CN111440959A - Method for adjusting metallurgical flue gas components of smelting furnace - Google Patents

Abstract

A method for adjusting metallurgical flue gas components of a smelting furnace belongs to the technical field of non-ferrous metallurgy and chemical engineering, and comprises the following steps: spraying pulverized coal, air and oxygen into the furnace through a spray gun; and (3) adding the concentrate into the furnace, performing primary air distribution and anoxic combustion in the furnace, primarily adjusting smoke components by secondary air distribution of a waste heat boiler, and performing tertiary air distribution of an acid making system. The metallurgical flue gas generated by the invention stabilizes the production of an acid making system, ensures the production safety, improves the quality of sulfuric acid products and reduces the environmental protection pressure of tail flue gas.

Description

Method for adjusting metallurgical flue gas components of smelting furnace

Technical Field

The invention belongs to the technical field of non-ferrous metallurgy and chemical industry, and particularly relates to a method for adjusting smoke components of an oxygen-enriched smelting furnace in a nickel metallurgy production process.

Background

The smelting plant Ausmelt furnace is an oxygen-enriched top-blown smelting furnace. The smelting temperature is 1300-1400 ℃. The metallurgical flue gas generated in normal production contains SO₂CO, elemental S and NO_XEtc. gas of CO and simple substance S, NO_XAnd the like can affect electric dust collection, an acid making and purifying system, product sulfuric acid and tail smoke exhaust gas. In order to ensure safety, reduce environmental risks, reduce cost, stabilize production and achieve optimal economic benefits, a method for improving metallurgical smoke components of an oxygen-enriched smelting furnace in the production process is urgently needed.

Therefore, there is a need in the art for a new solution to solve this problem.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the method for adjusting the metallurgical flue gas components of the smelting furnace is provided, the produced metallurgical flue gas stabilizes the production of an acid making system, ensures the production safety, improves the quality of sulfuric acid products, and reduces the environmental protection pressure of tail exhaust gas.

A method for adjusting metallurgical flue gas components of a smelting furnace is characterized by comprising the following steps: comprises the following steps which are sequentially carried out,

step one, mixing pulverized coal, air and oxygen in a mass part ratio of 4 per cubic meter: 13: 7, mixing in proportion, and spraying into a molten pool through a spray gun;

step two, adding the nickel sulfide concentrate into a molten pool through a belt, wherein the concentrate comprises the following components in percentage by mass: 5 to 10 percent of nickel, 2 to 4 percent of copper, 0.1 to 1 percent of cobalt, 22 to 31 percent of iron, 16 to 22 percent of sulfur, 15 to 30 percent of silicon dioxide, and the balance of impurities, wherein the sum of the content percentages of the components is equal to 100 percent;

step three,Adjusting the primary air distribution point air distribution in the Ausmelt furnace, controlling the concentration of air distribution oxygen to be 21% -80%, controlling the content of CO in the flue gas of the Ausmelt furnace to be less than 1%, and controlling the content of simple substance S to be less than 1g/NM³；

Adjusting the air distribution point of the Ausmelt furnace waste heat boiler, and carrying out secondary air distribution, wherein the air distribution oxygen concentration is 21% -100%, the CO content in the flue gas of the Ausmelt furnace waste heat boiler is controlled to be less than 3000ppm, and the simple substance S content is controlled to be 0;

and fifthly, adjusting an air distribution point at the inlet of the flue gas acid-making drying tower, and carrying out tertiary air distribution, wherein the concentration of air distribution oxygen is 21-100%, and CO with the residual concentration of less than 3000ppm in the flue gas acid-making drying tower is combusted in a converter to supplement the heat of the converter.

Through the design scheme, the invention can bring the following beneficial effects: the method for adjusting the metallurgical flue gas components of the smelting furnace has the advantages that the produced metallurgical flue gas stabilizes the production of an acid making system, ensures the production safety, improves the quality of sulfuric acid products and reduces the environmental protection pressure of tail exhaust gas.

Further, the present invention is to suppress thermal NO by appropriately reducing the air volume (oxygen volume) in the Ausmelt furnace_XThe generated sulfuric acid can improve the quality of sulfuric acid products and reduce NO in tail exhaust gas_XAnd (4) content.

According to the invention, the secondary air is added into the boiler to adjust the CO content to be below 3000ppm, so that the explosion of the subsequent electric dust collection is prevented, and the safety is ensured.

The invention completely changes the simple substance S into SO by adding secondary air into the boiler₂The blockage of an acid making purification system caused by elemental S desublimation is prevented, and stable production is ensured.

In the invention, tertiary air is distributed at the drying inlet of the acid making system, so that the residual CO reacts in the converter to generate CO₂Supplement heat for the converter and improve SO₂Conversion to SO₃The conversion efficiency of the furnace reduces the power consumption of the electric furnace and saves energy.

Drawings

The invention is further described with reference to the following figures and detailed description:

FIG. 1 is a schematic block diagram of the flow of a method for adjusting metallurgical flue gas components of a smelting furnace according to the present invention.

Detailed Description

The first embodiment,

A method for adjusting metallurgical fume components of a smelting furnace, as shown in figure 1, comprises the following steps which are carried out in sequence,

step one, spraying pulverized coal, air and oxygen into a molten pool through a spray gun, wherein the pulverized coal, the air and the oxygen are used in cubic dosage Kg/m³4: 13: 7 is sprayed into the furnace;

step two, adding the nickel sulfide concentrate into a molten pool through a belt, wherein the concentrate comprises the following components in percentage by mass: 5 to 10 percent of nickel, 2 to 4 percent of copper, 0.1 to 1 percent of cobalt, 22 to 31 percent of iron, 16 to 22 percent of sulfur, 15 to 30 percent of silicon dioxide, and the balance of impurities, wherein the sum of the content percentages of the components is equal to 100 percent;

step three, adjusting the primary air distribution point air distribution in the furnace by an Ausmelt furnace operator, controlling the oxygen concentration of the air distribution to be 21% -80%, controlling the CO content in the flue gas of the smelting furnace to be less than 1%, and controlling the elemental sulfur content to be less than 1g/NM³；

Step four, the waste heat boiler of the Ausmelt furnace is mainly operated, secondary air distribution point air distribution is adjusted, the oxygen concentration of the air distribution is 21% -100%, the flue gas of the smelting furnace is controlled to contain CO less than 3000ppm, and the content of elemental sulfur is 0;

and fifthly, the flue gas acid-making drying tower is mainly operated to adjust a tertiary air distribution point at the inlet of the drying tower to distribute air, the concentration of air distribution oxygen is 21-100%, the residual CO with the concentration of less than 3000ppm is combusted in the converter, and the heat of the converter is supplemented in an auxiliary manner.

Example II,

A method for adjusting metallurgical flue gas components of a smelting furnace comprises the following steps,

step one, spraying pulverized coal, air and oxygen into a molten pool through a spray gun, wherein the pulverized coal, the air and the oxygen are used in cubic dosage Kg/m³According to the following steps of 4: 13: 7 is sprayed into the furnace;

step two, adding the nickel sulfide concentrate into a molten pool through a belt, wherein the concentrate comprises the following components in percentage by mass: 5 to 10 percent of nickel, 2 to 4 percent of copper, 0.1 to 1 percent of cobalt, 22 to 31 percent of iron, 16 to 22 percent of sulfur, 15 to 30 percent of silicon dioxide, and the balance of impurities, wherein the sum of the content percentages of the components is equal to 100 percent;

step three, adjusting the primary air distribution point air distribution in the furnace by operating personnel of the Ausmelt furnace (hereinafter referred to as the Ausmelt furnace), wherein the oxygen concentration of the air is 21-80%, the CO content of the flue gas of the smelting furnace is controlled to be less than 1%, and the elemental sulfur content is controlled to be less than 1g/NM³；

Step four, the Australian furnace waste heat boiler is mainly operated, secondary air distribution point air distribution is adjusted, the oxygen concentration of air is 21% -100%, the CO content of flue gas of the smelting furnace is controlled to be less than 100ppm, and the elemental sulfur content is 0;

step five, simultaneously accessing Australian furnace flue gas and converter flue gas into the acid making system;

step six, ensuring that SO in the flue gas is enough through primary air distribution in step three and secondary air distribution in step four₂All converted to SO_3，And at the moment, the flue gas acid making main operation closes the tertiary air distribution point at the inlet of the drying tower for air distribution.

Example III,

A method for adjusting metallurgical flue gas components of a smelting furnace comprises the following steps,

a conventional Ausmelt furnace is adopted for nickel metallurgy operation,

step one, the acid making system is only connected with converter flue gas;

step two, adjusting tertiary air distribution point air distribution of the inlet of the drying tower by the flue gas acid making main operation to ensure SO₂All converted to SO₃。

The invention distributes air in a flue gas pipeline from a smelting furnace to an acid making system in sections so as to achieve the following purposes:

first, thermal NO inhibition in smelting furnace_XGenerating;

secondly, air (oxygen-enriched air and oxygen) is added into the 600-800 ℃ section of the boiler, the CO concentration in the flue gas is controlled below 3000ppm, and the safe operation of electric dust collection is ensured;

and thirdly, air (oxygen-enriched air and oxygen) is added into a drying inlet of the acid making system, so that CO with the concentration of less than 3000ppm in the residual flue gas is completely combusted, and a part of heat is provided for the converter.

The above description is only a part of the embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims (1)

1. A method for adjusting metallurgical flue gas components of a smelting furnace is characterized by comprising the following steps: comprises the following steps which are sequentially carried out,

step one, mixing pulverized coal, air and oxygen in a mass part ratio of 4 per cubic meter: 13: 7, mixing in proportion, and spraying into a molten pool through a spray gun;

step two, adding the nickel sulfide concentrate into a molten pool through a belt, wherein the concentrate comprises the following components in percentage by mass: 5 to 10 percent of nickel, 2 to 4 percent of copper, 0.1 to 1 percent of cobalt, 22 to 31 percent of iron, 16 to 22 percent of sulfur, 15 to 30 percent of silicon dioxide, and the balance of impurities, wherein the sum of the content percentages of the components is equal to 100 percent;

adjusting the primary air distribution point air distribution in the Ausmelt furnace, controlling the concentration of air distribution oxygen to be 21% -80%, controlling the CO concentration content in the flue gas of the Ausmelt furnace to be less than 1%, and controlling the content of simple substance S to be less than 1g/Nm³；

Adjusting the air distribution point of the Ausmelt furnace waste heat boiler, and carrying out secondary air distribution, wherein the air distribution oxygen concentration is 21% -100%, the CO content in the flue gas of the Ausmelt furnace waste heat boiler is controlled to be less than 3000ppm, and the simple substance S content is controlled to be 0;

and fifthly, adjusting an air distribution point at the inlet of the flue gas acid-making drying tower, and carrying out tertiary air distribution, wherein the concentration of air distribution oxygen is 21-100%, and CO with the residual concentration of less than 3000ppm in the flue gas acid-making drying tower is combusted in a converter to supplement the heat of the converter.

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