基于可见光-近红外光谱的BIF磁性率确定方法研究

铁矿中磁性率是评价铁矿床工业价值和划分矿石工业类型的重要指标。传统的磁性率测定法存在工作量大、效率低、周期长的缺陷,成为经济、合理、高效开采铁矿资源的瓶颈问题。采用便携式地物光谱测试仪对辽宁省鞍钢集团鞍千矿业有限责任公司的BIF实验样品进行可见光-近红外光谱测试,分析了光谱特征,构建了比值指数(RI)、差值指数(DI)和归一化指数(NDI),并确定光谱指数与样品磁性率相关性最显著的敏感波段及对应的相关系数值;优选出与样品磁性率相关性最显著的比值指数(RI),构建实验样品磁性率的定量反演模型,并进行了验证。结果表明,三种光谱指数与样品磁性率敏感波段均位于935与1 050nm,且该波段处的相关系数均达到0.9以上,其中比值指数与样品磁性率的相关性最高;基于比值指数构建的实验样品磁性率定量反演模型的预测误差为0.038,反演磁性率与实测磁性率的判定系数(R2)为0.964 5,预测结果比较理想。为确定BIF的磁性率提供了一种新方法,该方法具有工作强度小、经济、高效、便捷的优点,且对遥感找矿具有一定指导意义。

某铁矿选厂氧化矿系列浮选给矿磁性率提高实践

司家营铁矿选矿厂氧化矿选别系列重选精矿,通过增加弱磁选脱硫作业降低铁精矿硫含量,但造成浮选作业给矿磁性率下降、浮选精矿指标恶化,因此进行浮选给矿磁性率试验。结果表明,在一定范围内,给矿磁性率越高,氧化矿系列浮选精矿铁品位越高;将磁铁矿选别系列部分一磁精矿给入氧化矿系列一段旋流器泵池进行改造,以增大浮选给矿磁性率。改造后,氧化矿系列浮选给矿磁性率由7.5%增大到11.0%,浮选精矿铁品位合格率增加了25.0个百分点以上,且提高了磁铁矿系列流程处理能力,综合效益明显。

便携式磁吸仪在磁铁矿磁性率测定中的应用

为了快速、简便、准确地测定磁铁矿的磁性率,介绍了采用定量称取式样,利用自主研发的便携式磁吸仪测定磁铁矿磁性率的方法步骤及优点等。利用便携式磁吸仪测定磁铁矿简便、快速,且操作中磁铁矿粉不会散落,非磁性矿粉也不会混杂其中,可有效确保测定结果的准确性,可大大节省化验时间与成本,经济效益、环保效益显著。

对包钢选矿铁收率的粗浅探讨

本文对选矿厂长期生产实践的分析之后,提出了影响铁精矿铁收率的重要因素及其对策.

硫酸沸腾炉排出磁性矿渣工业生产试验初步总结

一、前言硫酸生产时沸腾炉排出红渣还是黑渣?如何降低升华硫和酸雾的大量生成与危害?如何降低浇渣(灰)残硫?它们之间有什么内在关系?排出不同性质烧渣对硫的有效利用率有什么影响?这些问题一向为硫酸工作者所关心。

浅论舞阳铁矿铁山矿床工业指标的修订

论述了由于铁山矿床矿石资源的组分变化,原工业指标不能指导采选生产,经研究该矿床的矿石性质,结合生产实际,按新规范对工业指标进行了修订,取得了较好的效果。

某选铁厂重选精矿流程优化

某选铁厂重选精矿铁品位不达标,同时重精筛上返回系统再磨再选矿量增加,造成系统循环量增大及矿石过磨等恶性循环。为解决上述存在的问题,根据原矿石的磁性率高低,对重选精矿进行了磁选—高频细筛试验研究。试验结果表明:无论原矿磁性率高低,高频细筛筛上返回量较少,大大减少了系统循环量,避免了矿石的过磨,同时增加了一定的经济效益。

3D anisotropic modeling and identification for airborne EM systems based on the spectral-element method

The airborne electromagnetic （AEM） method has a high sampling rate and survey flexibility. However, traditional numerical modeling approaches must use high-resolution physical grids to guarantee modeling accuracy, especially for complex geological structures such as anisotropic earth. This can lead to huge computational costs. To solve this problem, we propose a spectral-element （SE） method for 3D AEM anisotropic modeling, which combines the advantages of spectral and finite-element methods. Thus, the SE method has accuracy as high as that of the spectral method and the ability to model complex geology inherited from the finite-element method. The SE method can improve the modeling accuracy within discrete grids and reduce the dependence of modeling results on the grids. This helps achieve high-accuracy anisotropic AEM modeling. We first introduced a rotating tensor of anisotropic conductivity to Maxwell＇s equations and described the electrical field via SE basis functions based on GLL interpolation polynomials. We used the Galerkin weighted residual method to establish the linear equation system for the SE method, and we took a vertical magnetic dipole as the transmission source for our AEM modeling. We then applied fourth-order SE calculations with coarse physical grids to check the accuracy of our modeling results against a 1D semi-analytical solution for an anisotropic half-space model and verified the high accuracy of the SE. Moreover, we conducted AEM modeling for different anisotropic 3D abnormal bodies using two physical grid scales and three orders of SE to obtain the convergence conditions for different anisotropic abnormal bodies. Finally, we studied the identification of anisotropy for single anisotropic abnormal bodies, anisotropic surrounding rock, and single anisotropic abnormal body embedded in an anisotropic surrounding rock. This approach will play a key role in the inversion and interpretation of AEM data collected in regions with anisotropic geology.

河南省舞钢市铁山庙铁矿床氧化带研究

本文以铁山庙矿床的地质资料为依据,对矿床氧化带进行了多方面研究。氧化带按磁性率(TFe/FeO)值进行划分,分别讨论了氧化深度、矿石特征、矿床氧化作用规律,确定氧化带的空间分布与古风化面的关系密切。本文的研究对矿石类型划分和矿石选冶性能评价具有指导意义。

EFFECTS OF VITAMIN D RECEPTOR GENE POLYMORPHISMS ON SUSCEPTIBILITY TO TYPE 1 DIABETES MELLITUS

Objective To investigate the influence of vitamin D receptor （VDR） gene polymorphisms on susceptibility to type 1 diabetes mellitus （T1DM） in the Chinese Han population. Method One hundred and thirty-six Chinese Han people, including 54 T1DM patients and 82 unrelated healthy subjects as control were genotyped by polymerase chain reaction-restriction fragment length polymorphism for three restriction sites in the VDR gene, which were ApaI, TaqI, and BamL Results The frequency of B allele of BsmI site in VDR gene was significantly higher in T1DM patients than in healthy subjects （ P = 0. 033 ） while no difference was found between the two groups in the distribution of ApaI and TaqI polymorphisms. Conclusion The BsmI polymorphism of VDR gene may be associated with the susceptibihty to T1DM in the Chinese Han population of Beijing.

Magnetic Behavior of Ferri-ferromagnetic Alloy in Presence of External Magnetic Field

The magnetic behavior of the mixed ferro-ferrimagnetie alloy with （Aa Bb Cc）y D structure composed of Ising spins SA=1, SB = 5/2, SC= 2, and SD = 3/2 in the presence of the external magnetic field is investigated by the use of the effective field theory. The role of concentration b is discussed in this system in detail. Results show that for a =0.4, only when the concentration b is in the region 0.60 ≥b 〉 0.34 can the ferrimagnetic behavior be seen. Otherwise, the alloy shows ferromagnetic behavior.

DNA methyltransferase 3B promoter polymorphism and its susceptibility to primary hepatocellular carcinoma in the Chinese Han nationality population:A case-control study

AIM： To investigate the correlation between C/T single nucleotide polymorphism （SNP） in the promoter of the DNA methyltransferase 3B （D/VMT3B） gene and risk for development and progression of primary hepatocellular carcinoma （HCC）. METHODS： One hundred case subjects were selected consecutively from Tongji Hospital （Wuhan, China）. from March to November 2006. They did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed HCC. One hundred and forty control subjects having no history of cancerous or genetic diseases were healthy volunteers to Wuhan Blood Center in the same period. Frequency was matched for sex, age, alcohol consumption and cigarette smoking status of the case subjects. C/T polymorphism of the DNMT3B promoter was analyzed using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and sequencing analysis. The association between genotypes of DNMT3B and clinicopathological parameters among cases was also studied. RESULTS： The CC genotype HCC patients and controls. was not detected in both In control subjects, the frequency of TT and CT genotypes was 99.3% and 0.7% respectively, and that of T and C alleles was 99.6% and 0.4% respectively. The frequency of CT genotype was higher in HCC （3.0%）. The frequency of T and C alleles was 98.5% and 1.5% respectively. However, the genotype and allelotype distribution in HCC patients was not significantly different from that in controls. CONCLUSION： C/T polymorphism is not associated with the increased risk of HCC. DNMT3B genetic polymorphism is variable in different races, ethnic groups or geographic areas. Further study is needed to clarify the role of DNMT3B SNP in the development of HCCamong other populations.

Effect of pulsed electromagnetic frequency on the microstructure, wear and solid erosion resistance of CrAlN coatings deposited by arc ion plating

In this work,the chromium aluminum nitride(CrAlN)coatings were prepared on TC11 titanium alloy by composite magnetic field cathodic arc ion plating with controllable pulse electromagnetic combined with permanent magnet.The effects of electromagnetic frequency on the morphology,microstructure,nano-hardness and elastic modulus of the coatings were investigated by scanning electron microscope(SEM),X-ray diffraction(XRD)and nano-indenter.This paper has mainly studied the influence of CrAlN coatings which are prepared at various electromagnetic frequencies on the wear and erosion resistance through a series of wear and solid particle erosion experiments.It was found that the deposition rate of CrAlN coatings increases with the increase of electromagnetic frequency.And CrAlN coatings all preferentially grew along the(111)crystal plane.At 16.7 Hz,with the increase of pulsed electromagnetic frequency,the hardness is the highest(23.6 GPa)and the adhesion is the highest(41.5 N).In addition,the coating deposition exhibited the best wear and solid erosion resistance at 16.7 Hz and 33.3 Hz,the friction coefficient is about 0.35,and the erosion rate is about 0.2μm/g at 30°and less than 1μm/g at 90°,respectively.These results indicate that the CrAlN coating formed at an appropriate pulsed electromagnetic frequency can achieve excellent mechanical properties,wear and solid erosion resistance.

Phase, magnetism and thermal conductivity of glass ceramics from iron ore tailings

In order to develop the applications of ore tailings, the glass ceramics were prepared by using a conventional melting-quenching-sintering process. The phase component, microstructures, magnetic properties and thermal conductivities of the prepared glass ceramics were investigated by using X-ray diffractometer, scanning electron microscopy, vibrating sample magnetometer and thermophysical properties tester, respectively. The results show that orthorhombic olivine-type phase and triclinic sunstone-type phase formed when the glass was annealed at 700 oC, the concentration of olivine-type and sunstone-type phases decreased, the spinel-type cubic phase occurred and the amount increased when the annealing temperatures increased. The magnetic properties from the cubic spinel ferrites were detected in the glass ceramics, and the related saturation magnetization increased with the annealing temperature increasing. The porous glass ceramics with magnetic property showed much lower thermal conductivity, compared with the non-magnetic porous glass-ceramic and the dense glass-ceramics.

重介选煤用磁铁矿粉的特性与评价指标研究

介绍了影响介质消耗的主要因素有:磁铁矿粉质量,产品带介量,磁选机回收效率等,其中磁铁矿粉质量是最主要的影响因素。通过对西曲选煤厂使用过的多家磁铁矿粉进行研究,分析不同质量磁铁矿粉在不同磁场强度下磁性物含量的变化,以及温度对磁铁矿粉的磁性物含量的变化的影响,结合生产中的消耗情况,找出满足生产需要的磁铁矿粉的主要指标。

脱介弧形筛的工艺效果分析

梗阳选煤厂对精煤、中煤脱介弧形筛的工业性试验检测表明,对于小于2 mm的煤粒磁性物脱除率分别达96. 81%和96. 57%,全粒级脱水率分别为95. 47%和96. 00%,小于0. 25 mm粒级脱泥率分别为95. 77%和95. 87%,说明弧形筛在介质回收系统中对脱介、泄水、脱泥都起到了关键作用;建议在保证弧形筛处理能力的前提下减小分级粒度,尽可能多回收0. 5～0. 25 mm粒级物料,避免重复分选和不必要的粗煤泥循环。

Effects of solidification rate and excessive Fe on phase formation and magnetoclaoric properties of LaFe_(11.6x)Si_(1.4)

The effects of solidification rate and excessive Fe on phase formation and magnetocaloric properties of LaFe11.6xSi1.4(x=1.1,1.2)were investigated by XRD,SEM and VSM measurements.The XRD results show that the amount of LaFeSi phase in the as-cast melt-spun ribbons prepared by a copper wheel at a speed of10m/s is less than that in the as-cast arc melting buttons with the same x values.The annealed melt-spun ribbons contain smaller amount of La(Fe,Si)13(1:13)phase than the corresponding annealed arc melting buttons.Although the melt-spun sample has finer crystalline grains ofα-Fe,as indicated by SEM analysis,its crystalline size has not reached nano-scale.Therefore,the magnetic exchange-coupling between1:13phase andα-Fe phase has not been observed in melt-spun ribbons.Further,the maximum negative magnetic entropy change(?SMax)and relative cooling power(RCP)of annealed melt-spun ribbons under a field change of0?2T are weaker than those of the corresponding annealed arc melting buttons.

Deformation and Failure Mechanism of Phyllite under the Effects of THM Coupling and Unloading

Although the study of TM(Thermo Mechanics),HM(Hydraulic-Mechanics) and THM(Thermo-Hydraulic-Mechanics) coupling under a loading test have been under development,rock failure analysis under THM coupling and unloading is an emerging topic.Based on a high temperature triaxial unloading seep test for phyllite,this paper discusses the deformation and failure mechanism of phyllites under the "H M,T→H,T→M" incomplete coupling model with unloading conditions.The results indicate that the elastic modulus and initial permeability decrease and the Poisson's ratio increases with increasing temperature;the elastic modulus decreases and the Poisson's ratio and initial permeability increase with increasing water pressure.During the unloading process,rock penetrability is small at the initial elastic deformation phase,but the penetrability increases near the end of the elastic deformation phase;mechanisms involving temperature and water pressure affect penetrability differently.Phyllite failure occurs from the initial thermal damage of the rock materials,splitting and softening(which is caused by pore water pressure),and the pressure difference which is formed from the loading axial pressure and unloading confining pressure.The phyllite failure mechanism is a transtensional(tension-shearing) failure.