Extraction processes definition

Zirconium presents a particular problem and is a major constituent of at least one crud in a uranium processing circuit. Also, as stated earlier, zirconium will tend to hydrolyze in an HNO3-TBP circuit given the right conditions of shear and of energy input (proximity to saturation of the solvent and the type and construction of contactor, particularly in the coalescing zone). The use of Teflon plates in columns for such an extraction process definitely increased coalescence and decreased the tendency for hydrolysis and crud formation [40]. 

The solvent extraction process has not yet undergone pilot plant investigation, and all the above estimates are based on small laboratory or bench scale experiments. If further testing under practical conditions substantiates the laboratory observations, it appears that the solvent extraction process definitely has an area of specialization in the over-all saline water conversion program. 

Integrating liquid-liquid extraction and detection is far from easy, as reflected in the few attempts made so far. Many of the devices developed for this purpose fail to comply with the definition of sensor. Such is the case with continuous liquid-liquid extraction systems without phase separation, where programmed switching of the propulsion system (a peristaltic pump) allows the extracting phase to be passed iteratively by the detection point in a back-and-forth motion that enriches it gradually with the extracted species [9-11]. This type of system is much too Complex to be considered a sensor, though in addition, the extraction process is not completely simultaneous with detection. 

This definition does not apply to flavouring extracts, processed natural food substances or mixtures of flavouring substances... 

A product or a mixture prepared for its flavouring properties and produced from ingredients or mixtures of ingredients which are themselves permitted for use in foodstuffs, or are present naturally in foodstuffs, or are permitted for use in process flavourings, by a process for the preparation of foods for human consumption. Flavour adjuncts may be added. This definition does not apply to flavouring extracts, processed natural food substances or mixtures of flavouring substances. 

Frater Albertus stated that after three or four extractions a definite change of colour is noticed in the contents of the flask. From this statement we are assuming that Frater Albertus replaces the contents of the thimble every few hours with fresh herbs this process taking a total of about 48 hours. The herb replaced (dead matter or faeces) is kept in a porcelain or earthenware dish for later calcining. 

Inclusion of this technique to the BOHLM has to be explained. Solvent extraction or partition of the solute between two immiscible phases is an equilibrium-based separation process. So, the membrane-based or nondispersive solvent extraction process has to be equilibrium based also. Liquid membrane separation is a rate process and the separation occurs due to a chemical potential gradient, not by equilibrium between phases [114]. According to these definitions, many authors who refer to their works as membrane-based or nondispersive solvent extraction processes are not correct. 

Initial economic comparison of the dissociation-extraction type process with the chemical-consuming process of caustic wetsh, acidification, euid solvent extraction indicates that the dissociation extraction process, which has lower operating costs but may have higher capital cost for contactors and ctssociated equipment, may be less costly overall. A process optimisation cuid more detciiled economic assessment would have to be made, however, before a definite decision could be made between the two processes. 

Classification Petroleum hydrocarbon Definition Complex combination of hydrocarbons obtained as the raffinate from a solvent extraction process consists of predominantly C5-11 aliphatic hydrocarbons Properties B.p. 35-190 C Toxicology OSHA PEL 400 ppm Uses Solvent... 

Denis, C Masse, A., Flemence, J., and Jaouen, P. (2009a) Concentration and pre-purification with uhrafiltration of a R-phyco-erylhrin solution extracted from macro-algae Gratdoupia turuturu Process definition and up-scaling. Separ. Purif. Tedinol., 69, 37-42. 

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

Oakmoss. Extracts of oakmoss are extensively used in perfumery to furnisli parts of the notes of the fougnre or chypre type. The first step in the preparation of an oakmoss extract is treatment of the Hchen Evemiaprunastri (L.) Ach., collected from oak trees mainly in southern and central Europe, with a hydrocarbon solvent to obtain a concrete. The concrete is then further processed by solvent extraction or distillation to more usable products, of which absolutes are the most versatile for perfumery use. A definitive analysis of oakmoss volatiles was performed in 1975 (52). The principal constituents of a Yugoslav oakmoss are shown in Table 15 (53). A number of phenoHc compounds are responsible for the total odor impression. Of these, methyl P-orcinol carboxylate is the most characteristic of oakmoss. 

In order to illustrate an example of process design for the manufacture of enantiopure drug substances on an industrial SMB system, consider manufacturing 10 ton/ year of an enantiopure drug. The racemic drug by definition is a 50 50 mixture of each enantiomer (products A and B). The goal is to process enantiopure drug substances in order to obtain 99 % purity for both the extract and the raffinate. 

Extraction of tantalum and niobium with 2-octanol -definition of the process parameters... 

Definition and verification of the process parameters when making the transition from laboratory measurements to a laboratory extraction system and ultimately to a pilot extraction plant, are reported in [471 - 473] and will be discussed below as an example of the process development. 

The second step in the process is the definition of the optimal mixing time and solution temperature. It was found that for both niobium and tantalum, the mixing time for extraction and stripping must not exceed one minute. No concentration changes were observed in the temperature range of 25-50°C. 

The ability of SFE-FTIR to perform a variety of extraction methods is a definite advantage, especially for the study of complex mixtures containing analytes of varying solubility. For analytes which are readily solubilised in C02, direct dynamic and direct static-dynamic SFE-FTIR methods are quite successful. Elimination of the trapping process reduces both analysis time and potential analyte loss arising from... 

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