阅读说明：本技术 一种炼铁高炉用酸性烧结矿的生产方法 (Production method of acid sinter for iron-making blast furnace ) 是由 周文胜 郭庆华 汤新彦 于 2019-02-20 设计创作，主要内容包括：本发明公开了一种炼铁高炉用酸性烧结矿的生产方法,采用如下重量百分比的原料进行烧结,入烧矿40%、钒钛铁精粉33.2%、返矿20%、焦粉5%、生石灰1.8%；各原料粒度均小于8mm,在430m<Sup>2</Sup>烧结机上进行生产时,控制参数如下：上料量：350-650t/h、料层厚度500-650mm、主抽风门开度35-50度、铺底料厚度100mm、点火温度1050±50℃、混合水分8.0±0.5%、制粒水分9.5±0.5%；将酸性烧结矿碱度控制在0.6倍。本发明利用大型烧结机生产酸性烧结矿,既拓展了高炉炼铁原料的使用范围,丰富了高炉炉料调剂手段,又为高炉进一步优化炉料结构降低铁水成本提供了一条行之有效的新途径。(The invention discloses a production method of acid sinter for an iron-making blast furnace, which comprises the following steps of sintering raw materials by weight percent, wherein the raw materials comprise 40% of sintered ore, 33.2% of vanadium-titanium-iron fine powder, 20% of return fine ore, 5% of coke powder and 1.8% of quick lime; the particle size of each raw material is less than 8mm and is 430m 2 When the sintering machine is used for production, the control parameters are as follows: feeding amount: 650t/h of 350-; the alkalinity of the acid sinter is controlled to be 0.6 times. The invention utilizes the large sintering machine to produce the acid sintering ore, not only expands the application range of blast furnace ironmaking raw materials, enriches the means of blast furnace burden regulation, but also provides an effective new way for further optimizing the burden structure of the blast furnace and reducing the molten iron cost.)

1. A production method of acid sinter for an iron-making blast furnace is characterized in that the following raw materials are adopted for sintering, and 40% of ore burning, 33.2% of vanadium-titanium iron fine powder, 20% of return fine, 5% of coke powder and 1.8% of quick lime are added; the particle size of each raw material is less than 8mm and is 430m²When the sintering machine is used for production, the control parameters are as follows: feeding amount: 650t/h of 350-; the alkalinity of the acid sinter is controlled to be 0.6 times.

Technical Field

The invention relates to a production method of acid sinter for an iron-making blast furnace.

Background

The acid sinter refers to alkalinity (CaO/SiO)₂) Sintered ore with basicity lower than that of blast furnace slag (generally less than 0.9) is made up by sintering iron ore concentrate or rich ore powder without or with less flux. At present, the main raw materials for blast furnace iron making in China mainly comprise high-alkalinity sinter and pellet, part of iron and steel enterprises increase the sinter yield in order to reduce the molten iron cost and reduce the dosage of the pellet, and part of acid sinter is added in order to adjust the blast furnace acid-base balance. The furnace charge of the blast furnace of the eight-steel company adopts a furnace charge structure of high-alkalinity sinter matched with acid pellet, and the sintering machine always produces high alkaliThe alkalinity of the sintered ore is 1.6-2.3 times, and the cost of the blast furnace pig iron is always high due to the problems of high price, long transport distance and unstable supply of the outsourced pellet ore.

Disclosure of Invention

The invention aims to provide a production method of acid sinter for an iron-making blast furnace, which utilizes a large sintering machine to produce the acid sinter and is matched with the blast furnace to reduce the use proportion of high-price pellets, thereby expanding the use range of blast furnace iron-making raw materials, enriching the means of regulating the burden of the blast furnace, and providing an effective new way for further optimizing the burden structure of the blast furnace and reducing the molten iron cost.

The technical scheme adopted by the invention for solving the technical problems is as follows: a production method of acid sintering ore for an iron-making blast furnace adopts the following raw materials by weight percent for sintering, 40 percent of burning ore, 33.2 percent of vanadium-titanium-iron fine powder, 20 percent of return fines, 5 percent of coke powder and 1.8 percent of quick lime are added; the particle size of each raw material is less than 8mm and is 430m²When the sintering machine is used for production, the control parameters are as follows: feeding amount: 650t/h of 350-; the alkalinity of the acid sinter is controlled to be 0.6 times.

(1) The general trend of the industrial production of the acid sinter is basically consistent with the test result of the laboratory sintering cup and is successful, and the actual performance of the main control index is R₂=0.56 times, TFe =53.14%, TiO₂=4.04% and 80.22% of a rotary drum, realizes the production of high alkalinity and acid sinter ore by the same sintering machine set, and the yield and the quality both meet the expected requirements.

(2) The blast furnace is reasonably added with the acid sinter to replace part of high-price acid pellet furnace burden, the furnace condition can be kept stable and smooth, meanwhile, the self-produced acid sinter has the price advantage of being 200 yuan/t lower than that of the purchased pellet, and due to the price difference, the raw material cost can be saved, and the molten iron cost can be reduced.

In using 430m²Before the sintering machine produces the acid sintering ore, a plurality of groups of sintering machines with alkalinity of 0.25, 0.3, 0.4, 0.6, 1.3, 1.55 and 1.7 times are firstly carried out under laboratory conditionsCup test, simulation production process control and control parameters, material layer thickness of 700, 650, 580mm, bedding material of 1.5kg, height of about 30mm, ignition negative pressure 7850Pa, ignition time of 2min, sintering negative pressure 13730Pa, different alkalinity sinter series test results show that it is feasible to control the alkalinity of the acid sinter at about 0.6 times in the industrial production process, the corresponding technical and economic indexes of the acid sinter are optimal, and the sintering production process is easier to control. Thus, in combination with the raw material conditions, 430m²Sintering machine for producing acid sinter with R₂And the index of which is 0.6 times is taken as a reference parameter, and vanadium-titanium-iron fine powder is taken as a main raw material for production organization.

The invention has the advantages that: the general trend of industrial production of the acid sinter is basically consistent with the test result of a laboratory sintering cup, the success is achieved, and the yield and the quality both meet the expected requirements. The blast furnace is reasonably added with the acid sinter to replace part of high-price acid pellet furnace burden, the furnace condition can be kept stable and smooth, meanwhile, the self-produced acid sinter has the price advantage of being 200 yuan/t lower than that of the purchased pellet, and due to the price difference, the raw material cost can be saved, and the molten iron cost can be reduced.

Detailed Description

The present invention is further illustrated with reference to examples.

1) Preparing raw materials:

and (3) reserving a certain amount of qualified iron raw materials for producing the acid sinter in a sintering stock dump by combining the condition of raw material resources, wherein the qualified iron raw materials comprise vanadium-titanium-iron fine powder and sintering ore. According to the production plan of the acid sinter, the iron material consumption and the inventory condition, the purchasing department is coordinated in time to organize the work of feeding the iron raw materials of the above varieties, and the stable supply of the raw materials is ensured.

2) The feeding and production mode comprises the following steps:

considering that the independent production of the blending material for the acid sintering ore is limited by site factors, the iron raw material required in production is not independently mixed in a sintering material site, but the mode that vanadium-titanium-iron fine powder and the sintering ore are directly supplied to a sintering process through a feeding pit for production is directly adopted. The existing equipment, machines and personnel are utilized and arranged in the same station 430m²The sintering machine is used for producing two types of high and low alkalinity sintering ores,the production process of the high-alkalinity sintering ore is switched to the production process of the acid sintering ore, the machine is stopped for 2-4 hours, and the two types of sintering ore are separated and independently stockpiled on a stock yard.

3) Selecting an initial production ratio:

in order to improve the problem of material layer permeability in the production of acid sintering ore, the sintering ore is added according to the proportion of 40% in the sintering ore blending in the initial production stage so as to improve the granularity of the original material. The selected production initial ratio is as follows:

40% of roasted ore, 33.2% of vanadium-titanium-iron fine powder, 20% of return mine, 5% of coke powder and 1.8% of quick lime.

4) Controlling parameters of the production process:

in the production process of the acid sinter, suitable production parameters are controlled as follows:

feeding amount: 650t/h of 350-.

5) The key points of the production operation of the acid sinter are as follows:

(1) when the materials produced by the acid sinter are selected, the raw materials with low natural alkalinity are selected, and the proportion of the quicklime can be properly improved during production, so that the pelletizing effect of the mixture can be improved, and the sintering process is strengthened.

(2) The binding phase of the acid sinter is mainly calcium-iron olivine, and the binding phase of the high-alkalinity sinter is mainly calcium ferrite. In order to increase the binding phase in the sintering process of the acid sintering ore and increase the temperature of a combustion zone in the sintering process, the coke powder proportion needs to be properly increased, so that the FeO content of the acid sintering ore is higher than that of the high-alkalinity sintering ore.

(3) The raw material proportion of the particle size of 0-8 mm is large so as to ensure the original particle size of the sintering material.

(4) The flux ratio is low in the production process of the acid sinter, the balling property of the mixture is poor, and the air permeability is poor in the sintering process. In order to improve the granulating effect of the mixer, the water content value of the mixture can be properly improved, and the rotating speed of the granulator is reduced, so that the reinforced granulating effect is achieved.

(5) Air quantity in process of producing acid sinter by sintering machineThe air quantity is moderate and corresponds to the feeding quantity, and the sintering process is not facilitated when the air quantity is too large or too small. 430m²The main draft fan opening corresponding to 350t/h feeding amount of the sintering machine is 30-35%, the air quantity is about 3000Pa, the first 4 air boxes are properly closed, when the feeding amount reaches 650t/h, the main draft fan opening is 50-55%, the phenomenon that the air draft of a material layer is too strong is avoided, and the air permeability of the material layer is reduced.

A production method of acid sintering ore for an iron-making blast furnace adopts the following raw materials by weight percent for sintering, 40 percent of burning ore, 33.2 percent of vanadium-titanium-iron fine powder, 20 percent of return fines, 5 percent of coke powder and 1.8 percent of quick lime are added; the particle size of each raw material is less than 8mm and is 430m²When the sintering machine is used for production, the control parameters are as follows: feeding amount: 550t/h, material layer thickness 550mm, main draft opening 40 degrees, bedding material thickness 100mm, ignition temperature 1050 +/-50 ℃, mixed moisture 8.0 +/-0.5 percent and granulation moisture 9.5 +/-0.5 percent; the alkalinity of the acid sinter is controlled to be 0.6 times.