CN110668704A - Comprehensive utilization method of blast furnace cloth bag dedusting ash and coal ash - Google Patents

Abstract

The invention discloses a method for comprehensive utilization of blast furnace bag dust and fly ash, comprising the following steps: S1, respectively testing the raw material components of blast furnace bag dust, fly ash and binder, the proportioned mixture, and the mixture In the middle, the blast furnace bag dust is 70-85 parts by mass; the fly ash is 15-30 parts by mass; the binder is 0.3-1 parts by mass; S2, pelletizing the mixture; S3, adding the pellets Submerged arc furnace, use submerged arc furnace to heat and reduce pellets to generate molten iron and slag; S4, molten iron and slag are discharged from the tap hole and slag tap of submerged arc furnace respectively; S5, molten iron is discharged and cast into iron After the slag is discharged, it is made into slag wool by spinning. The method makes full use of thermal energy, can realize the utilization of two industrial solid wastes in one smelting, and finally obtains two products of iron nugget and slag wool, so that the recycling has the advantages of low cost and high added value, and has great application in industrial applications. Strong practicality.

Description

Comprehensive utilization method of blast furnace bag dust and fly ash

technical field

The invention relates to the recycling and utilization of industrial solid waste, specifically a method for comprehensive utilization of blast furnace bag dust and fly ash.

Background technique

Blast furnace bag dust and fly ash are both industrial solid wastes, and their hazards are serious, mainly in: polluting water, polluting the atmosphere, polluting soil, occupying land and endangering human health. In addition, the above-mentioned industrial solid waste also has the characteristics of large production capacity and small amount of consumption. According to statistics, the annual output of domestic fly ash is about 500 million tons, and the annual output of blast furnace bag dust is more than 5 million tons. For blast furnace bag dust, there are many harmful elements and low reuse value, which is difficult for iron and steel enterprises to deal with. For the comprehensive utilization projects of fly ash at home and abroad, including fly ash aerated concrete, concrete hollow block, fly ash expanded perlite concrete insulation block, fly ash concrete pavement brick, fly ash brick, fly ash Ash ceramsite and concrete products, fly ash concrete lightweight partition boards, etc., but still not enough to digest its production capacity.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a comprehensive utilization method of blast furnace bag dust and fly ash, which fully utilizes thermal energy, can realize the utilization of two kinds of industrial solid wastes in one smelting, and finally obtains iron lumps and slag wool The two products make recycling have the advantages of low cost and high added value, and have strong practicability in industrial applications.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical means:

A method for comprehensive utilization of blast furnace bag dust and fly ash, comprising the following steps:

S1, respectively test the raw material components of blast furnace bag dust, fly ash and binder, and grind them into a mixture of the required ratio for smelting according to the test results. In the mixture, the blast furnace bag dust is 70-85 mass parts; fly ash is 15-30 parts by mass: binder is 0.3-1 parts by mass;

S2, pelletizing the mixture;

S3, adding the pellets into the submerged arc furnace, and using the submerged arc furnace to heat and reduce the pellets to generate molten iron and slag;

S4, molten iron and slag are respectively discharged from the tap hole and the slag tap of the submerged arc furnace;

S5, after the molten iron is discharged, it is cast into iron blocks, and the slag is discharged into slag wool by spinning.

The present invention that adopts the above-mentioned technical scheme, compared with the prior art, its outstanding feature is:

Submerged arc furnace smelting is to use the heat generated by the arc to smelt ore, and the temperature of the arc zone is above 3000 ℃. The submerged arc furnace has a flexible process, can effectively remove impurities such as sulfur and phosphorus, the furnace temperature is easy to control, and the equipment occupies a small area, which is suitable for the smelting of this project.

The slag wool fiber-forming process is that the slag enters the adjustable movable launder through the slag outlet and flows to the four-roller centrifuge to form fibers. These fibers are removed by the slag removal roller under the action of negative pressure and then sent to the Settlement chamber, the lower part of the sedimentation chamber is provided with a mesh belt conveyor, and there is a suction duct under the mesh belt, which is connected with the negative pressure fan through the air duct and the filter chamber. Thus, the slag wool felt with uniform thickness can be obtained.

The technical scheme of the invention makes full use of thermal energy, and can realize the utilization of two industrial solid wastes in one smelting, and finally obtain two products of iron nuggets and slag wool, so that recycling has the advantages of low cost and high added value, and is suitable for industrial applications. There is a strong practicality.

Further preferred technical solutions are as follows:

In the step S1, after grinding, the particle size of blast furnace bag dust, fly ash and binder is 80-130 mesh.

The particle size after the above treatment is small and the mixing is uniform, which is convenient for heat treatment.

In the step S3, the heating reduction temperature of the submerged arc furnace is controlled at 1400-1600°C. Control the current intensity of the submerged arc furnace, which not only satisfies the melting reduction, but also does not waste energy.

Described slag wool is used for making slag wool felt, and making slag wool felt includes the following process steps:

(1) The slag is transported to a four-roller centrifuge to form fibers;

(2) Under the action of negative pressure, the fibers are sent to the mesh belt conveyor in the sedimentation chamber to remove the slag balls through the slag removal roller to obtain slag wool felt with uniform thickness.

The slag enters the adjustable movable launder through the slag outlet and makes it flow to the four-roller centrifuge to form fibers. These fibers are removed by the slag removal roller under the action of negative pressure and then sent to the settling chamber after removing slag balls larger than 0.2mm in diameter. There is a mesh belt conveyor in the lower part of the settling chamber. Under the action of negative pressure, the fibers fall evenly on the mesh belt, and the mesh belt mesh number is 0.2mm, so that the slag wool felt with uniform thickness can be obtained.

Detailed ways

Below in conjunction with embodiment, the present invention is further described.

Tests show that the main quality components of blast furnace bag dust in the examples of the present invention are: TFe: 25-35%; C: 15-25%; Zn: 2-25%; SiO ₂ : 10-30%; Al ₂ O ₃ : 5-15%; CaO: 10-30%; MgO: 3-8%.

Main mass components of fly ash: TFe: 4～8%; SiO ₂ : 30～70%; Al ₂ O ₃ : 20～50%, CaO: 2～18%, MgO ₂ ～5%, and the rest are trace other components : NaO, K ₂ O, etc.;

Independent research and development of starch binder, its main mass ratio is: corn starch: 50-70%, potassium pyroantimonate 0-2%, borax 4-10%, solid sodium hydroxide: 20-40%.

Example 1:

The blast furnace bag dust in a steel enterprise, the fly ash of a power plant and the binder are ground to a particle size of less than 100 mesh, and the mixture is mixed according to the mass ratio of 79.5:20:0.5 and evenly mixed to obtain a mixture, and then the mixture is put into the press The ball machine is pressed into pellets with a particle size of ф10mm, and the pellets are fed into the submerged arc furnace through the feeding system. The slag wool is made by spinning the silk. The iron content obtained by the test contains Fe95.2, Si1.19S0.02 and C3.17. The acidity coefficient of the slag wool reaches 1.63, which is in line with and better than the national standard.

Example 2:

A steel company's blast furnace bag dust, a power plant fly ash and binder are ground to a particle size of less than 100 mesh. The raw material composition is different from that of Case 1, and it is mixed evenly according to the formula; the ingredients are mixed according to the mass ratio of 75.1:24.4:0.5. Mix uniformly to get the mixture, then put the mixture into the ball press and press it into pellets with a particle size of ф10mm. The pellets are fed into the submerged arc furnace through the feeding system. After the submerged arc furnace is smelted, molten iron is produced and discharged through the tap hole. It is made into iron blocks, and the slag generated after smelting in the submerged arc furnace is spun into slag wool. The iron content obtained by the test contains Fe95.3%, Si1.27%, S0.03% and C2.77%. 1.73.

Example 3:

A steel enterprise's blast furnace bag dust, a power plant's fly ash and binder are ground to a particle size of less than 100 mesh. The raw material composition is different from that of Cases 1 and 2, and they are mixed evenly according to the formula; the mass ratio is 81.8:17.7:0.5. The mixture is prepared by batching and mixing uniformly, and then the mixture is put into the briquetting machine to be pressed into pellets with a particle size of ф10mm, and the pellets are fed into the submerged arc furnace through the feeding system. It is discharged into iron blocks, and the slag generated after smelting in the submerged arc furnace is spun into slag wool. The iron content obtained by the test contains Fe95.5, Si1.07S0.03, and C3.03, and the acidity coefficient of the slag wool reaches 1.65.

The above descriptions are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of rights of the present invention. Any equivalent structural changes made using the contents of the description of the present invention are included in the scope of rights of the present invention.

Claims (4)

1. a blast furnace bag dedusting ash and fly ash comprehensive utilization method is characterized in that comprising the following steps: S1, grind and prepare the mixture of the required proportions for smelting, in the mixture, the blast furnace bag dust is 70-85 parts by mass; the fly ash is 15-30 parts by mass; the binder is 0.3-1 part by mass; S2, pelletizing the mixture; S3, adding the pellets into the submerged arc furnace, and using the submerged arc furnace to heat and reduce the pellets to generate molten iron and slag; S4, molten iron and slag are respectively discharged from the tap hole and the slag tap of the submerged arc furnace; S5, after the molten iron is discharged, it is cast into iron blocks, and after the slag is discharged, the slag wool is made by spinning. 2. The comprehensive utilization method of blast furnace bag dust and fly ash according to claim 1, is characterized in that: in described step S1, after grinding, blast furnace bag dust, fly ash and binder granularity are: 80-130 mesh. 3. The method for comprehensive utilization of blast furnace bag dust and fly ash according to claim 1, characterized in that: in the step S3, the heating reduction temperature of the submerged arc furnace is controlled at 1400-1600°C. 4. The method for comprehensive utilization of blast furnace bag dust and fly ash according to claim 1, characterized in that: described slag wool is used for making slag wool felt, and making slag wool felt comprises the following process steps: (1) The slag is transported to a four-roller centrifuge to form fibers; (2) Under the action of negative pressure, the fibers are sent to the mesh belt conveyor in the sedimentation chamber to remove the slag balls through the slag removal roller to obtain slag wool felt with uniform thickness.