THE EVALUATION OF NA2O2 AS A SINTERING AGENT IN SOLID STATE DISSOLUTION OF POTENTIAL SECONDARY SOURCES FOR RARE EARTH ELEMENTS

Soroaga, L. -V.; Arsene, C.; Olariu, R. -I.
Abstract:
Solid-state dissolution by sintering in the presence of Na2O2, a strong oxidizing agent, isreported in the present study as a preparatory procedure prior analysis by ICP-MS. Theadequacy of the combined procedure for the purpose of identification of potentialsecondary sources for REEs from difficult matrixes like, for example, mining wasteswas investigated. The method was applied to Certified Reference Materials (CRMs)with silicate-rich complex matrices, namely rhyolite, and granite. From each materialtwo sample were prepared, at different times and the solutions were analyzed over atwo-year period, each sample being analyzed in at least three separate sequences,summing 13 measurements for rhyolite CRM and 9 measurements for granite CRM.Internal standard quantification method was used for all REEs, and the obtainedconcentrations are in good agreement with the certified values. Great emphasis wasgiven on the evaluation of repeatability and reproducibility of the overall procedure.The statistical evaluation of the data sets obtained in repeatability conditions, consistingof concentrations of REEs estimated using the described procedure, and especially thep-values from the t-test:Paired, namely, 0.534, 0.984 and 0.079, at alpha=0.01, allowedus to infer that no significant differences exist between the investigated data sets. Forthe evaluation of reproducibility all 13 measurements for rhyolite CRM and 9measurements for granite CRM were used, although some differences could beidentified. It is worthy to mention the time required for sample processing, the timeelapsed since the preparation step until analysis was performed, standards used forquantification, among others. Correlation matrices were generated for both rhyolite andgranite data sets and the obtained p-values indicated significant correlation between theresults. The correlation factors were found to be very good even for the lowest obtainedvalues of 0.973 for granite and 0.968 for rhyolite. The obtained results support that theprocedure can be used for both rapid screening of REEs from silicate-rich secondarysources and accurate quantification of these elements from complex solid matrices. Theprocedure has the potential to be also suitable for a wide range of other applications,with minimal studies on recovery for the analytes
SGEM Research areas:
Year:
2021
Type of Publication:
In Proceedings
Keywords:
Rare Earth Elements; Na2O2 sintering; ICP-MS
Editor:
• Prof. DSc. Oleksandr Trofymchuk, UKRAINE • Prof. Dr. hab. oec. Baiba Rivza, LATVIA
Volume:
21
SGEM Book title:
21st International Multidisciplinary Scientific GeoConference SGEM 2021
Book number:
4.2
SGEM Series:
SGEM International Multidisciplinary Scientific GeoConference
Pages:
41-48
Publisher address:
51 Al. Malinov blvd, Sofia, 1712, Bulgaria
SGEM supporters:
SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci
Period:
7 - 10 December, 2021
ISBN:
978-619-7603-34-7
ISSN:
1314-2704
Conference:
21st International Multidisciplinary Scientific GeoConference SGEM 2021, 7 - 10 December, 2021
DOI:
10.5593/sgem2021V/4.2/s18.08
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