CN1201835A

CN1201835A - Production of sintered pelletized minerals

Info

Publication number: CN1201835A
Application number: CN 98102028
Authority: CN
Inventors: 潘宝巨; 王志花
Original assignee: Central Iron and Steel Research Institute
Current assignee: Central Iron and Steel Research Institute
Priority date: 1998-05-29
Filing date: 1998-05-29
Publication date: 1998-12-16
Anticipated expiration: 2018-05-29
Also published as: CN1055318C

Abstract

A process for making spherical sintered ore as raw material of smelting iron includes such steps as proportioning raw materials, mixing, granulating, proportioning again, mixing, feeding and sintering, and features that the hot retured ore is added at the second mixing to increase the temp of mixture, resulting in saving energy, improving the quality of sintered ore, speeding up sinter and increasing the output of sintered ore by 10-15%.

Description

A kind of manufacture method of pellet agglomerate

The invention belongs to iron-smelting raw material pellet agglomeration field.

At present, the used iron ore material of domestic and international most of blast furnace is pellet and the agglomerate that thin iron ore concentrate is made.Particularly China's iron ore deposit lean ore is many, and rich ore is few, and complex ore is many, and single iron ore is few.All need be selected through fine grinding, form high-grade fine iron concentrate powder, make pellet or agglomerate then, could be as blast furnace raw material.Thin iron ore concentrate is because particle diameter is little, and ventilation property is poor during sintering, and sintering velocity is slow, and the fuel consumption height yields poorly.Therefore, the agglomerate of fine iron concentrate powder, characteristics are agglomerate of 100% fine iron concentrate powder, are difficult problems that does not solve fully as yet.

In the prior art skill, Chinese patent ZL92101964.5 provides a kind of manufacture method of pellet agglomerate.The raw material of its pellet agglomerate comprises iron ore material, hot returning ore, coldly returns mine, unslaked lime, Wingdale, coal dust and additive; Its manufacture method comprises the steps: batching, mixed once, makes ball, secondary mixing outer roll coal, cloth sintering.These manufacture method characteristics be not only in the iron ore material fine iron concentrate powder can reach 100%, and the moisture content in the fine iron concentrate powder can be up to 16%, it is to be that core is made ball with the return fines material.The main drawback of this method is: hot returning ore is to add when mixed once, and the temperature that causes compound after the mixed once is up to 60-70 ℃, when subsequent processing is made ball, owing to add cold water, produce a large amount of steam, particularly winter, quantity of steam is bigger, makes to make the deterioration of ball workshop condition; In addition, make ball, mixture temperature is dropped to below 40 ℃, cause forming excessive moistening layer in the sintering process easily, sintering velocity is slowed down owing to add water.In addition, NKK Corp provides a kind of manufacture method of pellet sintering piece at the patent application CN87108122A of China, it is based on rich ore powder, adding a small amount of fine ore and fusing assistant is that raw material carries out mixed pelletizing, its shortcoming is that compound does not add hot returning ore, mixture temperature is obviously low, generally below 40 ℃, therefore is provided with dryer section before the igniting; In addition, use range is narrow, and condition restriction is many, bad adaptability.

The object of the present invention is to provide a kind of can the improvement to make the ball workshop condition, again can save energy, improve the manufacture method of the pellet agglomerate of pellet agglomerate output and quality.

At above-mentioned purpose, the major technique measure of manufacture method of the present invention is: the raw material that is adopted comprises the iron ore material, coldly returns mine, hot returning ore, unslaked lime, Wingdale, rhombspar, solid fuel; Batching does not add hot returning ore when mixed once, but the secondary mixing of making behind the ball is fashionable, adds hot returning ore, and promptly the fashionable raw material of secondary mixing comprises green pellets, hot returning ore and rolls fuel outward.

Blast furnace of the present invention comprises the steps: with the manufacture method of pellet agglomerate

(1) once the batching and mixed once

Once Pei Liao raw material comprise the iron ore material, coldly return mine, unslaked lime, Wingdale, rhombspar, solid fuel, its concrete proportioning raw materials (weight %) is: iron ore material 50-80%, the cold 0-20% that returns mine, unslaked lime 1-8%, Wingdale 0-15%, solid fuel 0.5-2%, rhombspar≤5%.

Wherein, the iron ore material is made up of fine iron concentrate powder and rich ore powder, and both proportionings (weight %) are: fine iron concentrate powder 40-100%, rich ore powder≤60%.Both require＜16% by institute's water content.Fine iron concentrate powder comprises ground hematite, magnetite powder, brown ocher, sparring breeze, sulfate slag and manganese ore powder.

Solid fuel be in coal dust or the coke powder any.

After preparing material by the above-mentioned raw materials proportioning, put it into and carry out mixed once in the mixing machine, by control rotating speed, time and mixing machine inclination angle, the compound that can obtain to mix.

(2), make ball

To make ball in the mixed once material input pelletizer that mix.It is to be that core forms pelletizing with cold return fines material.The output and the pelletizing granularity of may command pellets such as rotating speed, inclination angle and the blanking amount by regulating pelletizer, amount of water.The pelletizing granularity is advisable with 5-10mm.

(3), second batch and secondary mix

With green pellets, the hot returning ore made with roll outward and carry out secondary in the fuel input mixing machine and mix, the fashionable proportion scale (weight %) of secondary mixing is: green pellets 65-85%, hot returning ore 13-28% rolls fuel 2-7% outward.

Roll fuel outward and be in coal dust or the coke powder any, the granularity of hot returning ore is less than 8mm.

Twice mixed pelletizing granularity is that 5-10mm accounts for more than 80%.

After secondary mixed, the temperature of pelletizing (compound) can reach 50-70% ℃.

(4), cloth, sintering

Adopt shuttle-type belt or wide leather belt material distributing device, the compound (green pellets) that will come out from second drum mixer cloth equably guarantees that pelletizing is not broken to pallet.Bed thickness is advisable with 550-650mm.

Because hot returning ore is in the fashionable adding of secondary mixing, mixture temperature can be brought up to more than 60 ℃, has avoided excessive moistening layer formation, so can not establish dryer section, direct ignition sintering behind the cloth before the igniting.Sintering temperature is controlled at 1200-1350 ℃, and adopts negative-pressure operation.By regulating negative pressure, the control sintering velocity by control basicity, can be produced acid pelletizing sinter (basicity is 0.1-0.8), fluxed pellets agglomerate (basicity is 0.8-1.4) or fluxed pellets agglomerate (basicity is 1.4-2.0).

Because hot returning ore of the present invention is that secondary mixing is fashionable, add mixing machine with certain temperature, heat mixture in advance makes the material temperature of the compound (raw pellet ore) that comes out after the secondary mixing can bring up to 50-70 ℃, medial temperature is more than 60 ℃.Like this, do not produce excessive moistening layer (because of the temperature that produces excessive moistening layer in the bed of material is below 60 ℃) in the sintering process of igniting back, so the bright industry of bed permeability is improved (can have a strong impact on ventilation property because of producing excessive moistening layer in the bed of material), so sintering velocity is accelerated, the pellet sintering process that its rate ratio hot returning ore adds when mixed once will improve 10-15%.The quality of pellet agglomerate can be improved, output can be improved again.Also saved the energy simultaneously.

Adopt the present invention to make pellet agglomerate, the sintering utilization coefficient can reach 2.0t/m ².h more than, tumbler index (ISO) can reach more than 70%, fuel consumption is below 50 kilograms/ton, FeO is below 10%, reduction degree reaches 85-90%, the low temperature reduction degradation degree is less than 15%, and every index all is better than ordinary sinter technology and the described method for preparing pellet sintered ore of Chinese patent ZL92101964.5.

Compared with prior art, the present invention has following advantage;

(1) because hot returning ore does not add when the mixed once material,,, makes not produce steam when making ball, make the ball workshop condition and be greatly improved generally below 30 ℃ so the mixture temperature that comes out after the mixed once is low.

(2) can bring up to 50-70 ℃ because secondary mixes the temperature of back compound (green pellets agglomerate), the green pellets agglomerate temperature that promptly enters sinter machine improves 20-40 ℃ than prior art, so can not establish dryer section, has saved the energy widely.

(3) because secondary mixes the back mixture temperature improves, the bed permeability during sintering be improved significantly, not only burns the mineral amount and improve, and sintering velocity accelerates, its output can improve 10-15%.

Embodiment

Adopt manufacture method of the present invention on the sintered cup of Φ 300mm, high 500mm, to prepare three batches of pellet agglomerates.Proportioning raw materials during at first by mixed once is prepared burden, and drops into then and carries out mixed once in the mixing machine, after mixing, makes ball on pelletizer; The then bead that will make, hot returning ore and roll fuel outward and send into and carry out outer fuel and the preheating of mixed material of rolling in the second drum mixer.

The fashionable proportioning raw materials of mixed once and secondary mixing is as shown in table 1.Twice mixed mixture temperature and sintering process parameter are as shown in table 2.Behind the sintering three batches of test portions are carried out granularity, moisture, dropping strength and ultimate compression strength and detect, its result lists table 3 in.Mixed once and secondary blended proportioning raw materials (weight %) when table 1 embodiment prepares burden Table 2 embodiment twice mixed mixture temperature sintering process parameter and index

The performance of table 3 embodiment pellet sintering stove

Claims

1, a kind of manufacture method of pellet agglomerate comprises the steps: to be equipped with raw material by the proportioning raw materials of pellet agglomerate; Confected materials sent in the primary mixer mix; The compound input pelletizer that mixes is made ball; Carry out secondary in the green pellets refuel input second drum mixer that will make and mix, subsequently with the green pellets compound equably cloth carry out sintering to burning on the machine trolley, its spy is:

(1), the proportioning raw materials (weight %) during mixed once is: iron ore concentrate 50-80%, the cold 0-20% that returns mine, unslaked lime 1-8%, Wingdale 0-15%, rhombspar≤5%, solid fuel 0.5-2%.

(2), the fashionable adding hot returning ore of secondary mixing, the fashionable proportion scale (weight %) of secondary mixing by: made green pellets 65-85% after the mixed once, hot returning ore 13-28%, solid fuel 2-7%.

2, manufacture method according to claim 1, the granularity that it is characterized in that hot returning ore is less than 8mm.