Spectrophotometric Study of Nd²⁺ Ions in LiCl-KCl Eutectic Melt

Abstract

A UV and visible spectrophotometric study was made in order to prove the existence of Nd 2+ and clarify the equilibrium among Nd metal, Nd 2+ , and Nd 3+ in LiCl-KCl eutectic melt. Spectra assigned to Nd 2+ were observed for NdCl 2 in (LiCl-KCl) eut. and Nd-NdCl 3 in (LiCl-KCl) eut. melts. Black corrosion products were observed on the surface of the glass cells used for the measurements, where the spectra assigned to Nd 2+ were observed. X-ray diffraction measurements and electron-probe micro-analyses of the corroded glass cells revealed that the corrosion products contained NdOCl.

Electrochemical synthesis of nanosized powders of neodymium and praseodymium hexaborides and ternary compounds based on neodymium (praseodymium), boron and iron group metals from chloride-fluoride melts.

“…Так, эти вопросы, а также определение кинетических параметров электродных процессов в низкотем-пературном хлоридном расплаве LiCl-KCl и рас-плаве LiCl-CaCl 2 являются предметом изучения японских, испанских и российских ученых [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Электрохимическому получению сплавов интер-металлических соединений на основе празеоди-ма и неодима в галогенидных расплавах методом диффузионного насыщения посвящены работы [16][17][18].…”

“…В исследуемых системах в зависимости от со-става и параметров электролиза были получены как индивидуальная фаза бора, фаза высшего бо-рида NdB 6 , так и смеси этих фаз, включая NdB 4 .…”

“…1 показаны распределения по раз-мерам частиц гексаборида неодима, а на рис. 2 -плоская и объемная сканограммы порошка NdB 6 .…”

Separation of Nd metal by using disproportionation reaction of Nd(II) in molten chlorides

“…The cathodic peak current was proportional to the concentration of NdCl 3 between 0.2 and 0.7 mol%. Since the rate of disproportionation is much smaller than the potential scanning rate [5], we assumed that the concentration of Nd 2+ is equal to that of Nd 3+ added and the redox reaction of the Nd 2+ |Nd couple was reversible [12]. E 0 NdðIIÞ=Nd was calculated to be À3.081 ± 0.005 V vs. Cl 2 |Cl À .…”

“…Neodymium (Nd) is one of the Ln that has divalent state and its chemical behavior has been investigated in molten LiCl-KCl eutectic [3][4][5]. Nd 2+ disproportionates into Nd 3+ and metallic Nd in molten chlorides [3,5]. The equilibrium constant of the disproportionation reaction is large enough to proceed quantitatively [4].…”