JPS58171516A - Transferring apparatus of preliminarily reduced powdery and particulate ore in melt reduction equipment - Google Patents

Abstract

PURPOSE:To prevent a back flow of solid powders caused by a gas by providing a blowing hole of a carrying gas on the way of the transferring pipe. CONSTITUTION:Plural discharging holes 5 provided at a fluidized layer of a preliminary reduction furnace 2 and plural tuyeres provided at a melting reduction furnace 3 are connected with plural carrying pipes 6 of preliminarily reduced ore. A blowing hole 11 of the carrying gas of preliminarily reduced ore is provided on the midway of the pipe 6 which is divided into an upper gravity transferring part 6a and a lower gas transferring part 6b by this hole 11. The back flow preventing vessel 10 is provided at the part 6a, the height H2 of the part 6b of the pipe 6 is <=30% of H1+H2 which is the whole height of the transferring pipe, and a horizontal distance L2 occupied by the part 6b is <=60% of the horizontal distance L1+L2 of the transferring pipe. The ore is discharged from the hole 5 of the furnace 2 to the part 6a, and the gas is blown succeedingly from the hole 11 to the part 6b.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used in a method for producing molten metal by preliminary reduction of powdery ore containing metal oxides and then melting reduction.
The present invention relates to a device for transferring pre-reduced granular ore from the pre-reduction furnace to the smelting-reduction furnace in a smelting-reduction facility comprised of a pre-reduction furnace and a smelting-reduction furnace.

In recent years, ore raw materials containing various metal oxides have become less bulky ores and more powdery or small-grained ores.
The proportion of powdery ore will continue to increase in the future. Conventionally, granular ore is used as agglomerates such as pellets F and sintered ore by adding binders and carbonaceous materials, which not only requires extra resources and energy for agglomeration, but also requires calcination. If necessary, there is a drawback that the cost for treating NOx, dust, etc. in the gas discharged from the kiln is large.゛In addition, when smelting is done in an electric furnace, as in the production of aerenv chromium by smelting chromium ore, the electricity consumption rate reaches several thousand kilowatt hours per ton, making it extremely costly in areas where electricity rates are high. Get high.

The present inventors have invented a method in which powdery ore can be directly used without first agglomerating it, and molten metal can be produced from it without using electricity. )CIThe gist of this invention is to pre-reduce powdery ore in a fluidized bed format in a one-arm reduction furnace, and to pass the obtained powdery pre-reduced ore through a plurality of tuyeres each provided in one upper and lower stage. The molten ore is transferred to a vertical smelting reduction furnace equipped with a smelting reduction furnace, and is blown into the smelting reduction furnace from the tuyeres together with high temperature air to melt and reduce the molten ore. It is a method of manufacturing metal.

Therefore, in a smelting reduction facility consisting of a pre-reduction furnace and a smelting reduction furnace, the following conditions are satisfied when transferring powdered ore from the pre-reduction furnace to the smelting reduction furnace compared to normal powder transfer. need to be done.

(1) Pre-reduction ore shall be discharged from the pre-reduction furnace at high temperature.

(2) The transfer distance should be short to reduce the temperature drop in the preliminary reduction furnace.

(3) Evenly distributing the pre-reduced ore from the pre-reducing furnace to the numerous tuyeres of the smelting reduction furnace.

(4) Since the inner pressure is higher in the lining portion into which the pre-reduced ore is injected than in the pre-reducing furnace, blockage caused by powder in the transfer pipe and backflow of powder due to this can be prevented.

(5) Since the carrier gas for transferring the pre-reduced ore is blown into the smelting reduction furnace together with the powder, it is desirable that the carrier gas be as small as possible.

(6) It is possible to prevent reoxidation of the pre-reduced ore during transportation.

An object of the present invention is to provide an apparatus that can effectively, smoothly, and stably transfer powdery pre-reduced ore in a smelting reduction ff equipment by satisfying the above-mentioned special conditions. be.

That is, the gist of the present invention is as follows.

In a smelting reduction installation consisting of a preliminary reduction furnace and a smelting reduction furnace for producing molten metal from granular ore, a plurality of discharge ports provided in the fluidized bed of the preliminary reduction furnace and a plurality of discharge ports provided in the smelting reduction furnace are provided. A plurality of pre-reduced ore transfer pipes are connected to the plurality of tuyeres, an injection port for a carrier gas for the pre-reduced ore is provided in the middle of the transfer pipes, and the transfer pipes are moved vertically with the injection port as a boundary. Each is divided into a gravity transfer part and a gas transfer part, a backflow prevention tank is provided in the gravity transfer part, and the height occupied by the gas transfer part of the transfer pipe is set to be 30 meters or less of the height occupied by the entire transfer pipe, and the horizontal distance occupied by the gas transfer section is 60 times or less of the horizontal distance occupied by the entire transfer pipe, and the pre-reduced ore in a high temperature state in the form of powder and granules is transferred from the discharge port of the pre-reduction furnace. The ore is discharged into a gravity transfer section of the pipe, and then the ore is sent to the side of the smelting reduction furnace through the gas transfer section of the transfer pipe by means of a carrier gas supplied from the gas inlet. , a device for transferring powdery pre-reduced ore in a smelting reduction facility.

The present invention will be explained below based on a sheet 70 of a transfer device for pre-reduced ore in a smelting reduction facility shown in FIG.

Ore containing oxides in powdery gold 1 is supplied from a supply device 1 to a preliminary reduction furnace λ. A part or all of the high-temperature generated gas discharged from the vertical smelting reduction furnace J is introduced into the preliminary reduction furnace through the exhaust gas pipe/tube, and is supplied with reducing gas and solid reducing agent from the supply channel as necessary. , 7 lux, air, etc. are supplied, and the powdery ore is dried in a fluidized bed format!
Heated and pre-reduced. Preliminary reduced ore is an outlet! The air is discharged from the smelting-reducing furnace 3 through the transfer pipe number and blown into the smelting-reducing furnace 3 together with high-temperature air from the upper stage impeller of the smelting-reducing furnace 3.

Inside the melting reduction furnace J, a packed bed is formed of a lumpy carbon-based reducing agent supplied from a charging device t.

The pre-reduced ore injected into the smelting reduction furnace J is melted in the raceway at the tip of the tuyere, and reduced while dripping down the lower part of the furnace J to produce molten metal and molten slag, which are then discharged from the furnace through the discharge port T in a timely manner. is discharged to.

As described above, the present invention is directed to a device for transferring pre-reduced ore between outlet #j of pre-reduced ore and blade lower 7'. Since a large number of blades are arranged so as to surround the melting reduction furnace 3 in an annular manner, the number of discharge pipes and transfer pipes 4 of the preliminary reduction furnace is set to be the same as the number of corresponding blowing tuyeres. Even when the pre-reduced ore is injected into each of the upper and lower tuyeres, this can be done in the same way by increasing the number of transfer pipes. The discharge of the pre-reduced ore from the pre-reduction furnace is carried out using an overflow pipe system so that it can be distributed evenly to each transfer pipe number, and the transfer pipes are used to transfer high-temperature materials. The insulation type shall be suitable for

However, in Fig. 1, the preliminary reduction furnace J-, the smelting reduction furnace J-
Transfer pipe 6 #Exhaust gas pipe/l showing each position = B
e Oe D -E KaiF The distribution of internal pressure during operation in 豐G is shown in Fig. S1, and the pre-reduced ore -
Exhaust port! The pressure is higher at one point in the lower part of the blade than at the other point. For this reason, since the gas flows backward in the transfer pipe from one point to the second point, it is important to prevent the backflow of powder and gas and blockage of the pipe, and to smoothly transfer the pre-reduced ore.

Therefore, various tests were conducted regarding the requirements for smooth transfer, and the following measures were found to be effective. (1) A backflow prevention tank 10 is provided in the middle of the transfer pipe 6.

(2) A carrier gas blower and inlet 11 is provided in the middle of the transfer pipe 1, and from this inlet, the powder is transferred by gravity in the preliminary reduction furnace side, and by gas in the smelting reduction furnace 3 side.

Therefore, a carrier gas blowing port // is provided in the middle of the transfer pipe 6, and the first! ! ! If the position directly above the inlet 7 of the transfer pipe 6 in l is O, and the position immediately below it is D, then
Regarding the transfer pipe numbers, the upper part with the air inlet/l as a boundary is the gravity transfer part 6a (between M-c), and the lower part is the gas transfer part 4b (between D and E).

The backflow prevention tank 10 is provided in the middle of the gravity transfer part 6a of the transfer pipe 6, but this only requires making the diameter of the transfer pipe in this part 3 to 30 times larger than the diameter of the transfer pipe in other parts. This prevents backflow in the transfer pipe, and even if backflow occurs, it is possible to prevent the backflow from spreading to the preliminary reduction furnace side. In addition,
A powder flow meter/J is installed in the gravity transfer section 6 & of the transfer pipe 6 to detect the amount of solid powder flowing out, and if backflow is detected,
The transfer pipe can be shut off with the valve /3 provided at the gravity transfer section number & of the transfer pipe. The gravity transfer section 6&' is effective for preventing gas backflow due to the powder seal, and the gas transfer section 6b is effective for stably injecting powder into the melting reduction furnace J under high pressure.

In this way, by providing the carrier gas inlet // in the middle of the transfer pipe B, the 0 point and the D point on the pressure distribution diagram in Figure 1 can be connected to the polygonal line Since they can be located on both sides, backflow of solid powder due to gas in the transfer pipe 1 is prevented.

Furthermore, in order to prevent backflow of powder in the transfer pipe B, the position of the installation of the inlet 1/ with respect to the transfer pipe B is important. In FIG. 1, the height occupied by the gravity transfer section 6a of the transfer pipe 6 divided by the position of the inlet l/ is designated as Hl, the height occupied by the gas transfer section 61) is designated as H2, and the gravity transfer section 6 & When the horizontal distance occupied is Ll and the horizontal distance occupied by the gas transfer section 6b is L2 (therefore, the height and horizontal distance occupied by the entire transfer pipe 6 are respectively 111 + H74e L1 + L2.) , H2/(Hl +
The ranges of H2) and L2/(L1+Ll) are as shown in FIG.

As is clear from Fig. 3, the position of the inlet port required for stable powder transfer is the height H2) occupied by the gas transfer section of the transfer tube and the height H1+ occupied by the entire transfer tube.
H2) is 30% or less, and the horizontal distance (L2) occupied by the gas transfer section is 60% or less of the horizontal distance (L1+Lg) occupied by the entire transfer pipe.

Examples of the present invention are shown below.

Example (1) Melting reduction furnace inner diameter /, Jma (tuyere part) (2) Preliminary reduction furnace inner diameter /, /! 11(3)
Air blowing number Upper row (Powder cooking) Lower row Y (Total) (4) Air flow volume 100 MI113/kr (5) Powder transfer pipe Inner diameter X-'Ik4I (6) Vertical power distribution of transfer pipe 111. - j; 3 m H2-0, 7~O6 heavy H2/(H1+H2)-o, tt ~o, t4I horizontal direction Ll-J, l! ~Da, Jho L$/(L1+L2)-0.33~0.3t()) Powder carrier gas type N2 (8) Backflow prevention tank inner diameter/Yo-k4I 1. - Production of 7ep chromium from powdered iron ore (average particle size 0: 1 -) and smelting of pig iron from powdered iron ore (average particle size 0.Jtwm) operation, and was able to stably transfer pre-reduced ore from the pre-reduction furnace to the smelting reduction furnace.

The effects of the present invention are summarized as follows.

(1) The fluidized bed preliminary reduction furnace and the smelting reduction furnace can be connected through multiple transfer pipes.

(2,) Even though the internal pressure of the smelting reduction furnace is higher than the internal pressure of the pre-reduction furnace, granular pre-reduced ore can be blown into the smelting reduction furnace without causing backflow.

(3) Even if backflow occurs partially in the transfer pipe, it can be prevented from spreading to the entire transfer pipe.

(4) The pre-reduced ore can be blown into the smelting reduction furnace at a higher temperature. (5) It is easy to uniformly distribute the pre-reduced ore to each blade and mouth of the smelting reduction furnace.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet of a transfer device for pre-reduced ore in a smelting-reduction equipment according to the present invention, Fig. 2 is a chart showing the distribution of internal pressure at each position of the smelting-reduction equipment in Fig. FIG. 2 is a chart showing the relationship between the provided carrier gas injection position and the stable operation range for the transfer of preliminary reduced ore. FIG. l...Ore supply device, λ...Preliminary reduction furnace, J...
Melting reduction furnace, da... Reducing gas is a solid reducing agent, air supply path,! ...Preliminary reduced ore discharge port, 6...Transfer pipe for 1,000 fIn original ore, 6 &...Gravity transfer section of 1 transfer pipe, 4
k... Gas transfer section of the above transfer pipe %? 17'... Supply of preliminary reduced ore and high temperature air, t... Solid carbon-based reducing agent supply device, t... Discharge port for molten metal and molten slag,
lθ...Backflow prevention tank, /c...Carrier gas inlet, l
/′... Carrier gas blowing path, /ko... Powder flow meter,
/3...Shutoff valve, llI...Exhaust gas pipe of the melting reduction furnace. Patent applicant Kawasaki Steel Corporation Patent attorney Mura 1) Political pressure -1 Figure 30 0.2 0.4 0.6 0.8 1.
0'2/(Ll・shi2)

Claims (1)

[Claims] 1. In a smelting and reduction equipment consisting of a preliminary reduction furnace and a smelting reduction furnace for producing molten metal from granular ore, a plurality of discharge ports connected to the fluidized bed of the preliminary reduction furnace, and the smelting and reduction furnace A plurality of tuyere provided in is divided vertically into a gravity transfer section and a gas transfer section, a backflow prevention tank is provided in the gravity transfer section, and the height occupied by the gas transfer section of the transfer pipe is increased by 30% of the height occupied by the entire transfer pipe.
- and the horizontal distance occupied by the gas transfer section is not more than u% of the horizontal distance occupied by the entire transfer pipe, and the pre-reduced powder and granules are in a high temperature state from the outlet of the pre-reduction furnace. The ore is discharged into the gravity transfer section of the transfer pipe, and then the ore is sent to the surface of the smelting reduction furnace through the gas transfer section of the transfer pipe using a carrier gas supplied from the gas inlet. A device for transferring powdery pre-reduced ore in a smelting reduction facility, characterized by