JP2007254863A - Sintered material with the use of organic waste, method for producing the sintered material, and refining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sintered material which can be produced at a reduced fuel cost, by more flexibly using a material for thermal energy in a sintering furnace to reduce an amount of coke used for treatment in a blast furnace, when organic waste is used in refining treatment. <P>SOLUTION: A carbide is produced by the steps of: charging the organic waste containing calcium oxide such as municipal solid waste, sewage sludge and industrial waste into a carbonizing apparatus 1 for heating materials at a high temperature; supplying a flue gas sent from a combustion apparatus 3 and further an exhaust gas generated in an incineration facility and an in-house power generating station to the carbonizing apparatus 1; and roasting the organic matter at 400 to 700°C. The sintered material of a mixture of the carbide and sintered ore is produced by the steps of: supplying the carbide obtained in the carbonizing apparatus 1 and fine iron ore to an external heating type sintering furnace 4 for heating materials at a high temperature; and heating the mixture at 900°C or higher from the external part with hot blast such as the flue gas sent from the combustion apparatus 3 to bake the mixture of carbide and calcium oxide and the fine iron ore. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a sintered product using organic waste containing calcium oxide such as general waste, industrial waste, and sewage sludge, a method for producing the sintered product, and a refining treatment method.

Regarding the treatment of organic waste, there is a great social interest, and what is used for the production of sintered ore for blast furnaces has been known.
In other words, glass, ceramics, and metals are removed from municipal waste, household waste, industrial waste, general waste, shredder dust, etc., and then the waste mainly composed of combustible materials is crushed or Grind and dry. After the dried waste is crushed or pulverized again, a dechlorinating agent, a water removing agent, and a solidifying agent are added as necessary, and then, for example, a solid waste fuel having a crayon-like outer shape is produced. The waste solid fuel is transported to the carbonization process, carbonized to produce carbonized solid waste fuel, transported to a sintering plant at the steel mill, and used as an alternative to the powder coke used in the sintering machine. It is comprised so that it may be used (refer patent document 1).
JP 2000-109935 A

  However, in the case of the conventional example, in order to replace the powder coke at the time of sintering, the sintering process is performed in an ignition furnace, and the solid fuel carbide is burned during the sintering process, During the reduction treatment in the blast furnace, it was necessary to add a large amount of coke to the obtained sintered product.

  The present invention has been made in view of such circumstances, and the invention according to claims 1 and 2 increases the degree of freedom in terms of thermal energy in a sintering furnace, and coke during processing in a blast furnace. The invention according to claim 3 aims to provide a sintered product that can reduce the fuel cost when refining treatment using organic waste. The object is to make it possible to produce the product at a low cost. Further, the invention according to claim 4 aims to make it possible to produce pig iron at a low cost, and the invention according to claim 5 aims to make it possible to produce phosphorus-containing steel at a low cost.

In order to achieve the object as described above, the sintered product using the organic waste of the invention according to claim 1
It is characterized in that a mixture of a carbide and calcium oxide produced by carbonizing an organic waste containing calcium oxide and iron ore powder ore are baked and solidified.
Typical organic waste containing calcium oxide includes miscellaneous general waste, sewage sludge treated from domestic wastewater, industrial waste, etc., but organic substances containing calcium oxide, calcium oxide Substances containing calcium oxide and organic components, or substances containing calcium oxide (including organic substances), such as a mixture of inorganic and organic substances, or a mixture of organic substances and organic substances containing calcium oxide ) And a substance containing an organic component.
The carbide produced by carbonizing an organic waste containing calcium oxide refers to a carbide after carbonizing, gasifying or pyrolyzing an organic waste containing calcium oxide.

(Action / Effect)
According to the structure of the sintered product using the organic waste of the invention according to claim 1, calcium oxide in the mixture produced by carbonizing the organic waste forms a glass phase during sintering. Then, it can be granulated into iron ore powder ore by using it as a sintering agent and baked.
Therefore, during sintering, the carbides are not baked and hardened by heating from the outside, so that the carbides can be used as a fuel for processing in the blast furnace, and the carbon in the carbides is oxygen in the iron ore. It can be used as a reducing agent by combining with carbon dioxide and can be used as a reducing agent. In the sintering process, combustible gas generated in various processes without using conventional powder coke and carbide as an alternative, and city Various heating heat sources can be used, such as using external fuel such as gas, and exhaust heat, increasing the degree of freedom in terms of thermal energy in the sintering process, and using carbide as fuel and reducing agent in the blast furnace It is possible to provide a sintered product that can reduce the amount of coke used in processing in a blast furnace and reduce the fuel cost when performing refining processing using organic waste.

Moreover, the manufacturing method of the sintered compact using the organic waste of the invention according to claim 2 is to achieve the object as described above.
An organic waste containing calcium oxide is carbonized to produce a mixture of carbide and calcium oxide, and the mixture and iron ore powder ore are baked and hardened in an externally heated sintering furnace.

(Action / Effect)
According to the structure of the method for producing a sintered product using the organic waste of the invention according to claim 2, the calcium oxide in the mixture produced by carbonizing the organic waste is converted into an external heating type sintering furnace. A glass phase is formed during sintering at, and iron ore fine ore can be granulated and baked by using it as a sintering agent.
Therefore, during sintering, the carbides are not baked and hardened by heating from the outside, so that the carbides can be used as a fuel for processing in the blast furnace, and the carbon in the carbides is oxygen in the iron ore. It can be used as a reducing agent by combining with carbon dioxide and can be used as a reducing agent. In the sintering process, combustible gas generated in various processes without using conventional powder coke and carbide as an alternative, and city Various heat sources such as gas and other external fuels and exhaust heat can be used in an external heating type sintering furnace, increasing the degree of freedom in terms of thermal energy in the sintering process and carburizing the carbide Sinter that can be used as a fuel and reducing agent in the blast furnace, reduce the amount of coke used in blast furnace treatment, and reduce the fuel cost for refining treatment using organic waste Kill.

In order to achieve the above-described object, the invention according to claim 3
In the manufacturing method of the sintered compact using the organic waste of Claim 2,
The gas component of unburned carbon generated in the carbonization process is used as a fuel for a heating heat source of the external heating type sintering furnace.

(Action / Effect)
According to the structure of the manufacturing method of the sintered compact using the organic waste of the invention according to claim 3, the gas component of unburned carbon generated in the carbonization process is used as the fuel of the heating heat source of the external heating type sintering furnace. Since it uses, the consumption of the fuel for exclusive use used for an external-heating-type sintering furnace can be reduced, and a sintered compact can be manufactured cheaply.

Further, the refining treatment method of the invention according to claim 4 is to achieve the above-described object,
An organic waste containing calcium oxide is carbonized to produce a first mixture of carbide and calcium oxide, and the first mixture and iron ore powder ore are heat-treated in an externally heated sintering furnace. Then, a second mixture of carbide and sintered ore is produced, and the second mixture and coke are heated in a blast furnace to produce pig iron.

(Action / Effect)
According to the configuration of the refining treatment method of the invention according to claim 4, the calcium oxide in the first mixture produced by carbonizing the organic waste is subjected to sintering in the external heating type sintering furnace. A glass phase is formed, and it can be used as a sintering agent to granulate and sinter iron ore powder ore. When the iron ore powder ore is granulated and baked, the second mixture of sintered ore and carbide and coke are heated in a blast furnace, and the carbide not burned by the sintering process is refined in the blast furnace. It is possible to produce pig iron by reducing iron oxide with carbide and carbon in coke.
Therefore, during sintering, the carbides are not baked and hardened by heating from the outside, so that the carbides can be used as a fuel for processing in the blast furnace, and the carbon in the carbides is oxygen in the iron ore. It can be used as a reducing agent by combining with carbon dioxide and can be used as a reducing agent. In the sintering process, combustible gas generated in various processes without using conventional powder coke and carbide as an alternative, and city Various heat sources such as gas and other external fuels and exhaust heat can be used in an external heating type sintering furnace, increasing the degree of freedom in terms of thermal energy in the sintering process and carburizing the carbide It can be used as a fuel and a reducing agent in the blast furnace, the amount of coke used in the treatment in the blast furnace can be reduced, and pig iron can be manufactured at low cost by effectively using organic waste.

In order to achieve the above-described object, the invention according to claim 5
In the refining processing method according to claim 4,
The first mixture includes sewage sludge carbide obtained by carbonizing sewage sludge and carbide obtained by carbonizing organic waste other than sewage sludge, and is configured to adjust the content of the sewage sludge carbide.

(Action / Effect)
According to the configuration of the refining treatment method of the invention according to claim 5, the phosphoric acid contained in the sewage sludge carbide obtained by carbonizing the sewage sludge is effectively used, and the content is adjusted to cope with the production of phosphorus-containing steel. can do.
Therefore, when manufacturing phosphorus-containing steel, it is not necessary to use phosphorus, or even if it is used, the amount of use can be reduced, and phosphorus-containing steel can be manufactured at low cost.

As apparent from the above description, according to the sintered product using the organic waste of the invention according to claim 1, calcium oxide in the mixture produced by carbonizing the organic waste is sintered. In this case, a glass phase is formed, and the iron ore powder ore can be granulated and baked by using it as a sintering agent.
Therefore, during sintering, the carbides are not baked and hardened by heating from the outside, so that the carbides can be used as a fuel for processing in the blast furnace, and the carbon in the carbides is oxygen in the iron ore. It can be used as a reducing agent by combining with carbon dioxide and can be used as a reducing agent. In the sintering process, combustible gas generated in various processes without using conventional powder coke and carbide as an alternative, and city Various heating heat sources can be used, such as using external fuel such as gas, and exhaust heat, increasing the degree of freedom in terms of thermal energy in the sintering process, and using carbide as fuel and reducing agent in the blast furnace It is possible to provide a sintered product that can reduce the amount of coke used in processing in a blast furnace and reduce the fuel cost when performing refining processing using organic waste.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a flow sheet of an embodiment showing a method for producing a sintered product and a refining treatment method using an organic waste according to the present invention. A carbonizing apparatus 1 for high-temperature heating such as a rotary kiln is provided with a drying apparatus 2. And the combustion device 3 are connected. The drying apparatus 2 is charged with organic waste containing calcium oxide such as miscellaneous general waste, sewage sludge treated with domestic wastewater, and industrial waste, and the organic waste after drying is input to the carbonization apparatus 1. It comes to be thrown in.

  Combustion device 3 includes an external fuel such as city gas, a combustible gas generated in a waste incineration facility, a gas component of unburned carbon generated by carbonization in carbonization device 1, and generated in external heating type sintering furnace 4. The gas component of the unburned carbon, the digestion gas generated in the sewage treatment plant, etc. are supplied and combusted by the combustion air supplied through the air preheater 5. Combustion exhaust gas from the combustion apparatus 3 and further exhaust gas generated in an incineration facility or in-house power generation facility are used as a heat source and an atmospheric gas in the heat treatment in the carbonization apparatus 1 and the external heat sintering furnace 4, and the carbonization apparatus 1 and the outside It is supplied to the thermal sintering furnace 4.

  The carbonization device 1 is used for recovering waste heat from combustible gas generated at a waste incineration facility, combustion equipment for combustible gas generated by carbonization (including the combustion device 3), and private power generation equipment. Steam from an boiler is supplied, and organic waste containing calcium oxide is steamed (carbonized) at a temperature of 400 to 700 ° C. to release volatile components and a mixture of carbide and calcium oxide (claim 4). Corresponding to the first mixture).

  The air preheater 5 is supplied with a part of the exhaust gas generated in the private power generation facility, and further, waste heat generated in the carbonization apparatus 1 and the external heating type sintering furnace 4. The combustion air for the combustion apparatus 3 for generating combustion exhaust gas in is heated.

  A mixture of carbide and calcium oxide obtained in the carbonization apparatus 1 and iron ore powder ore are supplied to an external heating type sintering furnace 4 for high-temperature heating such as a rotary kiln. In the external heating type sintering furnace 4, heat treatment is performed at 900 ° C. or more from the outside with hot air such as combustion exhaust gas from the combustion device 3, and a mixture of carbide and calcium oxide and iron ore powder ore are baked and hardened, and the carbide and A sintered product (corresponding to the second mixture of claim 4) mixed with the ore is formed. Up to the above configuration corresponds to the method for producing a sintered product of the present invention.

  A sintered product, which is a mixture of carbide and sintered ore generated in the external heating type sintering furnace 4, and coke are supplied to the blast furnace, and in the blast furnace, hot air of 1000 to 1200 ° C. is blown to blow the carbide and The carbon in the coke reacts with the hot air to produce reducing gas, and the reducing gas reacts with oxygen in the sintered ore to become carbon dioxide, so that reductive melting proceeds and pig iron is produced. ing. At the same time, calcium oxide or the like becomes slag and is discharged out of the furnace from the hearth (not shown).

  The exhaust gas that has passed through the air preheater 5 is supplied to the exhaust gas treatment device 6, subjected to detoxification treatment such as desulfurization and denitration treatment, and dust is collected by a dust collector (not shown), and then is discharged to the atmosphere by the chimney 7. To be released inside.

As an example of organic waste containing calcium oxide, sewage sludge is taken as an example, and the composition of raw materials, carbides, and sintered products (all are in weight percent) is shown in (a) of the following table. Street. Taking the general waste as an example, the composition of the carbide and sintered product (both are in% by weight) is as shown in (b) of the following table.

Usually, substances having a high water content such as sewage sludge are subjected to a dehydration process and a subsequent drying process as a pre-treatment for heat treatment to obtain a carbide, and this pre-treatment reduces the water content to 40% or less. Heat treatment. Taking the sewage sludge in the table as an example, a dehydrated cake with a moisture content of 80% is obtained by dehydration treatment, and then dried to a dry sludge with a moisture content of 30%, and then this is used as a raw material to obtain a carbide by heat treatment. Yes.
Moreover, in the case of raw materials having a moisture content of 50 to 80% such as garbage, the carbide is obtained by heat treatment after the moisture content is reduced to 40% or less by drying treatment.
In the table, the calcium in the carbide and sintered product is mainly calcium oxide.

  With the above configuration, the organic waste containing calcium oxide is carbonized by the carbonization apparatus 1 to form a mixture of carbide and calcium oxide, and the mixture and the iron ore powder ore are externally heated. A sintered product in which carbide and sintered ore are mixed is manufactured by heat treatment in No. 4, and then the sintered product and coke are heated in a blast furnace to produce pig iron.

  As described above, by using a carbide obtained by carbonizing general waste having a high calcium oxide concentration as a sintering agent, the fluidity of the melt is maintained even in sintered ore having a high content of silicic acid and aluminum oxide, Fine iron ore having a high content of silicic acid and aluminum oxide, which has been low in demand, has an advantage that it can be used as a steelmaking material.

For example, with respect to 100 tons of iron ore powder ore, the fluidity of the melt can be secured if there is about 5 tons or more of calcium oxide, and a certain product yield can be secured even if silicic acid and aluminum oxide are present. Can do.
As is clear from the above table, about 10 tons of calcium oxide is contained in 10 tons of carbide obtained by carbonizing organic waste, and in 100 tons of iron ore powder ore. On the other hand, if there is about 50 tons of carbide, a useful sintered product can be obtained.

  In the blast furnace method, which is a general steel refining method, about 10 tons of coke is consumed to produce 100 tons of pig iron. The carbon present in 50 tons of sintered carbide is 10 to 50% by weight, and the amount of coke to be charged can be reduced by consuming this carbon as a fuel and a reducing agent. In particular, in the method of igniting coke after sintering iron ore powder ore with only calcium oxide, the amount of heat is low because the sintered ore is composed only of ore, resulting in a decrease in yield. On the other hand, the yield can be improved by using carbide as a sintering agent.

As a specific blending ratio, calcium oxide is desirably 5 to 30% by weight. If it is less than 5% by weight, the granulation is suppressed and it does not function sufficiently as a sintering agent. On the other hand, if it exceeds 30% by weight, the calorie of the sintered ore is lowered and the yield is lowered.
If it is 5 to 30% by weight, both silicic acid and aluminum oxide increase the binding phase between the iron oxide particles, so that the reduced powdering property, which is a concern when sintered only with calcium oxide, can be suppressed. it can.
Since calcium oxide in the sintered product of general waste is expected to be about 5 to 20% by weight, the sintered product to be blended with respect to 100 ton of iron ore powder ore is 20 to 100 ton.

  Further, a certain amount of sewage sludge carbide containing abundant phosphoric acid is contained in a carbonized carbonized organic waste other than sewage sludge, and the phosphoric acid content in the sintered product is 0.01 to 0.1 weight. By setting it as%, it is possible to produce phosphorus-containing steel that can ensure a certain strength while maintaining elongation. Moreover, since it can collect | recover phosphoric acid as yellow phosphorus by setting carbonization temperature to 1000-1400 degreeC, it is also possible to adjust phosphoric acid content by carbonization.

It is the flow sheet of the Example which shows the manufacturing method and refining process of the sintered compact using the organic waste which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Carbonization apparatus 4 ... External heating type sintering furnace

Claims (5)

  An organic waste comprising a mixture of carbide and calcium oxide produced by carbonizing an organic waste containing calcium oxide and iron ore powder ore is baked and solidified. Used sintered product.   An organic waste characterized by carbonizing an organic waste containing calcium oxide to form a mixture of carbide and calcium oxide, and baking the mixture and iron ore powder ore in an externally heated sintering furnace For manufacturing sintered products using toxic waste. In the manufacturing method of the sintered compact using the organic waste of Claim 2,
A method for producing a sintered product using organic waste, in which a gas component of unburned carbon generated by carbonization is used as a fuel for a heating heat source of an external heating type sintering furnace.   An organic waste containing calcium oxide is carbonized to produce a first mixture of carbide and calcium oxide, and the first mixture and iron ore powder ore are heat-treated in an externally heated sintering furnace. Then, a second mixture of carbide and sintered ore is produced, and the second mixture and coke are heated in a blast furnace to produce pig iron. In the refining processing method according to claim 4,
A refining treatment method in which the first mixture is composed of sewage sludge carbide obtained by carbonizing sewage sludge and carbide obtained by carbonizing organic waste other than sewage sludge, and adjusting the content of the sewage sludge carbide. .

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