露天爆破中岩根和大块产生的原因及对策研究

露天爆破大块率和根底率是衡量爆破质量的2项重要指标.但是, 因环境条件、 地质结构、 岩性组成、爆破参数与技术和施工与管理等因素的影响, 往往达不到理想的爆破效果, 爆破后难免会产生部分大块、 根底甚至底板大面积抬高等问题.基于此, 本文主要探讨产生根底及大块的原因, 然后提出针对性的预防大块及根底产生的对策.

台阶爆破岩根和大块二次处理的一种新方法

岩根和大块不仅影响铲装、运输作业,并且分布比较分散、装药量小、填塞质量不佳、施工比较繁琐、不利于集中装药作业。为此,提出一种爆破后岩根和大块二次处理的新方法,通过制作一种便于装药的小袋子,改进装药与填塞方式,使岩根和大块孔二次处理装药与填塞工作变得简便易于操作,提高施工效率,减少安全隐患,为矿山爆破作业提供参考。

Microbial Solubilization of Phosphorus from Nano Rock Phosphate

Phosphorus （P） is a major growth-limiting nutrient, and unlike the case of nitrogen （N）, there is no large atmospheric source that can be made biologically available. Moreover, P governs crucial role in plant as it stimulates root development and growth, gives plant rapid and vigorous start leading to better tillering and essential for many metabolic processes for seed formation. Soil microbes play very important role in bio-weathering and biodegradation. The microorganisms produce low molecular mass organic acids, which attack the phosphate structure and transform phosphorus from non-utilizable to the utilizable for the plants form. The test of the relative efficiency of isolated strains is carried out by selecting the microorganisms that are capable of producing a halo/clear zone on a plate owing to the production of organic acids into the surrounding medium. It is a well-known fact that as the particle size of rock phosphate decreases, the microbe mediated solubilization of rock phosphate increases in soil. In the present investigation, microbial solubilization of nano rock phosphate （〈 100 nm） particles was studied. Experimental results revealed that Pseudomonas striata solubilized 11.45% of the total P after 24 h of incubation from nano rock phosphate particles while 28.95% and 21.19% of the total P was solubilized by Aspergillus niger （black pigmented） and Aspergillus niger （green pigmented）, respectively. It was also observed that Aspergillus niger has the higher ability to dissolve Udaipur rock phosphate than Pseudomonas striata.

SEDIMENTARY ORGANIC MATTER'S CLASSIFICATION OF OIL-GAS SOURCE ROCKS IN CHINA

According to the study on the oil-gas source rocks in China for ten years,in connection with the microscopic, submicroscopic levels, the authors used the microscope photometry together with transmission electronic microscopy, scanning electronic microscopy and proposed a new classification for sedimentary organic matters.

Soft rocks in Argentina

Soft rocks are a still fairly unexplored chapter in rock mechanics. Within this category are the clastic sedimentary rocks and pyroclastic volcanic rocks, of low to moderate lithification （consolidation, cemen- tation, new formed minerals）, chemical sedimentary rocks and metamorphic rocks formed by minerals witk Mohs hardness less than 3.5, such as limestone, gypsum, halite, sylvite, between the first and phyllites, graphitic schist, chloritic shale, talc, etc., among the litter. They also include any type Of rock that suffered alteration processes （hydrothermal or weathering）. In Argentina the study of low-strength rocks has not received much attention despite having extensive outcrops in the Andes and great impact in the design criteria. Correlation between geomechanical properties （UCS, deformability） to physical index （porosity, density, etc.） has shown promising results to be better studied. There are many studies and engineering projects in Argentina in soft rock geological environments, some cited in the text （Chihuido dam, N. Kirchner dam, J. Cepernic Dam, etc.） and others such as International Tunnel in the Province of Mendoza （Corredor Bioceanico）, which will require the valuable contribution from rock mechanics. The lack of consistency between some of the physical and mechanical parameters explored from studies in the country may be due to an insufficient amount of information and/or non-standardization of criteria for testing materials. It is understood that more and better academic and professional efforts in improv- ing techniques will result in benefits to the better understanding of the geomechanics of weak rocks.

Influence of Limited Soil on the Root Distribution and Anchorage of Vitex negundo L.

Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes.

Effects of uranium on hydrocarbon generation of hydrocarbon source rocks with type-Ⅲ kerogen

Organic-inorganic interaction exists universally and is important in the process of mineral resources formation.It is the essential reason why organic oil,gas,coal and inorganic uranium coexist,accumulate,and mineralize in the same sedimentary basins.Hydrocarbon-generating simulation experiment was conducted using low-mature hydrocarbon source rock containing kerogen type III with uranium(UO2CO3 solution)added to study the effects of uranium on the hydrocarbon generation of hydrocarbon source rocks.Experiment results show that uranium can enhance the yield of gas hydrocarbon,promote the total gas output,and increase the total hydrocarbon production(mass or volume).Uranium may lower the hydrocarbon generation threshold temperature and lead to the generation of liquid hydrocarbon in the relative low temperature of hydrocarbon source rock.Uranium can enhance the yield of saturated hydrocarbon,promote the low molecular weight hydrocarbons generating,and in turn increase the content of CH4 and the content of dry gas of the generated hydrocarbons.Uranium is one of the potential inorganic accelerating factors of the immature hydrocarbons.

A comparative study of the specific surface area and pore structure of different shales and their kerogens

The pore structures and controlling factors of several different Paleozoic shales from Southern China and their kerogens were studied using nitrogen adsorption and scanning electron microscopy methods. The results indicate that： 1） The specific surface area is 2.22-3.52 m2/g and has no correlation with the TOC content of the Permian Dalong Formation shales, nanopores are extremely undeveloped in the Dalong Formation kerogens, which have specific surface areas of 20.35-27.49 me/g; 2） the specific surface area of the Silurian Longmaxi Formation shales is in the range of 17.83-29.49 m2/g and is positively correlated with TOC content, the kerogens from the Longmaxi Formation have well-developed nanopores, with round or elliptical shapes, and the specific surface areas of these kerogens are as high as 279.84-300.3 m2/g; 3） for the Niutitang Formation shales, the specific surface area is 20.12-29.49 m2/grock and increases significantly with increasing TOC and smectite content. The Niuti- tang Formation kerogens develop a certain amount of nanopores with a specific surface area of 161.2 m2/g. Oil shale was also examined for comparison, and was found to have a specific surface area of 19.99 m2/g. Nanopores are rare in the Youganwo Formation kerogen, which has a specific surface area of only 5.54 m2/g, suggesting that the specific surface area of oil shale is due mainly to the presence of smectite and other clay minerals. The specific surface area and the number of pores present in shales are closely related to TOC, kerogen type and maturity, smectite content, and other factors. Low-maturity kerogen has very few nanopores and therefore has a very low specific surface area, whereas nanopores are abundant in mature to over- mature kerogen, leading to high specific surface areas. The Longmaxi Formation kerogen has more developed nanopores and a higher specific surface area than the Niutitang Formation kerogen, which may be due to differences in the kerogen type and maceral components. A high content of smectite may also contribute to shale surface area. The pore volume and specific sur- face area of low-maturity kerogens are mainly attributable to pores with diameters above 10 nm. By contrast, the pore volume of mature kerogens consists predominantly of pores with diameters above 10 nm with some contribution from about 4 nm diameter pores, while the specific surface area is due mainly to pores with diameters of less than 4 nm. Through a comparative study of the specific surface area and pore structure characteristics of different shales and their kerogens, we conclude that the Longmaxi Formation shales and Niutitang Formation shales have greater sorption capacities than the Dalong Formation shales.