Aeris Minerals edition
The exploitation and mining of new Sn-W-Nb deposits requires more accurate and more frequent monitoring during mine planning and ore beneficiation. The knowledge of the mineralogical compositions is the key for efficient characterization of the ore grade and defines the behavior of the ore during the different processing steps. Frequent monitoring of the mineralogy saves costs for reagents and leads to an efficient concentration of the ore minerals from the raw ore feed. This data sheet describes the benefits of resolving the mineralogical ore composition by use of X-ray diffraction (XRD) in order to optimize operational efficiency of the mining and beneficiation process of Sn-W-Nb ore.
The presented data were collected on the 600 W Aeris Minerals edition equipped with a Co long fine focus (LFF X-ray tube) and the highly acclaimed PIXcel1D strip detector which allow rapid, high-quality analysis of ores, rocks and minerals. The measurement time for each sample was 12:32 min. Data evaluation was performed using the HighScore software suite.
Six samples from a large tin deposit in Central Asia were analyzed. Geologists currently interprete it as rare-earth- niobium-tungsten-tin bearing weathering crust. In addition to tin, the primary ore also contains over 70 other minerals containing valuable elements such as W, Ta, Nb, Mo, Be, Bi, Cu, F, S.
All present mineral phases were simultaneously quantified using the full pattern Rietveld method , see examples in Figure 1. The samples are characterized by a complex mineral composition. Main ore minerals are cassiterite SnO2 and sphalerite ZnS. Characteristic for the mineralization is the occurrence of fluorite CaF2, and garnet (andradite Ca3Fe3+ [SiO ] and grossular Ca Al [SiO ] ). In total 23 different mineral phases could be identified and quantified in the six samples. Besides the ore minerals also oxides, mica, feldspar, topaz and vesuvianite were found (see Figure 2 and Table 1). Muscovite and biotite were summed up as mica-1 and mica-2 since their exact stoichiometry in these samples was not known. Similarly chamosite represents a member of the chlorite group.
Figure 1. X-ray diffraction pattern and quantitative results of a lower grade garnet-rich sample (top) and a higher grade ore sample with a typical tin mineralization, cassiterite (bottom)
Figure 2. Comparison of the quantitative results of six samples from a Sn-W-Nb bearing weathering crust
The results of the determination of the mineral composition are illustrated in Figure 2. All samples are characterized by slightly different mineral paragenesis and ore grades. Sample 1 is very rich in garnets whereas samples 5 and 6 contain about 25% topaz. Samples 2 to 6 contain high amounts of quartz and mica. Fluorite is present in all samples with exception of sample 6. Main ore bearing samples are samples 2 (2.4% cassiterite) and 6 (6.6% cassiterite). No mineral phases that contain significant amounts of W, Nb and REE could be found. Rare metal mineralization (W, Nb, REE) is generically connected with muscovite . The case study demonstrates that X-ray diffraction (XRD) on a benchtop instrument can be used to quantify even complex ores with more than 20 minerals accurately and fast.
Table 1. Quantitative results of 6 Sn-W-Nb ore samples
Rapid mineralogical analysis on the Minerals edition of Aeris offers a reliable method to determine the complex mineralogical composition of Sn-W-Nb ores. Minor minerals can be detected within minutes. Frequent monitoring enables immediate decision making and fast counteraction.