RU2000117458A - METHOD OF REFORMING A GAS-DETERMINANT IN THE PROCESS OF OXIDE REDUCTION IN A PSE-WATERATED LAYER - Google Patents

Claims (24)

1. A method of reforming a gaseous deoxidizing agent in a fluidized bed deoxidation process in a series of deoxidizing ore reactors, which consists in passing the ore through several deoxidizing reactors comprising the last reactor and at least one previous reactor, and the gaseous deoxidizer is passed through the last reactor with a gaseous deoxidizer so as to deoxidize the ore in this last reactor, whereby a part of the exhausted gaseous deoxidizer flows from this last reactor, including methane and metallized iron dust, with a partially used gaseous deoxidizing agent, mix the oxygen source so that this oxygen source can burn off part of the methane in the presence of metallized iron dust and get the reformed gaseous deoxidizer, and the reformed gaseous deoxidizer is fed into the previous reactor. 2. The method according to claim 1, wherein the deoxidizing capacity (N _R ) of the partially spent gaseous deoxidizing agent is 4.5 and in which the deoxidizing capacity of the gaseous deoxidizing agent subjected to reforming is 6.2, and the deoxidizing ability is determined as follows
N _R = (H ₂ + CO) / (H ₂ O + CO ₂ ),
where H ₂ , CO, H ₂ O and CO ₂ mean the percentage volume content of these components in the partially spent gaseous deoxidizer and the gaseous deoxidizer subjected to reforming. 3. The method according to p. 1, in which the partially exhaust gaseous deoxidizer, exhaust from the last reactor, characterized by the following volumetric composition: about 48-52% hydrogen, 6-10% carbon monoxide, 20-27% methane, 1.0-1 , 5% carbon dioxide, 10-12% water vapor and the rest nitrogen, and temperatures ranging from about 750 to about 790 ^o , and the reformed gaseous deoxidizer is characterized by the following volume composition: about 50-62% hydrogen, 12-20% monoxide carbon, 4-12% methane, 1-4% carbon dioxide, 8-10% water vapor and the rest azo t, and a temperature in the range from about 780 to about 800 ^o C. 4. The method according to p. 3, in which at the stage of mixing receive a mixture of products of partial combustion, which is characterized by the following volumetric composition: about 40-46% hydrogen, 6-8% carbon monoxide, 17-20% methane, 3-6% dioxide carbon, 12-18% water vapor and the rest nitrogen, and a temperature in the range from about 780 to about 820 ^o C. 5. A method according to claim 1, wherein the partially spent gaseous deoxidizer comprises metallized iron dust in an amount from about 5 to about 50 g / m ³ .  6. A method according to claim 5, in which the metallized iron dust contains from about 78 to about 85% metallic iron.  7. A method according to claim 1, wherein the last reactor and the previous reactor communicate via a gas line to transfer the partially spent gaseous deoxidizer and in which a source of oxygen is introduced into this gas line to mix with the partially used gaseous deoxidizer.  8. The method of claim 7, wherein the oxygen source is selected from the group consisting of air, oxygen, and mixtures thereof.  9. The method according to claim 1, wherein in the mixing step, a mixture of gaseous products of partial combustion is obtained, which enters the previous reactor, and in which in this previous reactor there are internal surfaces with which the mixture of gaseous products of partial combustion contacts, and the method further includes managing this process in such a way that metallized iron dust forms deposits on these surfaces, resulting in deposits of metallized iron dust on these surfaces, whereby such deposits of metallized iron dust act as a catalyst for converting a mixture of gaseous products of partial combustion into a reformed gaseous deoxidizer.  10. The method according to p. 9, in which the deposits of metallized iron dust are characterized by the following mass composition: about 78-85% metallic iron, 0.1-0.6% calcium oxide, 0.1-0.3% magnesium oxide, 0 , 9-2.5% silica, 0.5-1.8% alumina and 12-20% iron oxide. 11. The method according to claim 9, wherein the deposits of metallized iron dust are characterized by a specific surface area ranging from about 3 to about 10 cm ² / g. 12. The method according to claim 9, which includes an initial stage in which the previous reactor operates at a temperature ranging from about 780 to about 790 ^o C and on which deposits of metallized iron dust are formed on said surfaces, and a subsequent stage in which the previous reactor operates at a temperature in the range from about 760 to about 770 ^o C and which suppresses further formation of deposits of metallized iron dust. 13. The method according to p. 1, in which the stage of mixing includes mixing the oxygen source with a partially exhaust gaseous deoxidizer in such a way as to obtain a mixture, which is characterized by the value of the reforming ratio (CH ₄ / N _oh ) ranging from about 57 to 72, where CH ₄ indicates the volume percentage of methane, and the value of N _ooh is determined as follows
N _oh = (CO ₂ + H ₂ O) / (CO + CO ₂ + H ₂ + H ₂ O),
where CO, CO ₂ , H ₂ and H ₂ O mean the percentage by volume of these components in the mixture. 14. The method according to claim 1, wherein the last reactor and the previous reactor operate at a temperature difference of not more than about 20 ^o C.  15. The method of claim 1, wherein the mixing step is carried out under conditions selected so that the metallized iron dust acts as a catalyst for the methane conversion reaction in a partially spent gaseous deoxidizer.  16. The method according to claim 1, which before the stage of mixing includes, in addition, 10 stage of introduction into the partially exhaust gaseous deoxidizer additional methane.  17. The method according to claim 1, wherein the reactors operate at a process temperature and in which a preheating process is further provided, during which the reactors are heated to this process temperature, while (a) the mixture of inert gas with methane is passed through the last reactor such in such a way that in this last reactor it contacts with ore, as a result of which a gas stream comprising inert gas, methane and iron dust carried away from the last reactor, (b) an oxygen source is mixed with the gas stream so that the oxygen source burns part of the methane in the presence of iron dust, resulting in a gaseous deoxidizer, including hydrogen and carbon monoxide, and a gaseous deoxidizer is supplied to the previous reactor so that the ore is preliminary deoxidized. 18. The method according to p. 17, in which the next stage (a) - (C) is carried out at a temperature in the previous reactor in the range from about 700 ^o With up to the process temperature. 19. The method according to p. 18, in which the process temperature is approximately 900 ^o C.  20. A method of preparing a gaseous deoxidizer during preheating to the process temperature during the process of deoxidizing ore in a fluidized bed in a series of deoxidizing ore reactors, consisting in that (a) an inert gas mixture with methane is passed through the last reactor so that this last reactor was contacted with the ore, as a result of which a stream of gas, including inert gas, methane and carried away iron dust, flows from the last reactor, (b) sources are mixed with the gas stream oxygen in such a way that the oxygen source burns part of the methane in the presence of iron dust, resulting in a gaseous deoxidizer, including hydrogen and carbon monoxide, and (c) a gaseous deoxidizer is supplied to the previous reactor so that preliminary deoxidation occurs in this previous reactor ore. 21. The method according to p. 20, further comprising the implementation of stages (a) - (C), when the temperature in the previous reactor is in the range from about 700 ^o C to the process temperature. 22. The method according to p. 21, in which the process temperature is approximately 900 ^o C. 23. The method according to claim 1, wherein the deoxidizing ability (N _R ) of the partially spent gaseous deoxidizer is from about 4.0 to about 5.6. 24. The method according to p. 1, in which the deoxidizing ability (N _R ) subjected to the reforming gaseous deoxidizer is from about 4.4 to about 9.1.