CN102268502B

CN102268502B - Spongy iron preparation method by smelting refractory iron ore (slag) with reduction rotary kiln

Info

Publication number: CN102268502B
Application number: CN201010200213.0A
Authority: CN
Inventors: 李维成; 王金槐; 李睿; 昌晶
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-06-03
Filing date: 2010-06-03
Publication date: 2015-03-04
Anticipated expiration: 2030-06-03
Also published as: CN102268502A

Abstract

The invention provides a method that various refractory iron ores (slag), reduction coal and lime are placed in a rotary kiln for reduction, so as to prepare industrial spongy iron (TFe>=70-93%, metallization rate>=90-95%) and a baking-free brick raw material, and recover nonferrous metals. A process flow comprises steps of raw material preparation, reduction in the rotary kiln, cooling in a cooling kiln, concentration processing, and briquetting and balling. A granularity of the ore (slag) is no more than 20mm; a coal granularity is less than 15mm; and a lime granularity is no more than 0-2mm. A primary air and a secondary air are employed to combust the coal. A reduction roasting time is 3-10h; a combustion temperature in the kiln is controlled at 1000-1200 DEG C; and water and wind are used for cooling in the cooling kiln. The materials are cooled to a normal temperature under 40 DEG C, and treated with the concentration processing, briquetting and balling, so as to prepare the industrial spongy iron and recover the nonferrous metals. The method of the invention has advantages of simpleness, energy saving, emission reduction, waste reutilization, low production costs, good product quality, green and environmental protection, large market and strong competitiveness; besides the method has good economic benefits as well as good social benefits, and solves a domestic technical problem of refractory iron ore and an environmental protection problem of changing waste into valuables.

Description

The method of sponge iron is produced with reduction smelting in rotary kiln refractory iron ore (slag)

Technical field

The present invention relates to one and directly process refractory hematite, limonite, pyrrhosiderite, spathic iron ore, weak magnetite with reverting back rotary kiln, and iron slag produces the method for industrial sponge iron.

Background technology

There are a lot of grade different nonmagnetic refractory hematite, limonite, pyrrhosiderite, spathic iron ore in China, and weak magnetite Mineral resources, because ore dressing difficulty is large, cannot exploit utilization always; In addition also have the smelting of some iron content, chemical sludge is piled into mountain, ferro element wherein and some non-ferrous metals cannot utilize, and serious environment pollution, waste resource.

Summary of the invention

The object of the invention is to overcome above-mentioned shortcoming, there is provided a kind of mechanization degree high, reduction temperature is low, can process multiple refractory iron ore and waste residue, and sweetening agent desulfurization can be added, energy-conservation, economize coal revert back rotary kiln, furnace charge reduces through rotary kiln, isolated Rapid cooling in the air in cooling kiln, furnace charge, through the magnetic separation again of magnetic separation ore grinding, waits selected process to obtain technical grade sponge iron.Non-burning brick raw material is made without magnetic fine powder foam.Can become abandoned mine mountain into mine of living, change waste residue is product, and eliminate secondary pollution, protection of the environment is a kind of new and high technology smelting choosing method.

Technical scheme of the present invention is that reduction coal and lime, be placed in rotary kiln by weight ratio by the iron ore of component (slag), produces industrial sponge iron and non-burning brick raw material.Its composition weight proportioning is: 20 ~ 80 points, iron ore (slag), reduction coal 4 ~ 25 parts, and lime is: 0.1 ~ 2 part.

Production process of the present invention is: preparation of raw material, and rotary kiln reduces, and cooling kiln cools, selected process, briquetting balling-up.

Concrete steps are as follows:

A, raw material configure

By iron content 18 ~ 70%, the various iron ores (slag) of sulfur-bearing 0.01 ~ 1.5% are major ingredient pulverizing, granularity≤20mm.Join sulfur-bearing≤0.25 ~ 0.5%, phosphorus≤0.03%, thermal value >=5800 ~ 7500 kilocalorie/kilogram, agglomerating index≤3 (noncoking), the coal of fugitive constituent >=32% is as reduction coal and fuel coal powder injection, coal is pulverized, granularity≤15mm, join sulfur-bearing≤0.01 ~ 0.03%, the lime of phosphorus≤0.01 ~ 0.03% is sweetening agent, lime granularity≤0. ~ 2mm, iron ore (slag), the weight proportion of reduction coal and lime three kinds of compositions is: iron ore (slag): 20 ~ 80 parts, reduction coal: 4 ~ 25 parts, lime: 0.1 ~ 2 part.

B, rotary kiln reduce

According to the weight proportion of component, by various iron ore (slag), reduction coal and lime, add in kiln from the kiln tail mixing of rotary kiln and carry out reducing roasting.Then by fuel coal powder injection 5 ~ 8 parts, spray in kiln from the kiln hood coal spouting gun of rotary kiln and burn, add pressurized air simultaneously, its air quantity is 10 ~ 50m ³/ minute, blast controls at 30000 ~ 150000Pa.In kiln, carry out secondary air feed, utilize the heat-resistance stainless steel airduct be contained in kiln Middle pressure draught fan with it and kiln to carry out secondary air feed, its air quantity is 0.4 ~ 16m ³/ minute, blast 5000 ~ 18000Pa.Kiln hood keeps micro-pressure operation, and pressure-controlling is at 40 ~ 80Pa, and in kiln, maturing temperature controls at 1000 ~ 1200 DEG C, and the reducing roasting time is: 3 ~ 10 hours.

C, cooling kiln cool

The metallic iron reduced enters in cooling kiln with material and carries out isolated Rapid cooling in the air, and for preventing metallic iron re-oxidation, cooling kiln adopts outer water spray and blowing that material is cooled to normal temperature less than 40 DEG C, then send selected process.

D, selected process

Cooled material first carries out magnetic separation, is separated Armco magnetic iron and nonmagnetics, and Armco magnetic iron is through ore grinding again, then iron is purified to commercial grade sponge iron index by the way of magnetic separation.Without magnetic fine powder foam as non-burning brick raw material.

E, briquetting balling-up

By iron sponge powder with the balling-up of physical method briquetting ball product.

Energy manufacture sponge iron (TFe >=70 ~ 93, degree of metalization >=90% ~ 95%) of the present invention and non-burning brick raw produce, can also reclaim other non-ferrous metal simultaneously.

The present invention is unprecedented, comparable without prior art, have energy-conservation, reduce discharging, turn waste into wealth, make Bian Huo mine, abandoned mine mountain, change waste material is product.

The inventive method is simple, energy-conservation, reduce discharging, profit is useless, production cost is low, good product quality, and environmental protection, the market competitiveness is strong, is conducive to large-scale industrial production, namely has good economic benefit, have again good social benefit.The technical barrier solving domestic refractory iron ore and the difficult problem of environmental protection of turning waste into wealth.

Embodiment

A, preparation of raw material

By iron content 18 ~ 70%, the various iron ores (slag) of sulfur-bearing 0.01 ~ 1.5% are major ingredient pulverizing, granularity≤20mm, join sulfur-bearing≤0.25 ~ 0.5%, phosphorus≤0.03%, thermal value >=5800 ~ 7500 kilocalorie/kilogram, agglomerating index≤3 (noncoking), the coal of fugitive constituent >=32%, as reduction coal and fuel coal powder injection, is pulverized coal, granularity≤15mm.Join sulfur-bearing≤0.01 ~ 0.03%, the lime of phosphorus≤0.01 ~ 0.03% is sweetening agent, lime granularity≤0 ~ 2mm.

The weight proportion of iron ore (slag) reduction coal and lime three kinds of compositions is, iron ore (slag) 20 ~ 80 parts, reduction coal 4 ~ 25 parts, lime: 0.1 ~ 2 part.

Iron ore (slag) 80 parts is got in the present embodiment; Reduction coal 12 parts, 1.2 parts, lime.

B, rotary kiln reduce

According to the weight proportion of component, by various iron ore (slag), reduction coal and lime add in kiln from the kiln tail mixing of rotary kiln and carry out reducing roasting.Then fuel coal powder injection 5 ~ 8 parts sprayed in kiln from the kiln hood coal spouting gun of rotary kiln and burn, add pressurized air, its air quantity is 10 ~ 50m simultaneously ³/ minute, blast controls at 30000 ~ 150000Pa.In kiln, carry out secondary air feed, utilize the heat-resistance stainless steel airduct be contained in kiln Middle pressure draught fan with it and kiln to carry out secondary air feed, its air quantity is 0.4 ~ 16m ³/ minute, blast 5000 ~ 18000Pa.Kiln hood keeps micro-pressure operation, and pressure-controlling is at 40 ~ 80Pa, and in kiln, maturing temperature controls at 1000 ~ 1200 DEG C, and the reducing roasting time is: 3 ~ 10 hours.

C, cooling kiln cool

D, selected process

Cooled material first carries out magnetic separation, is separated Armco magnetic iron and nonmagnetics, and Armco magnetic iron is through ore grinding again, then the way of magnetic separation, iron is purified to technical grade sponge iron index.Without magnetic fine powder foam as non-burning brick raw material.(reclaiming non-ferrous metal) simultaneously

E, briquetting balling-up

By iron sponge powder physical method briquetting balling-up, ball product.Energy manufacture sponge iron (TFe >=70 ~ 93%, degree of metalization >=90% ~ 95%) of the present invention and non-burning brick raw produce, can also reclaim other non-ferrous metal simultaneously.

Claims

1. a utilization reverts back rotary kiln and directly processes various refractory hematite, limonite, pyrrhosiderite, spathic iron ore, weak magnetite, and various iron slag produces the method for industrial sponge iron and non-burning brick raw material, described production method operation comprises: preparation of raw material, rotary kiln reduces, and cooling kiln cools; Selected process; Briquetting balling-up; It is characterized in that concrete steps are as follows:

A, preparation of raw material

By iron content 18 ~ 70%, the various iron ore of sulfur-bearing 0.01 ~ 1.5% is or/and iron slag is major ingredient pulverizing, granularity≤20mm, join sulfur-bearing 0.25 ~ 0.5%, phosphorus≤0.03%, thermal value 5800 ~ 7500 kilocalorie/kilogram, agglomerating index≤3 noncoking, the coal of fugitive constituent >=32% is as reduction coal and fuel coal powder injection, coal is pulverized, granularity≤15mm, join sulfur-bearing 0.01 ~ 0.03%, the lime of phosphorus 0.01 ~ 0.03% is sweetening agent, lime granularity 0 ~ 2mm, iron ore is or/and iron slag, the weight proportion of reduction coal and lime three kinds of compositions is: iron ore is or/and iron slag 20 ~ 80 parts, reduction coal 4 ~ 25 parts, lime 0.l ~ 2 part,

B, rotary kiln reduce

According to the weight proportion of component, by various iron ore or/and iron slag, reduction coal and lime, add in kiln from the kiln tail mixing of rotary kiln and carry out reducing roasting; Then by fuel coal powder injection 5 ~ 8 parts, spray in kiln from the kiln hood coal spouting gun of rotary kiln and burn, add pressurized air simultaneously, its air quantity is 10 ~ 50m ³/ minute, blast controls at 30000-150000Pa; In kiln, carry out secondary air feed, utilize the heat-resistance stainless steel airduct be contained in kiln Middle pressure draught fan with it and kiln to carry out secondary air feed, its air quantity is 0.4 ~ 16m ³/ minute, blast 5000 ~ 18000Pa; Kiln hood keeps micro-pressure operation, and pressure-controlling is at 40 ~ 80Pa, and in kiln, maturing temperature controls at 1000 ~ 1200 DEG C; The reducing roasting time is: 3 ~ 10 hours;

C, cooling kiln cool

The metallic iron reduced enters in cooling kiln with material and carries out isolated Rapid cooling in the air, and for preventing metallic iron re-oxidation, cooling kiln adopts outer water spray and blowing that material is cooled to normal temperature less than 40 DEG C, then send selected process;

D, selected process

Cooled material, first carries out magnetic separation, is separated Armco magnetic iron and nonmagnetics, and Armco magnetic iron is through ore grinding again, then the way of magnetic separation, iron is purified to commercial grade sponge iron, TFe70 ~ 93%, degree of metalization 90 ~ 95%; Without magnetic fine powder as non-burning brick raw material, reclaim non-ferrous metal simultaneously;

E, briquetting balling-up