JP2510193B2 - Sinter production method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a sinter, and more specifically, it uses calcination of quick lime used as a sintering raw material together with the efficiency of sensible heat recovery of the sinter. Related to technology to achieve

[Conventional technology]

As shown in FIG. 3, the continuous sintering machine supplies the bed ore from the bed ore hopper 2 and the sintering raw material from the ore hopper 3 on the pallet of the sintering machine 1, and The upper surface of the binder layer is ignited in the ignition furnace 4 and operated at the end of the sintering machine 1 so that the sintering is completed.

At this time, quick lime or slaked lime is added to the sintering raw material as a granulating agent in order to ensure air permeability, but since these granulating agents are manufactured or purchased separately, they are one of the causes of the increase in sintering cost. Has become.

On the other hand, the sintered ore after completion of the sintering is supplied to the cooler through the primary crusher (not shown). This sintered ore has a temperature distribution as shown in FIG. The upper half of the layer is cooled to near room temperature. However, in the conventional technique, since the sinter having a high powder rate at a low temperature is also supplied to the cooler, its cooling efficiency is low.

In addition, as a conventional technique, limestone is used instead of bedding as in JP-A-58-133330, and this is quick-calcified,
There is something to be recovered, but in this case, the particle size of limestone is large, so it was mixed into the product line as it was, and the recovery rate was low.

[Problems to be solved by the invention]

It was difficult to efficiently collect quicklime burned on a sintering machine by the conventional technique. Further, the sinter has a low cooling efficiency in the chiller because the portion of the upper layer of the pallet having a low strength and a high powder ratio is supplied to the cooler together with the sinter of the lower layer of the pallet having a high temperature.

[Means for solving problems]

The present invention, using a continuous sintering machine, after supplying the sintering raw material on the pallet, before the stage of igniting the raw material surface,
Limestone having a particle size of 5 mm to 15 mm is added to the upper layer portion of the sinter layer on the pallet, and the limestone is mixed together with a portion up to 150 mm from the surface of the upper layer portion of the raw material sintered layer, and thereafter, the surface of the sintered layer is ignited, A method for producing a sintered ore, characterized in that limestone is sintered together with a sintering raw material to give quick calcification, and a portion up to 150 mm from the surface of the upper portion of the sintered layer is continuously taken out by a removing device.

In this case, it is preferable that the removing device is arranged on a sintering machine, the upper part of the sintered layer taken out by the removing device is returned to the return ore, and recycled as a raw material for quick lime into a sintering raw material.

[Action]

In normal operation, the drop strength is low and the powder rate after the primary crusher is high up to approximately 150 mm from the upper part of the sintered layer, that is, on the downstream side in the pallet advancing direction of the sintering machine. From the surface of the upper layer of the sintered layer on this pallet, add limestone with a grain size of 5 mm to 15 mm to the part up to 150 mm, and burn,
Then, the upper layer portion is cooled to around room temperature, and the upper layer portion is removed before being supplied to the primary crusher, whereby almost all of the quick-calcified limestone can be recovered together with the upper layer portion. Furthermore, by removing the upper layer of the raw material layer on this pallet, the processing amount in the cooler decreases, the powder rate of the ore processed in the cooler decreases, and the average temperature of the sintered ore sent to the cooler rises. Therefore, the cooling efficiency of the cooler is improved, and the amount of recovered exhaust heat can be increased.

The upper part of the sintered layer on the downstream side in the pallet traveling direction on the sinter machine pallet has a low drop strength, which causes an increase in the powder ratio of the processed material in the downstream process. Since this upper layer portion has low strength and is cooled to around room temperature, it is easy to remove it on the sintering machine.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. 1, 2, and 4.

As shown in FIG. 1, the bed mine ore hopper 2 supplies the bed mine ore to the pallet of the sintering machine 1, the raw material hopper 3 supplies the raw material, and the limestone hopper 12 supplies limestone to the upper surface of the raw material. To do. To further increase the firing efficiency of this limestone,
This limestone is mixed with the upper layer part of the raw material sintered layer in the mixing device 13. The upper surface of the mixed raw material is ignited in the ignition furnace 4, and the atmosphere is sucked from the upper surface to the lower surface of the raw material layer to perform sintering. In the portion on the downstream side of the pallet traveling direction of the sintering machine 1, the sintering of the upper layer of the raw material layer is completed and the calcification of limestone is also completed. Further, since the strength and temperature of the upper portion of the raw material layer in this portion are low, it can be easily removed by the removing device 6.

The removed upper layer portion is taken out of the system by a belt conveyor 7 arranged after the removing device 6 and recycled as return ore to improve the granulation property of the sintering raw material.

Next, as shown in FIG. 2, the removing device 6 excavates and collects the upper layer portion of the sintered layer 5, that is, a portion up to a depth of about 150 mm from the surface of the sintered layer, using the earth discharging plate 9. The sinter that has been excavated and collected is scraped up along the soil discharge plate 9 by the rake chain conveyor 8 and is fed to the subsequent belt conveyor 7. However, in order to remove only the low-strength portion of the upper portion of the sintered layer, the excavation plate 9 is provided with a digging resistance detection device (not shown), and the cylinder 10 operated by the signal tilts the support part 11 as a fulcrum. The amount of excavation is controlled as appropriate to prevent a decrease in the sintered ore retention.

As a result, it becomes possible to inexpensively produce and provide quicklime as a granulating agent. In addition, before supplying the sinter to the cooler, by removing the upper layer of the sintered layer, which has low temperature and low strength and is easily pulverized, the throughput of the cooler is reduced and the air permeability is improved to improve the cooling efficiency. Can be increased. In addition, since the average temperature of the sinter supplied to the cooler rises, the exhaust heat recovery efficiency increases and the exhaust heat recovery amount can be increased.

〔The invention's effect〕

Since the present invention is configured as described above, it has the following excellent effects.

(1) Quick lime as a granulating agent can be manufactured and provided at low cost using a sintering machine.

(2) The upper part of the sintered layer on the pallet is easily pulverized, and the part that does not need to be cooled is removed before the crushing and cooling, so the amount of processing in the cooling device is reduced and the ventilation resistance in the cooling device is reduced. Can be improved, cooling efficiency can be increased, and cooling fan power can be saved.

(3) Since the proportion of the low temperature part of the sinter provided to the cooling device decreases, the average temperature rises, the heat recovery efficiency of the cooling device having the exhaust heat recovery equipment increases, and the amount of recovered heat increases.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic side view of a sintering machine used for carrying out the method of the present invention, and FIG. 2 is a schematic side view of an example of a sintered ore removing device used for the method of the present invention. 3 is a schematic side view of a conventional sintering machine,
FIG. 4 is a temperature distribution curve diagram in the thickness direction of the sinter on the pallet immediately before being discharged from the sintering machine. 1 ... Sintering machine, 2 ... Floor ore hopper 3 ... Raw ore hopper, 4 ... Ignition furnace 5 ... Sintering layer, 6 ... Removal device 7 ... Belt conveyor 8 ... Rake chain conveyor 9 …… Soil dump plate, 10 …… Cylinder 11 …… Supporting device, 12 …… Limestone hopper 13 …… Mixing device

Claims (2)

(57) [Claims] 1. A continuous sintering machine is used to supply a sintering raw material onto a pallet, and before the surface of the raw material is ignited.
Limestone having a particle size of 5 mm to 15 mm is added to the upper layer portion of the sinter layer on the pallet, and the limestone is mixed together with a portion up to 150 mm from the surface of the upper layer portion of the raw material sintered layer, and thereafter, the surface of the sintered layer is ignited, A method for producing a sintered ore, characterized in that limestone is sintered together with a sintering raw material to give quick calcification, and a portion up to 150 mm from the surface of the upper portion of the sintered layer is continuously taken out by a removing device. 2. The removing device is arranged on a sintering machine, and the upper part of the sintered layer taken out by the removing device is returned to the return ore,
The method for producing a sinter according to claim 1, wherein the sinter ore is recycled as a lime raw material into a sinter raw material.