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Saint Petersburg, Russia

Nechaev A.F.,St Petersburg Technological Institute
Atomic Energy | Year: 2015

It is shown on the basis of an analysis of regulatory-legal documents that the assumptions characterizing very low-level wastes contain semantic contradictions and critical discrepancies of a classification nature regarding wastes containing natural radionuclides and are not consistent with the absolute values of the bounding indices – the dose rates and specific activity. The presence of these uncertainties and inconsistencies in the regulatory documentation makes reaching the primary objective of introducing very low-level wastes as a category – reduction of the cost of managing wastes by lowering the requirements for their isolation – problematic. Some variants of the elimination of normalization shortfalls are proposed. © 2015 Springer Science+Business Media New York

Zhantasov K.T.,South Kazakhstan State University | Altybayev Z.M.,South Kazakhstan State University | Zhantasov M.K.,South Kazakhstan State University | Yeskendirova M.M.,South Kazakhstan State University | And 2 more authors.
Eurasian Chemico-Technological Journal | Year: 2012

This article is dedicated to utilization of substandard phosphorite fines and simultaneously producing of fluxed sinter. Optimal technological parameters of the sintering process of phosphate fines with addition of the substandard underoxidized nickel-cobalt-containing ore and the internal overburden of coal mining industry were established. The addition of the nickel-cobalt ore and internal overburden containing nickel, cobalt, silicon and aluminum in the charge composition permits to produce the fluxed sinter with improved technological properties, with acidity module 0.90-1.08, with the high impact, abrasion and compression strength. Decrease of the fines output (less than 6 mm) on 10-15% (relatively) in comparison with the existing (traditional) sintering technology is explained with a content of carbon (up to 50%) in the internal overburden and increase of eutectic liquid phase amount at the expense of fusible components of the nickel-cobalt ore. The result of this process is the fluxed sinter with sufficiently high strength and improved technological properties. At the subsequent electro thermal sublimation of phosphorus from the fluxed sinter with high strength properties the ferrophosphorus alloy forms which contains the alloying metals such as Ni, Co, Cr and others. These additions containing silicon and aluminum create an exothermic effect, which leads to decreasing of fuel and energy consumptions. The suggested technology allows to decrease a melting point of the charge on 100°C due to presence of fusible compounds in the sintering mixture and to reduce the fuel and energy consumption for the sinter production. Found that the introduction of nickel-cobalt ore and internal overburden of coal industry in the sinter charge provides a fluxed sinter phosphorite with module of acidity 0.93-1.08 sufficiently high strength and improved technological properties, in addition, at subsequent electric sublimation of phosphorus from fluxed sinter the ferro alloy alloyed with nickel and cobalt is formed, which is a valuable raw material for the steel industry. According to the research it is assumed that the replacement of natural quartzite used as a flux to the nickel-cobalt-chromium containing ore and internal overburden, which include about 45% of silicon, as well as transition of nickel, cobalt and chromium ore into ferrophosphorous alloy with subsequent sales of its steel industry to a higher price will significantly improve the technical and economic indices of phosphorus production. © 2012 al-Farabi Kazakh National University.

Chugunov A.S.,St Petersburg Technological Institute | Nechaev A.F.,St Petersburg Technological Institute
Atomic Energy | Year: 2015

A comparative study is made of the properties of six types of carboxyl cationites differing by the composition and structure of the matrix. It is shown that the use of weakly acidic ionites as the charge in the upstream filters in the special water purification system and block desalination setups will make it possible to extract very efficiently the lithium, potassium, ammonium or monoethanolamine ballast salts from the purified flows with dealkalization of the flows. As a result, the effective capacity of the regular filters can be increased considerably and, correspondingly, their service life extended by decreasing the volume and salt content of the secondary liquid radioactive wastes. © 2015 Springer Science+Business Media New York

Nechaev A.F.,St Petersburg Technological Institute | Chugunov A.S.,St Petersburg Technological Institute
Atomic Energy | Year: 2014

The cost of conditioning and final disposal of radwastes is determined on the basis of an analysis of the officially accepted indices. It is shown that depending on the category the specific costs range from several hundreds of thousands to several millions of rubles per cubic meter of the initial radwastes. Some basic assumptions for choosing the best of the existing technologies and (or) developing new solutions for minimizing the volume of liquid wastes are formulated. It is confirmed experimentally that this problem can be solved by comparatively low-cost methods using the inherent properties of the initial solutions and without radically changing the existing technological schemes. © 2014 Springer Science+Business Media New York.

Lomanova N.A.,RAS Ioffe Physical - Technical Institute | Gusarov V.V.,St Petersburg Technological Institute
Russian Journal of Inorganic Chemistry | Year: 2010

The effect of the phase composition of the starting mixture on the formation of the layered perovskite-like compound Bi7Fe 3Ti3O21 in the Bi2O 3-TiO2-Fe2O3 system is reported. The rate-limiting process in the formation of this compound is reactant mass transfer to the reaction zone. © 2010 Pleiades Publishing, Ltd.

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