Development of Hydrometallurgical Process for Recovery of Rare Earth Metals (Nd, Pr, and Dy) from Nd-Fe-B Magnets

Non-availability of rich primary resources of rare earth metals (REMs) and the generation of huge amounts of discarded magnets containing REMs, compelled the researchers to explore the possibilities for the recovery of REMs from discarded magnets. Therefore, the present paper reports the recovery of REMs (Nd, Pr, and Dy) from discarded Nd-Fe-B magnets. The process consists of demagnetization, pre-treatment, and hydrometallurgical processing to recover REMs as salt. Leaching studies indicate that 95.5% Nd, 99.9% Pr, and 99.9% Dy were found to be dissolved at the optimized experimental condition i.e., acid concentration 2 M H2SO4, temperature 75 °C, pulp density 100 g/L, and mixing time 60 min. Solvent extraction technique was tried for the selective extraction/separation of REMs and Fe. The result indicates that 99.1% (24.42 g/L) of Nd along with 90% (1.08 g/L) of Pr and total Fe were co-extracted using 35% Cyanex 272 at organic to aqueous (O/A) ratio 1/1, eq. pH 3.5 in 10 min of mixing time. It requires multistage separation and therefore, not feasible in view of economics. Thus, direct precipitation of REMs salt and iron oxide as pigment was studied using two stages of precipitation at different pH. The obtained precipitate of REMs and Fe hydroxides were dried separately to remove the moisture and further treated at elevated temperature to get pure REMs oxide and red oxide.

A novel spatially resolved interactance spectroscopy system to estimate degree of red coloration in red-fleshed apple

Reliable information about degree of red coloration in fruit flesh is essential for grading and sorting of red-fleshed apples. We propose a spatially resolved interactance spectroscopy approach as a new rapid and non-destructive technique to estimate degree of red coloration in the flesh of a red-fleshed apple cultivar ‘Kurenainoyume’. A novel measurement system was developed to obtain spatially resolved interactance spectra (190–1070 nm) for apple fruits at eight different light source-detector separation (SDS) distances on fruit surface. Anthocyanins in apple were extracted using a solvent extraction technique, and their contents were quantified with a spectrophotometer. Partial least squares (PLS) regression analyses were performed to develop estimation models for anthocyanin content from spatially resolved interactance spectra. Results showed that the PLS models based on interactance spectra obtained at different SDS distances achieved different predictive accuracy. Further, the system demonstrated the possibility to detect the degree of red coloration in the flesh at specific depths by identifying an optimal SDS distance. This might contribute to provide a detailed profile of the red coloration (anthocyanins) that is unevenly distributed among different depths of the flesh. This new approach may be potentially applied to grading and sorting systems for red-fleshed apples in fruit industry.

Extraction of Lactic Acid from Whey of Yoghurt by Solvent Extraction Technique

The aim of this paper is to investigate the possibility to recover lactic acid (LA) from the whey of yoghurt by easy and effective solvent extraction technique using tri-n-octylamine, tri-n-butyl phosphate, and their mixtures as extractant. All parameters affecting the transfer of lactic acid to the organic phase were investigated including: time of stirring, tri-n-butyl phosphate and tri-n- octylamine concentrations, organic to aqueous phase ratio, temperature, NaCl concentration as a salting out agent, and number of contacts. The maximum yield of LA extraction can be obtained by using the following operation conditions: 0.8M TOA+11% TBP, Vorg/Vaq = 4/1, t = 30 oC, [NaCl] = 2M. Complete stripping of LA from loaded organic phase can be done in 2 stages using double distilled water at 60oC and Vaq/Vorg = 20/1.

Qualitative Analysis of Post-blast Residue using the Double Hyphenated UHPLC-(HESI)-MS/MS Technique

The thriving terror activity is a menace to our society. To mitigate this, there is a dire need of upgraded and innovative analytical techniques for forensic analysis of explosives. The complexity in the matrix, restrictions in the sample quantity and ambiguity in the data interpretation are the different challenges that a forensic scientist face. The solution to these problems lies in upgradation of extraction technique, screening technique & confirmatory techniques. In this paper, the identification and forensic analysis of post blast residues recovered from controlled blast site has been presented. The targeted sample was extracted from soil by using Accelerated Solvent Extraction technique. The target compound was primarily identified to be PETN (PentaErythritol TetraNitrate) by color test and TLC (Thin Layer Chromatography). The confirmatory test for the target analyte was done by using a hyphenated technique LC-MS/MS (Liquid Chromatography Mass Spectrometer with tandem Mass). This manuscript demonstrates the viability of LC-MS/MS in Forensic Science for a fast, accurate and quality-assured analysis of post-blast residue.

Recovery of Lithium from Simulated Secondary Resources (LiCO3) through Solvent Extraction

Lithium extraction is currently too inefficient to be economical or marketable. The objective of this work was to find the best extractant and the most inexpensive approach to recover lithium chemically from lithium ion batteries containing other desired metals using the solvent extraction technique. The extraction efficiency of various extracting types was investigated. The highest extraction efficiency of lithium ion from aqueous solution was obtained with bis(2-ethylhexyl) phosphate (DEHPA), with 75% recovery. Studying the effects of selected extractants in this experiment, it was found that the acidic extractant group provided better extraction efficiency than solvating extractants. Further investigation of influential variables was carried out, including extraction time, pH of aqueous solution, and initial concentration. The results indicate that 6 h of extraction brings the system to equilibrium, and pH 1.5 is the best for extraction efficiency.