CN1869251A

CN1869251A - Method for producing direct reduction iron using iron-contained waste material as raw material

Info

Publication number: CN1869251A
Application number: CNA2005100745208A
Authority: CN
Inventors: 袁建国
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-05-25
Filing date: 2005-05-25
Publication date: 2006-11-29

Abstract

The invention supplies a method to produce reduced iron from iron contained waste. It could protect environment, lower iron-making cost and improve the quality of the product.

Description

A kind of is the method for raw material production direct-reduced iron with the iron content waste

Technical field the present invention relates to a kind of production method of direct-reduced iron, and particularly a kind of is the method for raw material production direct-reduced iron with the iron content waste.Iron content waste herein is meant: a large amount of dedusting ash, iron scale, industrial refuse that the iron work of smelter, ferroalloy works, steelworks, Steel Mill produce aborning.

The production method of the existing direct-reduced iron of technical background, its used raw material is the fine iron breeze of FeO 〉=62%, its technical process generally is: with fine iron breeze add caking agent and additive through mix make spherical, drying puts into rotary kiln later or pot furnace is heated to about 1150 ℃ with coal or combustible gas, under this state, make the ferric oxide in the ball directly be reduced into iron.The deficiency that existing method exists has: 1, Lian Tie raw material only is confined to the fine iron breeze of FeO 〉=62%, this causes the problem of two aspects to I haven't seen you for ages: 1. raw material comes source range narrower, be vulnerable to material supplier's restriction, powdered iron ore price as China's import in this year, international vendor soars 75%, and the iron and steel enterprise of China also has to bear.2. be unfavorable for the utilization of resource.A large amount of dedusting ash, iron scale, industrial refuse that the numerous smelter of China produces aborning, though be waste, but still contain abundant ferro element in it, handle the raw material that can be used as ironmaking fully a little, and existing these wastes are not only utilized well, and being deposited in outer contaminate environment, this does not conform to China strategy of sustainable development.2, there is the problem of 2 aspects in the system ball in the technical process: 1. powdered iron ore because of and the caking agent and the additive of non-iron material mix the system ball, easily make product contain more impurity, influence the purity of product.2. the pressure of making ball is less, and the density of raw material spheroid is lower, thereby has the defective that ratio of briquetting is low and oxidizing reaction speed is slow, the production time is long.3, the raw material spheroid is kept in motion in reduction process always, the Pulverization ratio height of product.

Summary of the invention main purpose of the present invention is to open up the approach of new iron-smelting raw material; reduce ironmaking cost; protecting environment and proposing a kind of is the method for raw material production direct-reduced iron with the iron content waste, and another purpose is to optimize the technical process of ironmaking, improves product quality.

Close the iron waste as the raw material of producing direct-reduced iron, need through oven dry, magnetic separation, remove impurity, and reach following standard: dedusting ash and industrial refuse TFe 〉=50%; Iron scale TFe 〉=70%.

Can realize purpose of the present invention by following technical proposals: a kind of is the method for raw material production direct-reduced iron with the iron content waste, the raw material that it is characterized in that producing direct-reduced iron is the iron content waste, that is: dedusting ash, industrial refuse, iron scale, can be wherein a kind of, also can be its combination.

The technological process of production is, raw material (be can be rectangular parallelepiped with the press compression moulding more than 160 tonnages, square or right cylinder), parison is put into the saggar that the bottom is covered with one deck auxiliary material, auxiliary material is by reductive agent (coke powder, coal or charcoal) press 1-90 with sweetening agent (Wingdale or rhombspar or alkalimetal oxide): the 1-90 mixed constitutes, vacant part in saggar and above insert auxiliary material and pave, saggar packed into (adopt the tunnel kiln in the down-draft kiln, shuttle kiln technology is loaded onto kiln car with saggar, also can push in the kiln) calcination, temperature-rise period is: normal temperature → 600 ℃ 10 hours, 600 ℃ → 1150 ℃ 12 hours, 1150 ℃ are incubated 8 hours, naturally cool to the normal temperature kiln discharge.

The effect that implements the following aspects of the present invention: 1, searched out an approach for the reasonable utilization of a large amount of iron content wastes of China, not only make it not be discarded in outer contaminate environment, and can recreate wealth for society, the recycling of real realization resources effective, the while can be alleviated the situation of China's iron-smelting raw material anxiety.2, production cost can reduce 30-40% on existing basis: the reduction of first raw materials cost, it two is shortenings of production time, has saved a large amount of energy consumptions, can significantly reduce cost.Raw material is after being pressed into parison by the large-tonnage press, and its oxidizing reaction speed can greatly improve, and needs 50 hours reduction reaction in the past, and the present invention only needs 30 hours.3, the quality of product improves, and this is that mainly the raw material among the present invention does not add materials such as the caking agent of non-iron, additive in pressure or parison, thereby impurity is few in the product.4, yield rate height, Pulverization ratio are low, and this mainly is raw material by high-pressure molding and under static state finish reduction reaction, and still shape is as before after finishing reduction reaction for caked parison.

Embodiment: raw material screening, will come from iron content waste dedusting ash, industrial refuse and the iron scale of smelter, dry, magnetic separation and remove impurity, make it reach following standard, dedusting ash TFe 〉=50%; Industrial refuse TFe 〉=50%; Iron scale TFe 〉=70%.Auxiliary material is made of reductive agent and sweetening agent mixing, reductive agent is a kind of or combination wherein of coke powder, coal, charcoal, sweetening agent is a kind of or its combination wherein of rhombspar, Wingdale, alkalimetal oxide, and the blending ratio of reductive agent and sweetening agent is pressed the composition of raw material and determined.

Embodiment 1, get a saggar, the auxiliary material of its shop, bottom 10mm, auxiliary material is made of by 6: 4 (weight ratio) mixed reductive agent coke powder and sweetening agent limestone powder, raw material dedusting ash (TFe=61%), iron scale (TFe=72%) by 3: 2 (weight ratio) mixed, are pressed into rectangular parallelepiped with 165 tons of press, the parison of rectangular parallelepiped is put into saggar, the upper surface that reaches all around of parison is inserted auxiliary material in saggar, and concordant with the port surface of saggar.The saggar (several) for preparing material packed in the down-draft kiln (adopt tunnel kiln, shuttle kiln technology, with saggar load onto kiln car push in the kiln also can) carry out calcination, its heating curve is: normal temperature → 600 ℃ need 10 hours, 600 ℃ → 1150 ℃ need 12 hours, 1150 ℃ are incubated 8 hours, naturally cool to the normal temperature kiln discharge.

Embodiment 2, get a saggar, the auxiliary material of its shop, bottom 20mm, and auxiliary material is made of by 6: 4 (weight ratio) mixed reductive agent coal dust and sweetening agent ground dolomite.Primary industry rubbish (TFe=52%), iron scale (TFe=71%) by 1: 1 (weight ratio) mixed, are pressed into column with 250 tons of press, the parison of column is put into saggar, further part is identical with embodiment 1, no longer repeats.

Embodiment 3, get a saggar, the auxiliary material of the auxilliary 22mm in its bottom, auxiliary material is made of by 6: 4 (weight ratio) mixed reductive agent coal dust and sweetening agent limestone powder, raw material iron scale (TFe=71.5%) is pressed into square with 350 tons of press, the square parison is put into saggar, and further part is identical with embodiment 1, no longer repeats.

Claims

1, a kind of is the method for raw material production direct-reduced iron with the iron content waste, it is characterized in that, the raw material of producing direct-reduced iron is the iron content waste, that is: dedusting ash, industrial refuse, iron scale.Can be wherein a kind of, also can be its combination.

2, described by claim 1 is the method for raw material production direct-reduced iron with the iron content waste, it is characterized in that raw material is pressed into through the press more than 160 tons mixes the auxiliary material that constitutes with reductive agent and sweetening agent behind the parison and together puts into a saggar, calcination in the down-draft kiln of again saggar being packed into.

3, by claim 1 or 2 described be that ten thousand methods of raw material production direct-reduced iron is characterized in that the bottom of saggar is covered with one deck auxiliary material with the iron content waste, its thickness is between 10-25mm.