露天采场高边坡工程地质分区研究

拟建夏日哈木镍钴矿区露天采场东西长1670m,采深一般在300m以上,最高边坡高度超过600m,为重要工程。依据不同岩石饱和单轴抗压强度和边坡岩体结构类型2项指标将区内岩体工程地质类型划分为4个工程地质岩组。根据不同位置的边坡高度、工程地质岩组分布特征、各岩组岩体基本质量等级、边坡面倾向与各岩体优势结构面的关系、边坡岩体完整程度等多项指标将边坡分为5个区,对该地区类似工程具有借鉴意义。     

熵权属性未确知测度的边坡治理稳定性评价

边坡稳定是边坡工程的最终目的之一,但稳定性评价是一个多因素且动态复杂的非线性问题。基于未确知测度理论,建立露天边坡在治理前后的稳定性评价体系。从地形地貌、水文气象、岩体物理力学性质和工程因素等四个方面综合选取影响边坡稳定性的10项指标,根据某露天边坡在治理前后的指标值建立各指标的未确知测度函数,并利用熵权理论确定各指标权重,得出边坡在治理前后的稳定性评价结果。结果表明,熵权属性的未确知测度理论方法科学合理,评价结果与边坡治理前后的实际形态相符。     

基于物元模型的露天矿边坡稳定性评价

露天矿开采时边坡稳定性影响因素繁多,稳定性难以评判。以物元理论为基础,选取岩石力学性质、环境因素、地形地貌和岩体结构4个方面,建立露天矿山边坡稳定性评价模型,并以德兴铜矿为例,对其进行了露天边坡稳定性评价。通过指标的确定及边坡工程收集的数据分析表明,物元模型方法对露天矿边坡稳定性评价是有效可行的。     

基于博弈论综合评价云模型的露天矿边坡岩体稳定性分析

为了对露天矿山边坡稳定性进行可靠分析,从采矿地质、水文特征和工程施工3个层面选取14项评价指标建立稳定性评价体系,并基于博弈论构建露天矿边坡岩体稳定性综合评价云模型。以云南某露天矿边坡为工程案例,通过数学计算并评估其稳定性等级。结果表明:优化后的层次分析法能够明显改善主观权重的计算精度;选取的模型评价指标符合工程实际需要,且具有良好的独立性与代表性;博弈论可以较好地求出评价指标的综合权重,云模型能够逐级分析出各层指标与稳定性等级的相关程度,并根据最大隶属度原则,得出露天矿边坡岩体稳定性等级;结合现场实测,相较于传统评价模型,基于博弈论综合评价云模型适用性较好,分析结果准确可靠,能够为类似采矿地质条件矿山边坡岩体稳定性分析提供一定的理论参考。     

基于模糊聚类和hoek-brown准则的裂隙岩体力学参数计算

节理裂隙边坡岩体稳定性研究首先需要确定可靠的岩体力学参数。通过提依尔金矿露天边坡节理裂隙测量数据的统计分析,运用模糊等价聚类和模糊软划分聚类分别求得节理裂隙的最佳分组和中心产状。依据模糊聚类的结果,利用Hoek-Brown法确定出裂隙边坡岩体的力学参数。提依尔金矿露天边坡岩体参数的计算过程表明采用模糊聚类分析结合Hoek-Brown准则来确定岩体参数的方法在工程实践中简便易行、实用性强,对相似矿山的边坡稳定性分析工作具有借鉴意义。     

节理对岩体边坡稳定性的影响分析

为分析无桩加固边坡的稳定性,以鞍千矿业许东沟采场为工程背景,采用现场调查、理论分析和数值模拟等手段,主要研究无任何加固措施下,边坡中2个重要参数指标黏聚力和内摩擦角对边坡稳定安全性的影响,并分析了岩体含有节理时边坡的稳定性,研究不同节理的长度、角度和埋深等对边坡稳定性的影响。     

燕天飞渡人行桥高边坡危岩稳定性分析及处理方案

通过对燕天飞渡高边坡进行实地工程地质调查,结合现代岩体力学理论,对该工程作了稳定性分析,最后对燕子垭高边坡危岩块体的整治提出了处理方案,理论证明该方案科学的处理了后危岩块体稳定性问题,应用该方案加固边坡后,边坡至今稳定。     

基于未确知测度理论与Midas/GTS模拟的边坡稳定性分析

为研究岩质边坡的稳定性,基于未确知测度理论,建立评价模型。经过分析影响边坡稳定性因素,决定以RQD、岩体结构特征、地应力、C、φ、坡高、日最大降雨量作为评价指标,构造稳定性分析模型及函数。通过改进层次分析法求取指标权重,并按照置信度识别准则获得最终的稳定性评价等级。将此分析模型应用到某边坡工程中,分析结果表明,该边坡处于极不稳定状态。同时采用有限元软件Midas/GTS对该边坡进行了模拟分析,得到安全系数为0.2875,属极不稳定边坡。两种方法计算结果一致,说明基于未确知测度理论的模型具有一定的应用性和科学性。     

基于GIS的边坡危险区域等级划分

GIS系统在边坡稳定性分析中的应用越来越受到重视.以布沼坝露天边坡岩体力学参数、降雨量等6个因素为基础,利用模糊综合评判的原理,将GIS强大的数据处理和空间分析功能应用到露天矿边坡危险区域的等级划分,提出了利用模糊综合评判的方法,基于GIS的边坡危险区域等级划分的理论方法,由此可以区划出整个边坡岩体不同区域的安全度;考虑影响因素多,安全度评价结果用颜色分区更直观,弥补极限平衡方法分析边坡稳定性中的不足,为工程区域治理范围提供决策依据.     

边坡稳定性预测的DDA模型及应用

将距离判别分析法(DDA)应用于岩体边坡稳定性预测中,建立了边坡稳定性预测的距离判别模型。模型选取重度、黏聚力、摩擦角、边坡角、边坡高度和孔隙水压力比等6个指标作为判别因子;以边坡实测样本作为训练样本,建立相应线性判别函数对待判样本进行分类。研究结果表明,距离判别分析模型是边坡预测的一种有效方法,可以在实际工程中应用。     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸,掘进巷道受深部高应力的影响越来越大,巷道围岩整体稳定性差,矿山压力显现越剧烈现象,一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术,依据对巷道掘进之后变形监测数据的采集,对巷道变形机理进行分析研究,并对注浆时段进行了合理选择,在对巷道的注浆工艺进行了充分论证的基础上,对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要,巷道在恰当的时间内进行注浆加固施工,能有效控制巷道的变形,巷道注浆后变形量明显减小,岩体的稳定性明显增强,减少了巷道日常维修工作,降低了矿井的生产成本,保障了矿井的安全生产。     

Brief news

正China Minmetals Rare Earth Construction of Jianghua Separation Plant is set to complete at the yearend Civil works of Jianghua Separation Plant have been finished and the company is installing and debugging equipments now.It is estimated that construction of Jianghua Separation Plant will be     

Brief news

正Total transactions of rare earth in Rare Earth Ex-change Center of Hunan South Rare and Precious Metal Exchange neared 40 billion yuan from January to October From the opening in January of this year to the end of October,the total transaction of rare earth products in Rare Earth Exchange Center of Hunan South Rare and Precious Metal Exchange neared40 billion yuan.There are 16 varieties including dysprosium oxide and terbium oxide traded on the exchange center,one of the largest trading platforms for rare earth oxides in China.     

Theoretical basis for optimal collector concentrations and pulp pH values during flotation of sulfide-free minerals

A hypothesis that associates optimal conditions of mineral flotation with a zero charge of their surface is put forward. This hypothesis serves as a basis for a methodology to obtain and verify quantitative physical-chemical models for a minimal necessary concentration of a collector during flotation of sulfide-free minerals. These models may be of use for upgrading engineering processes of flotation and as a job for the concentration plant automation systems. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 89–99, March–April, 2006.     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium