KR100376540B1 - A method for manufacturing reduced ore by solid phase direct reduction process - Google Patents

Abstract

The present invention relates to a method for producing reduced iron, and provides a method for producing reduced reduced iron capable of producing a reduced reduced iron containing 85% or more of metal Fe by heat treatment after mixing spectroscopy with a particle diameter of 8 mm or less and a carbonaceous binder. I would like to, but its purpose is.

The present invention provides a method for producing reduced iron,

Spectroscopy having a particle size of 8 mm or less and a carbonaceous binder having a fixed carbon content of 50 to 70 wt% are mixed at a weight ratio of 50:50 to 80:20, and the mixture is kneaded to a melt mixture, and then 800 to 800 in an inert atmosphere. The technical summary of the method for producing the reduced iron by the solid phase reduction method, characterized in that the heat treatment at a temperature range of 1200 ℃.

Description

A manufacturing method of mass reduced iron by the solid state reduction method {A METHOD FOR MANUFACTURING REDUCED ORE BY SOLID PHASE DIRECT REDUCTION PROCESS}

The present invention relates to a method for producing unrefined fine iron, which is difficult to use in an ironworks, and more particularly, in a method for producing reduced iron, by mixing and heat treating fine unrefined ore carbonaceous binders, thereby producing a high yield of bulk reduced iron. It relates to a method for producing a bulk reduced iron that can be provided.

Currently, steelmaking technology has been using the blast furnace method for more than 200 years, but this method is a large-scale equipment industry, which is not only burdened by the initial entrants, difficulties in facility expansion, but also the environmental pollution burden due to environmental regulations on the global scale. Have.

On the other hand, in the steelmaking method of the blast furnace method can not use the fine iron ore as it is in order to ensure the air permeability and high temperature strength in the blast furnace, it is subjected to a sintering process for agglomeration as a pre-treatment for input into the blast furnace. In the sintering process, by mixing and heating the powdered iron ore, lime and coal, partial reduction and block formation are induced, which are charged into the blast furnace together with the coke and manufactured as molten iron.

Recently, in order to solve the problem of the blast furnace method, the development of the COREX method, which is a molten iron reduction iron method that can produce molten iron using iron ore and coal having a particle diameter of 8mm or more has been actively developed, but also in the case of such molten iron reduction method As mentioned above, since the particle diameters of the iron ore and raw coal which can be used are limited only to the raw material of the aggregate of 8 mm or more, there is a problem in that the fine iron ore and the raw coal cannot be used.

In order to solve this problem, the situation is rushing the development of FINEX process that can use the spectroscopy as it is. However, in the case of the FINEX method of directly injecting unspectral spectroscopy, since 30% or more of the unspecified spectroscopy is discharged out of the reaction system again, dust collection and circulation facilities for recycling them are required, and thus, enormous investment is required and the manufacturing cost is increased. It is acting as a factor.

In addition, in the case of direct reduction iron (DRI) manufacturing techniques such as the Midrex method and the SN / RL method, more than 30 to 70% of the raw iron ore must be used as a raw material, and the natural gas or coal is converted into a gaseous state as a reducing agent. There is a problem that must be used.

Meanwhile, in the case of manufacturing iron carbide (FeC ₄ : Iron carbide) using a fluidized-bed reduction furnace, fine powdered iron ore is used, but natural gas is used to serve as a reducing agent as well as a fluid gas for flowing iron ore. Because it must be, if not manufactured in the region or country that holds these raw materials, it is difficult to secure economic feasibility.

In order to solve the above problems of the prior arts, the present inventors have conducted research and experiments and proposed the present invention on the basis of the results, and the present invention provides a fine ore and carbonaceous binder having a particle diameter of 8 mm or less. By mixing and heat treatment, to provide a method for producing a reduced iron, which can produce a reduced iron containing 85% or more metal Fe, there is an object.

1 is a result of X-ray diffraction analysis of reduced iron prepared according to the present invention

The present invention provides a method for producing reduced iron,

Spectroscopy having a particle size of 8 mm or less and a carbonaceous binder having a fixed carbon content of 50 to 70 wt% are mixed at a weight ratio of 50:50 to 80:20, and the mixture is kneaded to a melt mixture, and then 800 to 800 in an inert atmosphere. It relates to a method for producing the reduced iron by the solid phase reduction method characterized in that the heat treatment at a temperature range of 1200 ℃.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is useful for producing finely divided ore containing no more than 40% of finely divided ore having a particle diameter of 8 mm or less, in particular, 0.1 mm or less. In addition, the present invention can be applied to fine ore of 1 mm or less.

The above-mentioned fine ore is mixed with a carbonaceous caking agent and heat-treated to produce mass reduced iron. The carbonaceous caking agent preferably has a fixed carbon content of 50 to 70 wt%. The reason is that if the fixed carbon content is less than 50wt%, the amount of organic matter is increased to increase the manufacturing cost, whereas if the fixed carbon content is more than 70wt%, it does not have caking force.

In addition, it is preferable to mix the spectroscopy and carbonaceous caking agent at a weight ratio of 80:20 to 50:50, because the reduction reaction is not sufficiently progressed if the composition ratio of the mixture is out of the range so that the reduction rate is low. Because.

On the other hand, the heat treatment is preferably carried out in a temperature range of 800 ~ 1200 ℃, when the temperature is less than 800 ℃ is not required to perform a reduction reaction smoothly, while on the other hand if the temperature is higher than 1200 ℃ This is because manufacturing cost rises due to an increase in energy requirements. Therefore, it is preferable to perform heat processing for 1 to 2 hours at 800-1200 degreeC.

Hereinafter, the present invention will be described in detail through examples.

(Example)

Using a 35 mesh sieve, only fine powder having a particle size of 8 mm or less (including 30% or more of 0.1 mm or less) is separated from the iron ore, and a pitch of 60 wt% of fixed carbon is used as a caking agent. Dry mixing was carried out at a weight ratio of 50:50 to 90:10. Then, the mixture was heated and kneaded using a kneader to obtain a mixture. The prepared mixture was heated up to 500 ° C. at an elevated rate of 3 to 5 ° C./min in an inert atmosphere, and then heated up to 600 ° C. to 1200 ° C. at 1 to 3 ° C./min, and then heat-treated for 1 to 5 hours to form massive reduced iron. Was prepared.

Thereafter, the properties of the reduced iron produced were measured, and the results are shown in Table 1 below.

Item Classification Spectroscopy / Binder Mixing Ratio (wt%) Heat treatment condition (℃ -hr) Reduction Rate (wt%) Inventive Example 1 80/20 1200-1 87 Inventive Example 2 70/30 1200-1 90 Inventive Example 3 60/40 1100-1 90 Inventive Example 4 50/50 1000-1 91 Inventive Example 5 60/40 800-2 86 Inventive Example 6 70/30 900-2 88 Inventive Example 7 80/20 800-2 85 Comparative Example 1 90/10 1200-1 75 Comparative Example 2 60/40 600-5 75 Comparative Example 3 50/50 700-3 78

As shown in Table 1, in the case of Inventive Examples (1) to (7), heat treatment was performed at 800 to 1200 ° C. for 1 to 2 hours, whereby the content of metal Fe exceeded 85 wt%. On the other hand, Comparative Examples (1) to (3) shows that the reduction ratio is less than 85 wt%, so that the reduction reaction does not proceed because the mixing ratio or heat treatment condition of the spectroscopy / binder is out of the range of the present invention. have.

On the other hand, Figure 1 shows the X-ray diffraction analysis (XRD) results for the reduced iron prepared as inventive example (1). As shown in the X-ray diffractogram, it was confirmed that the metal Fe was produced.

As described above, by producing the bulk reduced iron by the solid phase reduction method according to the present invention, it is possible to obtain a bulk reduced iron containing 85% or more of the metal Fe, thereby making it possible to use as a substitute for scrap for electric furnaces, as well as continuous manufacturing It is possible to have an effect that can shorten the manufacturing time.

Claims (3)

In the method for producing reduced iron, Spectroscopy having a particle size of 8 mm or less and a carbonaceous binder having a fixed carbon content of 50 to 70 wt% are mixed at a weight ratio of 50:50 to 80:20, and the mixture is kneaded to a melt mixture, and then 800 to 800 in an inert atmosphere. Process for producing mass reduced iron by solid phase reduction, characterized in that the heat treatment at a temperature range of 1200 ℃ The method for producing bulk reduced iron by the solid phase reduction method according to claim 1, wherein the spectroscopic stones contain 40% or more of finely divided ore having a particle diameter of 0.1 mm or less. The method of claim 1 or 2, wherein the heat treatment time during the heat treatment is 1 to 2 hours.