Metal preparation line

Plutonium metal is prepared by two methods--direct reduction of the oxide by calcium (DOR)U,2J, and reduction of PuF by calcium in our metal preparation line (MPL)(3) (see Figure 1). In the DOR process, the plutonium contenF of the reduction slag is so low that the slag can be sent to retrievable storage without further processing. Metal buttons that are produced are no purer than the oxide feed and/or the calcium chloride salt. Los Alamos purifies the buttons by electrorefin-ing(4i,5 ), yielding metal rings that are > 99.96 percent plutonium. 

MPL—See Metal preparation line Mulak model, PuF4.29-30... 

Measurement of Residual Stress and Strain. The displacement of the 2 -value of a particular line in a diffraction pattern from its nominal, nonstressed position gives a measure of the amount of stress retained in the crystaUites during the crystallization process. Thus metals prepared in certain ways (eg, cold rolling) have stress in their polycrystalline form. Strain is a function of peak width, but the peak shape is different than that due to crystaUite size. Usually the two properties, crystaUite size and strain, are deterrnined together by a computer program. 

The liquid sulfur dioxide solutions described in the preparations have a vapor pressure of about 3.3 atm at 21 °C. Therefore, well-constructed glass vessels and a glass (or metal) vacuum line must be employed to prevent pressure bursts. Thick leather gloves, safety goggles, a face shield, and a rubber apron should be worn and the experiments have to be conducted behind a safety shield or explosion-proof glass in a fume hood to prevent possible contact with the reaction mixtures as well as with AsF5 and SbFs. 

Bromine pentafluoride, which is commercially available from Baker Chemicals, Phillipsburg, NJ, or Union Carbide Corp., may be used as such with the typical impurity of several percent bromine. It should be handled in a metal vacuum line.4 Standard glass vacuum lines with Kel-F greased valves have also been used, but this technique results in a SiF4 impurity. Sulfinyl difluoride, if not available, is best prepared from SOCl2 and NaF in CH3CN at 70° and by redistillation of the product at -43°. This method can be used on the 100-500 g scale. 

A metal vacuum, line as previously described [13], provided for the distribution of gaseous reactants, but all of the preparations were carried out in all Teflon/FEP apparatus, isolated from the metal system by a Teflon valve [13] (with Kel-F stem and Teflon tip) closed, except in the transfer of... 

Coating of appliances involves several key steps on conveyorized lines. These are cleaning, metal preparation, priming, baking, topcoating, and baking. 

Processes that are essentially modifications of laboratory methods and that allow operation on a larger scale are used for commercial preparation of vinyhdene chloride polymers. The intended use dictates the polymer characteristics and, to some extent, the method of manufacture. Emulsion polymerization and suspension polymerization are the preferred industrial processes. Either process is carried out in a closed, stirred reactor, which should be glass-lined and jacketed for heating and cooling. The reactor must be purged of oxygen, and the water and monomer must be free of metallic impurities to prevent an adverse effect on the thermal stabiUty of the polymer. 

At X-ray fluorescence analysis (XRF) of samples of the limited weight is perspective to prepare for specimens as polymeric films on a basis of methylcellulose [1]. By the example of definition of heavy metals in film specimens have studied dependence of intensity of X-ray radiation from their chemical compound, surface density (P ) and the size (D) particles of the powder introduced to polymer. Have theoretically established, that the basic source of an error of results XRF is dependence of intensity (F) analytical lines of determined elements from a specimen. Thus the best account of variations P provides a method of the internal standard at change P from 2 up to 6 mg/sm the coefficient of variation describing an error of definition Mo, Zn, Cu, Co, Fe and Mn in a method of the direct external standard, reaches 40 %, and at use of a method of the internal standard (an element of comparison Ga) value does not exceed 2,2 %. Experiment within the limits of a casual error (V changes from 2,9 up to 7,4 %) has confirmed theoretical conclusions. 

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