RESEARCH ON DIRECT CURRENT ELECTRIC FIELD CHARACTERISTICS OF OVERBURDEN FAILURE AND ITS APPLICATIONS

The overburden failure causes the changes of the constant electric field, and the resistivity is the main parameter in these changes. The experimental simulation about the response relation between the overburden failure and its electrical parameter changes is made by building the similar material physics model of mining. The experiment results are used to analyze and test the in-situ detection. The research indicates that the resistivity changes with the electric characteristic of the rock in cracked zone and caving zone caused by overburden failure, the response characteristics of resistivity vary with the failure degrees at different overburden failure zone and that they are corresponding. The resistivity method used in monitoring the overburden failure can determine the height and the affecting scopes of the cracked zone and caving zone. This can provide reliable technological guarantee for mining design and safe production.     

ANALYSIS ON INCREMENTAL COHESION OF SURROUNDING ROCK DUE TO PRESTRESSED CABLE ANCHOR

A new method for determining the incremental cohesion △Cm of surrounding rock due toprestressed cable anchor is presented, and the formulas for △Cm are deduced and ACredistributions also are discussed, based on the two anchorage effects, one is the effect with theprestressed value △Q3 of cable anchor improving the stress state of surrounding rock andincreasing the surrounding rock strength, the other is the fully encapsulated effect. Thedetermined incremental cohesion △Cm is subjected to the model test and field measurement in thereferences, and coincides well with those tested results. The formulas for △Cm can be used indesigning supoport parameters and related numerical analyses of prestressed cable anchor.     

Experimental study of a new multifunctional device for rock fragmentation

A new multifunctional testing device for rock fragmentation was introduced,which can conduct many experiments such as single cutting under static load, crushing under impact load, thrusting under static load and cutting-impact test under the dynamic and static load. The results of granite and concrete‘s experiments with polycrystalline diamond compact (PDC) flat cutters and carbide alloy cutters under different Ioadings show that the device has good performance, and the characteristics of broken rock under the combined loads are similar to that under the single static pressure or impact crushing the rock, and the combined loads can increase the effect of rock fragmentation obviously.The experimental methods and effects have the important meaning for studying new drilling tool on hard rock fragmentation.     

Aspiration spiral-flow type centrifugal flotation machine

Aspiration spiral flow type centrifugal flotation machine takes full advantage of centrifugal force field and gravitational field, and strengthens flotation of coal slurry. As a newtype flotation machine of high efficiency, its key component is bubble generator. Which completes the process of ore pulp inflation and liberalization. The design, parameters and working principle of bubble generator provide the design of the same device in similar equipment with reference. The result of industrial operation shows that this machine is of such features as small occupational area, greater concentration ratio, high processing capacity, high efficiency and lower investment etc.     

Performance assessment of water mist applied in gas burning suppression in underground coal mine

The main objective of the present study was introduced water mist suppression technology to prevent and control gas burning which occurred during drilling at Wu20160 working-face in No.10 coal mine of Pingdingshan Ltd.. Based on the self-developed experiment platform, a series of fire suppression tests to evaluate the performance of a water mist system were conducted. The detailed measurements of the spray characteristics, i.e., the Sauter Mean Diameter （SMD）, the velocity and spray angle which are the main parameters considered in the study, were obtained by using LS-2000 Sizer. The amount of water consumed and the water flux density distribution over the cross section downstream the nozzle exit were measured by cup collector method. The operating pressure of the water mist nozzle is set to 0.5 MPa, the droplet SMD of 104 pm, the water flux density distribution from 0.71 to 8.47 L/（m^2·min）, the average velocity of 2.14 m/s. The experimental results show that the averaged time required for extinguishment is 3.14 s, and the corresponding amount of water used during fire test is about 0.11 kg. The gas fire suppression system reduces the temperature in combustion chamber of the experimental apparatus below the ignition point of the gas, which can effectively avoid the occurrence of the gas fire in coal mine.     

The creep experiment and theoretical model analysis of gas- containing coal

A creep experiment of preformed molding coal under different confining pressures were carried out using self-developed 3-triaxial creep loading device for gas-containing coal, which loaded by Shimadzu AGI-250 kN electrical servo-controlled stiffness testing machine. Based on the experimental results, the variation trend of axial deformation under different stress states was studied, and creep failure characteristics of gas-containing coal under different confining pressures were analyzed. The experimental results were identified with seven-component nonlinear viscoelasto-plastic creep model （Hohai model）, and the creep material parameters were obtained. The experimental result complies well with the theoretical value of this model. It indicates that creep constitutive relation of gas-containing coal can be expressed by nonlinear viscoelasto-plastic creep model correctly.     

Pumping characteristics of Ti-based non-evaporable getter

The application of non-evaporable getters is increasing, they have been widely used in sealed-off vacuum or controlled atmosphere devices. A new type of Ti-based sintered non-evaporable getter has been studied. The room temperature pumping speeds under three activation processes for H2 were measured as a function of sorbed gas quantities in this paper. At the same time, the optimal activation processes were discussed. The results indicate that the getter combines high porosity and large specific surface area which confirm good performances at room temperature. The threshold of activation temperature is about 500 ℃ and optimal pumping speed and pumping capacity can be achieved with activation temperature around 600℃ for 30 min. Besides, different configurations can be available in accordance with requirements.     

Pumping characteristics of Ti-based non-evaporable getter

The application of non-evaporable getters is increasing, they have been widely used in sealed-off vacuum or controlled atmosphere devices. A new type of Ti-based sintered non-evaporable getter has been studied. The room temperature pumping speeds under three activation processes for H2 were measured as a function of sorbed gas quantities in this paper. At the same time, the optimal activation processes were discussed. The results indicate that the getter combines high porosity and large specific surface area which confirm good performances at room temperature. The threshold of activation temperature is about 500 ℃ and optimal pumping speed and pumping capacity can be achieved with activation temperature around 600℃ for 30 min. Besides, different configurations can be available in accordance with requirements.     

MODEL DIAMOND-100A-D Drilling Machine for Gallery Use with Artificial Diamond Bit

Model Diamond-100A-D core drilling machine with diamond bit is suitable for the drilling at any slope angles in galleries. After some variation has been made to the vertical posts, the machine will also be suitable for the drilling at any slope angles on the earth's surface. The machine is highly mechanized and the structure is compact     

Research on virtual dynamic optimization design for NC machine tools

Virtual dynamic optimization design can avoid the repeated process from design to trial-manufacture and test. The designer can analyze and optimize the product structures in virtual visualization environment. The design cycle is shortened and the cost is reduced. The paper analyzed the peculiarity of virtual optimization design, and put forwards the thought and flow to implement virtual optimization design. The example to optimize the internal grinder was studied via establishing precise finite element model, modifying the layout of Stiffened Plates and designing parameters of the worktable, and using the technology of modal frequency revision and the technology of multiple tuned damper. The result of optimization design compared the new grinder with the original grinder shows that the entire machine＇s first orders natural frequency is enhanced by 17%, and the response displacement of the grinding-head has dropped by 28% under the first order natural frequency and by 41% under second order natural frequency. Finally, the dynamic performance of the internal grinder was optimized.     

新型精确快速定量装车系统应用研究

论文阐述了新型精确快速定量装车系统的主要结构及其装车流程,并分析了该装车系统在罕台川北站煤炭物流园区实际使用中所出现的溜槽与车皮碰撞问题,T型连接器的使用问题以及溜槽接缝在装车过程中的喷煤问题,并针对这些问题提出了相应的改进措施。     

中硬岩层钻进孕镶金刚石复合片钻头的研究与应用

针对中硬岩层的特点设计了一种孕镶金刚石复合片钻头,介绍了其切削结构、特点及切削原理。在钻进中硬岩层时,复合片切削齿和孕镶金刚石后支撑能够共同发挥切削作用,提高钻头钻进效率和钻头的稳定性并且能使钻头具有较长的寿命。     

新型羟肟酸捕收剂对硅孔雀石的浮选机理研究

随着易分选硫化铜矿日益消耗,氧化铜矿的开发显得尤为重要。针对硅孔雀石矿石采用直接浮选法存在捕收剂捕收能力不足的问题,研究中以苯甲酸甲酯和盐酸羟胺为原料合成了苯丙羟肟酸(BPHA),应用于硅孔雀石的浮选回收。微浮选试验表明,在pH值为9.0、BPHA用量为120 mg/L的浮选条件下,硅孔雀石的最大浮选回收率可达到75.2%。通过接触角、吸附量分析得出BPHA能提高硅孔雀石表面的接触角,增强其表面的疏水性。通过红外光谱(FT-IR)、X射线电子能谱(XPS)和扫描电子显微镜能谱仪(SEM-EDS)分析得出,BPHA与硅孔雀石作用后吸附在矿物表面,改变了矿物表面化学性质,并在矿物表面生成了疏水性的BPHA-铜物种,从而增加了硅孔雀石的可浮性。     

开滦煤矿唐山矿区与遂昌金矿矿山环境治理运作模式比较研究

本文在文献研究和实地调研的基础上,对比分析了开滦煤矿和遂昌金矿环境治理运作模式,分析发现开滦煤矿和遂昌金矿在矿山环境治理运作方式上的差异主要体现在治理主导者、治理主体、投资主体与融资模式、实施步骤和实施策略以及治理开发方式等方面。研究发现,矿区土地性质、参与主体利益诉求、环境问题性质及规模、矿区区位、矿山资源禀赋以及可资利用的条件等要素是造成两个矿山环境治理运作模式差异的主要原因。进一步分析发现,开滦煤矿环境治理运作模式,主要适应于毗邻城市、对城市生态环境影响巨大、以大面积采空区塌陷为主要地质环境问题的煤矿矿山废弃地的治理恢复;而遂昌金矿环境治理运作模式,主要适应于具有丰富矿山文化遗产资源和发掘价值、矿区在自然生态环境良好山区的金属类老矿山的治理恢复。     

Use of Pb, <Superscript>18</Superscript>O,and <Superscript>2</Superscript>H Isotopes in Mining-related Environmental Studies

Abstract.   An isotopic and geochemical study of surface water and groundwater was undertaken at the Sullivan Mine, a sediment-hosted Pb-Zn massive sulphide deposit with a well-defined homogeneous Pb isotopic composition. The Pb isotopic composition of surface water and groundwater samples from near the mine site define a mixing line between Sullivan Pb and at least one other end member. The ¹⁸O and D isotopic results fall along an evaporation line that shows mixing between water from evaporative sources with water from meteoric sources.     

Determining the amount of marketable blocks of dimensional stone <Emphasis Type="Italic">before</Emphasis> actual extraction

The lack of a proper decision variable impedes the planning of dimensional stone quarry operation. So far, “quasi-grade”, which may measure the stone quality, developed via multivariate statistical methods is offered as decision variable. However, the marketable blocks of dimensional stones should satisfy not only stone quality requirements, but also conform to certain dimensional standards, and these two are essentially incommensurable. Clearly, for stone with known quality, the amount of marketable dimensional stones (MDS) provides the best decision variable for planning (i.e. sequencing the operation of unit volumes). A method for determining the amount of MDS before actual extraction is presented. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 1, pp. 75–80, January–February, 2007.     

“一带一路”时期大型国有矿业资源型企业 “走出去”经营战略的研究

为了解决我国矿产资源日益突出的供需矛盾及重点资源后备储量严重不足的问题,我国在挖掘国内资源的同时,充分利用海外资源实施大型国有矿业资源型企业“走出去”战略,寻求和建立海外稳定的资源供应基地,成为维护我国经济安全,保障我国社会可持续发展目标的必然选择。为此,我国应成立政府专门部门协调和统筹大型国有矿业资源型企业国际化经营战略,制订大型国有矿业资源型企业走出去的国内扶植政策,开展围绕海外资源获取的资源外交;在税收、金融、社会咨询、军事保障等多个方面积极构建大型国有矿业资源型企业国际化经营的外部保障体系。     

The influence of MoS<Subscript>2</Subscript> on tribology characteristic parameter of Ni60A/MoS<Subscript>2</Subscript> composite lubricating coating

The influence of MoS₂ on the tribology characteristic parameter of Ni60A/MoS₂ composite lubricating coating was researched on the UMT-2 fretting abrasion tester (USA). The result shows that with increasing content of MoS₂, the hardness curve of the composite coating decreases and the trend accelerates. Under the same experimental conditions, the mass loss of plasma spray composite coating without adding MoS₂ is 1.27×10⁻² mg. When the amount of MoS₂ reaches 35%, the mass loss is 0.96×10⁻² mg. It can be seen that adding MoS₂ phase can improve the wear resistance, the amplitude of which is close to 30%. The friction coefficient of plasma spray composite coating without adding MoS₂ is 0.23. Adding MoS₂ could decrease the friction coefficient of the coating and presents a downtrend. When the mass fraction is 35%, the friction coefficient is the smallest (0.13), and the range is doubled.     

“一带一路”大战略推动下我国海外金矿投资策略

我国是世界上最大的黄金生产国、消费国,也是最大的黄金进口国。依据全球黄金储量、生产与消费的统计分析,得知“一带一路”包括的国家黄金储量占全球的65%,但产量只占39%,有继续扩大生产的潜力,同时消费占51%,有扩大生产满足市场需要的空间。基于国内金矿床的规模不大、品位不高、总量有限等问题,未来黄金的需求很难自给自足,需要海外投资进口来满足日益增长的黄金需求。考虑到国家“一带一路”大战略的推动,文章综合分析了世界以及“一带一路”相关国家的金矿资源与生产现状、黄金市场形势、 “一带一路”相关国家的投资环境,提出3个海外金矿投资的首选地区：1）俄罗斯、蒙古国;2）哈萨克斯坦、乌兹别克斯坦、吉尔吉斯斯坦、塔吉克斯坦、巴基斯坦和伊朗;3）南非、埃塞俄比亚、肯尼亚、坦桑尼亚、刚果等,并给出相应的投资策略。     

Electrochemical treatment of COD in biologically pretreated coking wastewater using Ti/RuO<Subscript>2</Subscript>-IrO<Subscript>2</Subscript> electrodes combined with modified coke

The electrochemical treatment of COD contained in biologically pretreated coking wastewater treated by a three-dimensional electrode system with modified coke as the particle electrode was investigated. And the electrochemical perfomance of the coke modified with various active components was studied. The results show that the coke modified with Fe(NO₃)₂ has the lowest energy consumption and higher COD removal rate under the same condition, and the modified coke has better surface characteristics for the purpose of this study. In addition, the kinetic constant was also calculated. The study shows that the three-dimensional electrode system with Fe (NO₃)₂-modified coke can give a satisfactory solution in biologically pretreated coking wastewater.