敏感性,通过对各因素的多元线性回归分析推荐了充填料浆最优配比。结果表明:当全尾砂不均匀系数大于5时,可用作充填骨料且制成的充填体密实程度好;胶结充填体抗压强度与灰砂比、质量浓度及养护时间成正比;灰砂比对充填体抗压强度的影响最敏感,养护时间次之,质量浓度最小;推荐该矿最优充填配比方案为灰砂比1∶4、质量浓度76%、养护时间28d。  相似文献   

4.
某新建矿山计划采用全尾砂膏体嗣后充填采矿法进行地下开采。为了提供经济合理、满足强度要求且有利于管道输送的全尾砂膏体充填最优配比方案,以料浆流动性能和充填体强度性能为考察指标进行正交组合配比试验。运用MATLAB软件对试验数据进行极差分析和多元线性回归分析,获得了灰砂比和料浆浓度对充填体强度影响的敏感性以及各力学参数预测模型。结果表明:(1)料浆质量浓度对塌落度的影响起主要作用,灰砂比次之;(2)充填体强度的敏感性随着灰砂比和料浆浓度的增加而增强,充填体强度对灰砂比更敏感,而对料浆浓度的敏感性较弱;(3)确定了全尾砂膏体最优配比:水泥用量为13%,充填料浆质量浓度为77%,此时全尾砂、水泥和水的用量分别占制备全尾砂膏体质量的68.14%、8.86%和23.00%。在该配比条件下,经28 d养护龄期后的抗压强度为2.6279 MPa、弹性模量为205.2 MPa、塌落度为23.7 cm,以较少的水泥用量满足了矿山充填强度指标和自流输送要求。  相似文献   

5.
以大冶铁矿全尾砂为原材料,采用水泥为胶结材料制作全尾砂胶结充填体,采用单因素五水平设计试验,研究了全尾砂胶结充填体强度与料浆中固相质量分数、灰砂配比及龄期之间的关系,并对敏感性进行了分析.胶结充填体强度随着料浆中固相质量分数的增加遵循指数函数增长,随灰砂配比的增加呈线性增长,随龄期增加遵循指数函数的增长,其中胶结充填体强度对龄期的敏感性最高,料浆中固相质量分数次之,灰砂配比最弱.胶结充填体抗压破坏试验结果显示,充填体的破坏经历了四个阶段,分别为微裂隙闭合阶段、线弹性阶段、微裂纹扩展阶段及裂纹贯通破坏阶段.   相似文献   

6.
考虑灰砂比、料浆浓度为充填料强度的主要影响因素,以播卡金矿全尾砂为骨料,通过设计试验方案,并对试验结果进行分析和处理,得出播卡金矿全尾砂胶结充填采矿所需的配比。  相似文献   

7.
金山店铁矿全尾砂胶结充填体性能试验研究   总被引:1,自引:0,他引:1  
陈丽  宋卫东  鲁炳强  王水平 《黄金》2011,32(12):31-35
采用普通水泥和其他两种固结剂为胶结材料对金山店铁矿全尾矿进行了胶结对比试验.对不同的养护龄期、料浆浓度及灰砂比下胶结体的单轴抗压强度进行测定,由此分析养护龄期、料浆浓度及灰砂比对胶结体抗压强度影响.最后,通过对不同龄期、料浆浓度及灰砂比的充填试样进行SEM扫描试验,分析各因素对生成水化物的影响,对充填体反应机理进行了探...  相似文献   

8.
为了提高高峰矿尾砂充填体强度和解决井下废石利用问题,开展高峰矿废石及尾砂混合充填材料的最优配比研究,设计了四因素四水平的正交试验,采用极差分析获得了影响充填体强度、料浆泌水率和料浆坍落度的主次因素,得到初步满足矿山要求的配比:料浆浓度为83%,灰砂比为0.25,废尾比为1.5,泵送剂添加量为0.5%。根据正交试验数据建立了28 d充填体强度、料浆泌水率和坍落度的二次多项式回归模型,基于NSGA-Ⅱ算法进行多目标优化,获得最优充填料浆配比。研究结果表明:灰砂比对充填体强度影响最大,料浆浓度和废尾比次之,泵送剂影响最小;灰砂比对料浆泌水率有明显的控制作用,废尾比和料浆浓度次之,泵送剂作用最小;料浆浓度对坍落度影响最大,泵送剂和灰砂比影响次之,废尾比影响最小;多目标优化后的配比:料浆浓度为82.989%,灰砂比为0.240,废尾比为1.419,泵送剂添加量为0.537%,优化后的配比方案所需充填材料成本相比正交试验确定的方案成本下降了2.9%。  相似文献   

9.
通过室内试验测定了尾砂的特性以及充填体强度随料浆浓度和灰砂比的变化规律,结合金厂峪金矿现场实际需求确定了充填灰砂比,根据现场地形及生产需要设计了皮带输送两段搅拌造浆充填系统,并分别从充填工艺及充填系统建设两方面介绍了碎石尾砂浇注胶结充填技术在桑家峪矿区的应用。可为类似条件空区处理提供借鉴。  相似文献   

10.
为研究含膨润土全尾砂充填料浆的泌水特性与规律,以掺膨润土的良山铁矿全尾砂作为试验材料,进行以灰砂比、料浆浓度和膨润土掺量的三因素四水平正交试验,通过室内试验来观察料浆在不同膨润土掺量下的泌水现象,进而分析在全尾砂胶结充填中添加膨润土对料浆泌水性的影响。结果表明:在一定的变化范围内,总泌水率与各因素呈反比关系,其中料浆浓度对总泌水率的影响最大,其次是膨润土掺量,灰砂比最小;料浆的动态泌水过程大致划分为前期快速泌水和后期稳定泌水2个阶段,且每个阶段持续时间因不同配比条件的影响而不同;根据动态泌水过程,膨润土掺量对整个动态泌水率影响最明显,而料浆浓度和灰砂比的影响较小。  相似文献   

11.
Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

12.
The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.  相似文献   

13.
鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".  相似文献   

14.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。  相似文献   

15.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

16.
17.
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.  相似文献   

18.
通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。  相似文献   

19.
20.
In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.  相似文献   

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