由矿岩性质确定爆破参数的研究与应用

在爆破理论的基础上分析了矿岩不同性质对爆破参数的影响，采用以爆破后岩体中裂隙区的大小来确定炮孔间距的方法，进一步确定合理爆破参数的初始值．这种方法在西石门铁矿的实际应用中获得了良好的效果．

地质结构与岩矿性质对发生矿山冲击地压的影响

1 地质结构对发生冲击地压的影响 金属矿床是由各种地质结构单元构成的,如大型岩体、大型构造块、矿体、矿层及相邻的脉石体、断裂破碎带、裂隙等。这些结构单元的形状与规模、赋存条件与位置均不相同,因此对矿山冲击地压的影响也不同。1.1

北宿、唐村高岭土矿石的性质及利用途径

文章介绍了北宿、唐村高岭土的赋存特征和矿岩性质,研究了矿石的化学成分、物相组成及工艺物理性能,同时分析了矿石的利用途径。

齐大山铁矿爆破技术的改进

简要论述了爆破技术的重要性和采用计算机技术改进爆破技术的方法和途径。

无底柱分段崩落法结构参数选取的影响因素

无底柱分段崩落法因其生产灵活、机械化程度高、生产能力大、开采成本低等优点在国内外金属矿山中有着广泛的应用。其中,采场结构参数的选取对矿山采矿规模和生产成本有着重要的影响。通过对无底柱分段崩落法的特点及其在国内外典型矿山中的应用现状的介绍,分析了采场结构参数对矿山采矿规模和生产成本的影响,并从矿岩性质和采矿设备等方面论述了选取结构参数时受到的制约因素。

基于模糊聚类分析的巷道分级支护研究

运用Excel软件对巷道不同地段岩性错综复杂的矿岩进行了高效准确的模糊聚类分析,将巷道不同取样地段的矿岩分为了3类。根据分类结果对各类矿岩巷道提出了相应的支护方案,分级支护方案取得良好的效果,并最终形成了巷道分级支护标准,实现了巷道的即时分类与可靠支护,为矿山巷道支护提供了科学的决策依据。

安徽省马鞍山高村采场爆破参数优化

高村采场台阶深孔爆破和预裂爆破一直沿用临近采场的爆破参数,在生产过程中发现部分爆破参数和爆破方法并非与高村采场的矿岩性质相适应,因此结合该采场的生产实际情况,进行了一系列的爆破试验。通过试验,分别得出适合坚硬矿岩和特别坚硬矿岩的爆破参数,对于特别坚硬岩石,可采用分段装药结构,对水孔采用导爆管雷管与导爆索联合起爆网路,可有效降低孔内装药不连续导致的装药困难。

Ground stability of underground gateroad with 1 km burial depth： A case study from Xingdong coal mine, China

This paper presents an integrated investigation of the ground stability of a deep gateroad with a 1 km burial depth based on a field test, case studies, and numerical modelling. In situ stress measurements and mechanical properties tests were first conducted in the test site. Then, the deformation behavior, stress and yield zone distributions, as well as the bolts load of the gateroad, were simulated using FLAC3D software. The model results demonstrated that the soft rock properties and high in situ stress were the main factors for the deep gateroad instability, and the shear slip failure induced by the high stress was the primary failure model for the deep rock mass. In addition, the unsuitable support patterns, especially the relatively short bolts/cables with low pre-tensions, the lack of high-strengthen secondary supports and the unsupported floor strata, also contributed to the gateroad instability. Subsequently, a new combined supporting strategy, incorporating longer bolts/cables, yielding ring supports, and grouting measures, was proposed for the deep gateroad, and its validity was verified via field monitoring. All these could be a reference for understanding the failure mechanism of the gateroad with 1 km burial depth.

Determination of ejection velocity of rock fragments during rock burst in consideration of damage

The ejection velocity of rock fragments during rock burst, one of the important indexes representing the rock burst strength, is used most conveniently in the supporting design of tunnel with rock burst tendency and is often determined by means of observation devices. In order to calculate the average ejection velocity of rock fragments theoretically, the energy of rock burst was divided into damage consuming energy and kinetic energy gained by unit volume of rock firstly, and then the rock burst kinetic proportional coefficient η was brought up which could be determined according to the rock-burst damage energy index W_D , at last the expression of the average ejection velocity of rock fragments during rock burst was obtained and one deep level underground tunnel was researched using the mentioned method. The results show that the calculation method is valid with or without considering the tectonic stress of tunnels, and that the method can be a reference for supporting design of deep mining.

Experimental Study on Mechanical Characteristics of Cracked Rock Mass Reinforced by Bolting and Grouting

The stress hardening characteristics of the reinforced rock mass in uniaxial compression tests were revealed by means of the experimental study on mechanical characteristics of cracked rock mass reinforced by bolting and grouting. And the load-beating mechanism of the reinforced rock mass was perfectly reflected by the experiment. The results can offer some useful advice for support design and stability analysis of deep drifts in unstable strata.

Electrokinetic and Flotation Investigations of Surface Properties Modification of Magnesite and Serpentinite Using Biosurfactants and Surfactants

This paper presents some results of zeta potential measurements performed into biosurfactant adsorption onto magnesite and serpentinite surface. Zeta potential and isoelectric point measurement of magnesite and serpentinite particles before and after interaction with biosurfactant broth solution and activator （nickel（II） ion solution） were carried out. The zeta potential results show that presence of biosurfactants changes both magnesite and serpentinite surface potential by physical adsorption which increases the hydrophobicity of mineral particles. Measurements of particles zeta potential in the presence of biosurfactant broth are relevant to the minerals flotation. Hallimod flotation response of magnesite and serpentinite as a function of collector concentration was investigated. Bioflotation test results show that at the presence of broth, the flotation separation of magnesite from serpentinite is possible.

Geomechanical and water vapor absorption characteristics of clay-bearing soft rocks at great depth

The geological and physico-mechanical properties characterization of deep soft rocks is one of the critical scientific issues for deep soft rock engineering. In the present study, X-ray diffraction(XRD) analysis,scanning electron microscope(SEM), and mercury intrusion porosimetry experiments were carried out to investigate the mineral compositions, microstructure and porosity characteristics of the 13 claybearing soft rock samples collected from a deep coal mine in China. Water vapor absorption and uniaxial compressive experiments were also performed to examine water absorption characteristics and waterinduced strength degradation effect of the investigated deep soft rock samples. The results show that the dominant mineral components in mudstone, coarse sandstone and fine sandstone samples were calcite, quartz and clay respectively. The contents of clay minerals in all samples were relatively high and ranged from 12.3%(N-4) to 56.5%(XS-1). Water vapor absorption processes of all the soft rock samples follow an exponential law which is very similar to the water vapor absorption behavior of conglomerate samples reported in our earlier study. Correlation analyses also suggested that there were good positive correlation relationships between water absorptivity and clay minerals for both mudstone and sandstone samples. Furthermore, it was found that vapor absorption was not correlated with the porosity for mudstone, however, positive correlation relationship was found between them for sandstone. Correlation analysis between UCS, modulus of elasticity and water content demonstrated that both of them tend to decrease with the increase of their water content due to water absorption.

Talc-bearing serpentinized peridotites from the southern Mariana forearc:implications for aseismic character within subduction zones

The serpentinized peridotites overlying the subducted zones in the Izu-Bonin-Mariana(IBM) arc system have been interpret as the cause of the low-velocity layer identified beneath the IBM froearc,in turn few earthquakes occurred along the plate boundary.Chrysotile,which is a low temperature and highly hydrated phase of serpentine with low frictional strength,has been suggested as the low velocity material in the serpentinized peridotites,besides,brucite is inferred to be likely conducive to stable sliding.However,such idea encounters challenging in our serpentinized peridotites from the southern Mariana forearc,which absent both the above minerals.The presence of talc,which characterized by its weak,low-friction and inherently stable sliding behavior,provides new clue.Here we report the occurrence of talc in serpentinized peridotites collected from the landward trench slope of the southern Mariana forearc.We infer that talc is mainly forming as a result of the reaction of serpentine minerals with silica-saturated fluids released from the subducting slab,and talc also occurs as talc veins sometimes.Due to its unique physical properties,talc may therefore play a significant role in aseismic slip in the IBM subduction zone.