Search

Purpose This study aims to present the results of inductively coupled plasma mass spectrometry (ICP-MS) determination of economically significant metals including rare-earth elements and Y (REY), Co + Ni + Cu obtained from the Fe-Mn deposits (FMD) of different areas selected along the Atlantic Ocean. Design/methodology/approach The description of the instrumental part of the analysis was shown in detail, including the choice of the acquisition mode and other settings of the quadrupole ICP-MS Agilent 7700x, which allow to eliminate spectral overlaps as much as possible and to achieve good precision and accuracy of the measurement. The accuracy of the obtained results was controlled by analysis of certified reference materials (CRM) of Fe-Mn nodules of the US Geological Survey – NOD-A-1 and NOD-P-1, as well as the Russian CRM samples of Fe-Mn nodule OOPE 603 (SDO-6) and ore crust OOPE 604 (SDO-7). Statistical processing of the analysis results demonstrated the acceptability of chosen sample preparation technique and ICP-MS tunes for the determination of REY in FMD. Findings The performed analytical research allowed giving a geochemical characteristic of studied FMD. The precision for the elements to be determined according to the relative standard deviation (RSD) was within 5.0%. Originality/value To move away from the subjective visual assessment of the analytical results quality in terms of absence (or presence) of the REE sawtooth distribution, an original objective mathematical method was proposed.

Experimental studies of the shaping of CO 2 laser beam by a reflective diffractive optical element have been performed. A formula that describes the distribution of power density in the form of an equation for a rectangular-shape heat source was obtained. Calculation of thermal processes under laser irradiation was made, taking into account changes in the absorption coefficient of the surface of the processed material using the "Sergey Korolev" computer cluster. To determine the temperature fields that occur during laser treatment of the DP 1000 dual phase steel, the CFX version 15.0 computational gas dynamics program was used. It was revealed that for the selected processing mode and the integrated value of coating absorption of 0.5, the maximum temperature on the front surface exceeds the liquidus temperature for the processed sheet material, and on the back side it is in the range of white heat.

This research presents results characterizing the mineral and chemical composition of ferromanganese (Fe-Mn) deposits from Yōmei Guyot (Holes 431 and 431A), recovered during the Deep-Sea Drilling Project (DSDP) Leg 55 R/V &ldquo, Glomar Challenger&rdquo, The Fe-Mn deposits are represented by sandy-gravel clasts. The mineral composition and bulk concentration of major and minor elements, as well as the distribution of rare earth elements and yttrium patterns in mineral fractions of Fe-Mn samples, showed that the deposits are composed of fragments of Fe-Mn hydrogenetic crusts and diagenetic nodules. The morphology of Fe-Mn clasts from Holes 431 and 431A DSDP, as well as a comparison with growth conditions of Fe-Mn deposits from N-W Pacific Guyots, allowed us to establish a Late Pliocene age for the formation of this Fe-Mn placer from Yōmei Guyot. Accumulations of ferromanganese clasts in a sedimentary unit led us to classify this geological body as a new mineral resource of the World Ocean.

This paper describes the organic geochemical characteristics and their roles on barium enrichment in the No. 2 Coal from Huanglong Jurassic Coalfield, China. A total of 18 bench samples were taken from Huangling Mine 2. The average content of barium (3701 mg/kg) was about 23 times higher than that of common world coals. Terrestrial higher plants were the main coal-forming parent material. Relying on the parameters of OEP, Pr/Ph and so on, there is little correlation between organic geochemical characteristics and barium enrichment. Therefore, organic material has little influence on the process of coal-forming and the enrichment of barium.