CN1804057A - Method for making pellet by fine-grinded steel slag instead of bentonite - Google Patents

Abstract

The method to use fine-grinding steel sludge instead of bentonite to prepare the pellet ore comprises: a. fine grinding the steel sludge into power with 200items content more than 90%; b. adding 1-10m% former steel sludge into refined iron powder instead of bentonite; c. adding 6-10% water into the mixture; generating 8-20mm raw roll; d. sending former balls into shaft furnace or chain-pellet for drying and baking. The experiments show the product has up to the standard, increases grade 2.2% and reduces SiO2 1.7%, and realizes sludge recovery.

Description

Utilize fine-grinded steel slag instead of bentonite to produce the method for pellet

Technical field:

The present invention relates to the utilization of waste material of bessemer furnace slag, specifically a kind of method of utilizing fine-grinded steel slag instead of bentonite to produce pellet.

Background technology:

At present, China is annual to discharge surplus the slag 4,000 ten thousand tons, accounts for 12.09% of Iron And Steel Industry solid waste, and its comprehensive utilization ratio only is 36%, mainly as blast furnace flux and agglomerate raw material, steel slag cement, brick and building block etc.Generally contain Fe in the bessemer furnace slag ₂O ₃15～25%, CaO45～50%, SiO ₂8～15% and a certain amount of MgO, S, P etc., in the slag metal Ferrum content in 14%, so, have a large amount of metals not to be recovered in the slag of banking up, and bessemer furnace slag throws aside in the slag field, not only wasted resource, also take a large amount of soils, and caused environmental pollution.Therefore, the comprehensive utilization of bessemer furnace slag has been included into the important step of steel industry recycling economy development, and the novel process of utilizing slag, reduction to consume, explore with fine-grinded steel slag instead of bentonite production pellet does not have bibliographical information as yet.Usually produce pellet and use wilkinite as additive, wilkinite contains SiO ₂About 60%, can cause the pellet iron-holder to descend, the blast furnace energy consumption raises.

Summary of the invention:

Purpose of the present invention aims to provide a kind of method of utilizing fine-grinded steel slag instead of bentonite to produce pellet, to realize the abundant recovery of metallic iron in the slag, make it a part as iron-smelting raw material, the bentonite resource of alternative costliness is as the additive and the binding agent of iron-smelting raw material again, and can also reduce the ironmaking energy consumption of blast furnace.

The technical scheme that realizes the foregoing invention purpose is: this utilizes its step of method of fine-grinded steel slag instead of bentonite production pellet as follows:

A, slag is finely ground to the steel-making slag powder of-200 order＞90%;

B, above-mentioned steel-making slag powder is substituted wilkinite join in the smart powder of iron as additive and binding agent, add-on is 1～10% of the smart grain weight amount of iron;

C, adding accounts for the water of both gross weights 6～10% in the mixing raw material that smart powder of above-mentioned iron and steel-making slag powder constitute, and makes the green-ball that granularity is 8～20mm by pelletizer;

D, above green-ball is sent into shaft furnace or the chain grate machine rotary kiln is dried and roasting, be made as the pellet of blast furnace with iron-smelting raw material.

According to the described method of utilizing fine-grinded steel slag instead of bentonite to produce pellet of this case, have following advantage and positively effect:

Advantage: bessemer furnace slag aboundresources, low price, through laboratory and back yard industry test, slag is finely ground to the alternative wilkinite of-200 order＞90% as producing the pellet additive and making the ball binding agent, its green ball strength, burst temperature experiment, roasting experiment, reductibility experiment all reach the pellet standard, and button calcium magnesium grade is higher by 2.2% than wilkinite pellet, SiO ₂Low by 1.7%, ultimate compression strength can reach 2040N.

Positively effect: saved valuable bentonite resource, reduced the ironmaking energy consumption of blast furnace, realized the recycle of waste steel slag, met the fundamental state policy that China built a conservation-minded society, made green iron and steel and Sustainable development.Therefore, the application of the technology of the present invention has crucial meaning for China's steel industry.

Embodiment:

Below in conjunction with embodiment in detail the present invention is described in detail.

The described method steps that utilizes fine-grinded steel slag instead of bentonite to produce pellet of present embodiment is as follows:

1, abrasive dust: the steel-making slag powder that bessemer furnace slag is finely ground to-200 order＞90%.

2, batch mixing: the steel-making slag powder that will meet above-mentioned 1 condition joins in the smart powder of iron, and add-on is 1～10% of the smart grain weight amount of iron.

3, make ball: in the mixing raw material of smart powder of the iron that meets above-mentioned 2 conditions and steel-making slag powder formation, add the water that accounts for both gross weights 6～10%, make the green-ball that granularity is 8～20mm by pelletizer; After testing, green-ball will have the good capability of antidetonance, higher does, wet bulb resistance to compression and dropping strength.

4, roasting: the green-ball that will meet above-mentioned 3 conditions sends into shaft furnace or the chain grate machine rotary kiln is dried and roasting.

5, after the roasting standard compliant pellet, change next process then over to as the blast furnace iron-smelting raw material.

Claims (1)

1, a kind of method of utilizing fine-grinded steel slag instead of bentonite to produce pellet, its step is as follows:

A, slag is finely ground to the steel-making slag powder of-200 order＞90%;

B, above-mentioned steel-making slag powder is substituted wilkinite join in the smart powder of iron as additive and binding agent, add-on is 1～10% of the smart grain weight amount of iron;

C, adding accounts for the water of both gross weights 6～10% in the mixing raw material that smart powder of above-mentioned iron and steel-making slag powder constitute, and makes the green-ball that granularity is 8～20mm by pelletizer;

D, above green-ball is sent into shaft furnace or the chain grate machine rotary kiln is dried and roasting, be made as the pellet of blast furnace with iron-smelting raw material.