阅读说明：本技术 一种喷吹处理脱硫脱硝后废弃活性炭的方法 (Method for treating waste activated carbon after desulfurization and denitrification by blowing ) 是由 张猛超 贾国利 杨文华 程洪全 王荣刚 王宇哲 段伟斌 贾新 林春山 赵满祥 于 2021-08-19 设计创作，主要内容包括：本申请涉及钢铁冶金中高炉炼铁领域,特别涉及一种喷吹处理脱硫脱硝后废弃活性炭的方法。所述方法包括：对废弃活性炭进行密封和制粉,得到废弃活性炭粉；根据所述第一灰分含量、所述第一硫含量、所述第一碳含量、第二灰分含量、第二硫含量、第二碳含量及混合煤粉剩余组分的成分,确定废弃活性炭粉在所述混合煤粉中的掺杂量；以所述掺杂量将所述废弃活性炭粉掺杂于所述混合煤粉,对所述混合煤粉进行预处理,得到混合粉；将所述混合煤粉喷吹入高炉后进行燃烧,用以实现废弃活性炭的循环回收；高效回收其中的固定碳资源,充分利用了高炉的高效脱硫效率,使85％以上硫进入到炉渣中并排出,从而避免了硫在烧结-高炉工序间循环。(The application relates to the field of blast furnace ironmaking in ferrous metallurgy, in particular to a method for treating waste activated carbon after desulfurization and denitrification by blowing. The method comprises the following steps: sealing and pulverizing the waste activated carbon to obtain waste activated carbon powder; determining the doping amount of the waste activated carbon powder in the mixed pulverized coal according to the first ash content, the first sulfur content, the first carbon content, the second ash content, the second sulfur content, the second carbon content and the components of the rest components of the mixed pulverized coal; doping the waste activated carbon powder into the mixed coal powder according to the doping amount, and pretreating the mixed coal powder to obtain mixed powder; the mixed pulverized coal is blown into a blast furnace and then combusted, so that the cyclic recovery of the waste activated carbon is realized; the fixed carbon resource in the waste gas is efficiently recovered, the high-efficiency desulfurization efficiency of the blast furnace is fully utilized, more than 85 percent of sulfur enters the slag and is discharged, and thus, the sulfur is prevented from circulating between the sintering and blast furnace processes.)

1. A method for treating waste activated carbon after desulfurization and denitrification by blowing is characterized by comprising the following steps:

sealing and pulverizing the waste activated carbon to obtain waste activated carbon powder;

obtaining a first ash content, a first sulfur content and a first carbon content of the waste activated carbon powder;

acquiring a second ash content, a second sulfur content and a second carbon content of the mixed pulverized coal;

determining the doping amount of the waste activated carbon powder in the mixed pulverized coal according to the first ash content, the first sulfur content, the first carbon content, the second ash content, the second sulfur content, the second carbon content and the components of the rest components of the mixed pulverized coal;

doping the waste activated carbon powder into the mixed coal powder according to the doping amount, and pretreating the mixed coal powder to obtain mixed powder;

and blowing the mixed pulverized coal into a blast furnace, and then burning the mixed pulverized coal to realize the recycling of the waste activated carbon.

2. The method according to claim 1, wherein the desulfurization rate of the blast furnace is 85% or more.

3. The method as claimed in claim 1 or 2, wherein the blast furnace has an effective volume of 5000m or less³Sulfur load in blast furnace production<4.5kg/t。

4. The method according to claim 1 or 2, characterized in that the blowing temperature is <90 ℃.

5. The method of claim 1, wherein the spent activated carbon has a seal time of 72 hours or less.

6. The method of claim 1, wherein the pre-treating comprises drying, milling, and mixing the components of the mixed coal fines in sequence.

7. The method according to claim 6, wherein the second ash content is 8-11%, the second sulfur content is 0.5-0.7%, and the second carbon content is 65-80% in mass fraction.

8. The method according to claim 6, wherein the components of the mixed coal fines comprise, in mass fractions: 53-60% of anthracite, 0-40% of bituminous coal and 0.5-7% of the waste activated carbon powder.

9. The method according to claim 8, wherein the chemical composition of the anthracite coal comprises, in mass fractions: the Ad is less than or equal to 11.0 percent, the St is less than or equal to 1.0 percent, and the volatile component of the anthracite is less than or equal to 13.0 percent.

10. The method of claim 8, wherein the chemical composition of the bituminous coal comprises, in mass fraction: less than or equal to 9.0 percent of Ad, less than or equal to 0.6 percent of St, and less than or equal to 40.0 percent of volatile components in the bituminous coal.

Technical Field

The application relates to the field of blast furnace ironmaking in ferrous metallurgy, in particular to a method for treating waste activated carbon after desulfurization and denitrification by blowing.

Background

The national control standard for the emission gases of sulfur dioxide, nitrogen oxide and the like in steel plants is more and more strict, and the treatment of waste gas needs to be increased so as to ensure that the emission reaches the standard. The nitrogen oxide produced by sintering and pelletizing accounts for more than half of the emission of the steel plant, and the sulfur dioxide accounts for about 70% of the total emission of the steel plant, so the desulfurization and denitrification of the sintering and pelletizing processes are very important. The desulfurization and denitrification are carried out by wet method, semi-dry method, dry method and other process categories, the efficiency of the active carbon combined desulfurization and denitrification can reach about 90 percent, and the desorbed product can be used for preparing sulfuric acid; meanwhile, the activated carbon also has a certain adsorption effect on dioxin and heavy metal poisons.

Most of the active carbon used in the sintering, pelletizing, desulfurization and denitration industry at present is cylindrical with the particle size of less than 9mm and the length of less than or equal to 15mm, the carbon content is more than or equal to 75 percent, the ash content is about 17 percent, the ignition point is more than or equal to 420 ℃, the wear-resistant strength is more than or equal to 97 percent, and the active carbon has stronger wear-resistant and pressure-resistant performances than the common active carbon. The activated carbon can be reused by desorption, but the adsorption and desorption processes are not infinitely cyclic. The activated carbon reacts with certain gases when in use, the pores of the activated carbon are blocked by certain dust, the activated carbon fails due to abrasion and crushing after use, and most of the waste activated carbon is inevitably generated. In the production, the active carbon is treated by an air screen before being analyzed, and is removed and cracked into waste active carbon with the powder less than 3mm and powder thereof by treatment of a vibrating screen after regeneration. The waste activated carbon before and after analysis is collected to a storage system through a discharge port. If not properly disposed of, it is not only a pollution to the environment, but also a waste of resources. The problem to be solved is to efficiently treat the waste activated carbon and the powder thereof generated after desulfurization and denitrification.

The traditional regeneration technology of the waste active carbon at the present stage mainly comprises a thermal decomposition method, a solvent regeneration method and the like.

In the patent documents of "a method for regenerating desulfurization and denitrification waste activated carbon" (patent No. CN110605108A), and "an activated carbon desulfurization and denitrification regeneration system" (patent No. CN110538647A), regeneration methods are proposed for waste activated carbon, but the treatment of the activated carbon which cannot reach the standard and cannot be used is not explained; the patent document "a method for recycling waste powdered activated carbon" (patent No. CN103721692A) is mainly applied to waste powdered activated carbon generated in a sodium glutamate refining process, and is not suitable for treating waste activated carbon and powder generated by iron-making, sintering, desulfurization and denitrification. Patent document "a drying and incinerating system for waste powdered activated carbon" (patent No. CN207298970U), although it can treat waste activated carbon, it needs to build a set of corresponding incinerating system, not only increases the investment of fixed equipment, but also can not optimize the value of waste activated carbon relative to the iron-making process.

Disclosure of Invention

The application provides a method for treating waste activated carbon after desulfurization and denitrification by blowing, which aims to solve the technical problem that the waste activated carbon cannot be efficiently recycled.

In a first aspect, the present application provides a method for treating waste activated carbon after desulfurization and denitrification by blowing, the method comprising:

sealing and pulverizing the waste activated carbon to obtain waste activated carbon powder;

obtaining a first ash content, a first sulfur content and a first carbon content of the waste activated carbon powder;

acquiring a second ash content, a second sulfur content and a second carbon content of the mixed pulverized coal;

determining the doping amount of the waste activated carbon powder in the mixed coal powder according to the first ash content, the first sulfur content, the first carbon content, the second ash content, the second sulfur content, the second carbon content and the components of the residual components of the mixed coal powder;

doping the waste activated carbon powder into the mixed coal powder according to the doping amount, and pretreating the mixed coal powder to obtain mixed powder;

and blowing the mixed pulverized coal into a blast furnace, and then burning the mixed pulverized coal to realize the recycling of the waste activated carbon.

Optionally, the desulfurization rate of the blast furnace is more than or equal to 85%.

Optionally, the effective volume of the blast furnace is less than or equal to 5000m³The sulfur load during blast furnace production was < 4.5 kg/t.

Optionally, the blowing temperature is <90 ℃.

Optionally, the sealing time of the waste activated carbon is less than or equal to 72 h.

Optionally, the pretreatment includes drying, grinding and mixing the components of the mixed pulverized coal in sequence.

Optionally, the second ash content is 8-11% by mass, the second sulfur content is 0.5-0.7% by mass, and the second carbon content is 65-80% by mass.

Optionally, the mixed pulverized coal comprises the following components in percentage by mass: 53-60% of anthracite, 0-40% of bituminous coal and 0.5-7% of the waste activated carbon powder.

Optionally, the anthracite comprises the following chemical components in percentage by mass: the Ad is less than or equal to 11.0 percent, the St is less than or equal to 1.0 percent, and the volatile component of the anthracite is less than or equal to 13.0 percent.

Optionally, the chemical components of the bituminous coal include, by mass fraction: less than or equal to 9.0 percent of Ad, less than or equal to 0.6 percent of St, and less than or equal to 40.0 percent of volatile components in the bituminous coal.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

the method provided by the embodiment of the application obtains the waste activated carbon powder, the particle size is controlled to be less than 3mm, so that the waste activated carbon powder can be effectively recycled, and the doping amount of the activated carbon powder in the mixed pulverized coal is determined according to the first ash content, the first sulfur content and the first carbon content; the explosiveness of the pulverized coal injection is reduced, the safety is ensured, meanwhile, the fixed carbon resource is efficiently recovered, the mixed pulverized coal is mixed, the pulverized coal is injected into the blast furnace for combustion, the efficient desulfurization efficiency of the blast furnace is fully utilized, more than 85% of sulfur enters the slag and is discharged, and therefore the sulfur is prevented from circulating between the sintering and blast furnace processes.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a schematic flow chart of a method for treating waste activated carbon after desulfurization and denitrification by blowing according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The application provides a method for treating waste activated carbon after desulfurization and denitrification by blowing, which comprises the following steps of:

s1, sealing and pulverizing the waste activated carbon to obtain waste activated carbon powder;

s2, obtaining a first ash content, a first sulfur content and a first carbon content of the waste activated carbon powder;

s3, acquiring a second ash content, a second sulfur content and a second carbon content of the mixed pulverized coal;

s4, determining the doping amount of the waste activated carbon powder in the mixed coal powder according to the first ash content, the first sulfur content, the first carbon content, the second ash content, the second sulfur content, the second carbon content and the components of the residual components of the mixed coal powder;

s5, doping the waste activated carbon powder into the mixed coal powder according to the doping amount, and pretreating the mixed coal powder to obtain mixed powder;

and S6, blowing the mixed pulverized coal into a blast furnace, and then burning to realize the recycling of the waste activated carbon.

In this application embodiment, abandonment active carbon can be sintering, waste active carbon and powder in the pelletizing SOx/NOx control storage storehouse. The waste activated carbon and the powder thereof contain SO₂、NO_XAnd dust and other harmful substances, and the carbon content of the carbon-containing material is over 75 percent.

In the embodiment of the application, after the doping amount of the waste activated carbon powder in the mixed coal powder is determined, the waste activated carbon can be metered and conveyed by using a belt electronic scale according to a calculated ratio during coal blending.

In this application embodiment, different coal types and abandonment active carbon in the mixed buggy can be carried to the coal pulverizer through fortune coal owner belt, through entering jetting jar such as feed, drying, crocus and mixture, finally adopts nitrogen gas to assist to spout and blows in the blast furnace. Other inert materials meeting the purpose can also be used for blowing the mixed coal powder into the blast furnace for combustion in an auxiliary mode.

In the embodiment of the application, the particle size fraction of the waste activated carbon is less than 3mm, the overlarge particle size of the waste activated carbon has regeneration conditions, the waste activated carbon can be recycled, additional treatment is not needed, the cyclic recovery rate of the activated carbon is improved, and the operation cost is reduced.

The mixed coal powder is mixed and injected into a blast furnace for combustion, so that the high desulfurization rate of the blast furnace can be fully utilized, and the aim of harmless reutilization can be fulfilled only in the scene similar to the combustion of the blast furnace.

As an alternative embodiment, the desulfurization rate of the blast furnace is more than or equal to 85 percent.

As an alternative embodiment, the effective volume of the blast furnace is less than or equal to 5000m³The sulfur load during blast furnace production was < 4.5 kg/t.

The quality requirements of blast furnace mixed injection coal with different volumes are stated according to the design specification GB50427-2008 of blast furnace ironmaking process (as shown in Table 1).

Table 1 blowing mix quality requirements.

Furnace volume blood3	1000	2000	3000	4000	5000
						Aad/％	≤12	≤11	≤10	≤9	≤9
St，ad/％	＜0.7	≤0.7	≤0.7	≤0.6	≤0.6

In the embodiment of the application, the sulfur load is the total amount of sulfur carried by the furnace charge when smelting each ton of pig iron.

As an alternative embodiment, the blowing temperature is <90 ℃.

As an alternative embodiment, the waste activated carbon alone can be stored for less than or equal to 72 h.

In the embodiment of the application, the reason that the single storage does not exceed 72 hours is that the single storage contains certain smoke adsorbates and the like, and the independent storage is too long, so that a small amount of analysis reaction is easily caused on gaseous pollutants such as sulfides, nitrogen oxides, dioxins and the like adhered to the activated carbon powder, and secondary pollution or equipment corrosion is caused. It is also the reason that the waste activated carbon is transported by closed tanker trucks and stored in separate storage bins.

As an alternative embodiment, the pretreatment includes drying, pulverizing and mixing the components of the mixed coal powder in sequence.

In an alternative embodiment, the second ash content is 8 to 11% by mass, the second sulfur content is 0.5 to 0.7% by mass, and the second carbon content is 65 to 80% by mass.

In the embodiment of the application, the ash content of the waste activated carbon is about 17 percent, which is slightly higher than 4 to 5 percent of that of the anthracite or bituminous coal injected at present; the volatile component is only 1.9 percent, and compared with anthracite, bituminous coal or other coal types, the volatile component is very low, so that the explosiveness of the injected pulverized coal is greatly reduced, and the method is particularly suitable for injecting a large proportion of bituminous coal.

In the embodiment of the application, the average sulfur content of the waste activated carbon is 1.7-2% and is obviously higher than the sulfur content of other injected coal, so the proportioning suggestion in the mixed pulverized coal is not more than 7%, otherwise, the sulfur load brought by the pulverized coal in the blast furnace is increased to influence the blast furnace smelting.

In the embodiment of the application, the content of the volatile components in the mixed coal powder is controlled to be less than or equal to 23.0 percent, and the mixed coal powder has the excellent effects of stabilizing the coal injection replacement ratio and reducing the fuel consumption.

As an alternative embodiment, the components of the mixed coal powder comprise, in mass fraction: 53-60% of anthracite, 0-40% of bituminous coal and 0.5-7% of the waste activated carbon powder.

As an alternative embodiment, the chemical composition of the anthracite coal includes, in mass fraction: the Ad is less than or equal to 11.0 percent, the St is less than or equal to 1.0 percent, and the volatile component of the anthracite is less than or equal to 13.0 percent.

The reason why the content of Ad of the anthracite is controlled to be less than or equal to 11.0 percent and the content of St is controlled to be less than or equal to 1.0 percent is to control the ash content and the sulfur content of the mixed coal to meet the requirements, and the method has the effects of improving the proportion of bituminous coal and controlling the cost; the reason for controlling the volatile content of the anthracite coal to be less than or equal to 13.0 percent is that the proportion of the high-volatile bituminous coal can be increased, and the anthracite coal has the excellent effects of increasing the combustion effect of mixed coal and reducing the cost.

As an alternative embodiment, the chemical composition of the bituminous coal comprises, in mass fraction: less than or equal to 9.0 percent of Ad, less than or equal to 0.6 percent of St, and less than or equal to 40.0 percent of volatile components in the bituminous coal.

The reason for controlling Ad to be less than or equal to 9.0 percent and St to be less than or equal to 0.6 percent of the bituminous coal is to control reasonable ash content and sulfur content, and has the excellent effect of improving the proportion of the bituminous coal; the reason for controlling the anthracite coal to also contain less than or equal to 40.0 percent of volatile components is to optimize the proportion of the anthracite coal with low volatility, and has the excellent effects of increasing the combustion effect of mixed coal and reducing the cost.

In the following examples, the embodiment of the blowing treatment of the desulfurization and denitrification waste activated carbon will be described.

Example 1A plant 2650m³A blast furnace is taken as an example.

The waste activated carbon powder under the sintering and pelletizing desulfurization and denitration sieve has no regeneration use value, is collected into a temporary storage bin, is hauled to a milling room by a closed tank truck, and is placed into a milling independent storage tank for no more than 72 hours. The addition amount of the waste activated carbon is determined according to the mass percent after the components of each coal are determined, and the specific components are shown in Table 2. According to the control requirements, the ash content of the mixed coal powder is 8-11%, the sulfur content is 0.5-0.7%, and the volatile matter is less than or equal to 23.0%. The final mixed coal ratio is 27% anthracite 1, 23% anthracite 2, 5% anthracite 3, 40% bituminous coal and 5% waste active carbon. Final Ad 10.45%, St 0.677%, volatiles 20.4%. The charging sulfur load of the blast furnace is 4.28 kg/t.

Table 2, ingredient and ratio table of each coal.

The method for treating the waste desulfurization and denitrification active carbon solves the problem that the waste active carbon cannot be used and treated in the sintering and pelletizing process, harmlessly treats sulfur and flue gas dust contained in the waste active carbon, completely recovers the heat value contained in the waste active carbon, and organically combines the harmlessness treatment of the waste active carbon with the maximization of added value.

Under the condition that stage parameters (atmospheric humidity, raw materials and coke quality) are stable, the coke load before and after the blast furnace is injected and added with the waste activated carbon mixed coal powder is 5.3t/t, and the coal injection ratio is not obviously changed. According to the fact that the price difference (Table 2) before and after mixing coal powder is 42.03 yuan, 2650m is adopted according to a certain plant³The blast furnace is matched and added with 5 percent of treatment, the coal injection amount per hour is calculated to be 46 tons, 46 multiplied by 24 multiplied by 5 percent can be processed every day, 55.2 tons can be processed, the operation time in the whole year is calculated to be 355 days, the matched and added coal injection amount per year is 355 multiplied by 55.2 tons, 19596 tons can be processed, and the coal injection cost can be saved by 82.36 ten thousand yuan per year.

Example 2 with a certain factory 4000m³A blast furnace is taken as an example.

The final mixed coal ratio is anthracite 1 of 28 percent, anthracite 2 of 25 percent, anthracite 3 of 5 percent, bituminous coal of 40 percent and waste active carbon of 2 percent. The final composition Ad is 10.30%, St is 0.644%, and volatiles is 20.70%. The blast furnace charging sulfur load was 4.08kg/t, and the other steps were the same as in example 1.

Table 3, composition and ratio table of each coal.

Under the condition that stage parameters (atmospheric humidity, raw materials and coke quality) are stable, the coke load before and after the blast furnace is injected and added with the waste activated carbon mixed coal powder is 5.35t/t, and the coal injection ratio of the comprehensive load of 3.17t/t has no obvious change. According to 4000m of a certain factory³2 percent of treatment is added in the blast furnace, 61 tons of coal injection amount per hour can be processed, 61 multiplied by 24 multiplied by 2 percent can be processed each day, 29.28 tons can be processed, the operation time of the whole year is 355 days, 355 multiplied by 29.28 tons can be added in one year,

the cost is reduced by 13.45 yuan after 2 percent of waste active carbon is added into each ton of mixed coal powder, and the coal injection cost is reduced by 13.98 ten thousand yuan per year.

Comparative example 1

The waste activated carbon is directly added into a sintering process and used as a substitute for part of fuels of a sintering mixture, and the waste activated carbon has high sulfur content, so that the sulfur content in flue gas of the sintering process exceeds the standard, and the circulation of sulfur elements in the sintering process and the burden of flue gas purification are increased. Therefore, this method of re-sintering the waste activated carbon cannot be applied. 360m of a certain factory²When the activated carbon powder is not added into the sintering machine, the average sulfur content of the inlet flue gas is 1000mg/Nm³Adding 5-10% of activated carbon in the test stage, wherein the sulfur content of inlet flue gas is more than 1400mg/Nm after the activated carbon is added³Too high a sulfur content in flue gas results in poor desulfurization. Therefore, the sintering process is forced to stop adding the waste activated carbon powder under the influence of environmental protection.

In one or more embodiments of the present application, the method for treating sintering and pelletizing waste desulfurization and denitrification activated carbon according to the present invention further has the following beneficial effects:

(1) the heat value of the injected anthracite is 26000-28000 kJ/kg, the calorific value of the waste activated carbon is about 28000kJ/kg, and the waste activated carbon can replace part of the anthracite and does not influence the change of the coal ratio.

(2) The waste active carbon is doped, so that the cost of coal dust injection in iron making production can be obviously reduced.

(3) The waste desulfurization and denitrification active carbon contains partial sulfides and adsorbed dust substances, and the waste active carbon generated for purifying sintering and pelletizing flue gas does not cause secondary influence on the environment.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.