scholarly journals A Study on the Leaching of Rare Earth Elements from Waste Phosphor Powder

2021 ◽  
Vol 59 (7) ◽  
pp. 459-468
Author(s):  
Gee Hun Lee ◽  
Chang Kwon Kim ◽  
Dong Hoon Lee ◽  
Young Jun Song
Keyword(s):  
Rare Earth ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Rare Earth Elements ◽  
Nitric Acid Solution ◽  
Reaction Rate ◽  
Phosphor Powder ◽  
Leaching Reaction

This study was carried out to obtain data to design a process to recover rare earth elements, specifically Y(Yttrium), La(Lanthanum), Ce(Cerium), Eu(Europium), Tb(Terbium) from waste phosphor powder. For this purpose, we investigated the effect of temperature, concentration, time and acids on leaching of the rare earth elements. The effect of roasting temperature, roasting time, roasting agent and its dosage on the leaching of rare earth elements were also investigated. 92% of the Yttrium, 70% of the Europium and 8% of the Cerium contained in the waste phosphor powder was leached at the condition of 50 oC and 0.3N HCl solution for 3hours. However, Terbium and Lanthanum were never leached at this condition. The leaching ratio increased to 100% of Yttrium and Europium, 98% of Cerium, 92% of Terbium and 89% of Lanthanum by leaching after soda ash roasting. In the leaching experiment with unroasted phosphor at 80 oC, the initial leaching reaction rate of Yttrium was 0.035 mol/L·s in 0.3N sulfuric acid solution, 0.033 mol/L·s in nitric acid solution and 0.028 mol/L·s in 0.3N hydrochloric acid solution. And the initial leaching reaction rate of Europium was 0.0017 mol/L·s in 0.3N sulfuric acid solution, 0.00114 mol/L·s in nitric acid solution and 0.00113 mol/L·s in 0.3N hydrochloric acid solution. For Cerium, the initial leaching reaction rate was 0.00019 mol/L·s in 0.3N sulfuric acid solution, 0.00025 mol/L·s in nitric acid solution and 0.00014 mol/L·s in 0.3N hydrochloric acid solution.

scholarly journals Diglycolamide-functionalized resorcinarene for rare earths extraction

2016 ◽  
Vol 40 (11) ◽  
pp. 9344-9351 ◽  
Author(s):  
Moheddine Wehbie ◽  
Guilhem Arrachart ◽  
Iyad Karamé ◽  
Leila Ghannam ◽  
Stéphane Pellet-Rostaing
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Acid Solution ◽  
Rare Earth Elements ◽  
Nitric Acid Solution ◽  
Rare Earths ◽  
Efficient Extraction

Efficient extraction of rare earth elements from nitric acid solution has been performed with tetrafunctionalized resorcinarene.

The Salt Makers

2019 ◽  
Author(s):  
Peter Wothers
Keyword(s):  
Organic Matter ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Periodic Table ◽  
Dilute Hydrochloric Acid ◽  
Common Salt ◽  
Distilled Water ◽  
Metal Sulfate

This chapter looks at the elements from the penultimate group of the periodic table—the halogens (‘salt-formers’). We shall see that the first of these elements was discovered by Scheele during his investigations of the mineral pyrolusite. Lavoisier knew of the element but he failed to recognize it as such since he was convinced the gas had to contain oxygen and so must be a compound. It was left to Davy to prove that this was not so, which led to the English chemist naming this element that had been discovered (but not properly named) over thirty years before by the great Scheele. Davy’s choice was to influence the names given to all the members of this group, including the most recent member named in 2016. There are three common acids known as mineral acids, since they may all be obtained by heating combinations of certain minerals. Their modern names are nitric acid, sulfuric acid, and hydrochloric acid. Of these three, hydrochloric was probably the last to be discovered. Nitric and sulfuric acids were obtained in the thirteenth or early fourteenth centuries, but the earliest unambiguous preparation of relatively pure hydrochloric acid is from a hundred years later, in a manuscript from Bologna which translates as Secrets for Colour. It gives a curious recipe for a water to soften bones: ‘Take common salt and Roman vitriol in equal quantities, and grind them very well together; then distil them through an alembic, and keep the distilled water in a vessel well closed.’ As we saw in Chapter 3, ‘Roman vitriol’ is a hydrated metal sulfate, probably iron or copper sulfate; its mixture with salt, when heated, produces water and hydrogen chloride, which together form the acid solution. Later texts from the sixteenth and seventeenth centuries include similar methods to prepare this so-called spirit of salt, or ‘oyle of salt’. The first mentioned use, to soften bones, is indeed best achieved with hydrochloric acid, which readily dissolves the minerals from bone to leave only the organic matter largely intact. Leave a chicken bone in dilute hydrochloric acid for a few hours, and it may easily be bent without breaking.

scholarly journals BEHAVIOR OF RARE-EARTH METALS IN HYDROMETALLURGICAL PROCESSING OF PYROCHLOR-MONAZITE-GOETHITE ORES

2018 ◽  
Vol 13 (3) ◽  
pp. 64-71
Author(s):  
N. A. Permyakova ◽  
E. I. Lysakova ◽  
S. I. Anufrieva ◽  
E. G. Likhnikevich
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Acid Solution ◽  
Nitric Acid Solution ◽  
Elevated Temperatures ◽  
Rare Earth Metals ◽  
Acid Leaching ◽  
Earth Metal ◽  
Hydrometallurgical Processing ◽  
Nitric Acid Leaching

The article is dedicated to finding out the specific features of the behavior of rare-earth metals in hydrometallurgical processing of pyrochlore-monazite-goetite ores of the Chuktukonsky ore field is shown in the work. Chuktukonsky ore field is a potential source of rare earth metals. The mentioned ores are practically unenforceable. Hydrometallurgical methods for their complex processing were suggested. Agitational and autoclave nitric acid leaching depending on such technological parameters as temperature, HNO3 concentration, process duration, S:L ratio and the use of H2O2 were studied. The possibility of transferring manganese (that is present in a significant amount in the ore) into a nitric acid solution by hydrogen peroxide was considered. Based on the results of the conducted studies, the distribution of REM in the products of the hydrometallurgical conversion of pyrochlore-monazitegoetite ore was estimated. It was found out that incomplete opening of the ore material was observed during agitational leaching: average REM recovery into the solution is 60%. The study made it possible to solve the problem of purifying nitric acid solutions from phosphorus that hinders the subsequent extraction and separation of rare earth metal ions forming strong complexes with rare earths. Removal of phosphorus from the solution was achieved by conducting the process under pressure at elevated temperatures (200-230 0C). It was found that the optimal decomposition conditions ensuring the transfer of almost 99% of the REM into the nitric acid solution are: 25% solution of HNO3, ore size - 0.071 mm; 5% by volume H2O2; t(160 0С) = 1 h; t(230 0С) = 1 h, gradual temperature increase from 160 to 230 0С; S:L = 1:8. Autoclave nitric-acid leaching allows selecting rare earth metals from the main part of iron, phosphorus and niobium.

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