矿物加工

矿物加工或提炼冶金是采矿业必备的一部分，它主要是从自然矿中提取金属。在所有矿物加工领域，利用矿物学识别矿物特征都是非常重要的一步。

复杂多变的矿物和矿物的不同组构，使得矿物学对仪器性能提出了更多的要求。在冶金提取方面，自动化的矿物学研究（AM）是一项非常重要的判别手段，它为传统的化学元素分析数据提供了矿石和矿物颗粒信息。AM 可用于项目开发、新矿床研究、日常生产情况判断等。在工业规模方面，相较传统的显微镜矿物学方法，极大地提高了生产率和加快矿物检索及结果解释流程。

研究需要大量的样品和抽样数据。这意味着人工测量的速度较慢，不具代表性。因此该行业需要自动化矿物分析。TESCAN 提供了专门的解决方案。TIMA（ TESCAN 集成矿物分析系统）就是为实现自动化运用而创建的系统。TIMA 的另一个特点就是 TESCAN 自动进样装置，该装置可以利用机械系统将大量样品自动装载到 SEM 样品仓中，从而实现更高水平的自动化。
电子束和样品的相互作用产生BSE和X 射线结合 BSE 成像和 X 射线成像，TIMA 可以自动评价各矿物间的关系。BSE 的强度与所观测的相的平均原子序数成比例关系。因此不同相间的界限可以轻松识别。
工厂和实验室测试所需的样品颗粒大小一般在几微米到几毫米之间。粉末样品需要制作成环氧树脂块，并进行切片，研磨，抛光成平滑的表面。接着在被抛光的样品上镀上一层薄的碳膜，其表面的光洁度要能够符合 BSE 强度对比和特征 X 射线的采集标准。
在 BSE 强度对比的基础上，从环氧树脂中识别矿物颗粒。环氧树脂被认为是低亮度的背景，分析时可以直接排除。
为减少测量时间，识别相的特征 X 射线仅从 BSE 强度的指定阈值区域收集。BSE 阈值也可排除形成岩石的常见矿物或脉石，将分析集中在含有高 BSE 强度相的颗粒上——典型案例：金或铂族矿物。

矿物鉴定是建立在 BSE 水平和相的化学成分基础上进行的，根据矿物分类方案制定一套预定义规则，可以自动鉴定矿物。
TIMA 可以对样品矿物组成进行模态分析。每个矿物颗粒都被视为是一个独立单位，可以由它的特性（大小、领近颗粒、自由表面程度等）来反映整个样品的特性-共生关系、解离度、颗粒大小等。
利用矿物学数据库的密度值，可以将所测样品的模态体积组成转化为单个矿物的质量组成。
矿物数据库可以估算出整个样品的平均密度和化学组成，并将其与化学分析得到的结果进行比对。
自动化矿物分析系统经常被用来解释浓缩器和和稀释液体中的金属回收率较低的原因。TIMA 可以提供客户感兴趣的矿物颗粒弱解离信息、影响矿石加工的脉石矿物信息、矿物之间贵金属赋存状态，以及加工过程矿物损失情况。这只是 TIMA 可以提供的分析结果的几个例子，分析报告可以以图像、表格、图表的形式呈现。

与白云母互生的钽铁矿颗粒

TIMA Modal Analysis - REE Mineralization in Silicate Rocks

Unusual rare-earth mineralization associated with primary silicates, carbonates and fluorite, and hosted by the silicate rocks, was discovered at alkaline complex and rare-earth deposit Lugiin Gol in South Mongolia. Whereas carbonatites as a primary REE source have been investigated in a fair amount of detail because of their economic potential, their associated silicate rocks are not as well understood. The predominant type of silicate rock at Lugiin Gol is leucocratic nepheline syenite. Representative syenite samples are composed of potassium feldspar, nepheline, sodalite, plagioclase, amphibole, biotite, cancrinite and minor quantities of calcite, titanite, magnetite, apatite and zircon. Primary carbonate phases usually occur close to drop-shaped fluorite clusters and contain both silicate glass and fluorite melt inclusions.

pdf – 5.2 MB

TIMA Study of Tantalum- Niobium-Tin Pegmatites and Its Residual Soil

Tantalum and niobium are rare and valuable metals which are needed for many high-technology applications. As the discovery of mineral resources becomes more difficult, more sensitive detection techniques are required. Microscope and electron microscope examination of heavy mineral grains is only occasionally used as an aid to geological interpretations. The high grade ore concentrates mineral composition should be also supervised before and during the ore metallurgical processing by electron microscope due to relatively cheap outlay and significant data profits. Samples of Tin-niobium-tantalum ore from Central Africa Great Lakes Region (Western Rwanda) have been studied.

pdf – 2.3 MB

Characterization of Platinum Group Minerals

The platinum-group metals (PGM) consists of six elements – platinum, palladium, rhodium, iridium, ruthenium and osmium. Chemical inertness, oxidation-resistance, biocompatibility, high melting temperature, good conductivity and electronic and catalytic properties are unique properties that make PGM irreplaceable starting material in many specific applications. The deposits in the Norilsk-Talnakh region of Northern Russia are the largest nickel-copper-palladium deposits in the world and, the intensive mining activity in this region, positions Russia as the world’s second global PGM supplier. In addition to PGM output, a by-product of this mining is nickel and copper extraction. In this application example the effectiveness of the separation process (gravity separation and hydro-separation) by comparison of PGM mineral content, both in concentrate and in tailings, is studied.

pdf – 2 MB