Russian processes

Russian Process Technology. Magnesium production ia the former Soviet Union is apparently done via molten chloride electrolysis (29,30). The basic process uses camaOite [1318-27-0], MgCl2 KCl 6H20, either from natural deposits or as a by-product of processiag natural salt deposits, as its... 

CH2 CH.CH CH2 which, in turn, can be obtd in 70% yield, by modified Russian Process from alcohol and acetaldehyde C2H5QH+CH3COH.- -CH2 CH.CH CH2+H20 This process is used now by Carbide and Carbon Chemical Corp... 

Ethanol is the key reactant in Eq. (1), and also in Eq. (2) because it is readily converted to acetaldehyde. The process based on Eq. 1 was developed in Russia and the process based on Eq. 2 was developed in the United States. The yield of butadiene for the Russian process is about 30-35%. It is about 70% if mixtures of ethanol and acetaldehyde are employed as in the U.S. process. Equation (3) represents a process that involves 2,3-butylene glycol, a product from the microbial conversion of biomass. The process is carried out in two sequential steps via the glycol diacetate in overall yields to butadiene of about 80%. The process of Eq. (4) starts with a biomass derivative, the cyclic ether tetrahydrofuran, and can be carried out at high yields. When this process was first operated on a large scale in Germany, acetylene and formaldehyde were the raw materials for the synthesis of intermediate tetrahydrofuran. It is manufactured today from biomass feedstocks by thermochemical conversion, as will be discussed later. 

The Russian process uses only a 25 per cent excess of caldum but also a quantity of caldum chloride is adddl to the readants, equivalent to 40 per cent of the weight of the thorium oxide. Leaching is with hydrochloric add, but this is followed by a polishing operation with 15 per cent nitric acid before washing and drying. 

An interesting feature of the Russian process is the two-step method employed for the complete recovery of arsenic from solution waste-streams. In the first step, which is similar to the recovery method used in the Thylox process, the solution is heated to 70°C (158 F), and arsenic sulfide is precipitated by the addition of 75% sulfuric acid. The precipitate is separated from the liquid by filtration, dissolved in aqueous sodium carbonate, and returned to the circulating solution-stream. The clear liquid is then passed to the second step where it is made alkaline with sodium carbonate solution and treated with a solution of ferric sulfate. In this operation the small amount of arsenic remaining in the solution after the first step is fixed and precipitated as ferric arsenite and arsenate. The precipitate is finally removed by filtration, and the filtrate, which contains about 10 to 20 ppm of arsenic, is either discarded or processed for recovery of thiosulfate. Wooden tanks lined with acid-resistant materials are used in both steps of the arsenic-recovery operation. Each tank is sized for a solution residence time of 4 hr and provided with a mechanical agitator. 

The modern Russian MIA flaw detectors use pulse version of the method [1-3], which peirnits to produce very portable (0.7 - 1.5 kg) and simple instruments, convenient especially for in-service testing. The objects to be tested are multilayer structures of reinforced plastics, metals and other materials honeycomb panels, antenna fairings, propellers, helicopter rotors and so on. In mentioned instruments amplitude-frequency analog signal processing is used. 

Russian production may be going to a flow line cell concept (35). In this process, dehydrated camaOite is fed to a chamber where it is mixed with spent electrolyte coming from the electrolytic cells. The spent electrolyte first enters a metal collection chamber, where the molten magnesium is separated. The electrolyte is then enriched with camaOite and any iasoluble impurities are allowed to settle. The enriched electrolyte is then returned to the electrolytic cells. The result is that most of the remaining impurities are removed ia the first electrolytic cell. 

Dead Sea Works Process. The Dead Sea Works, a subsidiary of Israel Chemicals Ltd., aimounced plans ia 1992 to constmct a 25,000 t/yr magnesium plant at Beer-Sheva, Israel. The plant, to be based on Russian camaHite technology, is designed to use an existing potash plant as the source of camaHte. The chlorine by-product can be either Hquefted and sold, or used ia an existing bromine plant. Waste streams from the camaHite process, as well as spent electrolyte from the electrolytic cells, can be returned to the potash plant. 

Phosphate rock, mined widely throughout the world for its fertilizer value (see Fertilizers), in certain regions contains a few percent of lanthanides. For example, the apatite deposits in the Kola peninsula on the Russian/Finnish border. The Ln content is recoverable from the various processing residues, and because other Ln-containing minerals, such as loparite [12173-83-0], are also found there, the location suppHes a significant part of the demand in Eastern Europe. 

The actual Russian standards allow presentation of hydrocarbon components of UGC as individual compounds only for C -C hydrocai bons. The rest is described as pseudo-compound C,, although its content may reach 60 % m/m. Apparently, the detailed determination of composition of hydrocarbons C, in UGC allows essentially to raise quality of both its processing and its record. The best method for the determination of heavy hydrocai bons is capillary gas chromatography. Typical approach is based on preliminary sepai ation of UGC samples to gaseous and liquid phases. 

Dremin, A.N. and Breusov, O.N., Processes Occurring in Solids Under the Action of Powerful Shock Waves, Russian Chem. Rev. 37 (5), 392-402 (1968). Gilman, J.J., Dislocation Dynamics and the Response of Materials to Impact, Appl. Meek Rev. 21 (8), 767-783 (1968). 

Adadurov, G.A., Experimental Study of Chemical Processes Under Dynamic Compression Conditions, Russian Chem. Rev. 55 (4), 282-296 (1986). 

Commercial interest in PVC also commenced at about this time. The Russian, I. Ostromislensky, had patented the polymerisation of vinyl chloride and related substances in 1912, but the high decomposition rate at processing temperatures proved an insurmountable problem for over 15 years. Today PVC is one of the two largest tonnage plastics materials, the other being polyethylene. 

Posokhin, V. N. 1984. Design of Local Ventilation Systems for the Process Plquipment with Heat and Gas Release (m Russian). Mashinostroyeniyc, Moscow. 

E. F. Vainstein Department of Kinetics and Thermodynamics of Cooperative Processes, N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia... 

The explicit mathematical treatment for such stationary-state situations at certain ion-selective membranes was performed by Iljuschenko and Mirkin 106). As the publication is in Russian and in a not widely distributed journal, their work will be cited in the appendix. The authors obtain an equation (s. (34) on page 28) similar to the one developed by Eisenman et al. 6) for glass membranes using the three-segment potential approach. However, the mobilities used in the stationary-state treatment are those which describe the ion migration in an electric field through a diffusion layer at the phase boundary. A diffusion process through the entire membrane with constant ion mobilities does not have to be assumed. The non-Nernstian behavior of extremely thin layers (i.e., ISFET) can therefore also be described, as well as the role of an electron transfer at solid-state membranes. 

S.A. Kuznetsov, P.T. Stangrit, Physicochemical investigations of rare elements and the processes of their separation from mineral raw material, Apatity, 1980, p. 25 (in Russian). 

R.B. Bursel, Ispolsovanie plazmi v khimicheskikh processakh (Application of plasma in chemical processes) edited by L.S. Polak Mir, Moscow, 1970 (in Russian). 

V.N. Troizky, B.M. Grebzov, I.A. Domashnev, S.V. Gurov, Plazmokhimicheskie reakzii i processi (Plasmochemical interactions and processes) Nauka, Moscow, 1977 (in Russian). 

Alkali metals are obvious examples of electron donors, and indeed polymerization of butadiene or styrene initiated by metallic sodium results from an electron transfer initiation process. This reaction has been, and is still, being studied by many investigators, notably by Ziegler55 and by Russian workers.1 In Ziegler s notation the initiation is represented by the equation... 

Nikolaev NI, Zolotarev PP, Popkov YuM, Ulin VI (1981) Theory and Practice of Sorption Processes, (in Russian) Voronezh University, Voronezh 14 12... 

Tomer RV (1972) Basic processes of polymer processing (Theory and calculations methods), M., Chemistry (in Russian)... 

Kim VS, Skachkov VV (1980) Dispersion and mixing in the processes of manufacture and processing of plastic materials, Moscow, Chemistry, p 240 (in Russian)... 

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