Roof bolting in underground mining: a state-of-the-art review   总被引：1，自引：1，他引：1  

Syd S. Peng  D. H. Y. Tang 《Geotechnical and Geological Engineering》1984,2(1):1-42

Conclusions With continuing investigations and developments, roof bolting today can in most cases successfully reinforce the mine roof in underground mining. In order to cope with the increasing use of roof bolts, efforts should be made to maximize the safety and minimize the cost. With regard to mechanical bolting, two important parameters need more advanced improvements and study, namely, optimum design of the shape and type of expansion shell and optimum bolt tension for a specific bolt pattern. For the fully grouted resin bolt, the most critical requirement is to develop a fast-setting, low-cost, intoxic, inflammable grouting material that can be used in the high speed mining cycle. It should be noted that geological conditions such as the strata type, rock properties,in situ stress, and planes of weakness play an important role in the successful application of any roof bolting system. These factors should be specified as accurately and quantitatively as possible in the design of any roof bolting system. Finally, proper and careful installation and continuous monitoring are imperative for the success of any roof bolting system.  相似文献   

Geochemical characteristics of tin-bearing magnetite-skarns     

Zhiji Ren 《中国地球化学学报》1984,3(2):115-127

Geological and geochemical characteristics of tin-bearing magnetite-skarns are reviewed in this paper, together with the author’s opinion with respect to the mechanism of transport of tin in this environment. In addition to cassiterite, the most common form of occurrence of tin in nature, three other forms of occurrence are also of interest in tin-bearing magnetite-skarns: (1) tin present in the form of fine exsolution colloidal grains of cassiterite; (2) tin found as independent tin-bearing minerals, such as malayaite, stokesite, nordenskiöldine, Sn-paigeite, Sn-ludwigite and hulsite in a variety of skarns; (3) tin occurring in the lattice of some skarn minerals, such as garnet, pyroxene, spinel, amphibole, epidote, wollastonite and axinite in the manner of ionic replacement. When Mg²⁺ and Fe²⁺ bearing minerals, in some cases even Sulfides or other mineralizer-containing minerals, replace tin-bearing Fe³⁺ and Ti⁴⁺ skarn minerals during the late stage of skarn alteration, tin in the pre-existing silicates maybe extracted and remobilized, thus contributing to the formation of associated tin deposits.  相似文献   

The abnormal periods of climate in china over the past 5000 years and their causes     

Ren Zhenqiu 《大气科学进展》1987,4(2):210-217

This paper points out that (1) there were 5 abnormal periods of climate in China over the last 1000 years, in which the frequency, the severity and the influenced area of such calamities as low temperature, drought and flood increased greatly; (2) there were 3 or 4 worse periods of climate over the past 5000 years which were more severe than the above-mentioned climate; (3) the momental effect of the geocentric synods of nine plan-ets is one of the important causes for the formation of the abnormal and worse periods of climate; and (4) from the 1960s to about 2000 A.D. China and the entire Northern Hemisphere would probably undergo another ab-normal period of climate.  相似文献   

江西某地钨、碲、铋石英脉型矿床地质及碲的赋存状态          下载免费PDF全文

任英忱  程敏清  王存昌 《地质找矿论丛》1986,(1):57-69

碲是很有价值的分散元素,在国外已得到了广泛的应用.碲主要应用在钢铁工业上,其次才是有色金属工业和化工上.过去,认为碲的主要矿床是超基性岩铜镍矿床和火山岩中的块状硫化矿床,而对钨、铋石英脉中含碲则了解甚少.经过研究,认为钨、铋石英脉型矿床中碲的品位高、碲呈独立矿物存在,规模可达大中型,是独立的钨、碲、铋矿床.  相似文献   

某些磷灰石矿物的红外吸收光谱   总被引：4，自引：3，他引：4  

彭文世  刘高魁  柯丽琴 《矿物学报》1986,(1)

本文讨论了各种磷灰石矿物的光谱特征,氟磷灰石和羟磷灰石的光谱-结构关系及磷灰石中CO_3~(2-)和OH~(-1)离子的存在形式。在结构资料基础上,对氟磷灰石和羟磷灰石中的PO_4~(3-)离子进行了相关分析,给出了内模式的分配数目。碳氟磷灰石中的CO_3~(2-)离子的光谱与简单无水碳酸盐和氟磷灰石混合物光谱之间的差异表明,C0_3~(2-)离子以类质同象形式进入磷灰石结构中。磷灰石中的P_2O_5含量随CO_2含量的增加而降低,PO_4~(3-)离子的v_4带随CO_2的增加或减少而变化,这表明PO_4~(3-)与CO_3~(2-)离子之间存在密切的相关关系,CO_3~(2-)-PO_4~(3-)取代是类质同象置换的一种形式。羟磷灰石OH-OPO_3中的O-O距离和它的高温光谱证明,OH~(-1)离子以氢键形式存在。  相似文献   

蛇纹石族矿物及其热转变产物的红外光谱研究     

彭文世  刘高魁 《矿物学报》1986,(2)

本文报道了蛇纹石族矿物及其热转变产物的红外光谱。在室温下斜纤蛇纹石,正纤蛇纹石,叶蛇纹石和利蛇纹石都具有各自的特征光谱。在结构资料基础上,我们解释了它们之间的光谱差异。无疑,红外光谱是区分各种蛇纹石矿物的有效手段。 样品加热到600—700℃时,3680cm~(-1)羟基带消失,这表明在该温度下蛇纹石矿物完全脱羟。与此同时,光谱中出现橄榄石870cm~(-1)的最强带和一个宽带1000cm~(-1),这说明蛇纹石已部分地转变为晶质橄榄石和形成一个无定形的中间相。800℃时,1060cm~(-1)新带的出现标志着顽火辉石的生成。在所有加热样品的光谱中都没有发现SiO_2吸收带,故可认为,在蛇纹石的热转变过程中没有出现SiO_2相。  相似文献   

合成斜方辉石系列的红外光谱研究     

彭文世  谢鸿森  张月明  薛承林  徐惠刚 《矿物学报》1986,(4)

在30kbar和900℃条件下,用等化学计量氧化物混合物合成了11个斜方辉石系列的样品,并对合成的样品进行了X射线粉晶分析和红外光谱分析。分析结果表明,晶胞参数和红外光谱随化学成分的改变而产生复杂的变化。不仅晶胞参数b和M而且频率ν_(670cm)-1和M之间存在很好的线性相关关系,通过用最小二乘法所拟合的相关方程可容易地测定斜方辉石的成分,但是α和c与M之间只有较差的线性关系,而ν_(450cm)-1和M以及ν_(380cm)-1和M之间并无简单的线性相关关系,这可归因于Fe~(2+)在M_1和M_2位置的有序分布。  相似文献   

四川攀西裂谷的构造环境及构造发展     

缪以琨  任祖德  陈小源  唐连江 《地球科学》1986,(6)

攀西的结晶基底岩系——康定群,褶皱基底岩系——会理群、昆阳群与北澳大利亚地区一致,是泛冈瓦纳大陆的组成部分。泥盆—二叠纪时期,扬予古陆发生强烈地裂运动,后期扬予古陆向北漂移,导致了它与澳大利亚的分裂,这时攀西不再是一个单纯的内陆裂谷,它发展为原大洋,成为扬予古陆西缘的被动大陆边缘裂谷。二叠纪末它可能与同步向北漂移的羌塘-印支古陆拼合:三叠纪初与华北陆块拼合;于侏罗纪、白垩纪分别与藏北及藏南陆块拼合;喜马拉雅运动,印度板块碰撞,形成了统一的亚洲大陆,本区受造山作用影响,形成广泛的冲断-推覆体构造形体。  相似文献   

Limits on the ventilation rate for the deep ocean over the last 12000 years     

M Andree  H Oeschger  W Broecker  N Beavan  M Klas  A Mix  G Bonani  H J Hofmann  M Suter  W Woelfli  T-H Peng 《Climate Dynamics》1986,1(1):53-62

In this paper we present accelerator radiocarbon measurements on hand picked benthic and planktonic foraminifera separated from two deep sea cores raised from the South China Sea. From the benthic-planktonic age differences we are able to place limits on the extent to which the ventilation rate of the deep Pacific Ocean has changed over the last 12000 years. While much work remains to be done before any definitive answers for the global oceans can be given, these results on cores with sedimentation rates suitably high to avoid major corrections for bioturbation effects suggest that the ventilation rate of the deep Pacific Ocean has remained nearly the same throughout Holocene time. Further, there is no suggestion that the rate was slower during the period of major glacial retreat. These results confirm that the changes in atmospheric¹⁴C/C ratio over the last 10000 years owe their origin to radiocarbon production rate changes.  相似文献   

地球自转减慢与厄·尼诺现象的形成   总被引：9，自引：0，他引：9  

任振球  张素琴 《气象学报》1986,44(4):411-416

著名的厄·尼诺现象的成因,目前尚无一致的结论。本文得到,地球自转大幅度持续减慢与厄·尼诺现象的发生,两者有相当一致的同步演变关系。并且,后者比前者平均滞后14天,南方涛动也比地球自转减慢滞后。表明地球自转急剧减慢很可能是形成厄·尼诺现象的一个重要原因。文中还从固体地球、大气、海洋三者总角动量守恒的假定出发,讨论了地球自转减慢影响赤道洋流、信风减弱的量级及其形成厄·尼诺的物理途径。  相似文献