岩金矿床资源储量估算品位域的确定及其意义

资源储量估算一般在特定的品位域内进行,其核心是确定采用哪些已知数据对未知点进行估值.传统方法在确定样品数据的特异值时,过多考虑矿床的经济性而忽略了其地质特征和品位统计特征.在勘查数据分析基础上,引入分形分析、边界分析和变异函数分析,以确定资源储量估算的品位域及相关参数.案例分析表明,改进的IDW法估值流程深化了样品数据...     

基于钻孔数据进行矿体克里金插值分析

为了确定矿区矿体的矿物分布,准确计算矿体的储量,研究选取110个钻孔资料,利用ArcGIS地质统计学模块对钻孔数据的特征进行分析,使用交叉验证的方法,确定克里金插值变异函数模型和步长数;对三维地质模型进行普通克里金分析,得到矿体模型的品位分布概率.研究结果表明,采用普通克里金法插值、高斯模型作为变异函数、步长数为6时,...     

碳钼矿中钼升华特性的研究

采用管式电阻炉研究了不同钼含量的碳钼矿样品中钼的升华特性.试验结果表明:钼的升华率随着温度的升高和碳钼矿中钼品位的增加而明显增加,当焙烧温度达到1 200℃时,硼(Mo)≥3%的碳钼矿均可获得很好的升华效果,其钼升华率在88%以上;当焙烧温度达到1 400℃时,各种品位的碳钼矿均可获得92%以上的钼升华率,而且品位越高,钼升华率也就越大,w(Mo)≥35%的碳钼矿中钼升华率高达99.6%.同时,焙烧温度对升华得到的MoO3的纯度影响很大,当焙烧温度低于1 200℃时,MoO3纯度大于96.9%;而当焙烧温度升高到1 400℃时,MoO3纯度降到87.3%.     

矿石堆场品位模型构建及取料品位估算方法

矿石堆场是大多数矿山不可或缺的重要组成部分,对其品位空间分布情况的精确掌控是后续工艺的基础.结合品位在线分析仪检测的实时品位数据,提出矿石堆场品位模型构建方法,将序列化的实时品位数据三维空间化;同时给出相应的取料品位估算方法,动态预测取料品位.为验证品位模型构建及取料品位估算的准确性,将取料品位估算结果与实验室化验结果...     

内蒙古乌兰察布市一钼矿或成为国内最大钼矿床

内蒙古发现很可能是国内最大的钼矿床。矿床初步估算资源量在230万t以上，平均品位是0．082％。内蒙古乌兰察布市兴和县曹四天钼矿副总工程师李香资介绍，整个项目目前已经完工钻孔19个，正在施工的钻孔是13个，控制矿体东西长2000余米，南北宽1400余米，最大厚度为906m，目前累计完成进尺是26952．34m。     

新疆巴里坤小加山东钨钼矿特征及成因分析

新疆巴里坤小加山东钨钼矿位于新疆东天山北部巴里坤县,是河南省地矿局第二地质勘查院2010年发现的小型钨钼矿,勘查程度达到详查。估算WO 3(332)+(333)金属量18317 t,矿床平均品位0.305%;Mo(332)+(333)金属量4346 t,矿床平均品位0.063%;该矿床的发现填补了东天山北部钨钼矿的空白,提高了对该区域矿产勘查工作的研究程度;矿床为一典型的钨钼共生矿,矿床类型为热液石英脉型矿床,矿体呈脉状产出;钨钼矿空间分布位置关系有明显的分带特征,矿床上部0~300 m以钨为主,下部300~700 m以钼为主;矿体主要赋存在泥盆系中统大南湖组下亚组(D 2 d b)火山碎屑岩(灰色凝灰岩)中,脆性断裂构造控矿,成矿母岩为华力西中期的斑状钠长花岗岩,为钨钼矿的形成提供了物质来源。     

提高钼精矿品位途径的探讨

通过对钼矿石和产品的分析,针对钼矿石的性质采取了相应的措施,探讨了提高钼精矿品位的途径.     

地质统计学在三道庄钼矿储量计算中的应用

本文以三道庄钼矿床为例,利用Surpac矿业工程软件,运用地质统计学方法,通过分析三道庄钼矿床钼品位分布规律,进行变异函数计算,建立矿床数学模型。在此基础上运用克立格法进行品位估值和储量计算,再结合传统断面法计算出的储量,将二者进行对比分析,认为采用克立格法计算的矿床储量具有先进性和实用性。     

钼浮选中矿处理新工艺应用实践研究

在生产过程中,钼矿浮选中矿由于解离度不够,使钼矿品位和回收率受到影响。本文就钼浮选中矿处理新工艺进行探讨,对原有的工艺流程进行优化,使钼浮选中矿处理质量和效率得到提升,提高钼矿品位和回收率。     

提高金堆城南露天钼矿石钼回收率浮选工艺试验研究

在查明南北露天矿物组成、赋存状态等的基础上,针对南露天钼矿石钼品位低、石英含量高、辉钼矿粒度细等与北露天钼矿石性质有较大差异的特点,经过认真分析和详细的试验研究,认为选厂目前的一段再磨细度-400目85％～90％的磨浮流程不太适合南露天钼矿石,所获钼精矿品位和回收率均偏低,要取得较高品位和较高回收率的钼精矿,两段再磨浮选流程较为合理。     

露天铀矿山爆区品位估算方法优选研究

爆区品位估算是露天铀矿山极其重要的日常性工作。为快速、准确地得到品位估算结果,从估算方法选取展开研究,介绍了最近距离法、距离幂次反比法和普通克里格法等品位估算方法的基本原理。以国外某铀矿为例,采用上述估算方法和三维矿业软件开展了爆区品位估算试验,并以普通克里格法的估算结果为标准,对最近距离法和距离幂次反比法的估算结果进行了偏差、统计和图形分析。结果表明：在矿石量和平均品位方面,与普通克里格法所得的估算结果相比,距离幂次反比法的偏差较小,而最近距离法的偏差较大;在估值准确性方面,距离幂次反比法基本接近普通克里格法,且估值精度满足矿山实际生产的要求,可用于爆区估值,而最近距离法的估值精度相对较差,不能用于爆区估值。距离幂次反比法作为爆区品位估算方法,操作过程简单且参数相对确定,在满足估值精度要求的同时可节约建模时间。该研究成果可为类似露天铀矿山进行爆区品位估算提供一定的指导。     

分形理论在距离幂次反比法估算矿体品位中的应用

在矿体品位估值过程中，合理确定距离幂次反比法中的幂次指数是一个十分重要的步骤。从分形几何角度出发，提出了一种分形幂次指数确定方法，通过对部分实际数据的交叉验证，证明该方法是可行的。     

不同巴西粉配比的低硅烧结矿粒度分布分形特征

探讨了低硅烧结矿在不同高品位巴西粉条件下粒度分布的分形特征,并用最小二乘法测定了其分形维数.低硅烧结矿的粒度组成具有分形特征,可以用分形维数定量表征低硅烧结矿的粒度组成,同时获得了其分形维数随巴西粉的增加而增加以及在不同巴西粉条件下烧结矿冷态冶金性能的变化趋势.研究表明,使用分形维数定量表征不同巴西粉条件下的粒度组成是可行的.     

分形理论在山西堡子湾金矿成矿预测中的应用

对山西省堡子湾隐爆角砾岩型金矿床钻孔岩芯的金品位进行了分形研究,其变化符合以分维值D 为特征的幂律分布。在垂向上,金品位的分维值由角砾岩体上部到下部逐渐增大。在平面上,分维值由南向北逐步减小。结合浅层地震勘探与坑探、钻探显示的角砾岩体结构特征、矿体赋存部位以及地表构造现象,讨论了金矿品位分维值D 的大小与品位的关系,提出了矿体可能的空间赋存规律。     

基于遗传算法优化的支持向量机品位插值模型

将支持向量机(SVM)和遗传算法(GA)集成应用到矿体品位插值问题中,利用遗传算法全局搜索的优势对支持向量机的三个关键参数——惩罚系数C、不敏感系数ε和核函数参数σ进行寻优,克服单纯支持向量机法中依靠经验确定参数的局限性.将优化参数代入到支持向量机中进行迭代训练,得到基于遗传算法参数优化的支持向量机(GA-SVM)矿体品位插值模型.以国内典型矿山的实际勘探数据为例,通过该品位插值模型计算结果与传统插值方法计算结果和矿山生产实际数据的对比分析,验证了其可行性和有效性.      

Stochastic Interpolation of Spatial Random Fields by BF/MCF-ISM

In the past, interpolation of random fields was successfully treated by Kriging methods for Gaussian fields, and by conditional simulation techniques for a class of non-Gaussian translation fields. Recently, bootstrap filter/Monte Carlo filter (BF/MCF) is extensively used for interpolation of general non-Gaussian fields. However, while BF/MCF is a versatile tool to interpolate non-Gaussian fields, that is an algorithm of generating a set of sample realizations of both a predicted state vector and a filtered state vector, the computational cost is expensive due to the required sample size. In order to reduce the required sample size, an importance sampling function derived from the updating theory of Gaussian fields is applied to the ordinary BF/MCF. Interpolation of spatial fields is first demonstrated by using numerically simulated data, and the BF/MCF incorporated with importance sampling technique (BF/MCF-ISM) for the state estimation of conditional non-Gaussian fields is performed with respect to its efficiency in variance reduction.     

大尹格庄金矿床金元素分形特征及地质意义

通过对大尹格庄金矿床的金品位数据进行含量一总量法分形研究,揭示了分形特征与金矿化的关系。利用金品位的多标度分形特征可将金品位分为4个区间,每个区间可能对应于金成矿期特定的成矿阶段,该分形特征为该矿床矿化的多阶段性及矿化叠加提供了证据。不同岩性带的金品位分维值与其金矿化强度具有一致性,这表明分维值的大小可以指示金矿化强度。钻孔金品位分维值等值线图显示出一定的规律,反映了深部仍有矿体存在,矿体向NE侧伏。     

Power spectral density of unevenly sampled data by least-square analysis: performance and application to heart rate signals

This work studies the frequency behavior of a least-square method to estimate the power spectral density of unevenly sampled signals. When the uneven sampling can be modeled as uniform sampling plus a stationary random deviation, this spectrum results in a periodic repetition of the original continuous time spectrum at the mean Nyquist frequency, with a low-pass effect affecting upper frequency bands that depends on the sampling dispersion. If the dispersion is small compared with the mean sampling period, the estimation at the base band is unbiased with practically no dispersion. When uneven sampling is modeled by a deterministic sinusoidal variation respect to the uniform sampling the obtained results are in agreement with those obtained for small random deviation. This approximation is usually well satisfied in signals like heart rate (HR) series. The theoretically predicted performance has been tested and corroborated with simulated and real HR signals. The Lomb method has been compared with the classical power spectral density (PSD) estimators that include resampling to get uniform sampling. We have found that the Lomb method avoids the major problem of classical methods: the low-pass effect of the resampling. Also only frequencies up to the mean Nyquist frequency should be considered (lower than 0.5 Hz if the HR is lower than 60 bpm). We conclude that for PSD estimation of unevenly sampled signals the Lomb method is more suitable than fast Fourier transform or autoregressive estimate with linear or cubic interpolation. In extreme situations (low-HR or high-frequency components) the Lomb estimate still introduces high-frequency contamination that suggest further studies of superior performance interpolators. In the case of HR signals we have also marked the convenience of selecting a stationary heart rate period to carry out a heart rate variability analysis.     

Comparison of projection algorithms used for the construction of maximum intensity projection images

OBJECTIVE: Four methods of producing maximum intensity projection (MIP) images were studied and compared. MATERIALS AND METHODS: Three of the projection methods differ in the interpolation kernel used for ray tracing. The interpolation kernels include nearest neighbor interpolation, linear interpolation, and cubic convolution interpolation. The fourth projection method is a voxel projection method that is not explicitly a ray-tracing technique. The four algorithms' performance was evaluated using a computer-generated model of a vessel and using real MR angiography data. The evaluation centered around how well an algorithm transferred an object's width to the projection plane. RESULTS: The voxel projection algorithm does not suffer from artifacts associated with the nearest neighbor algorithm. Also, a speed-up in the calculation of the projection is seen with the voxel projection method. Linear interpolation dramatically improves the transfer of width information from the 3D MRA data set over both nearest neighbor and voxel projection methods. Even though the cubic convolution interpolation kernel is theoretically superior to the linear kernel, it did not project widths more accurately than linear interpolation. A possible advantage to the nearest neighbor interpolation is that the size of small vessels tends to be exaggerated in the projection plane, thereby increasing their visibility. CONCLUSION: The results confirm that the way in which an MIP image is constructed has a dramatic effect on information contained in the projection. The construction method must be chosen with the knowledge that the clinical information in the 2D projections in general will be different from that contained in the original 3D data volume.     

内蒙古常福龙金矿床Au品位分布特征及其地质意义

矿床品位的统计分布特征和变异函数可以提供矿床成因和蚀变矿化三维空间形态与结构的重要信息。基于Micromine三维软件平台,对常福龙金矿床Au品位频率分布、分形分布以及变异函数等特征进行了研究。结果表明,常福龙金矿床Au品位统计分布具有多个成因总体混合的特征,可能与成矿前广泛发育的硅化和绿泥石化基础上叠加主成矿期硅化-钾化、黄铁绢英岩化和Au矿化有关;变异函数分析显示,目前的勘查工程间距选择是合理的,能有效地控制矿体。同时,由于品位分布特征受既有工程和样品分布制约,研究成果可以作为半定量分析,应用于矿山生产和勘查。