Papers by Keyword: Solvent Extraction

Abstract: The purification of mixed hydroxide precipitate leaching solution from impurities was conducted via solvent extraction using the commercial extractant di(2-ethylhexyl) phosphoric acid (P₂₀₄ or D2EHPA). The impurities that were removed are Mn²⁺, Cu²⁺, Ca²⁺, Mg²⁺, and Zn²⁺, while the desired metals remained in aqueous phase which are Co²⁺ and Ni²⁺. Solvent extractions were studied on a batch scale to improve the effect of organic-to-aqueous phase ratio, extractant concentration, saponification rate, and feed solution pH to the removal of impurities. High selectivity of impurities was obtained at a phase ratio organic to aqueous of 1.6:1, extractant concentration of 30 vol%, with saponification rate of 40%, and feed solution pH of 5. The extraction rate achieved for Mn²⁺, Cu²⁺, Ca²⁺, Mg²⁺, and Zn²⁺ are 88.46%, 82.24%, 95.21%, 38.10%, and 99.99% respectively while the co-extracted of Co²⁺ and Ni²⁺ are 17.76%, and 12.52%.

Abstract: Nickel and cobalt recovered from ternary leaching solutions have high market value and stability. In addition to preventing environmental damage, this recovery process is also very useful in the application of power energy storage and electric vehicles. Solvent extraction is an effective and selective method for separating elements in ternary leaching solutions. This research focuses on the separation stage of feed solution impurities, especially Cu, by optimizing the extraction process using multi-stage extraction. This method, which is adapted to a laboratory scale, mixes the feed solution with saponified P204 (prepared with NaOH) and then stirred until phase separation into a loaded organic phase and raffinate occurs. The use of P204 with 3-stage extractions with O/A= 1.5/1 and pH= 4.5 succeeded in separating 99.96% extraction of Cu with a primary yield of Cu value of 99.999%. This solvent extraction also successfully separated 99.23% of Mn, Ca=95.62%, and other impurity metals such as Fe, Zn, Li, and Si reaching a final concentration in the raffinate solution of only 10^-3 g/L. The results of this research are very useful in the subsequent extraction process in the form of separating the valuable elements nickel and cobalt. This method can potentially overcome environmental problems resulting from the disposal of NCM battery waste in the metallurgical field.

Abstract: Moringa oleifera is a plant that is predicted to be a potential source of vegetable oil. Moringa seeds contain 35-40% oil which is used in the pharmaceutical, cosmetic, automotive and fuel industries. Moringa oil contains oleic, palmitic, and behenic acid which is good for health. Obtaining oil from Moringa seeds in this study used the mechanical pressing method and continued with extraction using a solvent. Mechanical extraction was carried out by pressing Moringa seeds with a moisture content of 8 and 16% w/w. The best result was obtained with a moisture content of 8% with the yield of oil produced from 20 to 31% w/w. The pressing temperature also varied at 80, 100, and 120°C and the best result was given by the temperature of 100°C with the yield of oil produced 27.3-28.8% w/w at 8% moisture content of seeds and 20.9-23.6% w/w at 16% moisture content of seeds. The pressed cake from the mechanical pressing was extracted by maceration method using n-hexane as the solvent. The ratio of the amount of solvent to the amount of pressed cake (mL/gram) was 6/1, 8/1, and 10/1. The best ratio given by 8/1 with the yield oil produced from 8.44-22.82% w/w. Moringa oil was characterized using the standard method. The oil density obtained 0.912-0.919 g/cm³, saponification value 195-202 mgKOH/g oil, acid value 1.62-2.77 mgKOH/g oil, and peroxide value 1.85-3.70 meqO₂/kg.

Abstract: Moringa oleifera (M. oleifera) has been known as a medicinal plant. The objectives of this study is to identify the chemical compositions of M. oleifera pods extracts and to evaluate its total phenolic content (TPC) and antioxidant activity. The methodology of this study began with the collection of the pod's sample, drying and grinding the pods into powdered form. M. oleifera pods extracts were prepared by using methanol (MeOH), hexane, dichloromethane (DCM), and ethyl acetate (EtOAc) solvent which yielded respective residues. All extracts were subjected to Gas Chromatography-Mass Spectrometry (GC-MS) to identify its chemical compositions. Major compound found in hexane, DCM, EtOAc, and MeOH extracts were nonanoic acid (30.94 %), diisooctyl phthalate (89.45 %), benzoic acid, 4-hydroxy- (37.57 %) and octanoic acid (19.19 %), respectively. The TPC quantification was done via Folin-Ciocalteu method showed that EtOAc extract has the highest phenols content with 500.05 mg GAE/g. Generally, all extract contain moderate phenolic content. M. oleifera pods extracts were screened for the antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. Hexane, DCM and EtOAc extracts exhibited good free radical scavenging activity with IC₅₀ of 65.79 μg/mL, 74.93 μg/mL and 82.83 μg/mL, respectively. MeOH showed the lowest free radical scavenging activity with IC₅₀ 529.6 μg/mL. However, antioxidant activity of all extracts was low compared to standard, ascorbic acid (AA) with IC₅₀ of 19.57 μg/mL. The presence of various bioactive constituents in the M. oleifera pods extracts might contributed to the antioxidant activity of the plant.

Abstract: Protein is a substantial nutrition that essentially required by human. Spirulina platensis (Spp), well known as protein source could be a significant source to be used for many industrial applications. This study was investigated the effectiveness of ultrasound assisted extraction (UAE) method for protein extraction from Spp at various composition of solvent mixture and extraction time. Ethanol and mixture of methanol-ethanol were used as solvent. Extraction was conducted by varying ratios of solvent to biomass at 10:1, 12.5:1, and 15:1 (v/w), and extraction time (20, 35, and 50 min). Optimum protein recovery from dry Spp was 42.55 ± 0.43% obtained by using 20 ml of the mixture of methanol and ethanol at 50 min of extraction time. This study also conducted that mixture of methanol and ethanol was a better solvent on improving the ultrasound assisted extraction, as indicated by high protein recovery with less amount of solvent volume used.

Abstract: Development of body imaging techniques for medical diagnosis has future promising. To improve the image visibility, Gadolinium (Gd) has been known as an important material for preparing the contrast agent. However, since the rare earth metals have unique physical properties, the separation of Gd from the other metals by a simple, effective and efficient method is still challenging. Hereby, we report the separation of Gd from the rare earth mixture with dihexyl dithiophosphate (DHDTP) ligand by solvent extraction method. The amount of Gd before and after the extraction process was determined with ICP-OES. The results show that the extraction efficiency for the mixed samples of Gd (III) and Sm (III) is 53.10% with 51.10% purity of Gd (III) and extraction efficiency for mixed samples of Gd (III) and Dy (III) is 93.82% with 50.35% purity of Gd (III). This result indicates that DHDTP can be used for solvent extraction of Gd.

Abstract: Gaharu oleoresin is a mixture of wood resin and essential oil substances that naturally accumulates in the gaharu plants species. The aim of this study was to determine the appropriate solvent types and the contents of oleoresin and oil as well as the chemical compounds present in the gaharu extracts. Gaharu oleoresin can be extracted from gaharu powder using polar solvents and the essential oil can be separated using non-polar solvents. The extraction was done by Soxhlet method using methanol and ethanol for oleoresin extraction, and n-hexane and toluene for oil extraction from which the most appropriate solvents, extraction yields and the extracts quality were determined. The percentage of oleoresin extraction yield was found highest in methanol (6.97 %) followed by ethanol (6.85 % w/w). Meanwhile, the gaharu oil was found higher in toluene extract (1.06 %) compared to n-hexane (0.38 % w/w). The GC-MS results showed the extracts from ethanol and n-hexane solvents are the best quality due to the present of key compounds of 4-phenyl-2-butanone, β-guaiene, agarospirol, α–bisabolene, alloaromadendrene oxide, γ-Gurjunen and aromadenderene oxide. Different chemical component in gaharu oil determines the characteristic or quality of the gaharu. Meanwhile, the sesquiterpene compounds in gaharu produce its specialty aroma characteristics. Therefore, ethanol and n-hexane solvents are suitable to be used for oleoresin and oil extraction beside less expensive and more environmental-friendly.

Abstract: For several decades, zinc-manganese batteries have been created to serve many forms of electronic products. However, every creative act has its destructive consequence. Plenty of waste element inside has caused the irreversible contamination to our environment.This study will focus on dealing with zinc-manganese batteries using environmental technology and hydrometallurgy methods, such as physical pretreatment, acid leaching and solvent extraction. The goal of this research will concentrate on the recovery of zinc and manganese from zinc-manganese batteries. The pretreatment processes include crushing, sieving and magnetic separation to separate the waste plastic, scraps of paper and impurity from waste zinc-manganese batteries. Before the process of the solvent extraction zinc-manganese batteries will be leached by specific acid first. In next step, the solvent extraction will be carried out and investigated. The parameters such as extractant concentration, extraction time, equilibrium pH value and organic-aqueous ratio (O/A) are analyzed in detail. Finally, the products of Zn and Mn are obtained in high-purity level and the recovery rates are about 92% for Zn and 95% for Mn.

Abstract: Using a commercially available solvent impregnated resin, Lewatit TP272, in an ion exchange process, it was possible to extract up to 90 % indium from a feed containing as little as 1 mg/L indium in the presence of high amounts of impurities, i.e. 1000 mg/L iron and zinc each. It was demonstrated that through gradient regeneration of obtained loaded ion-exchange resin, it is possible to yield a solution containing as much as 400 mg/L indium along with 400 mg/L iron, thereby upgrading its purity more than 600 times. Moreover, it was shown that this solution can be fed into an existing solvent extraction procedure which would yield an indium oxide with more than 99 % purity.

Abstract: Pregnant leach solutions (PLS) resulting from bioleaching of copper concentrate from Kupferschiefer are characterized by low pH and high concentrations of Fe, Cu, Zn as well as significant amounts of Ni and Co. In order to recover the valuable metals for further processing, chemical methods and a novel biological-induced technique that promotes selective metal recovery and sulfate removal from acidic liquors were applied and a process scheme was developed.