JPS58199842A - Melt smelting method of powdery manganese ore - Google Patents

Abstract

PURPOSE:To stabilize operation and to improve the yield of Mn, by introducing preliminarily reduced powdery Mn ore and limestone into a reduction furnace, supplying lumped and powdery limestone selectively and performing reduction by melting under control of the compsn. of slag. CONSTITUTION:Powdery Mn ore 4 and powdery limestone 5 are charged into a preliminary reduction furnace 2 and are thereby reduced preliminarily. The preliminarily reduced Mn ore 4 and limestone 5 are blown together with high temp. air 8 from tuyeres 3 through a transfer pipe 7 into a melt reduction furnace 1. A carboneous material 9 and lumped limestone 10 are charged into the furnace 1 from the upper part thereof. The ratio of the limestone 5 to be blown through the tuyeres 3 in this stage is 100-50% of the entire amt. of the limestone, and the remaining limestone 10 is charged from the upper part of the furnace. The reduction by melting is accomplished in such a reaction atmosphere in which the slag 12 to be discharged from the furnace 1 consists, by weight %, of 27-45% CaO, 27-45% SiO2, 10-20% Al2O3 and <12% MgO. Molten metal 12 is drawn out through a discharge port 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molten MfR method for powdered manganese ore, and in particular, in a pre-reduced powdered manganese ore/limestone all-vertical smelting reduction furnace, it is possible to reduce We propose a method for obtaining molten ferro-manganese in a timely manner by selecting a supply means and placing it in a smelting reduction furnace with slag adjustment.Conventionally, the manganese ore melting and smelting method adopted for the production of ferro-manganese is as follows: The electric furnace method and the blast furnace method were the most common methods.0 Of these, the electric furnace method has a very low unit power consumption.

The cost is extremely high, reaching KWH/*. Moreover, since lump ore, or pre-treated agglomerated ore, is required as a raw material, powdered ore must be used after being agglomerated into pellets, sintered ore, briquettes, etc. The agglomeration process requires extra raw materials such as solvents and binders, and extra energy such as fuel and power.Furthermore, in this process, which uses a kiln for hot agglomeration, Normally, harmful gases such as No. 2 and SoX and dust are generated (accompanying this, if these are emitted as they are, they can cause air pollution, so equipment to prevent this is installed, but this requires a large amount of cost. Become.

On the other hand, the blast furnace method is more efficient than the electric furnace method in terms of energy consumption, but since it is a shaft furnace, in order to ensure ventilation inside the furnace, lumps of lump ore or fine ore must be In addition to requiring chemical conversion treatment, lump ore and coke are deposited in layers in the furnace, so in order to produce high-strength coke that requires high-strength coke, it is necessary to use resources as a raw material base. It is expected that there will be a shortage in the future, and it requires strong coking coal which is expensive, or if weak coking coal or steam coal is used, it will require modification, a 5" binder, etc., which will lead to an increase in manufacturing costs. The present invention is a method developed for the purpose of overcoming the drawbacks of the above-mentioned conventional technology for producing ferromanganese tM using powdered manganese ore as a raw material, and its gist is as follows: , Powdered manganese ore is pre-reduced in a fluidized bed pre-reduction furnace,
In a method for producing molten ferromanganese by subsequently introducing it into a vertical smelting furnace and smelting it, powdered manganese ore and powdered limestone are placed in a fluidized bed preliminary in which the high-reduction gas generated in the smelting and reduction furnace is introduced. The mixture of pre-reduced manganese ore and flux is fed into the reduction furnace and pre-reduced, and the mixture of pre-reduced manganese ore and flux is blown into the s*mye furnace together with warm air, and only a small amount of the total input amount is injected into the furnace. At least 509g of powder is softened through the slag, and the remaining amount is used to supply powder and limestone, which is charged as lumps from the upper part of the furnace together with carbonaceous materials, and the composition of the slag discharged from the smelting reduction furnace is So, M,
Melting reduction is carried out in a reaction atmosphere where O This is an example of equipment used in the implementation of
The furnace has tuyeres S-8' at a plurality of locations in the circumferential direction of the furnace, which are installed in two stages, upper and lower, in the lower part of the furnace.

The powdered manganese ore charged in the preliminary reduction furnace 2 and the powdered limestone flowing in contact with the high-temperature orphan gas (exhaust gas) 6 (generated from the smelting reduction furnace 1 introduced into the furnace) A reaction occurs and is pre-reduced with thermal decomposition.

The granular manganese ore and flux that have been pre-reduced in this way are transferred to a transfer pipe? [The high-temperature air 6 is blown into the smelting and reduction furnace l in which the reaction atmosphere is adjusted from the tuyere 3 located in the upper stage.
Only the air is blown.

1. Carbon material 9 and lump limestone 10 are charged from the upper part of the smelting reduction furnace 1. Of these, the carbon material 9 is weakly coking coal, low-strength coke, and the charred material is made of wood, etc. Use lumps.

Use both. -This method of using limestone has the advantage of making it easier to balance the use of powder and eliminating waste. Regarding the usage of the powdered lumps, powdered limestone is injected from the upper tuyere 8, and lumpy limestone is charged from the upper part of the furnace.Out of the total amount of limestone, the proportion of powdered limestone injected from the tuyere 8 is as follows: 5
04 or more: That is, 160 to 110 is good 0 The remainder is in lumps and is charged from the upper part of the furnace.The experimental results show that if the amount of powdered limestone injected from tuyere 8 is further reduced than 6011, the following (1) The melting speed of manganese ore at the tip of the tuyere has become slow and the amount of ore injected has decreased (productivity has decreased).In order to melt manganese ore quickly at the tip of the tuyere,
7 lacs such as powdered ore and powdered limestone are in good contact and
It is important that the amount of flux be a certain amount or more. i.e. tuyere tip,) 嘗ore. The melting rate has little effect on the amount of limestone charged into the furnace, and is influenced by the amount of powdered limestone injected into the furnace.
The melting rate gradually decreased as the temperature decreased further. 6
Crab in the corner with more than 0 regrets #! We were able to maintain smooth operations.

(s) Mn yield decreased. Generally speaking, the reduction rate of manganese oxide in the melt by a solid reducing agent and the manganese yield are better when the O&O/SiOs ratio is high.The slag-metal reaction rate in the hearth is important for the manganese yield, but , S fusion reduction progresses from the time when a flux such as limestone is blown into the tuyere together to form an initial melt.
The reduction rate during the dropping process also affects the manganese yield. In other words, the amount of powdered limestone injected from the tuyere is 60% of the total amount.
When the temperature decreases further, the 0100 ratio in the initial melt decreases (that is, the OaO/S 10 s ratio decreases), and the reduction rate of manganese oxides in the dropping overcage decreases, resulting in a decrease in manganese yield. Therefore, from the above results, the appropriate amount of powdered limestone to be injected from the tuyeres together with the powdered ore is 100 to 50% of the total charging amount, and the rest is in the form of lumps and is injected into the furnace. When Juben ore and flux, etc. are injected into the furnace filled with carbonaceous material and powdered limestone, the carbonaceous material in the packed bed burns near the tip of L, lower tuyere 8.8'. Since the atmosphere is m@n, the pre-reduced ore and powdered limestone are heated and melted, and while dripping in the packed bed, they are directly reduced by the solid carbonaceous material to form the molten metal 11. and slag 12Tt is generated. Then, it is stored at the bottom of the lower region, and is intermittently discharged from the molten air outlet 111 by the discharge means.

While the above-mentioned smelting reduction progresses, in the case of the present invention, by creating a reaction atmosphere that maintains the composition of the slag discharged outside the furnace within the following range, the stability of IIO operation and the manganese yield can be improved. I decided to try to improve ・i.e. 1'
The main constituents in the slag except Ml and no are overlaid; 0: 27-46%, 810: 2
? ~46 Section, A/20810.209G,
M, O < l! The reason for this limitation is that it has been found that when the M and O content in the slag exceeds 11, the melting point rises rapidly and operation becomes unstable. The limit for M and O usage is set to 124.
less than The other 8th order components OaO, St, , A/
, 08 were added based on the results of studies regarding the melting point, Mn yield, and viscosity. In other words, Figure 2 is
S i 010 aO-M'*088 original state diagram (M, O
lo 4 constant, except for MnO), and the area surrounded by points A, B, G, D, E↓ and 1 in the figure is the appropriate area for the discharged slag composition of the present invention. For example: , *A-F (510s: 45 winters) The amount of S10 exceeding (510s: 45 winter) is a region where the yield of In deteriorates rapidly, and 1A-B, +3~a, 0-D, D-x.

In the region outside E-F, the melting point and/or viscosity become high, making furnace operation difficult. Ore supply amount 880k
f/hr Preliminary reduction rate 6 (1 grain size Q, 5 mm or less (1 total supply of limestone @ 10 gke/hr) Limestone noodles in the form of blown through the tuyeres? 6 kg/hr (70 of the total amount
Excellent) Flavored limestone charged from the top of the smelting reduction furnace j18 B'q/hr (80 parts of the total amount) (8) Carbon-based solid reducing agent: Coke supply amount 8
501q/hr Particle size distribution 15-80 TYL/m (4) Air blowing to IIMli main furnace 9 14001m/hr
Blow temperature: 800-900℃ Blow tuyeres: 1 each on the upper and lower sides, 8 in total (a) Molten metal (ferromanganese) production volume: 2hOkf
/hr (@) Molten slag composition 0a0404. Mu/, 0
．． 1111.8in, 804゜M2O6%-MnOto
n Molten slag discharge amount 200 m/hr In the operation example according to the above embodiment, cheap carbon material (coke)
In addition, it was possible to operate smoothly using only hot air, significantly reducing energy costs, and the yield of manganese (ferromanganese 2 aokg/hr) was also the same as that of the conventional method.

The effects of the present invention can be summarized as follows.

(1) Since manganese ore can be used in powder form,
No clumping required. In addition, the exhaust gas from the smelting reduction furnace can be used for preliminary reduction, saving energy.

(1) By controlling the slag composition within the range,
It is possible to achieve operational stability and maintain a high level of manganese yield.

(8) It is easy to balance the use of limestone powder and lumps, and the entire amount can be used. Also, since the entire amount of limestone does not need to be crushed, a reduction in crushing costs can be achieved.

[Brief explanation of the drawing]

Figure 1 is a route map of the smelting reduction equipment adopted in the method of the present invention, Figure 2 shows the appropriate range of slag composition, Sin, -0a
O-mu t, 088 elemental state r, a. l... Melting reduction furnace, G... Yobi reduction furnace, 8.8
'...Win, No....Powdered manganese ore, 5...
Powdered limestone, 6...exhaust gas, ma...transfer pipe,
8... High temperature air, 9... Lump carbonaceous material, 10... Boundary limestone, 11... Molten metal, 12... Slag, 1B.
··Vent. Patent applicant Kawasaki Steel Corporation No. 11 No. 2 St'Oz 9t

Claims (1)

[Claims] L Powdered manganese magnets are pre-reduced in a fluidized bed pre-reduction furnace and continued! In a method for producing molten ferromanganese by introducing it into a smelting reduction furnace and smelting it, powdered manganese ore and powdered limestone are introduced into a fluidized bed pre-reduction furnace into which high-temperature reducing gas generated from the molten*a main furnace is introduced. A mixture of the pre-reduced powdered manganese ore and 7 lux is blown into a smelting reduction furnace together with high-temperature air through a tuyere, and only a small amount of the total input amount is injected into the furnace. At the very least, powder is injected through the tuyere, and the remaining amount is used to supply limestone, which is charged as lumps from the upper part of the furnace together with carbonaceous material, and the composition of the slag discharged from the smelting and reduction furnace is determined. It's heavy and ot
o: 2h to 4h, 8i0. : s full 0], Mu/, O, : l O ~ 1 ull, electric, O < ■ 1 Reaction gm Melting reduction under atmosphere 1 * Melting of powdered manganese ore to mold Smelting method/