scholarly journals Review of Rare Earth Elements as Fertilizers and Feed Additives: A Knowledge Gap Analysis

2020 ◽  
Author(s):  
Franca Tommasi ◽  
Philippe J. Thomas ◽  
Giovanni Pagano ◽  
Genevieve A. Perono ◽  
Rahime Oral ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Egg Production ◽  
Gap Analysis ◽  
Crop Productivity ◽  
Industrial Applications ◽  
Modern Technology ◽  
Feed Additives ◽  
Molecular Evidence ◽  
Positive Effects

Abstract Rare earth elements (REEs) are key constituents of modern technology and play important roles in various chemical and industrial applications. They also are increasingly used in agricultural and zootechnical applications, such as fertilizers and feed additives. Early applications of REEs in agriculture have originated in China over the past several decades with the objective of increasing crop productivity and improving livestock yield (e.g., egg production or piglet growth). Outside China, REE agricultural or zootechnical uses are not currently practiced. A number of peer-reviewed manuscripts have evaluated the adverse and the positive effects of some light REEs (lanthanum and cerium salts) or REE mixtures both in plant growth and in livestock yield. This information was never systematically evaluated from the growing body of scientific literature. The present review was designed to evaluate the available evidence for adverse and/or positive effects of REE exposures in plant and animal biota and the cellular/molecular evidence for the REE-associated effects. The overall information points to shifts from toxic to favorable effects in plant systems at lower REE concentrations (possibly suggesting hormesis). The available evidence for REE use as feed additives may suggest positive outcomes at certain doses but requires further investigations before extending this use for zootechnical purposes.

scholarly journals Study on the Effect and Mechanism of Impurity Aluminum on the Solvent Extraction of Rare Earth Elements (Nd, Pr, La) by P204-P350 in Chloride Solution

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 61
Author(s):  
Wenjie Zhang ◽  
Xian Xie ◽  
Xiong Tong ◽  
Yunpeng Du ◽  
Qiang Song ◽  
...  
Keyword(s):  
Rare Earth ◽  
Solvent Extraction ◽  
Rare Earth Elements ◽  
Organic Phase ◽  
Extraction Process ◽  
Industrial Applications ◽  
Separation And Purification ◽  
Aluminum Ion ◽  
Hydrochloric Acid Medium ◽  
Impurity Ion

Solvent extraction is the most widely used method for separation and purification of rare earth elements, and organic extractants such as di(2-ethylhexyl) phosphoric acid (P204) and di(1-methyl-heptyl) methyl phosphonate (P350) are most commonly used for industrial applications. However, the presence of impurity ions in the feed liquid during extraction can easily emulsify the extractant and affect the quality of rare earth products. Aluminum ion is the most common impurity ion in the feed liquid, and it is an important cause of emulsification of the extractant. In this study, the influence of aluminum ion was investigated on the extraction of light rare earth elements by the P204-P350 system in hydrochloric acid medium. The results show that Al3+ competes with light rare earths in the extraction process, reducing the overall extraction rate. In addition, the Al3+ stripping rate is low and there is continuous accumulation of Al3+ in the organic phase during the stripping process, affecting the extraction efficiency and even causing emulsification. The slope method and infrared detection were utilized to explore the formation of an extraction compound of Al3+ and the extractant P204-P350 that entered the organic phase as AlCl[(HA)2]2P350(o).

scholarly journals Perspectives for rare earth elements as feed additive in livestock — A review

2020 ◽  
Vol 33 (3) ◽  
pp. 373-381 ◽  
Author(s):  
Hujaz Tariq ◽  
Amit Sharma ◽  
Srobana Sarkar ◽  
Lamella Ojha ◽  
Ravi Prakash Pal ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Feed Additives ◽  
Egg Laying ◽  
Farm Animals ◽  
Feed Additive ◽  
Feed Conversion ◽  
Growth Promoters ◽  
Potential Growth ◽  
Safe Alternative

There is a need for newer feed additives due to legal prohibition on inclusion of growth promoting antibiotics in livestock diets in several countries due to antimicrobial resistance. In this context, rare earth elements (REE) have gained attention among animal nutritionists as potential growth promoters. Currently, several studies have reported better weight gain, milk production, egg laying capacity and feed conversion efficiency among different breeds of farm animals following supplementation with REE, with however largely inconsistent results. Furthermore, REE supplementation has also shown to improve ruminal fibrolytic and proteolytic activities as well as flavor of meat with negligible residues in edible tissue, however the mechanism behind this action is still unclear. According to existing research, due to their poor absorption and similarity with calcium REE might exert their action locally on gut microbial populations within the gastrointestinal tract (GIT). Moreover, REE have also shown anti-inflammatory, anti-oxidative as well as immune stimulating effects. The present review aims to broaden the knowledge about use of REE as feed additives for livestock and sum up efficacy of REE supplementation on performance and health of animals by comparing the findings. Till date, researches with REE have shown properties that make them a promising, new and safe alternative feed additive but further exploration is recommended to optimize effects and clarify discrepancy of various results before practical proposals can be drafted.

scholarly journals Recovery of Metals and Rare Earth Elements by Microwave heating Technology - A Review

2020 ◽  
Vol 7 (3) ◽  
pp. 196-206
Author(s):  
Shunda Lin ◽  
Mamdouh Omran ◽  
Shenghui Guo
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Microwave Heating ◽  
Industrial Applications ◽  
Metallurgical Waste ◽  
Microwave Technology ◽  
Valuable Metals ◽  
Rare Earth Minerals ◽  
Save Energy ◽  
Heating Technology

: Microwave heating technology is considered one of the most likely to replace traditional heating methods due to its efficient, quick, and green heating transmission that meets the requirements of sustainable development. Microwave heating can strengthen chemical reactions and change the morphology of minerals, and it can save energy and achieve rapid and efficient heating, clean production, and emission reduction. Therefore, this paper summarizes the research status of microwave heating in the recovery of valuable metals (Cu, Au, V),) from metallurgical waste ore and rare earth elements from rare earth minerals in recent years, expounds the principle of microwave heating, and summarizes the previous experimental phenomena. Finally, the development potential, opportunities, and difficulties of microwave technology in future industrial applications are discussed.

scholarly journals Laying performance and eggshell quality in laying hens fed diets supplemented with prebiotics and organic acids

2010 ◽  
Vol 55 (No. 7) ◽  
pp. 294-306 ◽  
Author(s):  
S. Świątkiewicz ◽  
J. Koreleski ◽  
A. Arczewska
Keyword(s):  
Organic Acids ◽  
Egg Production ◽  
Volatile Fatty Acids ◽  
Laying Hens ◽  
Feed Additives ◽  
Egg Mass ◽  
Positive Effects ◽  
Eggshell Quality ◽  
Laying Performance ◽  
Calcium And Phosphorus

The aim of the study was to evaluate the effect of organic acids and the prebiotic fructans on egg production and eggshell quality when added to the layer diet with different levels of calcium and phosphorus. The experiment was carried out on 168 Bovans Brown hens, allocated to 14 groups of 12 replications. Each hen (replication) was kept in an individual cage 40 cm × 40 cm in size. A 2 × 7 factorial arrangement, with two dietary levels of calcium and phosphorus (normal – 3.70% Ca, 0.65% P, and reduced – 3.25% Ca, 0.60% P) and with diets supplemented by selected additives (none, 0.75% inulin, 0.75% oligofructose, 0.50% volatile fatty acids (VFA), 0.25% medium chain fatty acid (MCFA), 0.30% VFA + 0.20% MCFA, 0.75% inulin + 0.50% VFA) was used. The experiment was carried out over 34 weeks, from the age of 26 to 70 weeks. There were no statistically confirmed effects of the factors studied in this experiment on egg performance, i.e. laying rate, egg mass, feed intake and feed conversion. Reducing the dietary levels of Ca and P significantly decreased eggshell percent, thickness, density and breaking strength. The additives used had a considerable effect on eggshell quality at 46, 58 and 70 weeks of age, and these positive effects were most pronounced in the case of inulin and MCFA. There was no significant interaction between Ca and P dietary levels and the additives used. It was thus concluded that selected feed additives which lower the pH of the diet and intestinal content can beneficially influence eggshell quality in older high-producing laying hens.  

scholarly journals Studies of the Effect of Crosslinking in the Strongly Basic Anion Exchanger Dowex 1 and the HNO3 Concentration Employed on the Separation of the SmIII–NdIII Pair in the Polar Organic Solvent–H2O–HNO3 System

2001 ◽  
Vol 19 (3) ◽  
pp. 219-228
Author(s):  
Z. Hubicki ◽  
M. Olszak
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Anion Exchanger ◽  
High Temperature Superconductors ◽  
Ceramic Materials ◽  
Modern Technology ◽  
Separation And Purification ◽  
Structural Stabilization ◽  
Component Content ◽  
Dowex 1

Because of their specific structure, rare earth elements are used for the modification or structural stabilization of many metallic or ceramic materials employed in modern technology and also in the metallic form, i.e. in alloys and compounds with unique properties. Industrial demand for rare earth metals has increased lately due to their new application possibilities, e.g. in supermagnets of the Nd–Fe–B type or in ceramic high-temperature superconductors. Equally, the application of rare earth elements in metallurgy, catalysis, ceramics, etc. remains of significant importance. The separation and purification of rare earth elements(III) which occur in groups with similar physicochemical properties involve extremely difficult and complex processes. Ion exchange is one method which enables such separation. This paper presents the results of studies of the influence of the extent of crosslinking in the anion exchanger Dowex 1 and the concentration of nitric acid on the separation of the SmIII–NdIII pair by frontal analysis in 90% v/v CH3COCH3– or the CH3OH–10% v/v × M HNO3 systems. The most effective results were obtained in the 90% v/v CH3OH–10% v/v 7 M HNO3 system employing the anion exchanger Dowex 1 × 4 allowing 0.11 kg samarium(III) to be purified on 1 dm3 ion exchanger in the nitrate form and leading to a decrease in the micro-component content to a value below 10−3%.

scholarly journals Rare Earth Elements: Industrial Applications and Economic Dependency of Europe

2015 ◽  
Vol 24 ◽  
pp. 126-135 ◽  
Author(s):  
Georgios Charalampides ◽  
Konstantinos I. Vatalis ◽  
Baklavaridis Apostoplos ◽  
Benetis Ploutarch-Nikolas
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Industrial Applications ◽  
Economic Dependency
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