某金矿全尾砂充填体早期强度性能分析

针对某金矿以水泥为主要胶凝材料造成的充填成本高、早期强度低的问题,以该金矿全尾砂为骨料,选用生石灰、石膏、水淬矿渣、水泥为辅料,在分析全尾砂物化性质的基础上,采用全面法试验设计,制备料浆质量浓度为70%、72%、74%、76%和灰砂比1∶4,1∶6,1∶10和1∶20的充填料浆,测定养护龄期为1,3,7,14d时抗压强度。结合Design-Expert软件筛选并评估影响全尾砂充填体早期强度的显著性因素。试验结果表明:料浆质量浓度和养护龄期一定时,充填体早期强度与灰砂比表现为正比关系;控制养护龄期和灰砂比不变,随着料浆质量浓度的增大,充填体强度增长越明显;在灰砂比和料浆质量浓度相同的条件,充填体强度与养护龄期呈正相关,对充填体早期强度影响敏感性顺序为灰砂比养护龄期料浆质量浓度。通过试验可知,在灰砂比1∶4,料浆质量浓度76%时,充填体1d强度可达0.76MPa,3d强度可达1.19 MPa,7d强度可达2.09 MPa,14d强度可达2.21 MPa。将试验结果应用于工程实践,可为矿山充填提供理论依据和数据参考。     

某铁矿胶结充填体特性试验及配比研究

为了找出最适合某铁矿充填料浆的优化配比方案,降低矿山充填成本,保证采空区的稳定性,通过设置不同灰砂比、重量浓度、养护龄期3种参数,对充填体单轴抗压强度、泌水率、固结率、固结比进行测定分析,研究结果表明:影响充填体强度的因素依次为养护龄期、灰砂比、质量浓度。确定最适合该矿山的充填料浆配比方案为灰砂比1∶4,料浆浓度为66%时充填体28d强度为3.48MPa。     

基于均匀试验的矿山充填料浆配比优化研究

以胶结充填体单轴抗压强度和料浆扩散度为试验目标函数,以充填料浆质量浓度和砂灰比为配比参数,建立基于均匀试验的矿山充填料浆配比优化模型,并揭示配比参数对充填料浆及胶结体性能的影响。根据试验因素和水平,选取均匀设计表,按均匀试验设计方法设计了12组抗压强度和扩散度试验,利用均匀设计软件回归分析了胶结充填体强度和料浆扩散度与各参数之间的关系。结果表明:均匀试验数据与回归方程计算结果基本一致,试验方法可信度高;该充填料浆最佳参数为:料浆质量浓度x1=72%,砂灰比x2=4,此时胶结充填体强度最大且充填料浆具有良好的流动性,与试验结果一致。综上所述,均匀试验设计方法为充填料浆配比优化研究提供了一种新的有效途径。     

井下采空区全尾砂充填材料试验研究

银鑫矿经过多年开采,井下形成较大采空区,为充填治理井下采空区,需要进行实验室充填材料试验。通过进行流动性和强度试验,并在室内和矿山井下采场中进行养护,优选得到最佳的充填料浆质量浓度和材料配比,确定了银鑫矿的充填工艺。结果表明,使用胶固粉G料作为胶凝材料,74%质量浓度、灰砂比1∶10可以达到3 d强度1 MPa以上;74%质量浓度、灰砂比1∶6可以达到28 d强度4 MPa以上,银鑫矿充填料浆在其井下采场条件下,充填体的强度明显降低,采场中的充填体强度只有室内试验试块强度的80%左右。     

充填料浆沉缩性能试验研究

沉缩率是矿山充填工程的一项重要指标,严重制约着充填接顶的质量。以保山金厂河铅锌矿的全尾砂为试验材料,研究了全尾砂的泌水沉缩特性与规律,分析了不同料浆浓度、水泥添加量对沉缩性能的影响。结果表明：①胶结充填料浆沉缩率小于非胶结充填料浆。②在胶结充填料浆中,随着料浆浓度增大,料浆沉缩率会逐渐减小。③在充填料浆浓度为60%～68%范围中,随着灰砂比增大,料浆沉缩率会逐渐减小;在料浆浓度达到70%时,料浆沉缩率变化幅度很小,基本没有沉缩。     

某矿全尾砂膏体充填自流输送可靠性分析

为探究某矿全尾砂充填料浆的管道自流输送可靠性,对各配比全尾砂充填料浆的塌落度、稠度、分层度、屈服应力及塑性黏度进行了测试,对当前充填系统条件下所推荐配比全尾砂料浆的临界流速和充填倍线进行了计算。结果表明,料浆质量浓度为70%～74%时表现出较好的流动性能;灰砂比1∶4、质量浓度74%的全尾砂充填料浆的临界流速较实际工作流速小,最大允许充填倍线为4.69,大于矿山绝大部分采场实际充填倍线;综合判断,矿山全尾砂可以作为充填料浆骨料。     

高硫尾矿充填体强度演化规律及其机理分析

针对国外部分金属矿山由于脱硫工艺及运输成本高等原因倾向于直接使用采选后的高硫尾矿(含硫量 >30%)用作充填材料的现象,采用全面法试验设计,研究灰砂比和料浆浓度对高硫尾矿充填体的长期强度影响规律, 并通过 XRD 和 SEM 等方法对高硫尾矿充填体中水化产物和微观结构进行微观机理分析,判断高硫尾矿是否适合直 接用作充填材料。 结果表明:灰砂比和料浆浓度对充填体强度影响非常明显,提高灰砂比或料浆浓度能够明显增大 充填体强度。 当料浆浓度为 72%和 74%时,充填体长期强度损失率随着灰砂比的提高先增大后减小;当料浆浓度为 76%时,充填体长期强度损失率与灰砂比则成正比关系。 在 1 ∶24 灰砂比条件下,74%浓度料浆和 76%浓度料浆的充 填体长期强度损失率相近;在 1 ∶12 灰砂比条件下,充填体长期强度损失率随着料浆浓度的提高先增大后减小;在 1 ∶8 灰砂比条件下,充填体长期强度损失率与料浆浓度成反比。 XRD 及 SEM 研究结果显示充填体水化反应中除了含有 大量未反应的黄铁矿,还会生成石膏和少量钙矾石等膨胀性产物,不仅会造成 C—S—H 凝胶发生脱钙现象,还会引起 充填骨架出现裂隙,导致充填体长期强度的减小。 因此,矿山使用高硫尾矿进行充填必须考虑充填体在不同龄期的 劣化程度,以及是否满足该龄期下的强度要求。     

某铜矿全尾砂/废石复合充填料浆流变特性研究

全尾砂充填料浆流变性能对管道输送及充填体强度有重要影响。对某铜矿充填料浆采用不同配比实验,通过实验数据选取合适的流变模型,用Origin模拟出回归方程,研究了屈服应力、表观黏度与质量浓度、废石掺量、灰砂比的关系。结果表明,屈服应力随质量浓度升高而增大,当全尾砂质量浓度超过70%,屈服应力显著增大;质量浓度为72%时,适量掺入废石能提高充填料浆的初始表观黏度,废石量超过10%,初始表观黏度则会逐渐降低;浓度低于66%,对初始表观黏度几乎没有影响;废石掺量为0时,灰砂比越大,屈服应力越大;废石掺量为10%、20%时,灰砂比大小对屈服应力几乎无影响;废石掺量为30%、40%时,灰砂比越大,屈服应力越小;质量浓度对屈服应力影响最为显著。     

某钒钛磁铁矿充填用尾砂料浆流动性及强度特性试验研究

针对某钒钛磁铁矿全尾砂充填料浆质量浓度波动大、充填成本较高、尾砂综合利用率不足且充填质量较差等问题,通过开展全尾砂胶结充填材料试验,对充填材料的物理化学性质进行了测定,并进一步研究了不同质量浓度和不同灰砂比条件下全尾砂的流动性和强度特性.结果表明:全尾砂化学成分安全,粒径－２００目以下颗粒所占比例为４６％,－２０μm 颗粒含量占比大于１５％,可以形成“结构流”,适合用于井下充填;充填质量浓度为６４％~７４％,灰砂比为１∶４~１∶１２时,料浆屈服应力小于１００Pa,管道流动阻力小于６．０kPa/m,充填料浆流动性较好,输送性能较佳;为满足矿山安全开采２８d强度１MPa的要求,且考虑充填成本,确定充填料浆最佳质量浓度为７４％、灰砂比为１∶８.     

戈壁料充填料浆坍落度参数影响因素研究

某金矿新建充填站采用戈壁料进行充填,为保证充填料浆输送的稳定性,研究不同粒级、不同质量浓度及不同灰砂比戈壁料充填料浆对坍落度参数的影响。结果表明：戈壁料充填料浆坍落度主要受戈壁料的粒级组成、料浆质量浓度及灰砂比的影响。质量浓度是影响坍落度值的主要因素,质量浓度越高,坍落度值越低;灰砂比对坍落度有一定影响,但灰砂比对坍落度的影响受限于戈壁料粒级,戈壁料粒级越粗,灰砂比影响越大。因此,应综合考虑多方面因素,选取合适粒级的戈壁料,同时在现场生产过程中应控制质量浓度,保证充填料浆输送的稳定性。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

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     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

正~~     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586