露天采石矿粉尘防治技术分析

我国露天采石矿数量众多,生产过程的粉尘污染严重。为保护环境、保障职业健康安全,矿山必须采取有效的粉尘防治技术措施。为引导矿山选取合适、有效的防尘技术措施,通过现场调研明确了产尘的主要工序及粉尘危害现状,并按照降尘措施的技术途径,分别从技术特性、降尘效果、使用要点等方面,梳理、探讨分析了生产工艺抑尘技术、化学喷雾抑尘技术、喷雾降尘技术和抽尘净化技术,归纳形成了露天采石矿粉尘防治工程技术对比分析表,可为露天采石矿制定粉尘治理工程措施提供指导及借鉴依据。

不同植物恢复措施对采石矿废弃地土壤物理性质的改良效果及评价

为揭示不同植物恢复措施对采石矿废弃地土壤物理性质的改良效果,选取白杨Populus tomentosa,侧柏Platycladus orientalis,油松Pinus tabulaeformis,黄栌Cotinus coggygria和油松+黄栌5种典型植物恢复措施,采用方差分析和主成分分析法对采用措施后的土壤物理性质进行综合评价。结果表明:①通过5种植物恢复措施对采石矿进行修复后的土壤粒径均主要分布在0.25~10.00 mm;②相比较于白杨、油松、黄栌、油松+黄栌4种恢复措施,侧柏恢复措施下土壤容重降低了2.51%~29.83%、土壤孔隙度增大了7.49%~24.16%、土壤持水量升高了3.74%~24.03%;③5种不同植物恢复措施治理后的表层土壤田间持水量比深层提高1.36%~24.30%;④运用主成分分析法对5种不同植物恢复措施下的土壤容重、田间持水率、土壤孔隙度等指标分析得出:矿区土壤物理性质质量从高到低排序为侧柏、油松+黄栌、油松、黄栌、白杨,其中侧柏、油松+黄栌、油松3种植物恢复措施最后综合得分无显著差异,即在采石矿的生态恢复中优先依次推荐。

非法开采石矿案件查办难点探析

随着社会经济的发展,由于供需矛盾紧张等原因,我国某些地区非法开采石矿现象日益严重,导致破坏生态环境、诱发生产安全事故等系列问题。在实践中,查办该类案件往往存在移送难、鉴定难、查处难等问题。为破解难题,亟需在"两法衔接"框架下,加强执法部门联动合作、强化关键证据收集、改进查办案件方式方法,同时严查其背后腐败问题,以精准有效打击非法开采石矿类型违法犯罪活动。

南宁市某废弃花岗岩采石矿边坡稳定性分析

采石遗留的深陡边坡的稳定性和安全性是目前矿山边坡治理的重要研究内容。依托南宁市宾阳县某废弃花岗岩矿山的边坡治理工程,介绍了边坡治理区的现状和选用的治理方法,在此基础上采用数值模拟的方法,建立治理前后边坡计算模型,分析一般工况、暴雨工况和地震工况下的边坡变形和稳定性变化规律。研究成果表明:无论何种工况,边坡斜面上的变形最大,沿着坡面的法向边坡内部不断减小;相同工况条件下,加固后岩体的整体性更好,岩体能充分利用内部岩体的抗剪强度进行抗滑;挂网客土喷播+锚杆技术能有效改善边坡的变形和提高其稳定性;边坡变形表现为坡面最大,坡顶次之,坡脚最小,计算结果与监测值接近。

青海阿尔金采石沟金矿地质特征及化探方法应用

青海阿尔金采石沟金矿是青海省有色矿勘院通过化探工作圈定异常,并经异常查证发现的。该矿床是与火山机构有关的火山-次火山岩矿床。就采石沟金矿化探方法的灵活应用进行探讨。

沟系岩屑测量在采石沟地区找矿中的应用效应

在干旱高山景区,以沟系岩屑测量对1∶5万水系沉积物异常进行检查,可达到快捷、经济、准确圈定矿化范围的目的。沟系岩屑测量是一种非正规网度的地球化学找矿方法,采集对象为风化过程中滞留在基岩表面和残破积层表面的岩屑。1998年青海省地方地勘项目《青海省茫崖行委采石沟—红水沟地区普查》工作中,利用沟系岩屑测量圈定了6处综合异常,并通过Ⅱ级查证,发现了4条含金矿化带。说明沟系岩屑测量在采石沟地区矿产资源评价工作中发挥了很好的指导作用。

采石尾矿机制砂取代率对混凝土强度影响研究

文中研究了母岩为石灰岩的采石尾矿机制砂取代率对混凝土强度影响规律,通过测试0%~100%机制砂取代率条件下C30、C50和C60级泵送混凝土的3、7、28d抗压强度与28d抗折强度,研究机制砂取代率对混凝土强度的影响。试验结果表明,与相同掺量河砂比较,随着采石尾矿机制砂取代率的提高,强度呈现先提高后降低的规律,对不同强度等级混凝土均存在最优掺量,C30和C50混凝土为60%,C60混凝土为40%。研究可为石灰岩质机制砂在混凝土中的应用提供相关参考。

阜新市矿山废弃地受损生态环境的恢复探讨

指出了矿山开采对阜新市的环境带来的巨大影响,介绍了阜新市目前矿山环境的基本现状,探讨了有关矿山修复及恢复的技术,并有针对性的提出了矿山治理的对策与建议,以彰武二道河子乡废弃采石矿坑为例,探讨了具体的恢复措施与对策,对于矿业生产中一些受到环境损坏的生态恢复具有一定的借鉴意义。

超大岩质高陡边坡生态修复工法研究与应用

在维持边坡绿化稳定性的基础上,重点探讨超大岩质高陡边坡不同工法的研究与应用。以A采石矿为案例,通过对其坡面的详细勘察与研究,根据各个创面的特点,运用工程绿化和文化景观的手法进行有针对性的设计,形成多样化的生态修复模式。该工程的高质量完成,将是矿山边坡生态修复技术上的重大突破。

Recovery of Zn, Pb, Fe and Si from a low-grade mining ore by sulfidation roasting-beneficiation-leaching processes

To recover Zn, Pb, Fe and Si from a low-grade mining ore in the Lanping basin, Yunnan Province, China, a novel technology using the roasting with pyrite and carbon followed by beneficiation and hydrochloric acid leaching was proposed. Firstly, several factors such as pyrite dosage, roasting temperature, carbon powder dosage, holding time and particle size affecting on the flotation performance of Zn(Pb) and magnetic separation performance of Fe were simultaneously examined and the optimum process parameters were determined. A flotation concentrate, containing 17.46% Zn and 3.93% Pb, was obtained, and the Zn and Pb recoveries were 86.04% and 69.08%, respectively. The obtained flotation tailing was concentrated by a low-intensity magnetic separator. The grade of iron increased from 5.45% to 43.45% and the recovery of iron reached 64.87%. Hydrochloric acid leaching was then carried out for the magnetic separation tailing and a raw quartz concentrate containing 81.05% SiO2 was obtained. To further interpret the sulfidation mechanism of smithsonite, surface morphology and component of the sample before and after reactions were characterized by XRD and EPMA-EDS. The aim was to achieve the comprehensive utilization of the low-grade mining ore.

Study of electromagnetic and acoustic emission in creep experiments of water-containing rock samples

Based on biaxial shear creep tests conducted on rock samples with different water contents, we present the results of our study on the regularities of electromagnetic and acoustic emission during the process of creep experiments in which we have analyzed the contribution of water to the occurrence of electromagnetic radiation. The result shows that in the creep-fracturing course of rock samples, when the water content increases, the initial frequency and amplitude of electromagnetic and acoustic emission also increases, but at a decreasing growth rate caused by loading stress. This can be used as a criterion for the long-term stability of rock masses under conditions of repeated inundation and discharge of water.

Numerical Simulation of Independent Advance of Ore Breaking in the Non-pillar Sublevel Caving Method

The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.

Opportunities and Challenges in Deep Mining： A Brief Review

Mineral consumption is increasing rapidly as more consumers enter the market for minerals and as the global standard of living increases. As a result, underground mining continues to progress to deeper levels in order to tackle the mineral supply crisis in the 21 st century. However, deep mining occurs in a very technical and challenging environment, in which significant innovative solutions and best practice are required and additional safety standards must be implemented in order to overcome the challenges and reap huge eco- nomic gains. These challenges include the catastrophic events that are often met in deep mining engineering： rockbursts, gas outbursts, high in situ and redistributed stresses, large deformation, squeezing and creeping rocks, and high temperature. This review paper presents the current global status of deep mining and high-lights some of the newest technological achievements and opportunities associated with rock mechanics and geotechnical engineering in deep mining. Of the various technical achievements, unmanned workingfaces and unmanned mines based on fully automated mining and mineral extraction processes have become important fields in the 21 st century.

Roadway deformation during riding mining in soft rock

"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.

Mechanical analysis on deformation of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face

Based on the movement regularity of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face(RPGERFCF),the me- chanical model of its surrounding rock was established and the calculating formulas of the deformation of the roof,coal wall and filling body were attained.By the mechanical analy- sis to the deformation of the surrounding rock of RPGERFCF,the major factors influencing the deformation of the surrounding rock were found out and the technologic approaches reduced the deformation and enhanced the stability of the surrounding rock were put for- ward.Consequently,the scientific bases were provided for the stability control of the sur- rounding rock of RPGERFCF.

Pump-lockage ore transportation system for deep sea flexible mining system

Based on characteristics of deep sea flexible mining system,a new pump-lockage ore transportation system was designed.According to Bernoulli equation and two-phase hydrodynamics theory,parameters of the new system were obtained and four ore transportation systems were analyzed.The results indicate that the pump head of 1 000 m mining system is 100-150 m and that of 5 000 m mining system is 660-750 m.In addition,based on similarity theory,a model of the new transportation system was made,which can simulate more than 5 000 m actual ore transportation system.So both theory and experiment prove that the new pump-lockage ore transportation system is an ideal design for deep sea flexible mining system.

Experimental Study of Preferential Solute Transportation During Dump Leaching

The production of dump leaching of the Dexing Copper Mine was affected by a preferential solution flow. Formative mechanism of the preferential solution flow was investigated by analyzing the relationship between both dump permeability and surface tension and ore diameter. The preferential solution flow occured in the fine ore area when the application rate was low. The preferential solution flow entered into the coarse ore area because the negative pore water pressure disappeared with an increase of the application rate. The preferential solute transportation experiment was conducted by selecting NaCl as mineral. Results of the experiment showed that the concentration of the outflow solution reduced over time. The concentration of the coarse ore area outflow solution was greater than that of the fine ore area. The process of NaCl leaching can be divided into two stages. NaCl was carried out directly by diffusion--convection during the first stage, so the leaching rate increased sharply. But in the second stage, only a small amount of NaCl dissolved in the immobile water. The leaching rate increased slowly because NaC1, dissolved in the immobile water, can only be leached by diffusion.

Support-surrounding rock relationship and top-coal movement laws in large dip angle fully-mechanized caving face

When mining the fully-mechanized longwall caving face along strike, the unstable equipment, the low top-coal recovery ratio and the difficulty in controlling surrounding rock may occur due to large dip angle. Considering the effects of strike angle on support stability, the ‘‘support-surrounding rock"mechanical models of support topple and support slip were established in this paper. On the basis, the influencing factors of support stability were analyzed and the technical measures of controlling support and surrounding rock stability were put forward. Then the loose particles simulation experiment was conducted to analyze the impacts of caving directions and methods on the top-coal recovery in large dip angle fully-mechanized caving face. Finally, the ‘‘upward sequence and double-openings doublerounds" caving technology was determined. The research results are of great scientific significance and practical values to improve large dip thick seam mining technology.

Gas and rock-bump hazard monitoring in the Polish mining

Described the main environmental hazards occurring in Polish undergroundmines and their continuous growth in recent years as well as equipment and systemswhich were used for monitoring mine air parameters and geodynamic phenomena.Thelatest versions of environmental hazard monitoring systems,having a form of a comprehensiveset of underground and surface equipment,are presented and their functionscharacterized.

Catastrophic destabilization of tunnel under rocks slipping in faultage

The model of catastrophic destabilization of tunnel under rock slipping in fault zone based on catastrophic theory and the potential function of fault movement were pre- sented.On the basis of the results above,through Taylor series expansion of the equation of equilibrium surface,its standard form was obtained.Analysis show that catastrophic destabilization of tunnel will occur only when stiffness ratio between elastic sector and strain weakening sector of soft rocks was larger than or equal to 1.On the other hand, sliding behavior and evolution path of fault were directly affected by exogenous process, and it was a major extraneous factor which leads to catastrophic destabilization of tunnel. In the condition of system catastrophe could be generated,if external forces vary from smaller to larger,firstly,fault sticks or creeps,and secondly,when external force equal to or larger than critical value,fault turns to slip suddenly.Inverse,if external forces vary from larger to smaller,fault smoothly slips firstly,when external force equal to or smaller than critical value,and fault turns to stick or creep suddenly.