A method of obtaining a fine powder carbonyl iron
(57) Abstract:The invention relates to the field of powder metallurgy, in particular the production of finely powdered carbonyl iron. The proposed method consists of cleaning liquid PENTACARBONYL iron, evaporation in the evaporator and decomposition when heated in a cylindrical reactor in the presence of gaseous ammonia, filed simultaneously with pairs PENTACARBONYL iron in the upper neck of a cylindrical reactor, and according to the invention the evaporation of PENTACARBONYL iron is carried out at the rate of feed to the evaporator 41-45 l/h, and gaseous ammonia is served in a number of 25-28 l 1 l liquid PENTACARBONYL iron, and the decomposition is carried out in the reactor divided by the heated zone, the temperature in the heated zone in the direction of the vapor PENTACARBONYL iron support: at the top 305-308oWith, in the middle 322-325oAnd at the bottom 280-290oC. Provides the carbonyl iron powder with low content of conglomerates of particles of 4% or less and with low content of bound nitrogen 0.6% and less. 1 C.p. f-crystals, 1 Il. The invention relates to methods of obtaining iron powders and neposredstvennogo in metallurgy (manufacture of precision steel and alloys, containing pure iron), powder metallurgy (non-waste methods of obtaining parts by sintering), in electronics and in industry wired connection (ferrites and devices for negotiations), as the magnetic fillers contactless powder clutch in instrumentation and automotive, powder testing (NDT cracks, voids, etc. in large parts), industrial composites as reinforcing fillers curable matrices) and for other purposes.A method of obtaining fine powder QOL (ed.mon. The USSR 479565, CL 22 F 9/12, 1975). In this way the liquid PENTACARBONYL iron through the dispenser with the speed 42-45 l/h served in the evaporator, the temperature of which support 106-108oC. Here a couple of PENTACARBONYL served in the upper part of the rector, this simultaneously serves gaseous ammonia with the speed of 1640 l/h Temperature in the upper and middle zones of the reactor support in the interval 345-350oWith, and in the lower zone - 320-330oC. the Disadvantage of this method is the presence of a large number of conglomerates of particles (30-35 wt.%) in the target powder QOL, as well as the presence of particles QOL large amounts of impurities nitrogen is rudovanie of powder metallurgy enterprises. - M.: metallurgy, 1988, S. 66-67), adopted as the closest analogue, including cleaning liquid PENTACARBONYL iron, evaporation in the evaporator and decomposition when heated in a cylindrical reactor in the presence of gaseous ammonia fed simultaneously from pairs of PENTACARBONYL iron in the upper neck of the cylindrical reactor.The disadvantage of the prototype method is the existence of a large number of conglomerates of particles (30-32 wt.%) in the target powder QOL and the presence of particles of large quantities of nitrogen (0,95-1,92 wt.%).The objective of the invention is to reduce the number of conglomerates in the target powder QOL and reduction in particle QOL nitrogen.The technical result consists in obtaining of carbonyl iron powder with low content of conglomerates of particles of 4% or less and with low content of bound nitrogen 0.6% and less.The technical result is achieved by the fact that in the known method of obtaining finely powdered carbonyl iron, including cleaning liquid PENTACARBONYL iron, evaporation in the evaporator and decomposition when heated in a cylindrical reactor in the presence of ammonia gas supplied in the shadow evaporation of PENTACARBONYL iron is carried out at the rate of feed to the evaporator 41-45 l/h, and gaseous ammonia serves in the number of 25-28 l 1 l liquid PENTACARBONYL iron, and the decomposition is carried out in the reactor divided by the heated zone, and the temperature in the heated zone in the direction of the vapor PENTACARBONYL iron support: in the upper - 305-308oWith, in the middle 322-325oAnd at the bottom - 280-290oC.The proposed method of producing fine particles of QOL is as follows. Liquid PENTACARBONYL iron (Slana, Blesk) from the top of the dipstick is served at the site fine filtration, consisting of a system of three filtering devices. Then cleaned of fine particles of sooty carbon liquid Slana, Blesk flows through the filter, deep cleaning evaporator evaporator type with speed 41-46 l/h Generated in the evaporator at a temperature 109-114oWith a pair of Slana, Blesk evenly with the evaporation pdout inside vertical hollow reactor decomposition Slana, Blesk diameter 1.1 to 1.2 m and a height of 8.5-9.5 m through the upper neck of the reactor diameter 0,18-0,20 m Tangentially to the axis of the reactor decay in the same neck of the pair serves MN3heated to a temperature of 120-125oSince, in the amount of 25 to 28 liters for each liter of Slana, Blesk entering the evaporator. In the upper zone of the rector is heated to 322-325o(The"completion particle"). And finally, the lower zone of the decomposition reactor has a heat equal to 280-290oFrom ("area terazosine vapor Slana, Blesk"). The resulting decomposition Slana, Blesk carbon monoxide WITH with suspension of fine particles of QOL is fed to the recirculation gases, sequentially pass through the filter bag type (here select the fine fraction of the powder) and then through the filters and cyclones fine purification and separation (here selected more fine powder QOL). Purified from powder QOL carbon monoxide WITH using gas return in recycling decomposition Slana, Blesk, further increasing the feed rate of vapor Slana, Blesk and leading to the formation of more fine powder QOL over laminarioides mode flow.Example 1
Liquid Slana, Blesk sent from the top of the dipstick into the site fine filtration. First, it passes the filter, where it is cleaned from mechanical impurities (coarse scale, small pieces of unreacted iron-rich pellets, dirt, etc ). In the second filter completes the cleaning of smaller solids. Finally, in the third filter special design is deep cleaning and the synthesis Slana, Blesk flow, coming from the receiver WITH pressure.After the final cleaning from fine particles of sooty carbon liquid Slana, Blesk served in the evaporator Slana, Blesk speed 42,4 l/h Pair Fe(CO)5coming out of the evaporator at a temperature 109-110oWith send in the mixer with a diameter of 0.2 m and a height of 0.3 m, located in the upper part of the vertical reactor decomposition Slana, Blesk, having a diameter of 1.2 m and a height of the cylindrical part 9,0 m Here in the mixer, but from the side (tangentially to its axis) direct the flow of gaseous ammonia, heated to a temperature of 120oC. the Flow rate of NH3support equal to 27 liters per 1 l of liquid Fe(CO)5then there 1144,4 l/hIn the decomposition reactor Slana, Blesk support transanally temperature, providing the necessary temperature gradient for nucleation and formation of particles QOL necessary dispersion. In the upper zone temperature is equal to 306oWith, in the middle zone 325oWith and in the lower zone 290oC.From the decomposition reactor Slana, Blesk unload 62% powder QOL with particle sizes from 0.5 to 1.9 μm. Of the filter bag for reactor decay Slana, Blesk unload 34% powder QOL with particle sizes of 0.3 to 1.9 μm. From the fine filter WITH cyclones and unload 4% more Bremerton (4% vs. 30-32% in prototype), has a low content of bound nitrogen in comparison with the prototype (less than 0.6% vs. 0.9 to 1.9 per cent in the prototype) and does not contain other undesirable impurities. With regard to impurities associated carbon and oxygen in the particles of the iron powder CVD-iron, then they are equal on each of 0.7-0.9 wt.% and not have a negative impact on its functional properties when using powders obtained QOL in all sectors of the economy, above.Example 2 (method prototype)
Pair Slana, Blesk from the evaporator at a rate of 10 l/h served in the rector, in which at the same time introducing gaseous ammonia in the amount of 40 l per 1 l of liquid Slana, Blesk. In the upper zone of the reactor to maintain the temperature of 345oWith that in average 350oAnd at the bottom 330oC.Get the powder QOL from the decomposition reactor in the amount of 71% with a particle size from 2.5-4.0 μm. From the filter for reactor receive 28% of the powder QOL with particle sizes of 1.7-3.5 µm. From the cyclones get 1% powder QOL with a particle size of 1.1 to 1.5 μm.The powder has an average of 32% conglomerates of particles, and particles containing 0.9 to 1.9 wt. % bound nitrogen. The number of bound oxygen and carbon varies in the range of 0.95 to 1.76 wt.%. 1. A method of obtaining a fine powder brown heating in a cylindrical reactor in the presence of gaseous ammonia, filed simultaneously with pairs PENTACARBONYL iron in the upper neck of a cylindrical reactor, characterized in that the evaporation of PENTACARBONYL iron is carried out at the rate of feed to the evaporator 41-45 l/h, and gaseous ammonia is served in a number of 25-28 l 1 l liquid PENTACARBONYL iron, and the decomposition is carried out in the reactor divided by the heated areas.2. The method according to p. 1, characterized in that the temperature in the heated zone in the direction of the vapor PENTACARBONYL iron support in the upper - 305-308oWith, in the middle 322-325oAnd at the bottom of 280-290oC.
FIELD: for producing powders of metals and alloys and for applying coatings by means of gas-phase process.
SUBSTANCE: evaporator includes heater, cylindrical cells forming reservoir for melt metal, jets, ducts for inlet of melt metal and for outlet of its vapors, by-passing distributing branch pipes. According to invention heater is assembled of hollow cylindrical members mutually joined through electrically conducting couplings. Each cylindrical member of heater along its height serves as wall of cylindrical cell limiting size of cell in radial direction. On end of disc-like covers of each cylindrical cell (except upper lid along axis of which plug with duct melt metal inlet is mounted) jets are arranged coaxially relative to axis of evaporator. Plug and jet of upper cell and each next jets of cells restrict annular cone-like cavity inclined towards lower jet. Cavities and axial openings of jets form duct for outlet of vapor of melt metal.
EFFECT: reduced consumption of material, electric energy, improved operational reliability of structure.
FIELD: production of powder materials and suspensions used in medicine, pharmacology and so on.
SUBSTANCE: method comprises steps of evaporating matter by means of very large impulse of laser irradiation with specific energy more than 109 Wt/cm2 and time period less than 10-8 in order to provide ionization of evaporated matter; moving evaporated matter in focal lane relative to focus point of laser irradiation; condensing vapor in optically transparent liquid; realizing random or discrete-path motion of evaporated matter.
EFFECT: enhanced efficiency of process, lowered coagulation of fine powders.
3 cl, 1 dwg, 4 tbl, 3 ex
FIELD: gas-phase technology for producing finely dispersed and ultra dispersed metal powders.
SUBSTANCE: method comprises steps of heating metal till boiling temperature; evaporating it and condensing vapor; feeding metal vapor stream to condenser having shape of its working surface maximally similar to that of contour of vapor stream emission. Condensation and growth of metal particles are realized in zone with thickness approaching to constant thickness. Deposited metal powder is removed continuously along the whole working surface of condenser.
EFFECT: stable fraction size of powder particles, continuous process for producing powder that provides good influence upon strength of equipment.
2 cl, 1 dwg, 1 ex
SUBSTANCE: invention refers to metallurgy, particularly to evaporators for metals and can be implemented for fabrication of metal powders and for applying coating on various surfaces. The evaporator consists of a resistive heater, a circular evaporating chamber with a steam pipeline and with circular capacities for metal melt having overflow ports, the circular capacities are located in the circular evaporating chamber, then the evaporator consists of a sprayer unit located in the steam pipeline of the evaporating chamber and of a channel for supplying melt into the evaporating chamber. Also the heater is made as a heating rod. The evaporator is equipped with a tube element placed on the outside of the heating rod and coaxial to it and with a curricular metal receiver-melter disposed coaxially to the tube element on its upper part. The circular evaporating chamber is arranged in the heating rod, while the steam pipeline is made in form of an axial channel in the upper part of the heating rod and in form of tangential channels conjugated with it and with upper part of the evaporating chamber. The tube element is connected with the heating rod in the zone of the spraying unit assembly, while the channel for melt supply is coupled with the circular metal receiver-melter and with the upper circular capacity of the evaporating chamber.
EFFECT: reduced losses of electric power, and preventing steam condensation in sprayer unit and its obstruction with condensate products.
4 cl, 2 dwg
SUBSTANCE: invention pertains to the method and device for obtaining nanopowder from different materials. Method includes the vapourisation of the target with an electron beam, condensing of vapour of the material in the evaporation chamber and precipitation of nanopowder. Vapourisation of the target is carried out with a pulse electron beam with energy of no more than 100 keV, length of the pulses from 20 to 300 microseconds, energy density of not less than 1 MJ/cm2. Electron beam passes through the system for creating gas differential pressure, with whose help pressure in the range of 1-20 Pa is created in the evaporation chamber to cool particles, their precipitation is carried out on the cooled rotating disk. Device for the realisation of this method contains a pulse electron beam with a hollow cathode, wiring system and electron beam focusing, evaporation chamber, target and powder collecting system. Powder collecting system is made in the form of a cold rotating disk with a scraper, and a wiring system and electron beam focusing contains a system for creating gas differential pressure, consisting of a gas-dynamic nozzle, which is made with the capability of creating pressure in the range of 1-20 Pa is in the evaporation chamber.
EFFECT: invention makes it possible to obtain nanopowder with a typical size 3-5 nm and agglomerate from them with high productivity and low power costs.
2 cl, 4 dwg, 3 tbl
SUBSTANCE: cylindrical screen and located inside it heater are located co-axial. Cartridge for melt is located from the outside the cylindrical screen with formation of evaporator tank between inner surface of cartridge walls and outer surface of cartridge walls. Cylindrical screen, heater and container are located by longitudinal axis in horizontal plane. In end wall of container it is implemented hole, located higher longitudinal horizontal axis of container. Screen wall is implemented with developed external emitting surface. At its butt side it is implemented axial lug, by means of which cylindrical screen contacts to internal butt of container with formation of channel for melt steam outlet through the hole, implemented in end wall of container. On the top of container in the boy of its wall it is installed facility for melting and feeding of liquid metal into evaporator tank, consisting of melting pot, crane and metal pipeline.
EFFECT: evaporator structure is simple for implementation and operation with high performance measure and coefficient of efficiency for recovery of high-fidelity.
2 cl, 1 dwg
SUBSTANCE: method involves heating a workpiece in a focal zone using combined laser-optical radiation. Heating is done using a polychromatic radiation source which activates the near-surface volume of the workpiece and a high-power concentrated pulsed radiation laser. After that the vaporous material is placed in a cooled coil for coagulation and nanopowder particles are precipitated. The device has a reactor, a gas pipe for feeding gas into the reactor, a radiation source, an expansion chamber with a cooled coil for coagulation of the evaporated material, and fitted with a cone-shaped dust collector. The radiation source is composite and consists of a light-beam type source of polychromatic radiation and high specific power concentrated coherent pulsed radiation laser.
EFFECT: obtaining nanopowder with given range of dimensions, wide field of use of the powder.
2 cl, 7 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to production of zinc powder and can be used in production of antirust paints from zinc-containing stock. Zinc, not containing metal oxide admixtures, is heated, melted and evaporated in furnace at boiling temperature and above it in atmosphere of nitrogen. Zinc vapors are transferred via steam line by rarefaction produced by blower and equal to 50-150 Pa and cooled in steam line abrupt-cooling zone to produce powder. Zinc powder, in getting into magnetic trap built in dust duct, downstream of steam line abrupt-cooling zone, is purified of intermetallic compounds. Pure finely-dispersed zinc powder containing 99.95% of metallic zinc and with dispersity of 0.5-5 mcm comes into cyclone to get settled on hopper, while more fine zinc powder is entrapped by sleeve filter mounted downstream of exhaust blower.
EFFECT: higher powder quality, expanded application, perfected production hardware.
4 cl, 2 tbl, 1 dwg
SUBSTANCE: invention refers to production of powders and can be implemented for production of fine dispersed powders of specified dimensions. The disclosed here procedure consists in generating vacuum-arc discharge using cathode out of metal of produced powder. Cathode metal is melt in a cathode spot of vacuum-arc discharge. Metal is evaporated from the cathode spot and condensed on a massive cooled substrate. Also metal is evaporated at cathode temperature corresponding to a boundary of transition of vacuum-arc discharge with an integral-cold cathode into arc discharge with a hot cathode. Temperature of the cathode spot is facilitated by modulation of discharge current with pulse feed source connected with the cathode and having inductive decoupling with the main source of current feed.
EFFECT: production of qualitative powder of specified dimension without oxide film.
SUBSTANCE: proposed device comprises melted metal feed device, evaporator made up of cylindrical container closed by face covers with cylindrical heater arranged in container top section aligned with container face cover holes and furnished with bore for metal vapour to escape into condensation chamber, and condensation chamber. Proposed method comprises metal melting, its feed into evaporator container and vapour flow discharge into condensation chamber. Melted metal is fed into proposed device. First evaporator container is filled to 0.57-0.60 of its volume and, then, metal intermittent pulsed feed if performed with adjustment of preset melt level to allow intensive efflux of metal vapour from container into condensation chamber. Note here that container filling, heating and metal melt evaporation are carried out without contact between melt and heater at current density of 1.6-1.8 A/mm2 over the heater section.
EFFECT: high specific power content, efficiency and yield.
6 cl, 1 tbl, 1 dwg, 1 ex
FIELD: chemical and paint-and-varnish industries; production of inorganic pigments.
SUBSTANCE: proposed method includes leaching-out of serpentine ore mixture containing magnesium and chromium by sulfuric or hydrochloric acid for obtaining iron-containing solution which is treated with hydrogen peroxide and is neutralized to pH= 7.0-8.0. Suspension thus obtained is filtered and iron hydroxide residue is dissolved with sulfuric or hydrochloric acid, then it is treated with alkaline reagent to pH=2.0-6.0 and is filtered. Then, iron hydroxide residue is washed off water-soluble ions, dried and burnt at temperature of 550-700C.
EFFECT: wide range of tints in processing and decontamination of sulfate and chloride waste obtained at production of periclase and chromite concentrate.
2 cl, 5 tbl, 6 ex