Extractions technology

Solvent Extraction Technology. The use of solvent extraction technology to replace traditional processes has been the subject of considerable research and development effort since the 1970s (12,14—21). This newer technique was being used commercially as of 1995 in at least three of the principal refineries. 

The discovery of aqua regia by the Arab alchemist Jabir Ibn Hayyan (ad 720—813) provided a new extraction technology. Amalgamation of silver in ores with mercury was extensively used during the late fifteenth century by the Spaniards in Mexico and BoLvia. In 1861 the complex ores of the Comstock Lode, Nevada, were ground together with mercury, salt, copper sulfate, and sulfuric acid, and then steam-heated to recover the silver. 

M. H. Corbin, N. A. Metzer, and M. P. Kress, Project Summary Field Investigation of Effectiveness of Soil Wapor Extraction Technology,... 

U.S. EPA, Resources Conservation Company B.E.S.T Solvent Extraction Technology Applications Analysis Report, EPA/540/AR-92/079 (1993). 

U.S. EPA, SITE Technology Capsule Terra-Kleen Solvent Extraction Technology, EPA/540/R-94/521a, Cincinnati, Ohio, 1995. 

Asphalt (bitumen) also occurs in various oil sand (also called tar sand) deposits which occur widely scattered through the world (17) and the bitumen is available by means of various extraction technologies. A review of the properties and character of the bitumen (18) suggests that, when used as an asphaltic binder, the bitumen compares favorably with specification-grade petroleum asphalts and may have superior aging characteristics and produce more water-resistant paving mixtures than the typical petroleum asphalts. 

The extraction technology is applied for scrap recycling of tantalum and niobium and for the treatment of related materials. Recovery of tantalum and niobium from secondary material, such as Sn slag, Ti slag, W slag, catalyst wastes, used cemented carbide and used tantalum capacitors was reviewed by Dai, Zhong, Li and Li [483]. 

The current state of analytical SPE was critically reviewed and no major changes of the technique have been observed. Overviews of the developments of the extraction technologies of secondary metabolites from plant materials refer to three types of conventional extraction techniques that involve the use of solvents, steam, or supercritical fluids. Each technique is described in detail with respect to typical processing parameters and recent developments. Eollowing the discussion of some technical and economic aspects of conventional and novel separation processes, a few general conclusions about the applicabilities of the different types of extraction techniques are drawn. ... 

Uranium Extraction Technology, A Joint Report by OECD Nuclear Energy Agency and the International Atomic Energy Agency, Paris, 1983. 

Conventional extraction technologies. . 59 from polymer/additive ... 

Liquid extraction technologies span a century. Extraction can be directly conducted as static, dynamic, static-dynamic, or dynamic-cryotrap. Cryotrapping enables analytes to be removed from a matrix and deposited onto a technically more inert surface. For analytes with complex matrices, this method is highly advantageous. For pure analytes or for analytes with simple matrices, however, cryotrapping can be overkill, as it effectively means two sample extractions for a given run. 

ASE is recognised as an official extraction method in US EPA SW-846 Method 3545 and has shown to be equivalent to standard EPA extraction technology in terms of recovery and precision. 

Experimental comparisons may suffer from a lack of optimal conditions for all methods considered or may be based on biased evaluation. It is frequently noticed that results quoted by the preferred extraction technique compare extremely favourably with existing extraction technology. Also, lack of prospects of using CRMs is not helpful for comparisons. However, it appears that for a given infrastructure (R D vs. plant laboratory) and need (routine vs. occasional operations), and depending on the mix of polymeric matrices to be handled, some preferences may clearly be expressed. 

Soxhlet extraction is well established, and generally exhaustively extracts all additives. The selection of extraction solvent can make large differences to the extraction time. The generally long extraction times followed by concentration steps may determine losses of volatile or thermally labile components. Because this form of extraction is one of the oldest and still widely used in industry, it is the standard to which many of the newer extraction technologies (which are likely to determine future applications) are referred. However, it should be realised that extraction mechanisms may be different, and thus comparisons are sometimes irrelevant. 

N. Simpson and K.C. van Home (eds), Varian Sorbent Extraction Technology Elandbook, Varian Sample Preparation Products, Harbor City, CA (1993). 

K. C. van Horne, Sorbent Extraction Technology, Analytichem International, Harbor City, CA (1985). 

U.S. EPA, Presumptive Remedy Supplemental Bulletin, Multi-Phase Extraction Technology for VOCs in Soil and Groundwater, Office of Solid Waste and Emergency Response, United States Environmental Protection Agency, Washington, DC, April, 1997. Available at cluin.org/download/toolkit/finalapr.pdf, 2009. 

The authors thank Western Extraction Technology, Inc. and EER Labs, Inc. for their partial financial support. We also would like to thank Dr. H. L. Wong and Mr. Leon Lemons for the preparation of this manuscript. 

Membrane Exctraction Technology, London, U.K., http //www.membrane-extraction-technology.com. 

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