CN103451421B - A kind of preparation method of blast furnace gas mud pre-reduced pellet - Google Patents

Abstract

The invention provides a kind of preparation method of blast furnace gas mud pre-reduced pellet, its raw materials quality per-cent is: blast furnace gas mud 10% ~ 30%, SiC powder 3.5% ~ 10%, iron ore concentrate 60% ~ 85%, wilkinite 1.2% ~ 1.5%; Respectively the 20%-30% of wilkinite total amount and blast furnace gas mud, SiC powder are mixed, the 70%-80% of iron ore concentrate and wilkinite total amount is mixed, makes compound.During pelletizing, first gas mud, SiC powder and bentonitic compound are caused ball; Add iron ore concentrate and wilkinite compound continuation pelletizing again; And wrap up in the rhombspar that one deck accounts for 0.5% ~ 1.5% of raw material total mass shaping pelletizing is upper outside, production technique makes pre-reduced pellet routinely.The present invention can digest blast furnace waste in a large number, and reduce the maturing temperature of pelletizing, increase the usage ratio of non-magnetite concentrate, non-caked between finished pellet, metallurgical performance is good, is conducive to improving the high efficiency of furnace, reduces blast furnace coke ratio.

Description

A kind of preparation method of blast furnace gas mud pre-reduced pellet

Technical field

The invention belongs to iron-smelting raw material production technical field, particularly a kind of preparation method of blast furnace gas mud pre-reduced pellet.

Background technology

Blast furnace gas mud is the stove dirt carried out by blast furnace gas in iron manufacturing process, through the product that wet type or dry gas cleaning obtain, is one of iron and steel enterprise's primary solids discharge.Gas mud particle diameter is little, and density is little, very easily flies away in air after drying, is easy to forming component complexity, floating dust that harm is larger in atmosphere, works the mischief to human body.Gas mud is also valuable secondary resource simultaneously, if can not effectively administer and utilize, not only causes the waste of resource, and causes great pollution to environment.The chemical composition more complicated of gas mud.Also have many unburns charcoal completely outside deironing, carbon content is about 20%.How utilizing gas mud, each enterprise is explored all to some extent.At present, the Land use systems of gas mud mainly contains: 1, wet underwater welding non-ferrous metal, iron and carbon return blast furnace; 2, beneficiation method reclaims iron or carbon; 3, pyrometallurgical smelting non-ferrous metal; 4, batching in sintering; 5, gas mud be used for direct-reduction or produce reducting pellet.

Prereduction pellet is the pelletizing with certain degree of metalization, and its metallurgical performance is good, uses prereduction pellet not only can reduce coke ratio in blast furnace, can also effectively improve blast fumance efficiency and economic benefit.Utilize the feature that gas mud carbon containing is high, gas mud is used for the production of prereduction pellet, gas mud resource not only can be made to be utilized, high-quality pre-reduced pellet can also be produced, effectively reduce blast fumance cost.

Document " producing the discussion of pre-reduced pellet " proposes with the technical process of High Carbon Content Cold-binding Iron Ore Briquette at gas-burning lime kiln roasting reduction, pre-reduced pellet can bring blast furnace part metals iron and coking carbon into, shorten the blast-furnace smelting cycle, make utilization coefficient raising, coke ratio reduction.Document " experimental study of blast furnace dust carbonaceous pelletizing direct-reduction " gas ash and iron scale is pulverized in laboratory, stirs, and carries out cold consolidation shaping, roasting in retort furnace with pair roller ball press." improving the experimental study that dirt mud carbonaceous pelletizing dries rear intensity " is mainly by feed change proportioning, intensity after the oven dry of the technique study pelletizings such as binding agent kind, pelletizing oven dry system, the compound pelletizing method wherein adopted mixing material point is added different binding agents carry out pelletizing.

Chinese patent CN99105541.1 adopts twice balling-up mode to make metallurgical composite pellet, its pelletizing is made up of pelletizing core and spherical shell, pelletizing core be with ferrous material and reduction coal dust or coke powder for raw material pelletizing obtain, spherical shell is for raw material with ferrous material and pelletizing core, another adding additives, with pelletizing core for the centre of sphere adopts disk pelletizing to obtain.Chinese patent 200610001254.0 discloses a kind of production method of fluxed iron ore powder composite pellet, and its principal character is the two basicity complex fluxed pellet of manufacture order ball, and core is adding portion flux in pellet formation.Chinese patent CN99105541.1 discloses a kind of blast furnace process using coal-based pre-reduced pellet, and its pre-reduced pellet is by obtained after 1200 ~ 1350 DEG C and reduction in 10 ~ 35 minutes in rotary hearth furnace after powdered iron ore, coal dust and binding agent according to a certain ratio ball processed.

Though above document is different with the method that patent adopts, core is joined carbon or is added flux in being all, but can not solve the bonding of pelletizing and the strength degradation problem of pelletizing completely.

Summary of the invention

The invention provides a kind of preparation method of blast furnace gas mud pre-reduced pellet, its object one makes full use of the high characteristic of gas mud carbon content, and the unworkable gas mud of a large amount of digestion, reduces pellet formation cost; Two is the bondings avoided between finished pellet, improves the metallurgical performance of pelletizing and the productive efficiency of blast furnace.

For reaching this object, this invention takes following technical solution:

A preparation method for blast furnace gas mud pre-reduced pellet, its concrete grammar is:

Raw material prepares:

Raw materials quality per-cent is: blast furnace gas mud 10% ~ 30%, SiC powder 3.5% ~ 10%, iron ore concentrate 60% ~ 85%, wilkinite 1.2% ~ 1.5%;

In proportion the 20%-30% of wilkinite total amount and blast furnace gas mud, SiC powder are mixed and make compound, compound is made in the 70%-80% mixing of iron ore concentrate and wilkinite total amount.

Pelletizing:

First by gas mud, SiC powder and bentonitic compound pelletizing, make ball; Add iron ore concentrate and bentonitic compound again, continue pelletizing; Then one deck rhombspar is wrapped up in shaping pelletizing is upper outside, join that rhombspar accounts for raw material total mass outward 0.5% ~ 1.5%; Last conveniently acid pellet production technique, makes pre-reduced pellet.

Described SiC Powder Particle Size≤320 object >=80%; Size of Dolomite≤200 object >=95%.

Beneficial effect of the present invention is:

The present invention utilizes blast furnace gas mud to produce prereduction pellet, can digest blast furnace waste in a large number, waste resource is utilized effectively, and reduces the quantity discharged of waste; Meanwhile, the maturing temperature of pelletizing can be reduced, effectively increase the usage ratio of non-magnetite concentrate, expand scope of resource; Can not bond between finished pellet after roasting, prereduction pellet metallurgical performance is good, is conducive to improving blast furnace usefulness, reduces blast furnace coke ratio, and therefore prereduction pellet of the present invention has more cost advantage than conventional acid pellet.

Embodiment

Embodiment raw materials used SiC Powder Particle Size≤320 object >=80%; Size of Dolomite≤200 object >=95%.Each component concentration is mass percent.

Embodiment 1:

By the blast furnace gas mud of 10%, 5.1% SiC powder and 0.5% wilkinite mix and make compound.Again the wilkinite of the iron ore concentrate of 84% and 0.9% is mixed, make compound.

In balling process, first by gas mud, SiC powder and wilkinite compound pelletizing, make ball.Add iron ore concentrate and bentonitic compound again, continue pelletizing.Then, the rhombspar that one deck accounts for raw material total mass 0.5% is wrapped up in shaping pelletizing is upper outside.Finally, adopt regular oxidation pellet formation technique, carry out drying, preheating and oxidizing roasting technique, make pre-reduced pellet of the present invention.

Embodiment 2:

The blast furnace gas mud of 29.8%, the SiC powder of 7% and the wilkinite of 0.45% are mixed and makes compound.Again the wilkinite of the iron ore concentrate of 62% and 0.75% is mixed, make compound.

In balling process, first by gas mud, SiC powder and wilkinite compound pelletizing, make ball.Add iron ore concentrate and bentonitic compound again, continue pelletizing.Then, the rhombspar that one deck accounts for raw material total mass 1.3% is wrapped up in shaping pelletizing is upper outside.Finally, adopt regular oxidation pellet formation technique, carry out drying, preheating and oxidizing roasting technique, make pre-reduced pellet of the present invention.

Embodiment 3:

By the blast furnace gas mud of 20%, 8.7% SiC powder and 0.3% wilkinite mix, make compound.Again compound is made in the wilkinite mixing of the iron ore concentrate of 70% and 1%.

In balling process, first by gas mud, SiC powder and wilkinite compound pelletizing, make ball.Add iron ore concentrate and bentonitic compound again, continue pelletizing.Then, the rhombspar that one deck accounts for raw material total mass 0.85% is wrapped up in shaping pelletizing is upper outside.Finally, adopt regular oxidation pellet formation technique, carry out drying, preheating and oxidizing roasting technique, make pre-reduced pellet of the present invention.

Claims (1)

1. a preparation method for blast furnace gas mud pre-reduced pellet, is characterized in that, concrete grammar is:

Raw material prepares:

Raw materials quality per-cent is: blast furnace gas mud 10% ~ 30%, SiC powder 3.5% ~ 10%, iron ore concentrate 60% ~ 85%, wilkinite 1.2% ~ 1.5%;

Described SiC Powder Particle Size≤320 object >=80%; Size of Dolomite≤200 object >=95%;

In proportion the 20%-30% of wilkinite total amount and blast furnace gas mud, SiC powder are mixed and make compound, compound is made in the 70%-80% mixing of iron ore concentrate and wilkinite total amount;

Pelletizing:

First by gas mud, SiC powder and bentonitic compound pelletizing, make ball; Add iron ore concentrate and bentonitic compound again, continue pelletizing; Then one deck rhombspar is wrapped up in shaping pelletizing is upper outside, join that rhombspar accounts for raw material total mass outward 0.5% ~ 1.5%; Last conveniently acid pellet production technique, makes pre-reduced pellet.