1、Measurement of magnetic susceptibility in titanium minerals processing Institution The University of Queensland Publication date 2004 Supervisor(s) Dr. Peter Holtham Dr Toni Kojovic Magnetic separation is routinely used in the processing of titanium minerals, and the efficiency of these operations c
2、an be determined by measuring the magnetic properties of the process streams. The valuable components in the feed to a titanium minerals plant have specific magnetic susceptibilities ranging from -10-9 m3kg-1(zircon) to 10-6 m3kg-1 (ilmenite). However, in an industrial environment, in which the mine
3、ral temperature may range from 20 to 120C, it is difficult to measure susceptibilities lower than about 10-7 m3kg-1. Hence laboratory testing of spot samples from magnetic separators is currently required to obtain accurate performance data. This is an inherently slow process and where feed grades a
4、re variable, optimum performance of separators is generally not achieved. This thesis describes the development of an inductance-based instrument for measuring down to low levels of magnetic susceptibility online in harsh plant environments. The major difficulties in developing this device were temp
5、erature induced changes in the resistance/ capacitance of the inductance coil and phase stability of the inductance coil excitation current. Coil temperature problems were solved by using a physical small coil in batch operation. Phase stability was overcome by designing a phase extraction system th
6、at used the coil excitation phase information as part of the phase extraction algorithm. Investigations were made into calibration and measurement error of the instrument. Calibration at low levels of magnetic susceptibility was performed using a range of chemical salts. For higher susceptibilities
7、no well defined calibration standards were found and a method to measure high levels of susceptibility was formulated. The method relies on diluting the highly magnetic material with salt to prevent magnetic interaction between particles. It was found that the resolution of the electronics was the m
8、ost significant error and the homogeneity of the sample the least significant. Plant samples were tested and the device was able to determine the zircon content in a zircon magnetics circuit, determine the TiO2 content in the non-mag stream of a magnetic circuit, determine the iron content in the ma
9、g stream of a magnetic circuit and determine the metallic iron content of reduced ilmenite. The device has also been used in a system to determine the mass distribution of the magnetic properties of a titanium mineral sample in less that 1 minute. Previously, the distribution was determined using a
10、laboratory scale magnetic separator (e.g. an Ore Sorters Permroll), with it taking approximately 40 minutes to process each sample. The system is best described as an hourglass with mineral flowing from a hopper through a small inductance coil. The impedance of the coil is proportional to the mean m
11、agnetic susceptibility of the number of particles within the coil (i.e. each measurement is the mean magnetic susceptibility of a fixed size group of particles). An algorithm has been developed to determine the percentage of the feed material at each level of magnetic susceptibility. Hence the resul
12、ts are identical to those determined using a laboratory magnetic separation. Accuracy of the device has been proven by simulation and by testing of plant samples using the new system and comparing the results with measurements made using a Permroll separator. The thesis also presents recommendations
13、 for future work and future potential applications of magnetic susceptibility measurement to mass flow of titanium minerals, measurement of moisture content and jigging operations. According to early literature reports, VCl3 reacts quickly with alcohols to give vanadium(IV)/(V) alkoxides leaving fre
14、e chloride in solution.Moreover, vanadium(III) is highly oxophilic and produces stable vanadyl complexes in the presence of traces of moisture or O2. Strict dioxygen and moisture exclusion conditions are needed to avoid oxidation and hydrolysis involving the metal. The formation of the desired VCl2T
15、i2(OPri)9 by the route described in this work is dependent on the preservation of the metal oxidation state and cannot be accomplished if vanadyl species are formed in the reaction mixture. Simple Schlenk line conditions give reproducible results for this preparation, but do not appear to be adequat
16、e to give the heterometallic product. Product 1 has been used as a precursor to nanosized particles of TiO2 by a sol-gel process. Details of these preparations will be described elsewhere. 钛矿物加工磁化率测量 机构 昆士兰大学 出版日期 2004 监事 彼得 Holtham 博士 托尼 Kojovic 博士 磁选钛矿物加工中经常使用的，可以通过测量过程流的磁学性质决定的，这些行动的效率。钛矿物植物饲料中的有
17、价值的成分，具有特定的范围从 10-9 m3kg-1（锆石）到 10-6 m3kg-1（钛铁矿）的磁化率。然而，在工业环境中，其中矿产温度范围可从 20 至 120 C，它是很难衡量的敏感性低于 10-7 m3kg-1。因此，磁选机现场抽取样品进行的实验室测试，目前需要获得准确的性能数据。这是一个固有的缓慢的过程和饲料等级是可变的，分离器的最佳性能，一般是不会实现。 本论文介绍了基于电感的仪器的发展水平低的磁化率，在恶劣的工厂环境在线测量。在开发这个装置的主要困难是温度引起电阻 /电容电感线圈和电感线圈励磁电流的相稳定性的变化。批处理操作中使用一个物理小线圈，线圈温度问题解决了。相的稳定性，克
18、服了设计相萃取系统，用于线圈励磁相位信息相位提取算法的一部分。 进入校准和测量仪器的误差进行了调查。磁化率低的水平校准进行了一系列的化学盐。对于较高的敏感性，发现没有明确的校准标准，并制定了一个方法来衡量高水平的易感性。该方法依赖于用盐水稀释的强磁性的材料，以防止颗粒之间的磁相互作用 。结果发现，电子的决议是最显着的错误和同质化的样品至少显著。 植物样品进行了测试和设备能够确定锆石锆石磁电路的内容，确定在非磁流的磁路 TiO2含量，确定在一个磁路的磁流的铁含量，并确定金属铁含量减少钛铁矿。 该器件还被用于在一个系统确定的质量分布的磁特性的钛矿物样品在不到 1 分钟。以前，分布确定使用的是实验室
19、规模的磁选机（如矿石选机蕊 ），它以大约 40 分钟过程中每个样本。该系统是最好的形容为一个沙漏与矿物从料斗通过一个小电感线圈。线圈的阻抗比例平均磁化率的粒子数内的线圈（即每个测量平均磁化率一个固定大小的颗粒群）。算法已经开发，以确定的比例的饲料原料，在每一级的磁化率。其结果是相同的那些决定使用实验室磁分离。精度的装置已经证明了仿真和测试的植物样品使用新系统和比较的结果与测量使用蕊分离器。 论文还提出建议，为今后的工作和未来的应用潜力，磁化率测量钛矿物的质量流量，测量水分含量和跳汰操作。 根据早期的文献报道， vCl3做出快速反应，与醇给钒 （ ） /（五）醇留下自由的氯溶液中。此外，钒（三）是高度亲氧并产生稳定的氧钒配合物中存在微量水分或氧气。需要严格的氧和水分的排除条件，以避免涉及金属的氧化和水解。所需 VCl2Ti2（ OPri） 9在这项工作中所描述的路线的形成是依赖于金属氧化状态保存，如果在反应混合物中形成钒物种无法完成。简单舒伦克行条件给该制剂可重复性的结果，但似乎没有足够给异的产品。 1 产品已被用作二氧化钛纳米粒子溶胶 - 凝胶工艺的前兆。这些准备工作的细节将在别处描述。
