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The literature provides reference for the accurate determination of boron by inductively coupled plasma-optical emission spectrometry (ICP-OES), but most of the studies are conducted on the standard substances of soil and stream sediment. In addition, the range of boron content is low, and the methods for the determination of high boron content in boron ores are few. A method of ICP-OES with sealed acid digestion at high pressure was developed for the determination of boron content in boron ores. Using nitric acid and hydrofluoric acid as reagents, the samples of boron ores were dissolved at high temperature and high pressure without acid drive, and ICP-OES equipped with a hydrofluoric acid-resistant sampling system was used to determine boron. The samples of boromagnesite, ludwigite, chambersite and salt lake type solid boron ore were taken as the research objects. The relative standard deviation (RSD, n=11) was 0.39%−2.66%, the detection limit of the method was 1.76µg/g, and the determination range was 5.87µg/g−10.8%. The measured values were consistent with the certified values after the verification of the reference materials. Compared with volumetric method and microwave digestion method, the results were in good agreement. This method does not require evaporating the sample solution, which solves the boron volatile loss problem. [ABSTRACT FROM AUTHOR]

Compared with the traditional ammonium acetate exchange method and calcium acetate exchange method to determine cation exchange capacity (CEC), hexamminecobalt trichloride method has obvious advantages in the analysis of large quantities of samples. However, the application scope of this method is limited, and the detection results of neutral and alkaline samples are good, but the detection results of acidic samples are as low as 50%. In order to solve these problems, the pH was adjusted to alkaline with 2mol/L sodium hydroxide solution, the CEC value of the sample was significantly improved, and the determination results of both acidic and alkaline samples reached the range of standard values. By drawing the pH adjustment curve, the volume of 2mol/L sodium hydroxide solution was obtained in soil samples with different pH ranges, so as to adjust the pH value of unknown samples and realize the accurate determination of CEC. On the basis of the original method, the pH of the sample was adjusted to alkalinity, and the precision of the optimized method ranged from 1.02% to 3.82% (n=6). After optimization, the application scope of the method is expanded, the precision and accuracy are improved, and the detection efficiency of a large number of samples is effectively improved. [ABSTRACT FROM AUTHOR]

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BACKGROUND: Beryllium ore is one of the scarce metal minerals in China. Beryllium ore is widely used mineral resources, but it has complex components, and is always concomitant with other metallic minerals. Accurate determination of primary and secondary elements in beryllium ore is significant for its comprehensive utilization. Inductively coupled plasma-optical emission spectrometry (ICP-OES) has been used in elemental analysis of beryllium ore. However, there are some disadvantages: It is considered that beryllium concentrate is difficult to completely decompose by acid dissolution; determination of beryllium concentrate by alkali fusion has serious matrix interference; the existing research focuses on analysis of a single type of beryllium ore. OBJECTIVES: To establish a multi-element simultaneous determination method, which is suitable for various types of beryllium ore samples and has little interference with the matrix of instrumental analysis solution. METHODS: Beryl, hsianghualite and helvite samples were selected in the experiment. Digestion effect on beryllium ore under eight different acid digestion conditions were compared, such as digestion on electric heating board, high pressure sealing, microwave digestion, different kinds of acid digestion and extraction acid. The weight of the sample, the volume of the acid, the digestion time and instrument measurement were optimized. At the same time, according to beryllium ore’s mode of occurrence of elements, the best spectrum lines of each element were determined. RESULTS: (1) The results show that the best mixed digested acid on electric heating board is nitric acidhydrochloric acid-hydrofluoric acid-perchloric acid. The best extracted acid is hydrochloric acid, which is better than nitric acid or aqua regia. The high-pressure sealing method cannot completely dissolve Al, Ca and Mg elements of beryl, and the microwave method has poor effect on the digestion of Mg elements of beryl. (2) The digestion conditions are determined. Weigh the sample of 0.1000g into polytetrafluoroethylene crucible, moisten the sample with a small amount of deionized water, and add 2mL nitric acid-3mL hydrochloric acid-5mL hydrofluoric acid-1mL perchloric acid; cover and place the crucible on electric heating plate; decomposing at 120℃ for 2h, then 150℃ for a further 2h; remove the lid and boil away perchloric acid at 190℃; extract with 4mL 50% hydrochloric acid and add deionized water to 25mL. The solution is determined by ICP-OES. The detection limit of Be is 0.0001%, which is lower than the boundary grade of beryllium ore. The detection limit of other elements is better than the existing standard method, and the precision RSD of each major element is <5%. By verification of standard materials, the accuracy of the method meets the needs of beryllium ore determination. The analysis accuracy and precision of three real beryllium ore samples from fields is satisfying. (3) By optimizing the conditions of mixed acid digestion and instrument determination of the existing method, the established method can also accurately determine concentrate sample, and the matrix of the solution is simple to be determined by the instrument. CONCLUSIONS: In this study, a mixed acid decomposition ICP-OES method for simultaneous determination of 9 elements including Al, Be, Ca, Fe, K, Na, Mg, Li and Mn in beryllium ore has been established, which can be applied to different types and contents of beryllium ore. The established method provides necessary technical support for the research and exploration of beryllium ore. [ABSTRACT FROM AUTHOR]

Copyright of Rock & Mineral Analysis is the property of Editorial Board of Rock & Mineral Analysis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rock & Mineral Analysis is the property of Editorial Board of Rock & Mineral Analysis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rock & Mineral Analysis is the property of Editorial Board of Rock & Mineral Analysis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rock & Mineral Analysis is the property of Editorial Board of Rock & Mineral Analysis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)