• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
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  • 优先权
    • 专利摘要:
    In a process for working up a melt containing iron oxide and phosphorus oxides to obtain elemental phosphorus by carbothermic direct reduction of the phosphorus oxides, the melt is atomized and the resulting droplets are passed in contact with carbon monoxide as a reducing agent over a direct reduction line, in which the phosphorus oxides contained at least partially in gaseous elemental phosphorus are reduced and from which the melt droplets are fed together with the gaseous elemental phosphorus to a separator, by means of which the gaseous elemental phosphorus is separated from the melt droplets.
    公开号:AT518979A4
    申请号:T522/2016
    申请日:2016-11-15
    公开日:2018-03-15
    发明作者:Edlinger Alfred
    申请人:Radmat Ag；
    IPC主号:
    专利说明:

    The invention relates to a process for working up a melt containing iron oxide and phosphorous oxides for the production of elemental phosphorus by carbothermic direct reduction of the phosphorus oxides, and to an apparatus for carrying out such a process.
    The work-up of organic wastes, e.g. sewage sludge, dry sludge, sewage sludge ash and meat-and-bone meal is an important aspect of environmental technology and is particularly difficult due to the complex composition of the waste in question, in addition to largely harmless natural products, environmental toxins, such as heavy metals, halogens, pesticides, herbicides, antibiotics, carcinogenic and mutagenic pollutants, chlorinated hydrocarbons, polychlorinated biphenyls, hormones and endocrines contained in the waste. If the waste materials contain phosphorus oxides, it is in the context of the processing of waste materials to recover phosphorus as elemental phosphorus.
    The extraction of phosphorus, however, is made considerably more difficult if iron oxides are contained in the waste. Elemental phosphorus dissolves in iron melt at high temperatures to phosphorous iron (e.g., FesP). In the known methods, therefore, a considerable part of the phosphorus goes into the iron phase also formed there.
    This balance reduces or prevents the yield of elemental phosphorus.
    The extraction of elemental phosphorus by carbothermic direct reduction of the phosphorus oxides from a melt containing iron oxide and phosphorous oxides is known in
    Matinde et al., "Phosphorus Gasification from Sewage Sludge during Carbothermic Reduction" ISIJ International, Vol. 48 (2008), No. 7, pp. 912-917, where again a significantly lower phosphorus yield was observed when the starting material has a higher iron oxide content.
    The present invention therefore aims to improve a method and an apparatus of the type mentioned in that the extraction of elemental phosphorus from waste materials in a simple process manner and with high phosphorus yield is made possible.
    To solve this problem, the invention consists in a method of the type mentioned, i. in the production of phosphorus by carbothermic direct reduction of the phosphorus oxides from a melt, essentially in that the melt is atomized, the resulting droplets are passed in contact with carbon monoxide as a reducing agent over a direct reduction section, in which the phosphorus oxides contained at least partially in gaseous elemental Phosphorus can be reduced and from which the melt droplets are fed together with the gaseous elemental phosphorus to a separator, by means of which the gaseous elemental phosphorus is separated from the melt droplets.
    According to the invention, the phosphate reduction is therefore carried out with the aid of carbon monoxide as the reducing agent, carbon monoxide is preferably used at a temperature of 1200 -1,500 ° C. The direct reduction reaction can be described as follows: P2O5 + 5C0 -> 5 CO2 + P2-Im. In contrast, the reduction is carried out in conventional methods, e.g. in the classic Wöhler low-shaft furnace, above C, at the same time FexO is metallised.
    The fact that the oxide pre-melt is atomized in melt droplets, the surface of the melt exposed to the strongly reducing atmosphere is substantially increased. A preferred procedure in this context is that the atomization to produce melt droplets with a droplet size of 50pm - 2mm takes place. At melt temperatures of preferably 1,200 to 1,500 ° C, a significant portion of the P2O5 contained in the melt sublimes from the melt droplets into the gas phase and is immediately reduced to P2. Generally, pure P2O5 already sublimes at 362 ° C. In parallel, a carburizing of the already metallized iron takes place. Due to the large surface area of the melt, the diffusion-controlled sublimation and reduction processes proceed rapidly, with the reaction surface constantly renewed by internal diffusion. This renewal process is improved by the lowest possible viscosity of the melt, wherein a preferred procedure provides that the melt is atomized with a melt viscosity of 0.1 - 2.8 Pa-sec.
    It was further observed that the surface tension of the molten droplets is comparatively low and may preferably be about 0.5 N / m, which naturally also favors the desired exchange reactions.
    The surface tension of the iron carrier droplets formed by the reduction is considerably greater in this case and is preferably at e.g. 2.0 N / m.
    The atomization of the melt is preferably carried out by applying a gas to the melt. At the same time, atomization is also aided by the abrupt increase in volume that occurs in the sublimation and reduction processes due to the gas-phase formation (P205, PO, P02, P2 / CO).
    In order to prevent phosphation of the iron contained in the melt, it is crucial to withdraw the gas phase formed (P2 / CO) as quickly as possible and thus to escape the corresponding equilibrium. According to the invention it is therefore provided that the melt droplets are fed together with the gaseous elemental phosphorus to a separator, by means of which the gaseous elemental phosphorus is separated from the melt droplets. The shortest possible residence time in the direct reduction section is also preferably achieved by injecting the carbon monoxide into the direct reduction section at high speed (for example> 300 m / sec, preferably 500-700 m / sec). As a result, the melt droplets are vortexed with high turbulence.
    A particularly advantageous procedure consists in that the melt is atomized with the aid of the reducing agent as Zerstäubermedium. This can be done, for example, that the melt is discharged as a hollow cylinder melt from a tundish and the reducing agent is ejected into the interior of the hollow cylinder, the reducing agent is preferably ejected at a speed of 500-700 m / s. The hollow cylinder is disintegrated by the action of the high-speed gaseous reducing agent in droplets, filaments, ligaments and threads. The suppression produced in the tundish by the high-speed gas jet can thereby be broken by supplying return gas (CO) or O 2 or by means of a further gasification reaction (C / O 2).
    Another effect that hinders the phosphination is that the gas volume (CO / P2) is much larger than the volume of the iron-containing droplets formed, so that the diffusion-controlled phosphation proceeds very slowly corresponding to the relatively small iron surface and kinetically strongly inhibited , High CO partial pressure also reduces the phosphation, as P2 is diluted in the gas, thus reducing P2 fugacity.
    The rapid withdrawal of the gas phase formed, including the gaseous elemental phosphorus, takes place via the separator mentioned above. This is designed so that entrainment of molten droplets is prevented. For this purpose, the procedure is preferably such that the melt droplets and the gaseous elemental phosphorus and the CO formed are passed at the end of the direct reduction section in a particular inductively heated carbon bed in which a
    Droplet agglomeration takes place and the dripping melt is collected. In the course of droplet agglomeration on the particular inductively heated carbon bed, a ready reduction of the melt can take place. The melt then flows preferably into a forehearth, where appropriate, a separation of a slag takes place from the pig iron. The finish reduction may also be carried out in an InduCarb reactor, an iron bath, a blast furnace, an electric low shaft furnace or an SLN rotary kiln method.
    The gaseous elemental phosphorus (together with CO) is preferably passed through the particular inductively heated carbon bed and guided over a plurality of particular obliquely upwardly directed channels in a arranged in the carbon bed separator tube of the separator. The withdrawal of the gas phase then takes place via the separator tube, which preferably also consists of carbon, in particular graphite, and is inductively heated. The withdrawn gas phase can be cooled, for example via a regenerator heat exchanger to about 300 ° and further treated in a conventional manner. For example, phosphorus is present in the separator as gaseous P2 and after gas cooling as P4. The condensed white phosphorus is withdrawn and part of the CO released from P4 can be used, for example, as a return gas for the tundish.
    The CO2 formed in the reduction of P2O5 is reduced in the reactor by means of C directly to CO, according to the Boudouard reaction: C02 + C -> 2 CO. The CO formed is again available as a reducing agent for the reduction of the phosphorus oxide to elemental phosphorus available. A preferred procedure in this context provides that carbon monoxide is introduced together with solid carbon, in particular powdered carbon.
    It is preferably provided here that the reducing agent is produced in a gasifier by partial combustion of a fine-grained carbon support to carbon monoxide and solid carbon. As the carbon carrier, e.g. Coke powder, activated carbon powder, charcoal powder, anthracite dust. Pure CO / C can also be generated, e.g. by sooting partial combustion, are used. It is important that the carbon carrier water or. is hydrogen-free to avoid unwanted phosphine formation.
    The direct reduction of P2O5 to P2 with the aid of CO is an endothermic reduction reaction which leads to a decrease in the temperature in the direct reduction section.
    In a secondary reaction, the CO 2 formed reacts with the optionally injected pulverized coal in the likewise endothermic Boudouard reaction to CO. This leads to a further decrease in temperature. However, in order to maintain an isothermal operating state, it is preferably provided that excess carbon particles are gasified exothermically. For this purpose it can be provided that oxygen or an oxygen-containing gas is injected into the direct reduction section in order to effect gasification of the solid carbon, which is preferably introduced with the reducing agent, into carbon monoxide. This results in very hot oxidizing combustion zones (C02-rich) of more than 2,000 ° C, which leads to the thermal dissociation and sublimation of P2O5, PO, P02.
    The injection of oxygen can be used simultaneously to form turbulent flow conditions, in particular a turbulent flow, in at least a portion of the direct reduction section. The generation of turbulent flow conditions in the direct reduction section is advantageous in order to maximize diffusion processes in the gas phase because the gas viscosity rises sharply due to the increase in temperature. If the melt atomization by means of ejected into the interior of a hollow cylinder hollow carbon monoxide, succeeds in a further disintegration of the
    Hollow cylinder by the fact that the oxygen is e.g. is ejected via a plurality of hole nozzles, wherein the hole nozzles are preferably arranged along a ring surrounding the dividing hollow cylinder.
    In particular, when the introduced melt has a high P20s content of e.g. greater than 8 wt .-%, may preferably be such that the injection of oxygen or an oxygen-containing gas to at least two, in particular several successive in the flow direction of the direct reduction section is carried out to fractionate the excess C-dust partially fractionated. Furthermore, it can be provided that solid carbon, in particular dust-like carbon, is introduced into the direct reduction section at at least two, in particular a plurality of points succeeding one another in the flow direction. By such a cascade-like arrangement of the oxygen and possibly Kohlenstoffaufgäbe along the direct reduction line succeeds a gradual reduction.
    A preferred procedure provides that the CC> 2 partial pressure prevailing at the end of the direct reduction section is measured. This metric gives the
    Carbon conversion level and can be used to control the amount of introduced solid carbon. In particular, the regulation can be made to the effect that only small or no C particles are introduced into the area of the separator, in particular into the carbon bed, in order to avoid blockages. The Fertigreduktion, possibly also the
    Iron metallization, will then be carried out in the carbon bed.
    The melts to be worked up in the process according to the invention can be used either as a by-product of a process, e.g. a metallurgical process, incurred directly in the form of a melt or are formed by melting solid waste.
    The melts to be worked up preferably comprise a homogeneous, molecularly disperse mixture of CaO, MgO, SiO 2, Al 2 O 3, FexO and P 2 O 5. The melting range is preferably between 1,180 and 1,480 ° C, depending on the composition. In particular, the content of FexO acts strongly liquefying and reduces the melting temperature range. To a lesser extent, this also applies to MgO.
    It is preferably provided here that the melt is atomized at a melt temperature of 1200-1500 ° C.
    Preference is given as a melt minette-ore melt, phosphathältige steelworks slags (especially from the LD converter or the electric furnace), apatite melt, molten sewage sludge ash, molten animal and / or bone meal, wavelellite melt, Vivianit melt or mixtures used hereof.
    The Ca0 / SiO2 ratio of the melt is preferably 0.8-1.4, preferably 0.8-1.2.
    The melt to be worked up in the context of the process according to the invention can, for reasons of reduction or for reasons of melt liquefaction, preferably start from a mineral premelt whose Ca0 / SiO2 ratio is adjusted to a value of 0.8-1.2 by means of silicate and / or lime carrier , Such pre-melts can be produced, for example, in a flash reactor, a melting cyclone, a rotary kiln or a gas-fired coke-free shaft furnace. Preferably, the pre-melt is recovered under oxidizing conditions. Various impurities, e.g. Hg, Cd, Zn, Pb, Cu, alkalis and halogens are volatilized and treated in a separate gas treatment. As lime carriers for setting a CaO / SiC> 2 ratio of 0.8-1.2, preference may be given to limestone, burnt lime, lime marl, CaCl 2 (for example as a by-product of the Solvay process), cement clinker furnace bypass dust, steelworks slag and / or refractory -Outbreaking material used. As silicate supports for setting a Ca0 / SiO2 ratio of 0.8-1.2, quartz dust, grinding dusts from the glass industry, waste glass and / or foundry used sand can preferably be used.
    It is preferably provided here that the melt is atomized with a melt viscosity of 0.1-2.8 Pa-sec.
    To solve the problem underlying the invention, a device for carrying out the method according to the invention is provided according to a further aspect, comprising a tundish with a leading into a direct reduction reactor outlet and an ejector for ejecting carbon monoxide and possibly C-dust in the region of the outlet for atomizing the outflowing melt in melt droplets, wherein the direct reduction reactor is followed by a separator which is designed to separate gaseous, elemental phosphorus and CO formed by the melt droplets in the direct reduction reactor.
    It is preferably provided that the separator comprises an in particular inductively heatable carbon bed, in which a droplet agglomeration takes place.
    The carbon bed consists of lumpy carbon, in particular graphite or metallurgical coke.
    Preferably, it is further provided that the separator comprises a Separatorrohr, which is arranged in the carbon bed and having a plurality of particular obliquely upwardly directed channels, via which the gaseous phosphorus from the carbon bed into the interior of the separator tube is feasible ,
    The Separatorrohr is preferably made of carbon, in particular graphite and may be inductively heated. The surface of the separator tube is siliconized for abrasion reasons (hard silicon carbide surface).
    It is preferably provided that at least one nozzle for the introduction of oxygen or an oxygen-containing
    Gas is provided in the direct reaction chamber. The annular nozzle may in this case be arranged coaxially to the axis of the Tundishauslaufes in the direct reduction chamber.
    It is preferably provided that nozzles for injecting oxygen or an oxygen-containing gas into the direct reaction chamber are arranged at at least two, in particular a plurality of, successive points in the flow direction or open into the direct reduction chamber.
    Furthermore, nozzles for the impingement of solid carbon, in particular dust-like carbon, may be provided on at least two, in particular a plurality of points of the direct reduction chamber which follow one another in the flow direction.
    A cascade arrangement is possible not only with respect to the nozzles for injecting oxygen and with respect to the nozzles for penetrating solid carbon, but also with respect to the separator. At least two, in particular a plurality of separators may be provided on or in the direct reduction chamber in order to remove fractionated P2 / CO and thus to bring the equilibrium in the desired direction.
    Preferably, a carburetor is further provided to which a fine-grained carbon carrier and oxygen can be supplied and which has a particular nozzle-shaped ejection opening, which forms the ejector for ejecting the carbon monoxide formed in the carburetor in the region of Tundishauslaufs.
    It is preferably provided that a particular height-adjustable weir tube is arranged in the tundish whose lower edge defines an annular gap-shaped outlet cross-section. In the weir tube here in particular a lance adjustable in height for the introduction of carbon monoxide can be arranged in the direct reduction reactor. By way of the annular chamber which is bounded on the outside by the weir tube and internally by the lance, carbon particles and possibly oxygen can preferably be sucked in and thus introduced into the reactor 7.
    The invention will be explained in more detail with reference to embodiments shown schematically in the drawing. 2 shows a detailed view of the melt atomization according to FIG. 1, FIG. 3 shows a detail view of a melt atomization in a modified embodiment, FIG. 4 shows an alternative embodiment of the direct reduction section of FIG 6 is a schematic representation of a carburettor combustion chamber for use in a device according to FIG. 1, FIG. 7 is a horizontal section of the device according to FIG. 6, FIG. 9 is a partial view of the annular nozzle according to FIG. 8 in a horizontal section and FIG. 10 is an enlarged partial view of the separator. FIG.
    In Fig. 1, a tundish is denoted by 1, in which the melt 2 to be worked up at a temperature of e.g. 1.200-1.500 ° C is present. The melt preferably consists of a homogeneous, molecularly disperse mixture of CaO, MgO, SiO 2, Al 2 O 3, FexO and P 2 O 5. The FexO content causes high refractory corrosion rates, so that the melt 2 to be processed is placed on a Sn / Ni / Cu bath 3 to protect the refractory lining of the Tundish 1. The metal bath also ensures the necessary even heat distribution, since the mineral melt, in contrast to the metallic melt has a low conductivity. This would cause the melt to freeze in the atomizer head. The outlet opening of the tundish 1 is denoted by 4 and may be formed by a perforated brick with an annular chamber 5 through which cooling medium is passed for cooling the perforated brick. The melt 1 runs out of the tundish 1 into the reactor 7 in the form of a hollow cylinder 6.
    In a pressure carburetor 8 arranged above the tundish 1, a solid, fine-grained carbon carrier tangentially fed via the line 9 is gasified by means of oxygen in order to produce gaseous CO and solid C. The carburetor 8 is preferably operated at a temperature of 1200-1,500 ° C and a pressure of 2-5 bar. Due to the tangential introduction of the carbon carrier, a cyclonic flow is formed inside the gasifier 8 with which the gasification product is transported in the direction of the discharge nozzle 10. CO and C is ejected from the carburetor 8 via the discharge nozzle 10 due to the pressure gradient at a speed of preferably 300-700 m / sec, the discharge nozzle 10 being arranged coaxially with the discharge opening 4 of the tundish 1. As clearly shown in Fig. 2, CO and C are discharged as a reducing agent in the reactor 7, wherein the reducing agent is simultaneously used as a sputtering medium for atomizing the hollow cylinder 6 melt into small melt droplets. For this purpose, the reducing agent is discharged from the discharge nozzle 10 into the interior of the hollow cylinder 6, where it disintegrates the hollow cylinder 6 in droplets, filaments, ligaments and threads.
    In the field of melt atomization, inside the reactor 7, an annular channel 11 for introduction of oxygen is arranged, which has a plurality of downwardly and / or inwardly converging hole nozzles, from which the oxygen is ejected directed onto the dispersing melt. This results, as indicated by the arrows 12, a turbulent flow in the diameter-expanded section 13 ("vortex chamber") of the reactor 7 and the particles are further disintegrated.
    In section 13 of the reactor 7 reach the
    Melt droplets in contact with the carbon monoxide from the gasifier 8, whereby the contained in the melt phosphorus oxides are at least partially reduced in gaseous elemental phosphorus. The formation of gaseous phosphorus increases the volume in section 13 of the reactor 7, so that this section is formed in comparison to the subsequent section 14 of larger diameter.
    The CO2 formed in the reduction of P2O5 is determined by means of the supplied from the carburetor 8 fixed
    Carbon particles reduced to CO according to the Boudouard reaction. The formed CO stands again as
    Reducing agent for the reduction of phosphorus oxide to elemental phosphorus available.
    The section 13 and the section 14 of the reactor 7 together form the direct reduction section in which the reduction reactions described above take place. The injection of oxygen takes place in order to maintain an isothermal operating state along the direct reduction section. With the injected oxygen, carbon particles are gasified exothermically to carbon monoxide. As a side reaction takes place: C / CO + O2 -> CO2 (about 2,200 ° C), causing a thermodissociation of P2O5 and immediately connect a back reaction and a cooling: CO2 + C -> 2C0.
    At the end of the direct reduction section, the melt droplets, together with the gas phase, which comprises the gaseous elemental phosphorus and CO and possibly CO 2, are fed to a separator 15, by means of which the gas phase is separated from the melt droplets. As the housing of the separator 15, the elongated housing of the reactor 7 can be used, so that an adjoining directly to the direct reduction section arrangement of the separator 15 is achieved. The separator comprises a carbon susceptor 16 of lumpy carbon, e.g. Graphite. The coil of the induction heating through which the alternating current flows is denoted by 17 and is arranged surrounding the housing.
    The melt droplets guided into the carbon susceptor 16 or the inductively heated carbon charge are subjected to droplet agglomeration there, wherein the dripping melt is collected in a collecting vessel 18 arranged underneath. In the carbon bed 16 also residual reduction processes can be performed. The gas phase passes through the carbon bed 16 and is guided into the separator tube 20 via a plurality of in particular obliquely upwardly directed channels 19 which are formed in a separator tube 20 of the separator arranged in the carbon bed 16. The separator tube may e.g. be formed as superficially siliconized graphite hollow cylinder. From there, the gas phase, which here has a temperature of about 1200-1,500 ° C, passes via a line 21 in a regenerator heat exchanger 22, with which the gas phase to e.g. 300 ° C is cooled. After gas cooling, the phosphorus is present as P4 and can be withdrawn as P4 condensate at 23. A portion of the CO exempted from P4 can be withdrawn via line 24 and used, for example, as a return gas for the tundish 1. Possible pollutants, alkalis, halogens and heavy metals condense at over 300 ° C and can be removed there by means of fractional condensation, so that pure P4 is recovered.
    The used fraction of the carbon bed 16 can be replaced by adding the material of the carbon bed to the reactor via a lock (not shown) arranged in section 14.
    The melt collected in the collecting vessel 18 is brought into a forehearth 25, from which slag 26 and pig iron 27 can be tapped separately.
    The inductive heating of the carbon bed 16 is preferably carried out according to a dual frequency method. The lumpy bed 16 well couples in at an inductively applied AC voltage between 80-160 kHz, but is transparent for frequencies between 2-15 kHz. At these frequencies, the separator tube 20 then optimally couples. Thus, the known skin effect can be equalized and you can move the temperature field depending on the performance over the cross section of the carbon bed 16. Operation can be either continuous or clocked / intermittent. The melt droplets from the reactor 7 coagulate in the carbon bed 16 to a continuous slag flow whose temperature can be adjusted depending on the power. It may be advantageous to let the melt solidify in the carbon bed 16 - this results in an absolutely droplet-free product gas, which is withdrawn radially. With a defined pressure loss between the carbon bed 16 and product gas take-off, the melt can be withdrawn again via a temperature increase and the carbon bed 16 thus regenerated.
    Of course, it is also conceivable to arrange such (even smaller) Separatoreinheiten already directly in or along the direct reduction section of the reactor 7, to realize here already partial product gas deductions. The balance of the phosphate reduction shifts in the desired direction. For example, the said separator units are flanged radially on the reactor tube.
    In the enlarged view of FIG. 2, the atomization of the expiring from the tundish 1 hollow cylinder 6 is shown, the training corresponds substantially to the training already shown in Fig. 1. Notwithstanding FIG. 1, however, a tundish 28 is arranged in the tundish 1, which separates the outlet region of the tundish 1 from the melt supply region.
    Furthermore, with reference to FIG. 2, the preferred nozzle parameters for atomizing the melt can be explained. The slag flow elevation with respect to the perforated stone of the tundish 1 may preferably be between 2 and 7 mm. The vertical distance between the Schmelzeabrisskante and the annular nozzle 11 is denoted by y and is highly dependent on the
    Melt viscosity: at high viscosity, it is preferable to choose y as 0 mm or slightly negative. At low viscosity, the distance y may be e.g. be chosen about 70 mm. Another influencing factor with regard to the atomization is the so-called "prefilming", ie the formation of the largest possible melt film surface by gravity.
    The horizontal distance between the exiting from the annular nozzle 11 secondary jet and the axis of the outlet opening 4 has a relatively small influence on the atomization. According to the Bernoulli equation, the high velocity of the oxygen emerging from the annular nozzle generates a suppression which accelerates the melt particles into the secondary gas flow (oxygen flow) and further disintegrates there.
    The angle .alpha. (Primary jet) can preferably be selected so that it lies between 15.degree. And 35.degree., Depending on the nozzle admission pressure. With regard to the secondary beam angle (angle of the beam emerging from the annular nozzle 11), good results were obtained at 0 ° (ie vertical). It is believed that angles of up to +/- 15 ° can also give good results. It is also conceivable to arrange the individual secondary jet hole nozzles alternately in +/- angular orientation. Thus, the best disintegration result seems possible.
    Furthermore, it has been observed that the secondary nozzle oxygen exiting via the annular nozzle 11 can advantageously effect the cooling (formation of slag fur) in the perforated brick. The secondary oxygen is heated isobarically, which leads to a better evaporation or sputtering result due to the increased 02 volume flow.
    In Fig. 3 a modified embodiment of the melt atomization is shown. The outlet opening 4 of the tundish 1 is delimited by an annular nozzle block 29, which is surrounded by a graphite ring 30, to which an inductor 31 connected to an AC voltage source 32 is assigned. The inductive heating of the tundish outlet 4 achieved thereby makes it possible to keep the outflowing melt at the required temperature. A weir tube 33, which is arranged coaxially with the outlet opening 4, now dips into the melt 2 and defines between its lower edge and the tundish bottom an annular gap over which the melt runs out. If the weir tube 33 is adjustable in height, the outflowing melt stream can be adjusted. Inside the weir pipe 33, a lance 34 is arranged adjustable in height, which extends with its lance nozzle 36 in the expiring melt hollow cylinder 6. CO is injected at high speed via the lance and atomizes the outflowing hollow cylinder 6 in the reactor 7. C and oxygen can be sucked in through the annular gap between the weir pipe 33 and the lance. In the reactor 7, in turn, an annular nozzle 11 may be arranged for the injection of oxygen.
    Fig. 4 shows an enlarged view of the portion 14 of the reactor 7 in a modified embodiment. Arranged along the direct reduction section are annular nozzles 37, via which oxygen can be injected into the section 14 of the reactor 7, this taking place in order to maintain an isothermal operating state by exothermically gasifying excess carbon particles with oxygen. Each annular nozzle 37 is assigned a temperature sensor 38, wherein the amount of oxygen to be injected takes place in dependence on the measured values of the respective temperature sensor 38. As shown in the cross-sectional view of FIG. 5, the annular nozzles 37 are designed so that oxygen is tangentially injected into the reactor 7, whereby a central reaction vortex is formed. In the immediate area of the oxygen introduction C02 focal spots 40 can arise, which can locally lead to temperatures up to 2200 ° C, causing a calcination or Thermodissoziation of Ca3 (PC> 4) 2. The above-described formation of a reaction vortex minimizes contact with the inner refractory lining of the reactor 7, so that it is not excessively attacked.
    Furthermore, solid carbon particles can also be introduced into the section 14 of the reactor 7 along the direct reduction section, as indicated by the arrows 39. The incorporation of the carbon particles is intended to cause the reaction of CO 2 formed in the reduction reaction in CO according to the Boudouard reaction. While there are oxidizing conditions in the reactor 7 in the region of the introduction of oxygen, there are in between, in particular in the region of
    Carbon input reducing conditions given.
    At the end of the direct reduction section, a sensor 41 may be arranged in the reactor 7, which measures the CÖ2 partial pressure. This measured value indicates the degree of carbon conversion, since preferably only small or no C particles are to be introduced into the carbon bed 16 of the separator 15 in order to avoid blockages. The introduction of oxygen via the lowermost ring nozzle 37 can be regulated here as a function of the measured values.
    Fig. 6 shows an embodiment of the carburetor 8 including carbon supply. Carbon dust is supplied via a pressure-resistant double pendulum flap 42, from which the carbon dust passes into a metering container 43. From there, the introduction into the gasifier 8 via a metering device, such. a rotary valve 44. The carbon dust is introduced from above via a central opening in the carburetor 8. The refractory lining of the gasifier 8 may e.g. consist of SiC.
    In Fig. 7 it can be seen that the oxygen introduction into the carburetor 8 via two diametrically arranged tangential feeds 45 takes place, whereby the desired cyclonic flow is generated in the interior of the carburetor 8.
    8 and 9, the annular nozzle 11 is shown enlarged. It can be seen that the annular nozzle 11 has an annular nozzle chamber 46 which has a circular row of hole nozzles 47 formed in a nozzle plate 51. The annular nozzle chamber 46 is surrounded by a cross-sectionally U-shaped cooling water channel 48, which comprises a cooling water inlet 49 and a cooling water outlet 50. Furthermore, the annular nozzle can carry a refractory jacket 52.
    In Fig. 10, the separator 15 is shown in a partial view. The separator 15 comprises a carbon susceptor 16 of lumpy carbon, e.g.
    Graphite or metallurgical coke or mixtures thereof. The alternating current through coil 17 surrounds the housing and suitable to heat the carbon susceptor 16 and the separator tube 20. The annular elements 53 projecting obliquely downwards on the separator tube form channels 19 running obliquely upwards and prevent melt droplets or the carbon of the susceptor 16 from being carried into the interior of the separator tube 20.
    权利要求:
    Claims (25)
    [1]
    Claims:
    1. A process for working up a melt containing iron oxide and phosphorus oxides to obtain elemental phosphorus by carbothermic direct reduction of the phosphorus oxides, characterized in that the melt is atomized, the resulting melt droplets are passed in contact with carbon monoxide as a reducing agent over a direct reduction section, in which contained phosphorus oxides are at least partially reduced in gaseous elemental phosphorus and from which the melt droplets are fed together with the gaseous elemental phosphorus to a separator, by means of which the gaseous elemental phosphorus is separated from the melt droplets.
    [2]
    2. The method according to claim 1, characterized in that the melt is atomized by means of the reducing agent as Zerstäubermedium.
    [3]
    3. The method according to claim 2, characterized in that the melt is discharged as a hollow cylinder melt from a tundish and the reducing agent is ejected into the interior of the hollow cylinder, the reducing agent is preferably ejected at a speed of 500-700 m / s.
    [4]
    4. The method of claim 1, 2 or 3, characterized in that the atomization for the production of melt droplets with a droplet size of 50μπι - 2mm.
    [5]
    5. The method according to any one of claims 1 to 4, characterized in that the melt is atomized at a melt temperature of 1,200 - 1,500 ° C and / or with a melt viscosity of 0.1 - 2.8 Pa-sec.
    [6]
    6. The method according to any one of claims 1 to 5, characterized in that carbon monoxide is introduced together with solid carbon, in particular pulverulent carbon, wherein carbon monoxide is preferably introduced at a temperature of 1200 - 1500 ° C.
    [7]
    7. The method according to claim 6, characterized in that the reducing agent is prepared in a gasifier by partial combustion of a fine-grained carbon support to carbon monoxide and solid carbon.
    [8]
    8. The method according to any one of claims 1 to 7, characterized in that is injected into the direct reduction line oxygen or an oxygen-containing gas to effect gasification of preferably introduced with the reducing agent solid carbon to carbon monoxide, wherein the injection preferably for the formation of turbulent flow conditions , in particular a turbulent flow, takes place in at least a portion of the direct reduction section.
    [9]
    9. The method according to claim 8, characterized in that the injection of oxygen or an oxygen-containing gas takes place at least two, in particular a plurality of successive points of the direct reduction section in the flow direction.
    [10]
    10. The method according to any one of claims 6 to 9, characterized in that solid carbon, in particular dust-like carbon, is introduced into at least two, in particular a plurality of successive points in the flow direction in the direct reduction section.
    [11]
    11. The method according to any one of claims 1 to 10, characterized in that the melt droplets and the gaseous elemental phosphorus are passed at the end of the direct reduction section in a particular inductively heated carbon bed in which or a droplet agglomeration takes place and collected the dripping melt becomes.
    [12]
    12. The method according to claim 11, characterized in that the gaseous elemental phosphorus is passed through the particular inductively heated carbon bed and is guided over a plurality of particular obliquely upwardly directed channels in a arranged in the carbon bed separator tube of the separator.
    [13]
    13. The method according to claim 12, characterized in that the separator tube made of carbon, in particular graphite and is inductively heated.
    [14]
    14. A device for carrying out a method according to any one of claims 1 to 13, comprising a tundish with a leading into a direct reduction reactor outlet and an ejector for ejecting carbon monoxide in the region of the outlet for atomizing the effluent melt in melt droplets, wherein the direct reduction reactor Separator connects, which is formed for the separation of formed in the direct reduction reactor, gaseous elemental phosphorus from the melt droplets.
    [15]
    15. The apparatus according to claim 14, characterized in that the separator comprises a particular inductively heated carbon bed, in which or a droplet agglomeration takes place.
    [16]
    16. The apparatus of claim 14 or 15, characterized in that the separator comprises a Separatorrohr, which is arranged in the carbon bed and having a plurality of particular obliquely upwardly directed channels, via which the gaseous phosphorus from the carbon bed in the interior of the separator tube is feasible.
    [17]
    17. The apparatus according to claim 16, characterized in that the separator tube made of carbon, in particular graphite and is inductively heated.
    [18]
    18. Device according to one of claims 14 to 17, characterized in that at least one nozzle for the introduction of oxygen or an oxygen-containing gas is provided in the direct reaction chamber.
    [19]
    19. The apparatus according to claim 18, characterized in that an annular nozzle is arranged coaxially to the axis of Tundishauslaufes in the direct reduction chamber.
    [20]
    20. The apparatus of claim 18 or 19, characterized in that nozzles are arranged for injecting oxygen or an oxygen-containing gas into the direct reaction chamber at least two, in particular a plurality of successive points in the flow direction or open into the direct reduction chamber.
    [21]
    21. Device according to one of claims 14 to 20, characterized in that nozzles are provided for the impingement of solid carbon, in particular dusty carbon, at least two, in particular a plurality of successive points in the flow direction of the direct reduction chamber.
    [22]
    22. Device according to one of claims 14 to 21, that a carburetor is provided to which a fine-grained carbon carrier and oxygen can be fed and which has a particular nozzle-shaped ejection opening, which forms the ejection device for ejecting the carbon monoxide formed in the carburetor in the region of Tundishauslaufs.
    [23]
    23. Device according to one of claims 14 to 22, that in Tundish a particular height-adjustable weir pipe is arranged, whose lower edge defines an annular gap-shaped outlet cross-section.
    [24]
    24. The device according to claim 23, that in the weir pipe, in particular a height-adjustable lance for the introduction of oxygen or an oxygen-containing gas is arranged in the direct reduction reactor.
    [25]
    25. The apparatus of claim 24, that an outside of the weir tube and inside of the lance limited annular chamber is connected to the carburetor and forms the ejector for carbon monoxide.
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    同族专利:
    公开号 | 公开日
    EP3541745B1|2021-12-22|
    EP3541745A1|2019-09-25|
    WO2018091959A1|2018-05-24|
    AT518979B1|2018-03-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4351813A|1981-05-20|1982-09-28|Occidental Research Corporation|Process for producing phosphorus pentoxide or phosphorus or phosphoric acid|
    AT509593B1|2010-11-15|2011-10-15|Sgl Carbon Se|METHOD FOR REPROCESSING ORGANIC WASTE MATERIALS|
    AT408437B|2000-02-22|2001-11-26|Holderbank Financ Glarus|DEVICE FOR SPRAYING LIQUID MELT|
    AT410640B|2000-07-07|2003-06-25|Tribovent Verfahrensentwicklg|METHOD AND DEVICE FOR SPRAYING METAL MELT|
    DE102013010138A1|2013-06-15|2014-12-18|ingitec Engineering GmbH|Production of elemental phosphorus from phosphorus-containing wastes in coke-fired shaft furnaces operated with air and / or oxygen|WO2021152386A1|2020-02-02|2021-08-05|Radmat Ag|Method for separating phosphorus and/or phosphorus compounds from phosphorus carriers and/or phosphate carriers containing iron |
    法律状态:
    2020-09-15| PC| Change of the owner|Owner name: ALFRED EDLINGER, AT Effective date: 20200721 |
    优先权:
    申请号 | 申请日 | 专利标题
    ATA522/2016A|AT518979B1|2016-11-15|2016-11-15|Process and device for working up a melt containing iron oxide and phosphorous oxides|ATA522/2016A| AT518979B1|2016-11-15|2016-11-15|Process and device for working up a melt containing iron oxide and phosphorous oxides|
    EP17805253.6A| EP3541745B1|2016-11-15|2017-11-15|Process and apparatus for workup of a melt containing iron oxide and phosphorus oxides|
    PCT/IB2017/001378| WO2018091959A1|2016-11-15|2017-11-15|Process and apparatus for workup of a melt containing iron oxide and phosphorus oxides|
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