CN114367184A

CN114367184A - Cement flue gas desulfurizer and application thereof

Info

Publication number: CN114367184A
Application number: CN202111567026.0A
Authority: CN
Inventors: 蒋卫和; 杨浴; 钱文斌; 屈铠甲; 王泫迈
Original assignee: Hunan Changde Environment Technology Co ltd
Current assignee: Hunan Changde Environment Technology Co ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-04-19

Abstract

The disclosure relates to a cement flue gas desulfurizer, which contains waste liquid produced by a rearrangement process for preparing caprolactam. The cement flue gas desulfurizer provided by the disclosure can recycle the waste liquid generated by the caprolactam preparation by the rearrangement method in the cement production, and has the comprehensive effects of desulfurization, coal saving and the like.

Description

Cement flue gas desulfurizer and application thereof

Technical Field

The disclosure relates to the field of desulfurizer and application thereof, and specifically relates to a cement flue gas desulfurizer and application thereof.

Background

The cement is made up by using calcareous material (limestone, lime mud and lime stone, etc.) and clayey material (clay, lime mud and clay, etc.) as raw material through the processes of proportioning, burning at high-temp. (1300-1450 deg.C) until they are partially molten, adding a proper quantity of gypsum into the clinker whose main component is calcium silicate, and grinding into fine powder to obtain the hydraulic cementing material. The cement production process is mainly divided into three steps, which are called two-grinding and one-burning for short. The first step is raw material preparation: the calcareous raw material, the clayey raw material and a small amount of correction raw material are crushed, mixed according to a certain proportion, ground and prepared into raw materials with proper components and uniform quality; the second step is clinker firing: adding the ground raw materials into a cement kiln, calcining until part of the raw materials are molten, and obtaining cement clinker taking calcium silicate as a main component; grinding the third clinker: the clinker is added with a proper amount of gypsum and sometimes some mixed materials, and ground into cement together.

The energy consumption of cement production is high, coal is the main energy source, but serious atmospheric pollution is caused by sulfur dioxide discharged by coal every year. The traditional desulfurization methods are generally a limestone-lime/gypsum method and a seawater desulfurization method, wherein the complex components of the desulfurization slag of the limestone-lime/gypsum method cause certain difficulty in treatment, are easy to cause secondary pollution and have great influence on the ecological environment; the seawater desulfurization has the characteristics of high efficiency, environmental protection, simple process flow and low investment and operation cost, but has the characteristics of small sulfur dioxide absorption capacity, easy corrosion of equipment, large seawater consumption and the like. Generally speaking, the traditional desulfurization method is mainly limited by factors such as maturity of production technology, difficulty in raw material cost and source, operation cost and maintenance cost, and subsequent treatment of byproducts. The spray drying desulfurization method is a relatively new desulfurization method, and is a desulfurization method which utilizes the force of mechanical or air flow to disperse a sulfur absorbent into ultrafine mist-shaped liquid drops, the mist-shaped liquid drops and flue gas form a relatively large contact surface area, and heat exchange, mass transfer and chemical reaction occur between gas phase and liquid phase. The commonly used sulfur absorbent is ammonia water, sodium hydroxide solution, lime milk, limestone slurry and the like, and most of the devices use the lime milk as the absorbent at present. Generally, the desulfurization rate of the method is 65-85%, and the automation is high, but the absorbent is very high in cost or low in absorption efficiency.

A process for preparing caprolactam by cyclohexanone-oxime rearrangement reaction comprises multiple refining steps of extraction, back extraction, ion exchange, rectification and the like besides an oxime rearrangement reaction process, wherein the steps can produce waste liquid while refining to obtain a product caprolactam and a co-product ammonium sulfate, and the waste liquid is called as the waste liquid for preparing caprolactam by the rearrangement method and mainly contains aminocaproic acid, caprolactam and oligomers thereof and ammonium sulfate. The waste liquid has high organic and inorganic contents and can not be directly biochemically treated; the burning method generally adopted in the caprolactam industry at present has the disadvantages of large investment, large energy consumption, certain environmental influence and resource waste.

Chinese patent document CN109824285A discloses a cement raw material desulfurizing agent using saponified waste alkali solution oxidized by cyclohexane as base material, which has the functions of raw material desulfurization and coal saving, but it can only solve the problem of pollution of saponified waste alkali solution oxidized by cyclohexane.

Disclosure of Invention

The method can reduce the emission of sulfur dioxide in the cement production process and realize the comprehensive utilization of resources of waste liquid produced by a caprolactam preparation method through a rearrangement method.

In order to achieve the above object, the first aspect of the present disclosure provides a cement flue gas desulfurization agent, which contains a waste liquid from a rearrangement process for producing caprolactam.

Optionally, the waste liquid from the rearrangement process for preparing caprolactam is at least one selected from the group consisting of a waste liquid from a sulfuric acid liquid phase rearrangement process for preparing caprolactam and a waste liquid from a sulfuric acid gas phase rearrangement process for preparing caprolactam; the waste liquid from the rearrangement process for preparing caprolactam contains water, 6-aminocaproic acid, caprolactam polymer and ammonium sulfate; the waste liquid of the rearrangement method for preparing caprolactam contains not more than 96 percent by weight of water and not less than 2 percent by weight of 6-aminocaproic acid, caprolactam and caprolactam polymer based on the weight of the waste liquid of the rearrangement method for preparing caprolactam.

Optionally, the waste liquid from the rearrangement process for preparing caprolactam is concentrated waste liquid; the concentrated waste liquid contains not more than 80 wt% of water and not less than 10 wt% of polymers of 6-aminocaproic acid, caprolactam and caprolactam, based on the weight of the concentrated waste liquid; preferably, the waste liquid from the rearrangement caprolactam preparation method is a concentrated waste liquid from solid-liquid separation; the concentrated solid-liquid separated waste liquid contains not more than 45 wt% of water and not less than 35 wt% of polymers of 6-aminocaproic acid, caprolactam and caprolactam based on the weight of the concentrated solid-liquid separated waste liquid.

Optionally, the cement flue gas desulfurization agent also contains saponification waste lye generated by oxidizing cyclohexane; optionally, the cyclohexane oxidation saponification waste lye accounts for no more than 95 wt% of the cement flue gas desulfurizer by weight; preferably 10 to 80 wt%.

Optionally, the cement flue gas desulfurization agent further contains at least one of an inorganic alkaline compound, a polyol ether additive and a polyamine additive; optionally, by weight, the inorganic alkaline compound accounts for 0-80 wt% of the cement flue gas desulfurizer, the polyol ether additive accounts for 0-80 wt% of the cement flue gas desulfurizer, and the polyamine additive accounts for 0-80 wt% of the cement flue gas desulfurizer.

Optionally, the cement flue gas desulfurization agent further contains an inorganic alkaline compound, a polyol ether additive and a polyamine additive; optionally, the cement flue gas desulfurization agent contains 2-20 wt% of inorganic alkaline compound, 3-50 wt% of polyol ether additive and 2-30 wt% of amine additive.

Optionally, the inorganic basic compound is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium oxide, sodium methoxide, sodium acetate, and potassium acetate; the polyol ether additive is at least one selected from polyols, alcohol ethers and saccharides; the polyalcohol is at least one selected from ethylene glycol propylene glycol, glycerol, polyethylene glycol, triglycerol and polypropylene glycol, the alcohol ether is selected from polyethylene glycol ether and/or polypropylene glycol ether, and the saccharide is at least one selected from glucose, fructose, sucrose, lactose, maltose, oligosaccharide, dextrin, starch and modified starch; the polyamine additive is selected from at least one of organic amine, alcohol amine, ether amine and amide; the organic amine is at least one selected from ethylenediamine, diethylenetriamine, polyethylene polyamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, and cyclohexanediamine; the alcohol amine is at least one selected from the group consisting of ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, triisopropanolamine, tricyclohexylamine, diethanolisopropanolamine, diethanolisocyclohexanolamine, diisopropanolamine, dicyclohexylamine, and dicyclohexylamine monoisopropanolamine; the ether amine is selected from polyethanolamine and/or polypropiolamine; the amide is selected from at least one of urea, formamide, acetamide, propionamide, butyramide, valeramide, caproamide, caprolactam and their corresponding alkylated amides, preferably N-methylformamide and/or N, N-dimethylformamide.

The second aspect of the disclosure provides an application of a cement flue gas desulfurizer in a cement production process, wherein the cement flue gas desulfurizer is the cement flue gas desulfurizer.

Optionally, the cement flue gas desulfurizer accounts for 0.03-1 wt% based on the weight of the cement raw material to be ground and calculated by the effective amount of the cement flue gas desulfurizer after water removal; preferably 0.08-0.5 wt%.

Optionally, the application comprises adding the cement flue gas desulfurization agent into a cement production process in at least one of the following ways:

a. mixing the cement flue gas desulfurizer with the cement raw material to be ground;

b. adding the cement flue gas desulfurizer into a lifting bucket of a cement decomposer;

c. the cement flue gas desulfurizer is sprayed into a C1-C2 air rising pipe for cement production;

d. and spraying the cement flue gas desulfurizer into equipment between a blower and a chimney in cement production.

Through the technical scheme, the waste liquid produced by the caprolactam preparation through the rearrangement method is used as the cement flue gas desulfurizer or the main component thereof, the cement flue gas desulfurizer can be added into a cement raw material grinding system, the grinding condition can be improved, the cement flue gas desulfurizer is fully and uniformly mixed with calcium carbonate, the absorption of sulfur dioxide is promoted, and meanwhile, the desulfurizer is sprayed out in a mist shape at the position of a C1-C2 air rising pipe, so that the content of the sulfur dioxide can be further reduced. The cement flue gas desulfurizer can solve the problem of reasonable treatment of waste liquid generated by a rearrangement process for preparing caprolactam, achieves the purposes of cleanness, environmental protection, low cost and comprehensive utilization of resources, has good grinding-aid effect, can improve the yield and reduce the emission of sulfur dioxide.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a process flow diagram of the production of waste liquid from the rearrangement of cyclohexanone oxime to caprolactam.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The first aspect of the disclosure provides a cement flue gas desulfurizer, which contains waste liquid from a rearrangement process for preparing caprolactam.

The cement flue gas desulfurizer not only can solve the problem of reasonable treatment of the waste liquid of caprolactam prepared by the rearrangement method, but also achieves the purposes of cleanness, environmental protection, low cost and comprehensive utilization of resources, and also has good grinding aid effect, the output can be increased, and the emission amount of sulfur dioxide is reduced.

In the present disclosure, the waste liquid from the rearrangement process for producing caprolactam is at least one selected from the group consisting of a waste liquid from the sulfuric acid liquid phase rearrangement process for producing caprolactam and a waste liquid from the sulfuric acid gas phase rearrangement process for producing caprolactam. The cement flue gas desulfurizer provided by the disclosure can recycle the waste liquid generated by the rearrangement process for preparing caprolactam in cement raw meal grinding and flue gas thereof, and has good comprehensive effects of desulfurization, coal consumption reduction and the like.

According to the present disclosure, cyclohexanone oxime undergoes an intramolecular rearrangement in the presence of sulfuric acid or oleum to give caprolactam, a reaction known as beckmann transposition rearrangement reaction. When fuming sulfuric acid is used, the fuming sulfuric acid is generally neutralized with ammonia water after rearrangement, and a large amount of ammonium sulfate is produced as a by-product. In order to improve the yield of caprolactam and ensure the quality, the ammonium sulfate solution is extracted subsequently, and the caprolactam crude product generated by rearrangement is extracted and back extracted. In addition, after extraction, the caprolactam is subjected to anion-cation exchange process to remove residual inorganic salts such as ammonium sulfate and the like. The waste liquid after extraction, the waste liquid after back extraction and the waste liquid after ion exchange, which are generated in the product refining steps, are called the waste liquid for preparing caprolactam by cyclohexanone-oxime rearrangement, and are called caprolactam waste liquid for short. The specific reaction process steps are shown in figure 1. The initial concentration of the waste liquid is about 5%, and the waste liquid is generally concentrated to the concentration of more than 20% before traditional incineration.

Besides water, the caprolactam waste liquid contains about 50-70% of main organic components such as aminocaproic acid, caprolactam polymer and the like, about 20-40% of main inorganic components such as ammonium sulfate, and about 5-10% of sodium chloride, sodium nitrate, sodium thiocyanate and the like. Through a large number of experiments, the inventor finds that amides and polymers thereof, 6-aminocaproic acid, ammonium sulfate and ammonium nitrate, sodium thiocyanate, sodium chloride and the like are effective grinding-aid components.

According to the present disclosure, the waste stream from the rearrangement process for producing caprolactam may contain water, 6-aminocaproic acid, caprolactam polymer and ammonium sulfate; the waste liquid from the rearrangement process for producing caprolactam may contain not more than 96% by weight of water and not less than 2% by weight of polymers of 6-aminocaproic acid, caprolactam and caprolactam, based on the weight of the waste liquid.

According to the disclosure, the waste liquid from the rearrangement process for producing caprolactam may be a concentrated waste liquid; the concentrated waste stream may contain not more than 80 wt% water and not less than 10 wt% of 6-aminocaproic acid, caprolactam and caprolactam polymer, based on the weight of the concentrated waste stream.

In a specific embodiment of the present disclosure, the waste liquid from the rearrangement process for producing caprolactam is a concentrated waste liquid; the concentrated waste liquid may contain 6-14 wt% caprolactam, 5-12 wt% 6-aminocaproic acid, 4-8 wt% caprolactam oligomer, 5-12 wt% ammonium sulfate, ammonium nitrate, less than 5 wt% of other impurities and the balance water.

Preferably, the waste liquid from the rearrangement caprolactam preparation method can be a concentrated waste liquid from solid-liquid separation; the concentrated solid-liquid separated waste liquid can contain not more than 45 wt% of water and not less than 35 wt% of polymers of 6-aminocaproic acid, caprolactam and caprolactam based on the weight of the concentrated solid-liquid separated waste liquid.

In a specific embodiment of the present disclosure, the concentrated solid-liquid separated waste liquid may contain not less than 10 wt% of caprolactam, not less than 8 wt% of 6-aminocaproic acid, and not less than 5 wt% of caprolactam oligomer. Specifically, the waste liquid after the concentration and the solid-liquid separation can contain 20 to 30 weight percent of caprolactam, 15 to 25 weight percent of 6-aminocaproic acid, 10 to 15 weight percent of caprolactam oligomer, 5 to 15 weight percent of ammonium sulfate, other impurities and the balance of water.

The waste liquid for preparing caprolactam by cyclohexanone oxime rearrangement can be directly used as a cement flue gas desulfurizer without any pretreatment; the effect of adding the regulating additive is better. The additive is added into the cement flue gas desulfurizer to improve the physical adsorption effect and the chemical reaction effect, and the composition and the addition amount of the additive are not limited in the disclosure, and the additive can be added as a single component or in a compound form.

As a preferred embodiment of the present disclosure, the cement flue gas desulfurization agent may further contain cyclohexane oxidation saponification waste lye, the components of which are mainly sodium organic acid, which may further improve physical adsorption effect and chemical reaction effect; optionally, the cyclohexane oxidation saponification waste lye accounts for no more than 95 wt% of the cement flue gas desulfurizer by weight; preferably 10 to 80 wt%. In the disclosure, the cyclohexane oxidation saponification waste alkali liquor and the rearrangement caprolactam preparation waste liquor can be stirred in the mixing process, so that the cyclohexane oxidation saponification waste alkali liquor and the rearrangement caprolactam preparation waste liquor can be fully mixed.

According to the disclosure, the cement flue gas desulfurization agent can further contain at least one of an inorganic alkaline compound, a polyol ether additive and a polyamine additive to further reduce the emission of sulfur dioxide, wherein the inorganic alkaline compound can further improve the chemical adsorption effect of the cement flue gas desulfurization agent, the polyol ether additive is beneficial to physical adsorption of sulfur dioxide, and the polyamine additive is beneficial to chemical reaction and physical adsorption of sulfur dioxide; optionally, by weight, the inorganic alkaline compound may account for 0 to 80 wt% of the cement flue gas desulfurization agent, the polyol ether additive may account for 0 to 80 wt% of the cement flue gas desulfurization agent, and the polyamine additive may account for 0 to 80 wt% of the cement flue gas desulfurization agent.

According to the disclosure, the cement flue gas desulfurization agent may further contain an inorganic alkaline compound, a polyol ether additive and a polyamine additive; through long-term experiments, the inventor of the application finds that when the cement flue gas desulfurizer contains 2-20 wt% of inorganic alkaline compound, 3-50 wt% of polyol ether additive and 2-30 wt% of amine additive by weight, the best desulfurization and yield improvement effects can be achieved.

According to the present disclosure, the inorganic basic compound may be at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium oxide, sodium methoxide, sodium acetate, and potassium acetate; the polyol ether-based additive may be at least one selected from polyols, alcohol ethers and saccharides; the polyol may be selected from at least one of ethylene glycol propylene glycol, glycerol, polyethylene glycol, triglycerol and polypropylene glycol, the alcohol ether is selected from polyethylene glycol ether and/or polypropylene glycol ether, the saccharide may be selected from at least one of glucose, fructose, sucrose, lactose, maltose, oligosaccharide, dextrin, starch and modified starch; the polyamine additive can be selected from at least one of organic amine, alcohol amine, ether amine and amide; the organic amine can be at least one selected from ethylenediamine, diethylenetriamine, polyethylene polyamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, and cyclohexanediamine; the alcohol amine may be selected from at least one of ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, triisopropanolamine, tricyclohexylamine, diethanolisopropanolamine, diethanolisocyclohexanolamine, diisopropanolamine, dicyclohexylalcohol monoethanolamine, and dicyclohexylalcohol monoisopropanolamine; the ether amine may be selected from a polyethanolamine and/or a polypropiolamine; the amide may be selected from at least one of urea, formamide, acetamide, propionamide, butyramide, valeramide, caproamide, caprolactam and their corresponding alkylated amides, preferably N-methylformamide and/or N, N-dimethylformamide.

The second aspect of the present disclosure provides an application of a cement flue gas desulfurization agent in a cement production process, wherein the cement flue gas desulfurization agent is the cement flue gas desulfurization agent, and the cement flue gas desulfurization agent can contribute to tail gas treatment in the cement production process.

According to the disclosure, the cement flue gas desulfurizer can account for 0.03-1 wt% based on the weight of the cement raw material to be ground and based on the effective amount of the cement flue gas desulfurizer after water removal; preferably 0.08-0.5 wt%.

As a specific embodiment of the disclosure, the application comprises adding the cement flue gas desulfurizer into a cement production process in at least one of the following ways:

a. mixing the cement flue gas desulfurizer with a cement raw material to be ground, and promoting the reaction or adsorption of sulfur dioxide in the process;

b. adding the cement flue gas desulfurizer into a bucket of a cement decomposer, and promoting the reaction or adsorption of sulfur dioxide in the process;

c. the cement flue gas desulfurizer is sprayed into a C1-C2 air rising pipe for cement production, and the reaction or adsorption of sulfur dioxide is promoted in the process;

d. and (3) spraying the cement flue gas desulfurizer into equipment between a blower and a chimney in cement production, and promoting the reaction or adsorption of sulfur dioxide in the process.

The cement decomposer, the C1-C2 updraft pipes and the cement production blowers and chimneys are all cement production equipment well known to those skilled in the art according to the present disclosure, and the detailed description of the present disclosure is omitted.

The present disclosure is further illustrated by the following examples, but is not to be construed as being limited thereby.

The caprolactam waste liquid used in the embodiments of the present disclosure is obtained from the hills petrochemical process and has the following properties: the relative density was 1.13g/cm³The solids content was 30% by weight, the pH was 5, the caprolactam content was 8% by weight, the aminocaproic acid content was 6% by weight, the caprolactam oligomer content was 5% by weight and the ammonium sulfate content was 8% by weight.

The inorganic alkaline compound, the polyol ether additive and the polyamine additive used in the examples are all commercially available products with different brands, and the use is not influenced. In the examples, the inorganic alkaline compound used was sodium hydroxide, the polyol ether additive was glycerol, and the polyamine additive was N-methylformamide.

In the examples, the mixing ratio of the cement flue gas desulfurizer to the cement raw material to be ground is cement flue gas desulfurizer/cement raw material to be ground.

In the examples, the mixing ratio of the industrial waste lye is industrial waste lye/cement raw material to be ground.

In the examples, the uptake pipe C1-C2 calculates the internal mixing ratio of the cement flue gas desulfurizer as the mist spraying amount (kg/h), wherein the internal mixing ratio is the cement flue gas desulfurizer/cement raw meal to be ground.

In the examples, the up-draft tube C1-C2 calculates the internal mixing ratio of the industrial waste lye in the form of mist spraying amount (kg/h), wherein the internal mixing ratio is the industrial waste lye/cement raw meal.

First, example SA1-SA8 and comparative example DA1 illustrate the influence of the use of the desulfurizing agent for flue gas of cement in the cement raw meal vertical mill on the grinding effect and the desulfurizing effect of the raw meal.

The experiment is carried out in a cement plant, and the specific operation steps are as follows: feeding cement raw materials to be ground into a vertical mill separately or together with a cement flue gas desulfurizer to grind the raw materials, wherein the fineness of 0.08mm of the raw material grinding is controlled to be less than 20 wt%, and the statistics of a main current of the mill is about 189A, the grinding pressure is 1.1MPa and the current of a circulating fan is 240A; the raw material grinding product is sent into a kiln system for decomposition and calcination, the calcination condition ensures that the clinker quality is qualified, the decomposition temperature is 860 ℃ and 870 ℃, and the kiln rotation speed is 3.6 r/min, so that the cement clinker to be ground is obtained; during the period, the average yield of the raw meal mill, the oversize of the raw meal with a fineness of 0.08mm, the decomposition rate of calcium carbonate, the average coal consumption and the SO before the inlet of the desulfurization tower were measured₂Concentration, etc.

It should be noted that, the set fineness is controlled during the grinding production in the cement plant, the powder concentrator is started, and the capacity change of the experimental mill is compared; the decomposition rate of the cement raw materials can also control the qualification rate and is quite level, and the standard coal consumption change and the sulfur content change in the flue gas of each ton of cement clinker in the experiment are compared.

Comparative example DA1

The raw materials to be ground of the cement are normally subjected to raw material grinding treatment and calcination, and specific conditions and results are shown in table 1.

Example SA1

Based on the weight of the cement raw material to be ground and based on the effective amount of the cement flue gas desulfurizer after water removal, 0.05 weight percent of caprolactam waste liquid (100 parts by weight) is mixed with the cement raw material to be ground to carry out raw material grinding treatment and calcination, and specific conditions and results are shown in table 1.

Example SA2

Based on the weight of the cement raw material to be ground and based on the effective amount of the cement flue gas desulfurizer after water removal, 0.4 weight percent of caprolactam waste liquid (100 parts by weight) is mixed with the cement raw material to be ground to carry out raw material grinding treatment and calcination, and specific conditions and results are shown in table 1.

Example SA3

Based on the weight of the cement raw material to be ground and based on the effective amount of the cement flue gas desulfurizer after water removal, 0.8 weight percent of caprolactam waste liquid (100 parts by weight) is mixed with the cement raw material to be ground to carry out raw material grinding treatment and calcination, and specific conditions and results are shown in table 1.

Example SA4

Adding 60 parts by weight of cyclohexane oxidized saponified waste alkali liquor (with the concentration of 40%) into caprolactam waste liquid (100 parts by weight) to serve as a cement flue gas desulfurizer. The raw material to be ground is mixed with cement in a proportion of 0.5 wt% based on the weight of the raw material to be ground and an effective amount of the cement flue gas desulfurizer after water removal, and the raw material is ground and calcined, wherein specific conditions and results are shown in table 1.

Example SA5

Adding 10 parts by weight of sodium hydroxide into caprolactam waste liquid (100 parts by weight) to serve as a cement flue gas desulfurizer. The raw material to be ground is mixed with cement in a proportion of 0.4 wt% based on the weight of the raw material to be ground and the effective amount of the cement flue gas desulfurizer after water removal, and the raw material is ground and calcined, wherein specific conditions and results are shown in table 1.

Example SA6

Adding 20 parts by weight of glycerol into 100 parts by weight of caprolactam waste liquid to serve as a cement flue gas desulfurizer. The raw material to be ground is mixed with cement in a proportion of 0.4 wt% based on the weight of the raw material to be ground and the effective amount of the cement flue gas desulfurizer after water removal, and the raw material is ground and calcined, wherein specific conditions and results are shown in table 1.

Example SA7

Adding 10 parts by weight of N-methylformamide into caprolactam waste liquid (100 parts by weight) to serve as a cement flue gas desulfurizer. The raw material to be ground is mixed with cement in a proportion of 0.4 wt% based on the weight of the raw material to be ground and the effective amount of the cement flue gas desulfurizer after water removal, and the raw material is ground and calcined, wherein specific conditions and results are shown in table 1.

Example SA8

Adding 20 parts by weight of cyclohexane oxidized saponified waste lye (with the concentration of 40%), 6 parts by weight of sodium hydroxide, 10 parts by weight of glycerol and 5 parts by weight of N-methyl formamide into caprolactam waste liquor (100 parts by weight) to serve as a cement flue gas desulfurizer. The raw material to be ground is mixed with cement in a proportion of 0.3 weight percent based on the weight of the raw material to be ground and the effective amount of the cement flue gas desulfurizer after water removal, and the raw material is ground and calcined, wherein the specific conditions and results are shown in table 1.

TABLE 1

As can be seen from Table 1, after a certain amount of cement flue gas desulfurizer is added into the raw meal mill, the effects of desulfurization and yield increase can be achieved, and with the addition of the mixing amount and the desulfurization auxiliary agent, the effects of desulfurization and yield increase are more obvious, and the sulfur reduction rate can reach 57.3 percent at most; particularly, when the cement flue gas desulfurizer simultaneously contains an inorganic alkaline compound, a polyol ether additive and a polyamine additive, the effect is best. Because the contact area and the contact time of the cement flue gas desulfurizer are limited, the cement flue gas desulfurizer which is not fully utilized in the raw material mill enters the subsequent process along with the raw material, the continuous desulfurization effect is realized, and the problem of overproof sulfur emission caused by stopping the raw material mill is avoided. In addition, the cement flue gas desulfurizer can improve the burnability of raw materials, thereby reducing coal consumption.

Secondly, the influence of the desulfurizer added at the position of the C1-C2 air rising pipe on desulfurization

Examples SC1-SC8 and comparative example DA1 illustrate the effect of adding a desulfurizing agent at the uptake duct of C1-C2 on desulfurization. Specifically, as shown in table 2.

Table 2 application comparative data

As can be seen from Table 2, in other processes in the cement production process, such as the up-draft tube C1-C2, the desulfurization and coal consumption reduction effects can be achieved, and the desulfurizer is added in the process flow behind the raw material warehouse, so that the advantages of quick effect and capability of emergently treating the problem of over-standard sulfur due to the use of small mixing amount are achieved; but the desulfurization effect is slightly worse than the desulfurization effect added in a raw material mill, and the grinding-assisted yield-increasing effect cannot be exerted.

As can be seen from tables 1-2, the cement flue gas desulfurization agent provided by the present disclosure has good desulfurization effect, and can also play a role in increasing yield and reducing coal consumption.

The preferred embodiments of the present disclosure have been described in detail above, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. The cement flue gas desulfurizer is characterized by containing waste liquid of caprolactam preparation by a rearrangement method.

2. The cement flue gas desulfurization agent according to claim 1,

the waste liquid from the rearrangement method for preparing caprolactam is at least one of waste liquid from the sulfuric acid liquid phase rearrangement method for preparing caprolactam and waste liquid from the sulfuric acid gas phase rearrangement method for preparing caprolactam;

the waste liquid from the rearrangement process for preparing caprolactam contains water, 6-aminocaproic acid, caprolactam polymer and ammonium sulfate;

the waste liquid of the rearrangement method for preparing caprolactam contains not more than 96 percent by weight of water and not less than 2 percent by weight of 6-aminocaproic acid, caprolactam and caprolactam polymer based on the weight of the waste liquid of the rearrangement method for preparing caprolactam.

3. The cement flue gas desulfurization agent according to claim 1 or 2,

the waste liquid of the rearrangement method for preparing caprolactam is the concentrated waste liquid; the concentrated waste liquid contains not more than 80 wt% of water and not less than 10 wt% of polymers of 6-aminocaproic acid, caprolactam and caprolactam, based on the weight of the concentrated waste liquid;

preferably, the waste liquid from the rearrangement caprolactam preparation method is a concentrated waste liquid from solid-liquid separation; the concentrated solid-liquid separated waste liquid contains not more than 45 wt% of water and not less than 35 wt% of polymers of 6-aminocaproic acid, caprolactam and caprolactam based on the weight of the concentrated solid-liquid separated waste liquid.

4. The cement flue gas desulfurization agent according to claim 1, wherein the cement flue gas desulfurization agent further comprises a saponification waste lye of cyclohexane oxidation;

optionally, the cyclohexane oxidation saponification waste lye accounts for no more than 95 wt% of the cement flue gas desulfurizer by weight; preferably 10 to 80 wt%.

5. The cement flue gas desulfurization agent according to claim 1, wherein the cement flue gas desulfurization agent further comprises at least one of an inorganic alkaline compound, a polyol ether-based additive, and a polyamine-based additive;

optionally, by weight, the inorganic alkaline compound accounts for 0-80 wt% of the cement flue gas desulfurizer, the polyol ether additive accounts for 0-80 wt% of the cement flue gas desulfurizer, and the polyamine additive accounts for 0-80 wt% of the cement flue gas desulfurizer.

6. The cement flue gas desulfurization agent according to claim 5, wherein the cement flue gas desulfurization agent further comprises an inorganic alkaline compound, a polyol ether-based additive, and a polyamine-based additive;

optionally, the cement flue gas desulfurization agent contains 2-20 wt% of inorganic alkaline compound, 3-50 wt% of polyol ether additive and 2-30 wt% of amine additive.

7. The cement flue gas desulfurization agent according to claim 5 or 6,

the inorganic alkaline compound is at least one selected from sodium hydroxide, potassium hydroxide, calcium oxide, sodium methoxide, sodium acetate and potassium acetate;

the polyol ether additive is at least one selected from polyols, alcohol ethers and saccharides; the polyalcohol is at least one selected from ethylene glycol, propylene glycol, glycerol, polyethylene glycol, triglycerol and polypropylene glycol, the alcohol ether is selected from polyethylene glycol ether and/or polypropylene glycol ether, and the saccharide is at least one selected from glucose, fructose, sucrose, lactose, maltose, oligosaccharide, dextrin, starch and modified starch;

the polyamine additive is selected from at least one of organic amine, alcohol amine, ether amine and amide; the organic amine is at least one selected from ethylenediamine, diethylenetriamine, polyethylene polyamine, propylenediamine, butylenediamine, pentylenediamine, hexylenediamine, and cyclohexanediamine; the alcohol amine is at least one selected from the group consisting of ethanolamine, diethanolamine, triethanolamine, propanolamine, dipropanolamine, triisopropanolamine, tricyclohexylamine, diethanolisopropanolamine, diethanolisocyclohexanolamine, diisopropanolamine, dicyclohexylamine, and dicyclohexylamine monoisopropanolamine; the ether amine is selected from polyethanolamine and/or polypropiolamine; the amide is selected from at least one of urea, formamide, acetamide, propionamide, butyramide, valeramide, caproamide, caprolactam and their corresponding alkylated amides, preferably N-methylformamide and/or N, N-dimethylformamide.

8. The application of the cement flue gas desulfurizer in the cement production process, wherein the cement flue gas desulfurizer is the cement flue gas desulfurizer described in any one of claims 1 to 7.

9. The use according to claim 8, wherein the cement flue gas desulfurization agent is present in an amount of 0.03 to 1% by weight based on the weight of the cement raw material to be ground and in an amount effective after removal of water from the cement flue gas desulfurization agent; preferably 0.08-0.5 wt%.

10. The use of claim 8, comprising adding the cement flue gas desulfurization agent to a cement production process in at least one of the following ways: