JPH0121854B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides a method for adding at least one of a carbonated binder and a hydraulic binder to iron ore powder, non-ferrous ore powder, dust made of iron or non-ferrous metal oxide, etc. are added and mixed to form a mixture, the mixture is formed into raw pellets or raw briquettes (hereinafter collectively referred to as "raw pellets"), and the thus formed raw pellets are subjected to a hydration reaction. Alternatively, the raw pellets can be cured by carbonation reaction and hardened without firing to produce unfired pellets or unfired briquettes (hereinafter referred to as "unfired pellets").
This invention relates to a method for producing unfired pellets, which comprises the following steps:

[Prior art and its problems]

Continuously feed raw pellets into a reaction container,
Then, the carbonated binder contained in the raw pellets is carbonated, thus hardening the raw pellets, and in order to continuously produce high-strength, high-quality unfired pellets at a high yield in a short time. As a method for this, the present applicant previously filed a patent application (Japanese Patent Application No. 30978/1983) for a device as shown in FIG. Second
The figure is a schematic diagram of this device. As shown in the drawing, a vertical reaction vessel 1 has a raw pellet inlet 2 at its upper end and a raw pellet discharge port 3 at its lower end. a pre-drying zone A for pre-drying the pre-dried raw pellets; and a pre-drying zone A for pre-drying the pre-dried raw pellets with a carbonation reaction gas to carbonate the carbonated binder contained in the raw pellets. It consists of a pre-drying zone A followed by a reaction zone B. The pre-drying zone A has a pre-drying gas blowing port 4 on one side wall 1a for blowing pre-drying gas into the zone A, and the other side wall 1b.
It has a pre-drying gas outlet 5 for discharging the pre-drying gas. The reaction zone B has a reaction gas inlet 6 on one side wall 1a for blowing the carbonation reaction gas into the zone B, and a reaction gas inlet 6 for blowing the carbonation reaction gas into the reaction zone B, and the other side wall 1b for discharging the reaction gas. It has a reaction gas outlet 7 for the reaction.

Further, a vertical drying container 10 having a raw pellet inlet 8 at its upper end and an unfired pellet outlet 9 at its lower end is used for carbonating raw pellets discharged from the reaction container 1 and supplied from the raw pellet inlet 8. It consists of a drying zone C for drying the green pellets in which the binder has been carbonated, and a cooling zone D following the drying zone C for cooling the dried uncalcined pellets.
The drying zone C has a drying gas inlet 11 for blowing drying gas into the zone C on one side wall 10a, and a drying gas blowing port 11 for blowing the drying gas into the same side wall 10b, and a drying gas blowing port 11 for discharging the drying gas on the other side wall 10b. Drying gas outlet 1
It has 2. Cooling zone D has one side wall 1
0a has a cooling gas inlet 13 for blowing cooling gas into the zone D, and the other side wall 10b has a cooling gas outlet 14 for discharging the cooling gas. ing.

15 is a conveyor for feeding raw pellets into the reaction vessel 1 through its inlet 2; 16;
19 is a conveyor for transferring the raw pellets discharged through the raw pellet outlet 3 of the reaction vessel 1 and in which the carbonated binder has been carbonated to the inlet 8 of the drying vessel 10; , a conveyor for transporting the unfired pellets discharged through the unfired pellet discharge port 9 of the drying container 10.

The green pellets continuously fed into the reaction vessel 1 through the green pellet inlet 2 at its upper end are pre-dried in a pre-drying zone A and then carbonated in a reaction zone B. After curing, the green pellets are discharged through the outlet 3. The raw pellets discharged through the raw pellet discharge port 3, in which the carbonated binder has been carbonated,
The pellets are continuously fed into the drying container 10 by the conveyor 16 through the inlet 8 at its upper end and are dried in the drying zone C to form uncalcined pellets. The non-calcined pellets are cooled in a cooling zone D following the drying zone C, discharged through a non-calcined pellet outlet 9, and transported by a conveyor 19.

In FIG. 2, 17 is a high-temperature gas generating furnace for preparing high-temperature drying gas that is blown into the drying zone C, and 18 is a heat exchanger. The high temperature gas generating furnace 17 has a fuel and combustion air supply pipe 2
Fuel such as heavy oil, natural gas, blast furnace gas, coke oven gas, etc. supplied through the combustion chamber is combusted by combustion air to generate high-temperature combustion exhaust gas. The temperature of the high-temperature combustion exhaust gas is discharged from the drying zone C through the drying gas outlet 12, and the temperature of the high-temperature combustion exhaust gas is
The temperature is adjusted to a predetermined value by adding a portion of the drying gas that is returned to the high-temperature gas generating furnace 17 through 2. The heat exchanger 18 cools the high-temperature combustion exhaust gas from the high-temperature gas generating furnace 17 by heat exchange with room temperature air supplied through the heat exchange air supply pipe 23, and cools the high-temperature combustion exhaust gas to a predetermined temperature for drying. Prepare gas.

In this way, the drying gas prepared in the heat exchanger 18 passes through the drying gas supply pipe 24 and the drying gas inlet 11 from the heat exchanger 18 to the drying zone C of the drying container 10. blown inside. The air whose temperature has increased due to heat exchange with the high-temperature combustion exhaust gas in the heat exchanger 18 is transferred to the cooling gas outlet 14 of the drying container 10 and the conduit 25.
conduit 26 with cooling gas exhausted through
and pre-drying gas inlet 4 of reaction vessel 1
is blown into the pre-drying zone A as a pre-drying gas.

The drying gas discharged from the drying zone C through the drying gas outlet 12 of the drying container 10 after the carbonated binder has dried the carbonated raw pellets in the drying zone C is passed through a conduit. 21 to a cyclone 27, where the dust contained in the drying gas is removed, and then to a conduit 28 to a cooler 2 for preparing the gas for the carbonation reaction.
Guided by 9. Note that a part of the drying gas from which dust has been removed by the cyclone 27 is returned to the high-temperature gas generating furnace 17 through the conduit 22, as described above, and is added to the high-temperature combustion exhaust gas in the high-temperature gas generating furnace 17. It is added to this for temperature control.

The drying gas led from the drying zone C to the cooler 29 passes through the carbon dioxide gas supply pipe 30 connected to the conduit 28, and combines with a predetermined amount of carbon dioxide gas supplied into the cooler 29. The mixture is cooled to a predetermined temperature in the cooler 29 by the cooling water injected into the cooler 29 through the cooling water supply pipe 31, and a predetermined amount of carbon dioxide and a predetermined amount of carbon dioxide are mixed. Prepare a carbonation reaction gas consisting of saturated water vapor and saturated water vapor.

The carbonation reaction gas prepared in this manner is blown into the reaction zone B from the cooler 29 through the reaction gas supply pipe 32 and the reaction gas inlet 6 of the reaction container 1.

According to the above-mentioned apparatus, the drying gas obtained by drying the raw pellets in which the carbonated binder has been carbonated in the drying zone C is used as the carbonation reaction gas,
In the cooling zone D, the cooling gas that has cooled the unfired pellets and the air whose temperature has increased through heat exchange with the high-temperature combustion exhaust gas in the heat exchanger 18 are used as pre-drying gas. As a result, the amount of heat required for pre-drying the raw pellets, carbonating the carbonated binder contained in the raw pellets, and drying the raw pellets can be significantly reduced, resulting in high strength. Unfired pellets of excellent quality can be produced continuously and economically at a high yield within a short period of time.

However, the above method has the following problems. That is, the pre-drying gas blown into the pre-drying zone A of the reaction container 1 through the pre-drying gas inlet 4, and the reaction zone B.
There are cases where the carbonation reaction gas blown through the reaction gas inlet 6 mixes within the reaction container 1. For example, when the carbonation reaction gas blown into the reaction zone B of the reaction vessel 1 through the reaction gas inlet 6 flows into the preliminary drying zone A, it is , the pre-drying conditions for the raw pellets in the pre-drying zone A deteriorate, and it becomes necessary to increase the calorific value of the pre-drying gas. Furthermore, when the carbonation reaction gas flows into the pre-drying zone A, an insufficient amount of the carbonation reaction gas in the reaction zone B, uneven flow, etc. occur, and the carbonation bond of the raw pellets in the reaction zone B is caused. The carbonation of the agent becomes uneven. On the other hand, pre-drying zone A
When the pre-drying gas blown into the reaction zone B through the pre-drying gas inlet 4 flows into the reaction zone B, the concentration of the carbonation reaction gas blown into the reaction zone B becomes diluted, and the reaction starts. The carbonation of the carbonation binder by the carbonation reaction gas containing saturated steam on the green pellets in zone B becomes uneven, making it impossible to uniformly harden the green pellets.

Further, when the cooling gas blown into the cooling zone D of the drying container 10 through the cooling gas inlet 13 flows into the drying zone C, the drying gas blown into the drying zone C The temperature of the gas decreases, and the drying conditions for raw pellets in dry zone C worsen,
It becomes necessary to increase the calorific value of the drying gas. On the other hand, in the drying zone C, the drying gas inlet 11
When the drying gas blown through flows into the cooling zone D, the cooling conditions for the unfired pellets in the cooling zone D deteriorate.

As described above, the pre-drying gas blown into the reaction container 1 and the carbonation reaction gas mix, and the drying gas and cooling gas blown into the drying container 10 mix. This causes a problem in that the thermal efficiency of each of the gases is deteriorated and that the processing conditions using each of the gases are adversely affected.

Such problems are not limited to curing treatment by carbonation reaction in reaction zone B as described above, but also apply to curing treatment by hydration reaction.
The same problem occurs when using one vertical reaction vessel consisting of a pre-drying zone, a reaction zone and a drying zone, and one vertical reaction vessel consisting of a pre-drying zone, a reaction zone, a drying zone and a cooling zone. .

[Purpose of the invention]

Therefore, an object of the present invention is to feed raw pellets into a vertical reaction vessel, and to pass through a pre-drying zone, a reaction zone, a drying zone and, if necessary, a cooling zone following the drying zone in this order. A pre-drying gas is blown into the pre-drying zone to pre-dry the raw pellets in the zone, and a reaction gas containing saturated water vapor is blown into the reaction zone to dry the raw pellets in the same zone. drying gas is blown into the drying zone to dry the raw pellets in the same zone, and if there is a cooling zone, cooling gas is blown into the cooling zone to dry the unburned pellets in the same zone. Cool, thus
In continuously producing non-calcined pellets, a pre-drying gas, a reaction gas containing saturated steam, a drying gas and a cooling gas are blown into the vertical reaction vessel and the vertical drying vessel. To provide a method for producing non-fired pellets, which can continuously and efficiently produce high-strength, high-quality non-fired pellets in a short time at a high yield without causing gases to mix with each other. There is a particular thing.

[Summary of the invention]

This invention provides iron ore powder, non-ferrous ore powder, and
Preparing raw pellets by adding a binder and water to a raw material consisting of at least one of dust containing mainly oxides of ferrous or non-ferrous metals, mixing these, and molding the resulting mixture. The raw pellets are continuously fed into a vertical reaction vessel consisting of a pre-drying zone, a reaction zone and a drying zone, and the raw pellets are fed into the pre-drying zone,
The raw pellets in the reaction zone and the drying zone are passed through the reaction zone and the drying zone sequentially, and a pre-drying gas at a predetermined temperature is blown into the pre-drying zone to pre-dry the raw pellets in the same zone. A reaction gas at a certain temperature is blown into the reaction zone to cure the raw pellets in the same zone, and a drying gas at a predetermined temperature is blown into the drying zone to dry the raw pellets in the same zone. Thus, in the method for producing uncalcined pellets in which uncalcined pellets are continuously produced by curing green pellets, at least a gas separation zone is provided between the pre-drying zone and the reaction zone, and the pre-drying The difference between the pressure of the pre-drying gas discharged from the zone and the pressure of the reaction gas discharged from the reaction zone,
The method is characterized in that the pre-drying gas and the reaction gas are controlled to a value such that they do not mix in the reaction container.

[Structure of the invention]

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a schematic diagram showing one embodiment of the apparatus used in the method of the invention. In FIG. 1, parts that are the same as those in FIG. 2 described above are designated by the same reference numerals as in FIG. 2, and their explanations will be omitted. In this invention, between the pre-drying zone A and the reaction zone B of the vertical reaction vessel 1, a pre-drying gas blown into the pre-drying zone A and a reaction gas blown into the reaction zone B are used. A first gas separation zone E is provided to prevent the gas from being mixed with the gas for use. and,
Between the drying zone C and the cooling zone D of the vertical drying container 10, the drying gas blown into the drying zone C and the cooling gas blown into the cooling zone D are prevented from mixing. A second separation zone F is provided for this purpose.

In FIG. 1, numeral 33 is a high-temperature gas generating furnace for preparing a pre-drying gas of, for example, 120° C., which is blown into the pre-drying zone A. The hot gas generator 33 is supplied through fuel and combustion air supply pipes 34 . Fuel such as heavy oil, natural gas, blast furnace gas, coke oven gas, etc. is combusted with combustion air to generate high-temperature combustion exhaust gas. The high temperature combustion exhaust gas thus generated passes through the conduit 25 via the conduit 36. The unfired pellets in the cooling zone D are mixed with the cooling gas, for example, 120
A pre-drying gas blowing port 4 provided at the upper part of the pre-drying zone A serves as a pre-drying gas at a temperature of ℃.
and is blown into the pre-drying zone A.

The amount of heat and flow rate of the cooling gas discharged from the cooling gas outlet 14 of the cooling zone D changes as the conditions for cooling the unfired pellets within the cooling zone D change. Therefore, the temperature of the pre-drying gas passing through the conduit 25 near the pre-drying gas injection port 4 is measured with the thermometer 37, and the temperature of the pre-drying gas blown into the pre-drying zone A becomes constant. As such, the amounts of fuel and combustion air supplied to the high-temperature gas generating furnace 33 are adjusted by the control valve 38 provided in the fuel and combustion air supply pipe 34.

As a result, the flow rate of the pre-drying gas blown into the pre-drying zone A through the pre-drying gas blowing port 4 changes. On the other hand, since the particle size of the raw pellets supplied in the pre-drying zone A and the gaps between the raw pellets are not constant, the filling state of the raw pellets in the pre-drying zone A also changes. like this,
The pressure of the pre-drying gas blown into the pre-drying zone A fluctuates depending on the flow rate of the pre-drying gas blown into the pre-drying zone A and the filling state of green pellets in the pre-drying zone A. .

On the other hand, the temperature of the drying gas passing through the drying gas supply pipe 24 is measured by a thermometer 39, and the fuel is supplied into the high-temperature gas generating furnace 17 so that the temperature becomes a constant value of, for example, 200°C. The amount of combustion air is adjusted by a control valve 40 provided in the fuel and combustion air supply pipe 20.

Furthermore, depending on the drying state of the unfired pellets in the drying zone C, the amount of drying gas discharged from the drying zone C that is returned to the high temperature gas generating furnace 17 through the conduit 22 can be controlled. For this purpose, it passes through the conduit 21. The temperature and output of the drying gas discharged from the drying zone C are measured with a thermometer 41 and a pressure gauge 42 provided in the conduit 21, and the blower 51
Accordingly, the amount of gas returned to the high temperature gas generating furnace 17 through the conduit 22 is adjusted by the control valve 43. Then, the control valve 44 adjusts the flow rate of the drying gas as the carbonation reaction gas guided to the reaction gas inlet 6 of the reaction zone B through the conduit 28 and the reaction gas supply pipe 32. Therefore, the flow rate of the carbonation reaction gas blown into the reaction zone B through the reaction gas blowing port 6 changes.

By changing the flow rate of the carbonation reaction gas blown into the reaction zone B and changing the filling state of raw pellets in the reaction zone B, the carbonation reaction gas blown into the reaction zone B Gas pressure fluctuates.

Due to the difference between the pressure of the pre-drying gas in the above-mentioned pre-drying zone A and the pressure of the carbonation reaction gas in the above-mentioned reaction zone B, the pre-drying gas flows into the reaction zone B, or , a phenomenon occurs in which the carbonation reaction gas flows into the pre-drying zone A.

Therefore, in this invention, from the pre-drying gas outlet 5 provided at the lower part of the pre-drying zone A,
of the pre-drying gas discharged through the conduit 45;
The pressure in the conduit 45 and the pressure in the conduit 46 of the carbonation reaction gas discharged from the reaction gas outlet 7 of the reaction zone B through the conduit 46 are measured by the pressure gauge 47. , the control valve 4 provided in the conduit 46 is set so that the pressure of the carbonation reaction gas passing through the conduit 46 is higher than the pressure of the preliminary drying gas passing through the conduit 45, for example by about 0 to 5 mmAq.
8 to adjust the pressure of the carbonation reaction gas.

By doing this, the pre-drying gas blown into the pre-drying zone A will no longer flow into the reaction zone B, which will prevent the above-mentioned troubles caused by the pre-drying gas flowing into the reaction zone B. is prevented.

The fact that the carbonation reaction gas blown into the reaction zone B flows into the pre-drying zone A is due to the pressure of the pre-drying gas passing through the conduit 45 and the pressure of the carbonation reaction gas passing through the conduit 46. By setting E within the above-mentioned specific range, the first gas separation zone E acts as a resistance and is almost prevented.

Next, the flow rate of the drying gas blown into the drying zone C through the drying gas blowing port 11 provided at the lower part of the drying zone C is as described above.
Depending on the dryness of the unfired pellets in the
Further, it changes depending on the amount of drying gas discharged from the drying zone C that is returned to the high-temperature gas generating furnace 17 through the conduit 22. Further, the pressure of the drying gas changes depending on the filling state of the raw pellets in the drying zone C, the temperature of the raw pellets, the moisture content, etc.

In addition, the blower 52 causes the cooling gas supply pipe 53 to
The pressure in the cooling zone D of the cooling gas blown into the cooling zone D from the cooling gas inlet 13 provided at the lower part of the cooling zone D is It varies depending on the filling state of pellets, the temperature of unfired pellets, etc.

Due to the difference between the pressure of the drying gas in the drying zone C described above and the pressure of the cooling gas in the cooling zone D described above, the drying gas flows into the cooling zone D, or the cooling gas flows into the cooling zone D. A phenomenon of flowing into the dry zone C occurs.

Therefore, in this invention, the drying gas is supplied into the drying zone C through the drying gas supply pipe 24 from the drying gas blowing port 11 provided at the lower part of the drying zone C. The pressure in the pipe 24 and the pressure in the pipe 25 of the cooling gas discharged from the cooling gas outlet 14 provided at the upper part of the cooling zone D through the pipe 25,
It is measured by the pressure gauge 49, and the drying gas supply pipe 2
The control valve 50 provided in the conduit 25 is configured such that the pressure of the drying gas passing through the conduit 25 is higher, for example, by about 0 to 5 mmAq, than the pressure of the cooling gas passing through the conduit 25.
to adjust the pressure of the cooling gas.

By doing this, the cooling gas blown into the cooling zone D will not flow into the drying zone C, and the above-mentioned troubles caused by the cooling gas flowing into the drying zone C can be prevented.

The fact that the drying gas blown into the drying zone C flows into the cooling zone D increases the pressure of the drying gas passing through the drying gas supply pipe 24 and the pressure of the cooling gas passing through the conduit 25. By setting the above-mentioned specific range, the second gas separation zone F acts as a resistance and is almost prevented.

In the above, the reason why the pressure on the inlet side of the drying gas passing through the drying gas supply pipe 24 and the pressure on the outlet side of the cooling gas passing through the conduit 25 are measured by the pressure gauge 49 is as follows. As shown in Figure 1, the drying gas blowing port 1 is blown into the drying zone C.
1 is provided in the lower part of the drying zone C near the second gas separation zone F, and the drying gas outlet 12 is provided in the upper part of the drying zone C farther from the second gas separation zone F. If the drying gas outlet 12 and the drying gas inlet 11 are provided in opposite positions to the above, the pressure on the drying gas outlet side is measured. Further, the cooling gas inlet 13 blown into the cooling zone D is connected to the second gas separation zone F of the cooling zone D.
A cooling gas outlet 14 is provided at the top near the cooling gas outlet 14.
is provided in the lower part of the cooling zone D that is faster than the second gas separation zone F, the pressure of the cooling gas is determined by measuring the pressure inside the cooling gas supply pipe 53.

The raw pellets are cured in the reaction zone B of the reaction container 1, as described above, by bringing the carbonation reaction gas into contact with the raw pellets to which the carbonation binder has been added. This process is particularly advantageous if it is carried out by carbonating the carbonated binder present.

That is, in order to carbonate the carbonated binder contained in the raw pellets, the reaction gas blown into reaction zone B needs to contain about 25 vol% or more of carbon dioxide gas. . For this,
There is also a method of adding a predetermined amount of carbon dioxide gas to the drying gas led from the drying zone C to the cooler 29, as in the prior art shown in FIG. 2 described above. However, even without such addition of carbon dioxide gas, the drying gas blown into the drying zone C will add to the high-temperature combustion exhaust gas generated by the high-temperature gas generating furnace 17.
The drying gas is discharged from the drying zone C through the exhaust port 12, and is passed through the conduits 21 and 22 to the high-temperature gas generating furnace 1.
Since a part of the drying gas returned to the drying zone C is added, the drying gas discharged from the drying zone C contains about 20 vol% carbon dioxide gas.

Therefore, by cooling such drying gas with the cooler 29 and removing the excess water vapor contained in the drying gas by cooling and condensing it, the carbon dioxide concentration in the gas is reduced to about 25 vol. %, it can be used as a carbonation reaction gas.

However, as described above, in the drying container 10, when the cooling gas blown into the cooling zone D flows into the drying zone C, the concentration of carbon dioxide in the drying gas becomes diluted, and the drying gas is left as it is. However, according to the present invention, since the cooling gas is prevented from flowing into the drying zone C, the above-mentioned problem does not occur and the drying gas cannot be used as a carbonation reaction gas. gas can be effectively used as a gas for carbonation reaction.

In the apparatus of the embodiment described above, the pre-drying gas blown into the pre-drying zone A generates high-temperature combustion exhaust gas by the high-temperature gas generating furnace 33,
This high-temperature combustion exhaust gas is prepared by mixing it with cooled exhaust gas, but instead of having such a high-temperature gas generating furnace 33, as in the conventional device shown in FIG. The high-temperature combustion exhaust gas from the high-temperature gas generating furnace 17 for preparing the high-temperature drying gas to be blown in is heat-exchanged with room-temperature air by a heat exchanger, and the air whose temperature has increased due to this heat exchange is It may also be prepared by mixing with cooled exhaust gas.

The drying container 10 may have a structure in which the cooling zone D is not provided and only the curing-treated green pellets are dried. In the case of such a structure, the unfired pellets that have been dried and hardened in the drying container 10 are discharged from the unfired pellet discharge port 9 and are naturally exposed to the atmosphere while being transferred by the conveyor 19. cooled down.

In addition, instead of being divided into a reaction vessel and a drying vessel, one vertical reaction vessel consisting of a pre-drying zone, a reaction zone and a drying zone, or one vertical reaction vessel consisting of a pre-drying zone, a reaction zone, a drying zone and a cooling zone is used. Vertical reaction vessels may also be used. In this case, between the preliminary drying zone and the reaction zone, between the reaction zone and the drying zone, or
Furthermore, the aforementioned gas separation zones are provided between the drying zone and the cooling zone, and the pressure of the gas is adjusted so that the pressure difference between the gases blown into each zone before and after the gas separation zone is a constant value. control.

〔Effect of the invention〕

As described above, according to the present invention, raw pellets are supplied into a vertical reaction vessel, and the pre-drying zone, reaction zone, drying zone and, if necessary, the cooling zone following the drying zone are fed into the vertical reaction vessel. , in this order, pre-drying gas is blown into the pre-drying zone to pre-dry the raw pellets in the same zone, and reaction gas containing saturated steam is blown into the reaction zone to dry the raw pellets in the same zone. drying gas is blown into the drying zone to dry the raw pellets in the same zone, and if there is a cooling zone, cooling gas is blown into the cooling zone to dry the raw pellets in the same zone. Cooling the unfired pellets,
Thus, in continuously producing non-fired pellets, the drying gas after drying the green pellets in the drying zone is used as the reaction gas, and
When a cooling zone is provided, the cooling gas after cooling the unfired pellets in the cooling zone is used as the pre-drying gas, so the amount of heat required for pre-drying and curing the green pellets can be significantly reduced. In addition, the pre-drying gas, reaction gas, drying gas, and cooling gas do not mix with each other in the vertical reaction vessel, producing high-strength, high-quality unfired pellets. It has a high yield and can be produced continuously and efficiently within a short period of time, resulting in excellent industrial effects.

[Brief explanation of drawings]

Figure 1 shows one of the apparatuses used in the method of this invention.
FIG. 2 is a schematic diagram showing an example of a device used in the conventional method. In the drawings, 1... Reaction container, 2, 8... Raw pellet inlet, 3... Raw pellet outlet, 4... Pre-drying gas inlet, 5... Pre-drying gas outlet, 6
...Reaction gas inlet, 7...Reaction gas outlet, 9...Non-fired pellet outlet, 10...Drying container, 11...Drying gas inlet, 12...
Drying gas outlet, 13... Cooling gas inlet, 14... Cooling gas outlet, 15, 16, 1
9... Conveyor, 17, 33... High temperature gas generating furnace, 18... Heat exchanger, 20, 34... Fuel and air supply pipe, 21, 22, 25, 26, 28,
36, 45, 46...Conduit, 23...Air supply pipe for heat exchange, 24...Drying gas supply pipe, 27...
Cyclone, 29... Cooler, 30... Carbon dioxide gas supply pipe, 31... Cooling water supply pipe, 32... Reaction gas supply pipe, 35, 51, 52... Blower, 3
7, 39, 41... thermometer, 42, 47, 49...
...Pressure gauge, 38, 40, 43, 44, 48, 50
...Control valve, 53...Cooling gas supply pipe, A...
Pre-drying zone, B...reaction zone, C...drying zone, D...
...cooling zone, E...first gas separation zone, F...second gas separation zone.

Claims (1)

[Scope of Claims] 1 A binder and water are added to a raw material consisting of at least one of iron ore powder, non-ferrous ore powder, and dust containing mainly iron or non-ferrous metal oxides, and the mixture is mixed. The resulting mixture is molded to prepare green pellets, and the green pellets are continuously fed into a vertical reaction vessel consisting of a pre-drying zone, a reaction zone and a drying zone. The raw pellets are passed through the pre-drying zone, the reaction zone and the drying zone sequentially, and a pre-drying gas at a predetermined temperature is blown into the pre-drying zone to pre-dry the raw pellets in the same zone. Blowing a dry reaction gas containing saturated water vapor at a predetermined temperature into the reaction zone to cure the green pellets in the zone, and blowing a drying gas at a predetermined temperature into the drying zone, In the method for producing uncalcined pellets, which comprises drying the raw pellets in the same zone and thus curing the raw pellets to continuously produce uncalcined pellets, at least a space between the pre-drying zone and the reaction zone is provided. , a gas separation zone or the like is provided to prevent the pre-drying gas blown into the pre-drying zone from mixing with the reaction gas blown into the reaction zone; The pressure of the discharged pre-drying gas and the pressure of the reaction gas discharged from the reaction zone are measured, and the reaction is carried out so that the pressure of the reaction gas is higher than the pressure of the pre-drying gas. 1. A method for producing non-fired pellets, which comprises controlling the pressure of a raw gas. 2 A binder and water are added to a raw material consisting of at least one of iron ore powder, non-ferrous ore powder, and dust containing oxides of iron or non-ferrous metals, and the resulting mixture is mixed. The green pellets are continuously fed into a vertical reaction vessel consisting of a pre-drying zone and a reaction zone, and the green pellets are fed into a vertical reaction vessel consisting of a pre-drying zone and a reaction zone. and the raw pellets in the reaction zone are passed through the reaction zone sequentially and continuously, and a pre-drying gas at a predetermined temperature is blown into the pre-drying zone to pre-dry the raw pellets in the same zone, and a reaction mixture containing saturated steam at a predetermined temperature is produced. blowing a gas into the reaction zone,
The green pellets in the same zone are cured, and then the green pellets cured in this way are continuously fed into a vertical drying container consisting of a drying zone and a cooling zone. The raw pellets are sequentially and continuously passed through the drying zone and the cooling zone, and a drying gas at a predetermined temperature is blown into the drying zone to dry and harden the raw pellets in the same zone. A method for producing uncalcined pellets in which gas is blown into the cooling zone to cool the uncalcined pellets in the zone, thereby continuously producing uncalcined pellets, wherein the pre-drying zone and the reaction zone are connected to each other. In between, a gas separation zone is provided to prevent the pre-drying gas blown into the pre-drying zone from mixing with the reaction gas blown into the reaction zone; A gas separation zone is provided between the zone and the cooling zone to prevent the drying gas blown into the drying zone from mixing with the cooling gas blown into the cooling zone. , the pressure of the pre-drying gas discharged from the pre-drying zone and the pressure of the reaction gas discharged from the reaction zone are measured, and the pressure of the reaction gas is higher than the pressure of the pre-drying gas. The pressure of the reaction gas is controlled to be higher than the pressure of the drying gas blown into or discharged from the drying zone, and the pressure of the drying gas blown into or discharged from the cooling zone. The pressure of the discharged cooling gas is measured, and the pressure of the cooling gas is controlled so that the pressure of the drying gas is higher than the pressure of the cooling gas. Production method.