Geology
Geology
X-ray fluorescence energy dispersive general purpose spectrometer BRA-135F
XRFA, wavelength-dispersive as well as energy-dispersive analysis, is widely used in geology to analyse rocks and ores for nearly all elements of the periodic table from Fluorine to Uranium. Leading Scientific-Research Institute of Ministry of Geology, All-Russian Scientific-Research Institute of Mineral Resources Named after N.M. Fedorovsky, has developed and approved hundreds of methods of ore and refined products analysis published at Yandex, tens of which are based on XRF analysis). The monograph by Aphonin V.P. and others demonstrates the basis of the method and its application to solve typical tasks of geology and geochemistry. In order to solve the majority of analytical geological tasks energy dispersive X-ray fluorescence spectrometer BRA-135 may be applied.
The largest and labour-intensive task of geology is a silicate analysis implemented about 40% of labor cost for analysis in geology which includes determination of rock-forming elements. These include Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe. The content of these elements in rocks is from 0.5 - 1 to tens of percents, but the main difficulty to make any accurate detection of elements from Na to Si is a low penetration capability of their fluorescent radiation measured in microns. In this connection specific intensity of fluorescence of the same element which is a part of grains of different minerals may differ significantly. The only way to provide the necessary accuracy of analysis convenient for the main components of rocks - SiO2 and Al2O3 up to 0.5 - 1% rel., is a homogeneization of the sample, alloying the test charge with lithium pyroborate. Currently numerous companies produce semi-automatic devices for alloying, the time of which is 5 - 10 minutes, and devices for sample preparation. Since the reference samples of rocks are available the applied method is multiple regression or the theoretical adjustment method.
High-speed method of silicate rock analysis is given in electronic educational and methodical materials.
Other the most important analytical task in geology is search, exploration and miming of ore deposits. In this case mass multielement analysis of selected samples for detection chemical elements from Titanium (Z=22) and above is used; requirements to the analysis accuracy are not strictly. In the course of searching deposits, a number of non-ferrous and rare metals (Co, Ni, Cu, Zn, Pb, Zr, Nb, Mo, Ag, Sn, Sb, Ta, W, Re, U and As as satellite of Au) is most interested. Method commonly applied is a method of reference background.
Geochronology
X-ray fluorescence energy dispersive general purpose spectrometer BRA-135F
Besides analysis of rocks and ore BRA-135 together with subsequent mass spectrometry can be applied to solve tasks of absolute geochronology, in particular to detect U, Th and Pb uranium-thorium minerals, Rb и Sr in rubidium minerals and K in glauconite and other glists.
Mining
X-ray fluorescence energy dispersive general purpose spectrometer BRA-135F
Mining includes extraction and processing of natural resources, first of all, ores of ferrous, non-ferrous and rare metals. In case of monometallic ores (as a rule, ores of ferrous metals - chrome, manganese and iron characterized by high commercial element content); head ore is divided into concentrate and tailings during enrichment process. X-ray separation as well as magnetic separation in case of iron ore with Fe3O4 is applied. Method of XRF analysis monitors the content of the base component and impurities in ores, concentrates and tailings. General requirements to methods of ferrous metal ore analysis are described in GOSTs.
Content of Mg, Al, Si and Ca for casting iron or ferroalloys and hazardous impurities – sulphur and phosphorus is controlled in all ores.
Polymetallic ores of non-ferrous metals usually contain ore minerals such as sulphides, i.e. CuFeS2, Cu2S, ZnS, PbS. In this case a complex flotation circuit is used to separate sulphides and to get individual concentrations during enrichment process. Preliminary crushed ore is floated in case of multiple usages of various floatation agents. The exact knowledge of the enriched product composition in separate details of flotation system is necessary. BRA-135 installed in the central laboratory ensures express analysis of samples from the required points that are delivered to the laboratory in pneumatic tube.
Further examples of sulphide-containing polymetallic ores include ores at Norilsk (Co, Ni, Cu) and Erdenet (Cu, Mo).
Because of absorbing inhomogeneity and mineral composition of ores and refined products the method of multiple regressions based on enterprise standard sample (ESS) is applied during analysis.
The final phase of ore processing is calculation of the base component balance (determination of fraction of the base component delivered to concentrations and tailings) and output quality inspection of concentrations performed to determine content not only of the base components but content of a number of impurities.
General requirements to chemical and instrumental procedures of ore and non-ferrous metal concentration analysis are specified in the relevant code.
General-Purpose X-ray diffractometers DRON-7(M) DRON-8
X-ray diffractometers DRON-7 and DRON-8 are efficiently used for qualitative and quantitative analysis of mineral compositions of ores and surrounding rocks, as well as in mineral processing, and for control of mining tailings.