CN103757169B

CN103757169B - A kind of process iron scale Shaft Furnace Direct Reduction Process

Info

Publication number: CN103757169B
Application number: CN201410065453.2A
Authority: CN
Inventors: 金明芳; 王玮; 印民; 董会国; 张玉栋
Original assignee: CISDI Shanghai Engineering Co Ltd
Current assignee: CISDI Shanghai Engineering Co Ltd
Priority date: 2014-02-25
Filing date: 2014-02-25
Publication date: 2016-04-27
Anticipated expiration: 2034-02-25
Also published as: CN103757169A

Abstract

The invention discloses a kind of process iron scale Shaft Furnace Direct Reduction Process, comprise the following steps: 1) sieving approach, iron scale is carried out screen, break process, be prepared into the volume particle size iron scale being not more than 3mm; 2) preheating hot-forming, entered to be preheating to 350 DEG C ~ 550 DEG C by granularity at the iron scale of below 3mm, sent into thermocompressor hot-forming; 3) shaft kiln directly reduced, hot-forming iron scale is loaded shaft furnace from shaft furnace top charging appts, the iron scale hot pressing entering shaft furnace is continuing heated by 830 DEG C ~ 1000 DEG C reducing gas and be reduced into sponge iron in slow decline process, and the sponge iron of generation is discharged by the discharge system bottom shaft furnace.Iron scale Shaft Furnace Direct Reduction Process flow process of the present invention is short, preparation energy consumption and cost low, the sponge iron stable components produced, purer.

Description

A kind of process iron scale Shaft Furnace Direct Reduction Process

Technical field

The invention belongs to the technical field of direct-reduction process sponge iron smelting or liquid steel, specifically relate to a kind of process iron scale Shaft Furnace Direct Reduction Process.

Background technology

Iron scale is the byproduct that refining steel and rolled steel produces, and its main component is FeO, Fe2O3, Fe3O4 and a small amount of iron and other impurity elements, TFe about 70%.Steel Plant's iron scale quantity is about 2% ~ 3% of steel output, it is one of very important Steel Plant's circulation iron-bearing material, China's steel industry will discard a large amount of iron scales every year, realizes being undoubtedly an energy-saving and cost-reducing job highly significant to effective utilization of these iron scales.

At present, the Application way of each Iron And Steel Company to iron scale mainly contains two kinds: one is applied to sintering as auxiliary material, one uses directly supplying steel-making after iron scale drying and processing as dissolving agent, iron scale also can be used to produce reduced iron powder, the production process that iron scale manufactures reduced iron powder is divided into thick reduction to reduce with essence substantially, through thick reduction process, iron scale is mixed the sponge iron being reverted to w (Fe) >95%, w (C) <0.5% by tunnel furnace technique at about 1100 DEG C with coal dust; Subsequently by gained sponge iron blocks pulverize, at the temperature of 800 ~ 1000 DEG C in ammonia dissolving atmosphere or pure hydrogen, carry out essence and reduce, finally, carry out pulverizing, sieve, adjust granularity, make iron powder, whole technical process is comparatively complicated, and energy consumption is high, and cost is high.

Summary of the invention

In view of this, the object of the present invention is to provide a kind of process iron scale Shaft Furnace Direct Reduction Process, this iron scale Shaft Furnace Direct Reduction Process by iron scale is carried out sieving approach, preheating heat molded after add in shaft furnace and be directly reduced to sponge iron, this processing method flow process is short, preparation energy consumption and cost low, the sponge iron stable components produced, purer.

For achieving the above object, the present invention's one process iron scale Shaft Furnace Direct Reduction Process, comprises the following steps:

A) sieving approach, is undertaken iron scale screening, break process, is prepared into the volume particle size iron scale being not more than 3mm;

B) iron scale forming processes, granularity through at the iron scale of below 3mm and being preheating to 350 DEG C ~ 550 DEG C, feeding thermocompressor is hot-forming, or at the iron scale of below 3mm, after chilling press compression moulding or disk pelletizing, baking and concretion is shaping again by granularity;

C) shaft kiln directly reduced, hot-forming iron scale is loaded shaft furnace from shaft furnace top charging appts, the iron scale hot pressing entering shaft furnace is continuing heated by 830 DEG C ~ 1000 DEG C reducing gas and be reduced into sponge iron in slow decline process, and the sponge iron of generation is discharged by the discharge system bottom shaft furnace.

Further, in step 1), the iron scale to screening, before break process carries out drying and processing, and the iron scale after oven dry is moisture≤and 5%.

Further, in step 1), iron scale is screened, the equipment of break process adopts trommel screen or vibratory screening apparatus.

Further, in step 2) in, the equipment of its pre-heating technique adopts smoke pre-heating stove.

Further, in step 2) in, the hot-forming shape of described iron scale is set to bulk, and the size of described bulk is 10 ~ 20cm ³.

Further, in step 3), described reducing gas is set to reducing gas that is arbitrary in coke-oven gas, gas maked coal, Sweet natural gas or coal-seam gas or combination.

Beneficial effect of the present invention is:

The present embodiment iron scale Shaft Furnace Direct Reduction Process by iron scale is carried out sieving approach, preheating heat molded after add in shaft furnace and be directly reduced to sponge iron, this processing method flow process is short, preparation energy consumption and cost low, the sponge iron stable components produced, purer, be more suitable for making high-quality steel scrap and use.

Accompanying drawing explanation

In order to make object of the present invention, technical scheme and beneficial effect clearly, the invention provides following accompanying drawing and being described:

Fig. 1 is a kind of schema processing iron scale Shaft Furnace Direct Reduction Process of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

Be illustrated in figure 1 a kind of schema processing iron scale Shaft Furnace Direct Reduction Process of the present invention; The present invention's one process iron scale Shaft Furnace Direct Reduction Process, comprises the following steps:

1) drying and processing, the wet oxidation iron sheet water content that Steel Plant's continuous casting and mill produce, 10% ~ 20%, adopts stoving process to dry wet oxidation iron sheet to moisture≤5%, then can not consider stoving process for dry oxidation iron sheet.

2) sieving approach, is undertaken the iron scale of drying screening, break process, by trommel screen or vibratory screening apparatus, and impurities removing and be greater than the volume particle size iron scale of 3mm, raw material cabin sent into by the iron scale that will be less than 3mm; If be greater than 3mm iron scale to account for larger proportion, can break process be considered, be broken into and send into raw material cabin after being less than 3mm and treat subsequent technique.

3) iron scale forming processes, granularity through at the iron scale of below 3mm and being preheating to 350 DEG C ~ 550 DEG C, feeding thermocompressor is hot-forming, or by granularity, at the iron scale of below 3mm, after chilling press compression moulding or disk pelletizing, baking and concretion is shaping again, and above balling technique all meets the requirement of shaft furnace pellet strength.

4) shaft kiln directly reduced, iron scale hot wafering is loaded shaft furnace from shaft furnace top charging appts, the iron scale hot pressing entering shaft furnace is continuing in slow decline process by high temperature reduction heated by gas, and being reduced into sponge iron gradually, the high-temperature sponge iron of generation is discharged by the discharge system bottom shaft furnace.

The present embodiment iron scale Shaft Furnace Direct Reduction Process by iron scale is carried out sieving approach, preheating heat molded after add in shaft furnace and be directly reduced to sponge iron, this processing method flow process is short, preparation energy consumption and cost low, the sponge iron stable components produced, purer, be more suitable for making high-quality steel scrap and use

Mode one

By the wet oxidation iron sheet of moisture 10% ~ 20 at dry kiln drying and processing, moisture after drying≤5%, again by trommel screen impurities removing and be greater than 3mm iron scale, if it is larger to be greater than 3mm iron scale content, can be broken into and be less than 3mm, then will be less than 3mm iron scale and add raw material cabin, hot-forming block 20 × 30 × 25mm of heat pressing forming machines is added after being preheating to certain temperature by preheating oven, block iron scale adds shaft furnace, direct-reduction sponge iron is produced under the effect of high-temperature reducing gas 830 DEG C, the middle metallic iron of sponge iron and the ratio of full iron are 92% ~ 94%.

Mode two

By the wet oxidation iron sheet of moisture 10 ~ 20% at dry kiln drying and processing, moisture after drying≤5%, again by trommel screen impurities removing and be greater than 3mm iron scale, if it is larger to be greater than 3mm iron scale content, can be broken into and be less than 3mm, then will be less than 3mm iron scale and add raw material cabin, by briquetting press coldmoulding or by after disk pelletizing, through sinter process process, improve pellet strength, iron scale after balling-up process adds shaft furnace, direct-reduction sponge iron is produced under the effect of high-temperature reducing gas 1000 DEG C, the middle metallic iron of sponge iron and the ratio of full iron are 93% ~ 94%.

Mode three

By dry oxidation iron sheet by by trommel screen impurities removing and be greater than 3mm iron scale, if it is larger to be greater than 3mm iron scale content, can be broken into and be less than 3mm, then will be less than 3mm iron scale and add raw material cabin, hot-forming block 20 × 30 × 25mm of heat pressing forming machines is added after being preheating to 550 DEG C by preheating oven, block iron scale adds shaft furnace, and under the effect of high-temperature reducing gas 900 DEG C, produce direct-reduction sponge iron, in sponge iron, the ratio of metallic iron and full iron is 93% ~ 94%.

Mode four

By dry oxidation iron sheet by by trommel screen impurities removing and be greater than 3mm iron scale, if it is larger to be greater than 3mm iron scale content, can be broken into and be less than 3mm, then will be less than 3mm iron scale and add raw material cabin, briquetting press coldmoulding or by after disk pelletizing, through sinter process process, improve pellet strength, iron scale after balling-up process adds shaft furnace, under the effect of high-temperature reducing gas 950 DEG C, produce direct-reduction sponge iron, in sponge iron, the ratio of metallic iron and full iron is 92% ~ 94%.

Technique of the present invention is compared with other techniques processing iron scale or method technical process, its equipment is few, less investment, technique simple, easy handling, flow process are short, efficiency is high, cost is low, be easy to scale production, there is very high practical value, adopt the present invention, eliminate the heavy-polluted sintering of traditional technology, coking process, the coke of scarcity of resources is instead of with non-coking coal, the present invention can Appropriate application natural resources and the energy to greatest extent, is that a kind of iron scale that utilizes carries out the high-efficiency environment friendly technique of smelting iron.

What finally illustrate is, above preferred embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although by above preferred embodiment to invention has been detailed description, but those skilled in the art are to be understood that, various change can be made to it in the form and details, and not depart from claims of the present invention limited range.

Claims

1. process an iron scale Shaft Furnace Direct Reduction Process, it is characterized in that: comprise the following steps:

1), sieving approach, carried out by iron scale screening, break process, be prepared into the volume particle size iron scale being not more than 3mm, the iron scale to screening, before break process carries out drying and processing, and the iron scale after oven dry is moisture≤5%;

2), iron scale forming processes, granularity through at the iron scale of below 3mm and being preheating to 350 DEG C ~ 550 DEG C, feeding thermocompressor is hot-forming, or at the iron scale of below 3mm, after chilling press compression moulding or disk pelletizing, baking and concretion is shaping again by granularity;

3), shaft kiln directly reduced, the iron scale that after hot-forming or coldmoulding or disk pelletizing, baking and concretion is shaping is again loaded shaft furnace from shaft furnace top charging appts, the iron scale entering shaft furnace is continuing heated by 830 DEG C ~ 1000 DEG C reducing gas and be reduced into sponge iron in slow decline process, and the sponge iron of generation is discharged by the discharge system bottom shaft furnace.

2. process iron scale Shaft Furnace Direct Reduction Process as claimed in claim 1 a kind of, is characterized in that: in step 1) in, iron scale is screened, the equipment of break process adopts trommel screen and/or vibratory screening apparatus.

3. a kind of process iron scale Shaft Furnace Direct Reduction Process as claimed in claim 1, is characterized in that: in step 2) in, the equipment of its pre-heating technique adopts smoke pre-heating stove.

4. process iron scale Shaft Furnace Direct Reduction Process as claimed in claim 1 a kind of, is characterized in that: in step 2) in, the hot-forming shape of described iron scale is set to bulk, and the size of described bulk is 10 ~ 20cm ³.

5. a kind of process iron scale Shaft Furnace Direct Reduction Process as claimed in claim 1, is characterized in that: in step 3) in, described reducing gas is set to reducing gas that is arbitrary in coke-oven gas, gas maked coal, Sweet natural gas or coal-seam gas or combination.