Determination Of Metallogenic Elements In Tungsten, Molybdenum And Tin Ores By X-ray Fluorescence Spectrometry

Tungsten, molybdenum and tin mineral resources are the important mineral resources in ourcountry, their minerals are often associated with the heavy metal elements such as copper, lead, zinc,bismuth, and so on. Methods for determination of metallogenic elements in tungsten, molybdenumand tin ores are single element analysis, and steps are complicated, long process, it took a lot ofmanpower，material and financial resources. The main purpose of this study is to adapt to the needsof the current state of mineral exploration, shorten the cycle, improve efficiency, and establish themethods for determination of metallogenic elements in tungsten, molybdenum and tin ores by X-rayFluorescence Spectrometry (XRFS). The main work contents are as follows:A method has been established for the determination of tungsten and tin in ores by XRFS withpressed powder pellets. The national standard materials and self-synthesized lab internal controlsamples were used to fit the calibration curves. Ranges of the tungsten, tin content are34μg/g～3.66%and14.8μg/g～2.24%respectively, method detection limit are4.9μg/g and3.8μg/g. Methodprecision (RSD) of tungsten and tin are1.72%and0.37%(GBW07241, n=12) while the instrumentprecision (RSD) are1.46%and0.25%respectively (GBW07241, n=12).Sample preparation issimple, economic and quick. According to the verification by the national standard materials andcompared with national standard methods, the method can meet the requirements of geology andmineral resources exploration. But for some different minerals or mineral combination ofnon-uniform samples, can cause the difference of X-ray absorption coefficient, constitute some faultdetection of tungsten ore and missed some tin ore.Another method was established for the determination of tungsten, molybdenum and tin in Oresby XRFS with fused beads. The national standard materials and self-synthesized lab internal controlsamples were used to fit the calibration curves. Preoxidation time, high temperature meltingtemperature, melting time, dosage of demoulding agent and dilution ratio were studied systematic;Ranges of the tungsten, molybdenum and tin content are126μg/g～3.66%,4.2μg/g～1.51%and33.2μg/g～1.27%respectively, method detection limit are36.4μg/g,3.3μg/g and12.8μg/g.Method precision (RSD) of tungsten, molybdenum and tin are0.91%,0.87%and0.52%(GBW07241,n=12) while the instrument precision (RSD) are0.48%,0.69%and0.67%(GBW07241, n=12)respectively. Compared with pressed powder method it is complex and the cost is higher, but it can eliminate mineral effect and size effect, improve the accuracy of the analysis. Verified by nationalstandard materials and the national standard methods show that the method can completely meet therequirements of geology and mineral resources exploration.