某钼钨矿夹石剔除方式的探讨

某特大型钼钨矿对于极大厚矿体采用自然崩落法开采,厚度较小的采用无底柱分段崩落法,在开采过程中受到夹石的影响矿石损失贫化大。针对无底柱分段崩落法在开采含夹层矿体存在的问题,给出了在单步距回采矿石时夹石可剔除厚度计算方法;通过精确控制放矿比例和放矿截止品位相结合来确定剔除夹石的方式。应用该方法,可提高矿山采出品位,使矿石贫化率下降了1%左右。研究成果拓宽了无底柱分段崩落法的适用范围,为同类地质条件的矿山开采提供了借鉴。     

采场地压及其控制方法数值模拟研究

以某锰矿一期开采-170~-250 m中段矿体厚度小于1.8 m的矿段为工程背景,研究以倾斜分条房柱采矿法回采矿体时采场的地压分布及采场稳定性问题。运用Flac3D数值分析软件,模拟矿体的开采过程,并分析矿体开采后采场的应力分布及塑性区分布。最后结合实际情况,提出相应的地压控制措施。     

铜矿床低贫损开采技术研究

随着铜矿的不断开采和利用,其受矿体条件和开采活动的影响,损失和贫化程度较高。为满足铜矿继续开采的标准,将0m～50m水平选用低贫损模式崩落法进行分段开采。通过矿体参数试验和轨道布置方式对开采场地结构进行优化。即根据不同的铜矿形态,设定不同的矿体结构参数;布置方式为菱形结构,调整了输送轨道的位置;并提出处理地层夹石方法及合适的爆破参数。采用倾斜的坡道,并采取分段回采的方法,将铜矿床贫化程度降到最低约为12%,有效地解决铜矿贫损的问题。     

无底柱小分段崩落采矿法在急倾斜不稳固薄矿体开采中的应用

采矿工艺及采掘设备与开采条件的优化结合,是实现高效率采矿的重要途径。以富家矿急倾斜不稳固薄矿体开采为工程背景,结合分层崩落采矿法与无底柱分段崩落采矿法各自特点设计了一种无底柱小分段崩落采矿法。详细介绍了无底柱小分段崩落采矿法采准工程布置、回采工艺过程及技术参数。富家矿80 m中段单线翼部矿体小分段崩落采矿法开采试验应用取得了较好的技术经济效果,并为后续类似矿体回采提供了技术支持。     

一种盘区式分段凿岩阶段出矿嗣后充填采矿法

盘区式分段凿岩阶段出矿嗣后充填采矿法适用于回采急倾斜及倾斜矿体,矿体顶板围岩稳固,矿体底板围岩不稳固,矿体为中等稳固,节理裂隙发育,具有明显似层状结构,致矿体、夹石及顶底板围岩力学强度有明显的差异性的矿体;该采矿法能实现高效率、低成本回采,矿石损失和贫化低,达到了安全高效开采、保护矿体上覆高承压含水层、控制地表沉降和塌陷的目的。     

上向进路充填采矿法在长田金矿的应用

长田金矿矿石中等稳固,围岩稳定性极差,顶板不允许要较大面积的暴露,开采范围内矿体小而多,空间上多个矿体重叠,垂直间距在10m～50m不等,根据矿岩稳定性的特点,对倾角30度以下的矿体采用上向进路充填采矿法开采,该采矿方法对国内同类矿山开采具有较高的推广价值。     

上向水平分层高浓度尾砂高水速凝充填采矿法试验研究

针对小海沟金矿矿体形态复杂,上盘近矿围岩不稳定及矿脉内穿插夹石的不利开采条件,采用多项新材料和新工艺,提出并试验成功了上向水平分层高浓度尾砂高水速凝充填采矿法,获得了显著的经济效益和社会效益,对类似矿山具有很大推广应用价值。     

分层崩落采矿法试验总结

一、地质赋存情况及采矿方法的确定 (一)地质赋存情况:岭前矿7号脉矿体,为接触交带硅(?)岩类型浸染矿体。走向近似东西,延长达1000余公尺。向北倾斜,倾角为20°～40°,延深达150公尺左右。厚度变化由0.8～20余公尺。近地表处氧化较多。矿体分枝,复合,膨缩现象频繁,一般可将整个矿体分为顶、底秀两条矿脉,分支处夹石厚度由几公分至十余公尺,最厚者达30公尺,靠顶盘矿体是辉钼矿赋存     

重叠矿段采动下的工程响应仿真与评价

重叠矿体开采的相互作用和响应规律是影响矿山开采安全的重要因素。以镜铁山桦树沟铜矿与上部铁矿体的重叠矿段为研究对象，采用3DMine-Midas-FLAC^3D耦合精细建模数值模拟技术，结合矿山实际工程和采充工序条件，建立了充填矿段铜矿体开采条件下的FeV矿体工程响应数值分析模型，获得了FeV矿体回采巷道等工程结构的位移和应力响应规律，对FeV矿体的开采进行了安全评价和分析。研究结果表明：（1）试验采场的采充过程中，FeV回采巷道2 865 m水平所受开挖扰动最大，最大位移达到2.3 cm，应力最大扰动幅度为11.34%，最大剪应力为1.27 MPa；（2）采充过程中，空区上方中心部分的Z方向应力会减小，应力向四周转移；空区上方中心位置剪应力无明显变化，剪应力在空区边缘变化明显；（3）在试验采场开采过程中，上部FeV矿体的2 880 m和2 895 m水平回采巷道处于稳定状态，建议矿山加快回采进度，实现强采强出，提高矿石回收率。     

崩落采矿法放矿的理论与实践研究

本文针对广西凤山县那林金矿矿床开采技术条件,即矿体赋存在破碎带中,矿体倾角45°～55°,矿体厚度8～20 m之间,品位低,矿岩硬度系数f值只有4～6,非常破碎.采矿方法试验研究采用中深孔无底柱分段崩落采矿法,分段高度10 m,进路间距也是10 m.其放矿方法为小型电动铲运机,试验是在一个不完整的采场进行,中段高度40 m ,而矿块高度仅有20 m,其余20 m高度矿体已被回采.在这种条件下,如何降低采矿损失贫化,尤其是做好低品位放矿工作,本文进行初步分析研究.     

转炉炉壳热应力分析

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。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

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)     

Comparison of rates of infection of two methods of emergency ventricular drainage

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.     

浅析《野草》的版画特征

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".     

四辊破碎机车刀架的改造

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。     

焦炭热性能指标意义浅析

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。     

Results of treatment of cancer of the cardia

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.     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

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.