The method of irradiation of minerals

 

(57) Abstract:

The invention relates to radiation treatment minerals to increase their jewelry values. The proposed method allows to reduce the induced activity of the samples due to thermal and resonance neutrons, which are formed in the working volume due to the slowing down of fast neutrons. The inventive thermal neutrons partially filtered out using a cadmium foil which is wrapped container. The container is filled with a substance or mixture of substances that absorb thermal and resonance neutrons, such as boron, cadmium, boron, indium, cadmium, tantalum, cadmium-indium, etc. Then post it minerals, and the ratio of proposed substances in the mixture and the density of its container calculated from the condition that at the time of exposure in the container, the ratio of the flux of fast neutrons to thermal neutron flux was greater than or equal to 10.

The invention relates to radiation treatment minerals to change their color, defects, and so on (with the aim of increasing their jewelry values).

A method of processing minerals and precious stones using uskoreniye 80oC to 350oC (DE, N 2910520, class C 04B 41/00, 1982).

There is a method of changing the color of the minerals in the reactor by the action of neutron and accompanying gamma radiation. The radiation produced by fast neutrons with energy below 0.5 MeV integral dose 51015- 11018neutrons/cm2and when the integral dose gamma irradiation 5106-1109x-rays at a temperature not exceeding 300oC. as a thermal neutron filter is used cadmium foil (DE, N 2934944, class C 04B 41/00, 1982).

There is also known a method of irradiation of minerals in the reactor in a stream of fast neutrons with energy below 0.5 MeV integral dose of 51015- 11018and integral dose of gamma radiation 5105-1109the x-ray. Thermal neutrons present in the spectrum of the flux of a nuclear reactor, filtered off with cadmium foil (NL, N 172467, class C 30 B 33/00, 1987).

Closest to the claimed method is the irradiation of minerals neutron and gamma radiation reactor (SU, N 601855, class B 01J 19/08, 1983). The method is used to optimize the characteristics of the resulting product fast neutrons with an energy of at least 2 MeV ori integrated neutron fluxes emitted. Thermal neutrons partially filtered using a cadmium foil, painting minerals irradiated in this way were stable to light and heat.

However, all the above methods require a long decay to eliminate the induced activity.

Proposed as a method of the invention allows to reduce the induced activity of the samples due to thermal and resonance neutrons, due to the slowing down of fast neutrons in the working volume. For this purpose, the method of irradiation of minerals in the neutron flux of the reactor, when thermal neutrons are partially filtered out using a cadmium foil, according to the claimed invention features.

The container (or the container), which placed irradiated minerals, fill with a substance or mixture of substances that absorb thermal and resonance neutrons, such as boron indium, cadmium, tantalum, cadmium-indium, and the relation of these substances in the mixture and the density of its container count so that at the time of irradiation in the container must be met condition

< / BR>
whereB. n.the flux of fast neutrons with energies above 1 Mo experimentally, reduces induced activity after two weeks exposure to 74 Bq/g, which by the standards of the IAEA does not represent a radiation hazard.

Since the materials usually contain activated impurities and their induced activity is proportional to thermal neutron flux, and to obtain a desired color of a mineral is necessary to irradiate them fluence of fast neutrons is not less than 1018n/cm2because the nuclear reactor, the ratio of the fast neutrons to thermal 1, the minerals in this exposure will get the same fluence of thermal neutrons, which leads to induced activity 1000 Bq/g, which is not valid. The irradiated container with minerals has a certain volume, and its shielding absorbing thermal neutrons material such as cadmium as a thermal neutron filter (which is used in the above analogues and prototype), does not provide the necessary ratio between the fast and thermal neutrons due to generation of thermal neutrons inside the container due to the slowing down of fast neutrons.

Experimentally it was determined the ratio of the flux of fast neutrons to thermal neutron flux inside the container at the time of irradiating the activity decreases in the order. For this purpose, can be used known absorbers of thermal and resonance neutrons, such as boron, indium, tantalum, etc. and mixtures thereof.

The density of the container absorbing substances is calculated in each case (based on the weight of the minerals of the neutron flux in the place of exposure, and so on), but it should be observed that in the container at the time of exposure

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The possibility of implementation of the method is confirmed by the following examples.

1. Topazes were placed in a container with a volume of 100 cm3screened cadmium filled with 185 g of minerals and 20 grams of boron carbide ( = 0.2 g/cm3). This calculation provides the container at the time of irradiation ratioB. n./the so-called= 12. The container was irradiated in the reactor channel, for 15 h of irradiation fluence of neutrons (with energies above 1 MeV) was 3,91018n/cm2. After two weeks of exposure activity Topaz was 47 Bq/g . After irradiation minerals acquired a dark blue color.

2. Topazes were placed in a container with a volume of 100 cm3screened cadmium filled with 185 g of minerals, 20 g India and 20 g of boron carbide. This calculation provides the container in momen MeV) 2,71018n/cm2. After two weeks of exposure activity Topaz was 8 Bq /g After exposure minerals acquired a dark blue color.

The method of irradiation of minerals in the neutron flux of the reactor in the container, characterized in that the container that hosts the irradiated minerals, also put a substance or mixture of substances containing elements that absorb thermal and resonance neutrons, and the relation of these substances and the density of the filling of the container is calculated so that at the time of irradiation of minerals in the container, the ratio of the flux of fast neutrons to thermal neutron flux must be greater than or equal to 10.

 

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FIELD: chemical industry; natural gas industry; petroleum industry; petrochemical industry and other industries.

SUBSTANCE: the invention falls into chemical industry, natural gas industry, petroleum industry, petrochemical industry and other branches pertaining to processing of hydrocarbon raw material, in particular, with production of a condensate consisting of light hydrocarbon gases and with processing of high-viscosity petroleum and petroleum residue. Substance of the invention: the method provides for a thermal treatment of the raw materials and treatment of a surface of a layer or a stream of a feed stock in a gaseous medium containing hydrogen and-or gaseous alkanes at a heightened temperature and an atmospheric pressure by ionizing radiation of relativistic electrons with energy in the range from about 0.5 up to about 10.0 MeV, preferably, from about 0.5 up to about 2.5 MeV at a width of the layer or a stream of a feed stock equal to the depth of sorption of the electronic emission, defined by the ratio λ x ρ = 0.5 E - 0.1, where λ - the depth of sorption of the electronic emission, cm; ρ - a density of the raw material, g /cm3; E - energy of electrons, MeV. Electrons irradiation is conducted onto the one side of the layer or from the two counter sides of the layer in the mode of a continuous irradiation or in a pulsed - periodic mode. The invention offers devices for realization of the method. The invention allows to increase output of the low-molecular hydrocarbons and to ensure a desirable productivity of the process.

EFFECT: the invention ensures an increased output of the low-molecular hydrocarbons and a desirable productivity of the process.

20 cl, 8 ex, 5 dwg, 3 tbl

FIELD: production of nanodispersed powders of refractory inorganic materials and compounds, in particular, installations and methods for realization of plasmochemical processes of production of nanodispersed powder products.

SUBSTANCE: the installation comprises production-linked: microwave oscillator 1, microwave plasmatron 2, gas-flow former 3, discharge chamber 4, microwave radiation absorber 5, reaction chamber 6, heat-exchanger 7, filter-collector of target product (powder) 8, device for injection of the source reagents in a powdered or vapors state into the reaction chamber, the installation has in addition a device for injection of the source reagents in the liquid-drop state, it has interconnected proportioner 9 in the form of cylinder 10, piston 11 with gear-screwed electric drive mechanism 12 adjusting the speed of motion of piston 1, evaporative chamber 13 with a temperature-controlled body for regulating the temperature inside the chamber that is coupled to the assembly of injection of reagents 14 in the vaporous state and to the assembly of injection of reagents 15 in the liquid-drop state, injection assembly 14 is made with 6 to 12 holes opening in the space of the reaction chamber at an angle of 45 to 60 deg to the axis of the chamber consisting at least of two sections, the first of which is connected by upper flange 16 to the assemblies of injection of reagents, to discharge chamber 4, plasmatron 2, with valve 17 installed between it and microwave oscillator 1, and by lower flange 18, through the subsequent sections, it is connected to heat exchanger 7, the reaction chamber has inner water-cooled insert 20 rotated by electric motor 19 and metal scraper 21 located along it for cutting the precipitations of powder of the target product formed on the walls of the reaction chamber, and heat exchanger 7 is made two water-cooled coaxial cylinders 22 and 23, whose axes are perpendicular to the axis of the reaction chamber and installed with a clearance for passage of the cooled flow, and knife 24 located in the clearance, rotating about the axis of the cylinders and cleaning the working surfaces of the cylinders of the overgrowing with powder, powder filter-collector 8 having inside it filtering hose 25 of chemically and thermally stable material, on which precipitation of powder of the target product from the gas flow takes place, in the upper part it is connected by flange 26 to the heat exchanger, and in the lower part the filter is provided it device 27 for periodic cleaning of the material by its deformation, and device 28 with valve 29 for sealing the inner space of the filter. The method for production of nanodispersed powders in microwave plasma with the use of the claimed installation consists in injection of the source reagents in the flow of plasma-forming gas of the reaction chamber, plasmochemical synthesis of reagents, cooling of the target product and its separation from the reaction chamber through the filter-collector, the source reagents are injected into the flow of plasma-forming gas, having a medium-mass temperature of 1200 to 3200 K in any state of aggregation: vaporous, powdered, liquid-drop or in any combination of them, reagents in the powdered state are injected in the form of aerosol with the gas-carrier into the reaction chamber through injection assembly 35 with a hole opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, reagents in the liquid-drop or vaporous state are injected into the reaction chamber through injection assemblies 15 or 14, respectively, in the form of ring-shaped headers, the last of which is made with 6 to 12 holes opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, each of them is blown off by the accompanying gas flow through the coaxial ducts around the holes, at expenditure of the source reagents, plasma-forming gas, specific power of microwave radiation, length of the reaction zone providing for production of a composite system and individual substances with preset properties, chemical, phase composition and dispersity.

EFFECT: universality of the industrial installation, enhanced capacity of it and enhanced duration of continuous operation, as well as enhanced yield of nanodispersed powders and expanded production potentialities of the method.

20 cl, 1 dwg, 4 ex

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