CN116751470A

CN116751470A - Modified separation and utilization method and system for gas slag

Info

Publication number: CN116751470A
Application number: CN202310801201.0A
Authority: CN
Inventors: 王建立; 李艺; 张世杰; 闫妍; 董乾; 马聪; 祁俊; 叶志刚; 李玉洋; 黄伟; 张乾; 王奇
Original assignee: China Shenhua Coal to Liquid Chemical Co Ltd
Current assignee: China Shenhua Coal to Liquid Chemical Co Ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2023-09-15

Abstract

The application discloses a modified separation and utilization method and a system for gas slag, wherein the method comprises the following steps: 1) Mixing and grinding the gas slag and the solid modifier to obtain modified slag; 2) Carrying out primary air current separation on the modified slag to obtain a coarse material and a fine material; 3) Carrying out secondary air flow separation on the fine materials to obtain modified lean carbon slag and gas with ultrafine particles; 4) And carrying out gas-solid separation on the gas with the superfine particles to obtain modified superfine carbon-rich slag. According to the application, the coal gasification slag is firstly ground and modified, and then the modified coal gasification slag is subjected to air flow separation to realize high-efficiency carbon ash separation, so that the high-value full-component utilization of the coal gasification slag is realized.

Description

Modified separation and utilization method and system for gas slag

Technical Field

The application relates to the technical field of comprehensive utilization of gas slag, in particular to a modified separation and utilization method and system of gas slag.

Background

According to the statistics of 2022, the annual coal consumption of modern coal chemical industry in China is about 2.5 hundred million t, wherein the total amount of the modern coal chemical industry coal which is converted into a tap by coal gas is more than 90%, the annual produced ash is over 5000 ten thousand tons, and the huge accumulated ash brings huge pressure to the sustainable development of enterprises. The existing large-scale utilization way of coal ash is mainly used for producing building material products such as cement, concrete, bricks and the like, but the content of carbon residue in the ash is not higher than 10%, and the coal gasification slag cannot be directly used as a raw material for producing the products due to higher carbon residue content. In addition, the carbon in the gasified ash is used as a combustible material after high-temperature treatment, almost contains no volatile matters, has developed gaps and higher graphitization degree, still has considerable utilization value, and is a potential resource repository. The coal gasification slag is subjected to carbon ash separation, and carbon black and white carbon black which are applied to rubber reinforcing filler are replaced, so that the high-value full-component utilization of coal gasification slag can be realized, a series of resource and environmental problems caused by the existing coal gasification slag stockpiling can be solved, and the method has great significance.

The grain form and composition of the gasified slag obtained by different types of coal gasification technologies are different, and the physical and chemical properties of the gasified slag are also obviously different, so that the gasified slag cannot be directly used as rubber filler. In order to prepare the rubber reinforcing filler with stable quality, the grinding/modification and quality classification of the gas slag are very necessary. The particle size is an important index for rubber filler, and the gas slag can obtain ultrafine particles through grinding and screening, so that the gas slag is favorable for filling in rubber, but when ore particles are ground to a certain particle size, fine particle ash is easy to agglomerate in the rubber under the actions of Van der Waals force, hydrogen bond, electrostatic action and other action force, so that a good filling effect is difficult to realize. The addition of the modifier to strengthen the hydrophilicity and hydrophobicity of the particle surface can enhance the compatibility and the dispersibility of ash particles in rubber, thereby reducing the agglomeration phenomenon during ash filling. However, when modifying by a dry method, the modifying effect is uneven due to different contact probabilities between different particles and the modifying agent; the wet modification is to dissolve all ash particles in the solution for mixing and stirring, and the problems of large modifier consumption, high re-drying energy consumption and the like are also existed. In recent years, an air classifier is adopted to modify superfine materials to be widely applied. CN 206296181U discloses an air classifier for preactivation modification of calcium carbonate powder, which introduces that after the air classifier is additionally provided with a spraying device, ultrafine powder is sprayed out under the action of air flow, so that better dispersibility is achieved, and meanwhile, an atomization activator is continuously added, so that the activation index of the powder is improved. For the gas slag, especially for the gas slag of different types with complex source and composition, no technology for mass modification and large-scale application of the system to rubber filler exists.

Disclosure of Invention

In view of the above, the main object of the present application is to provide a method and a system for modifying and sorting coal gasification slag, which grind and modify the coal gasification slag, and perform air current sorting on the modified coal gasification slag to efficiently separate carbon from ash, thereby realizing high-value full-component utilization of coal gasification slag.

In order to achieve the aim of the application, the first aspect of the application provides a modified separation and utilization method for gas slag, which comprises the following steps:

1) Mixing and grinding the gas slag and the solid modifier to obtain modified slag;

2) Carrying out primary air current separation on the modified slag to obtain a coarse material and a fine material;

3) Carrying out secondary air flow separation on the fine materials to obtain modified lean carbon slag and gas with ultrafine particles;

4) And carrying out gas-solid separation on the gas with the superfine particles to obtain modified superfine carbon-rich slag.

Further, in the step 1), the solid modifier adopts one or a combination of a plurality of silane coupling agents, aluminate coupling agents, titanate coupling agents, stearic acid, alkali activators and the like.

Further, in the step 1), the addition amount of the solid modifier is 0.1% -15%, preferably 6% -12% of the mass of the gas slag to be modified.

Further, in the step 1), the grinding is an air flow grinding until the particle size of the material is no more than 0.15mm.

Further, in the step 2), the particle size of the coarse material is larger than the reference particle size, the particle size of the fine material is smaller than the reference particle size, and the reference particle size is 5-74 μm. Preferably, the reference particle size is 10 μm, the particle size of the coarse material is more than or equal to 10 μm, and the particle size of the fine material is less than 10 μm.

Further, step 2) also comprises the step of returning the coarse material to step 1) for grinding again.

The second aspect of the application provides a modified separation and utilization system for gas slag, which comprises the following components:

the grinding machine is used for grinding the mixed gas slag and the solid modifier to obtain modified slag;

the first-stage air classifier is used for carrying out air flow separation on the modified slag to obtain coarse materials and fine materials;

the secondary air classifier is used for carrying out air flow separation on the fine materials to obtain modified lean carbon slag and gas with ultrafine particles;

and the gas-solid separator is used for carrying out gas-solid separation on the gas with the superfine particles to obtain modified superfine carbon-rich slag.

Further, the material inlet of the primary air classifier or the secondary air classifier is below the side face of the primary air classifier or the secondary air classifier body.

Further, a guide vane is arranged in the tangential direction of the air flow of the air material inlet of the primary air classifier or the secondary air classifier. Preferably, the guide vanes are perpendicular to the base of the primary air classifier or the secondary air classifier, the inclination angle is 20-60 degrees, and the number of the vanes is 5-40.

Compared with the prior art, the application has the following advantages:

the application firstly mixes and grinds the gas slag and the solid modifier, and the gas slag is modified by the modifier in the grinding process. The addition of the modifier can realize the effect of activating the gas slag, and only fully activated ash particles can be used as carbon black and white carbon black substitution products in qualified rubber reinforcing filler; on the other hand, the surface of the gasified slag is modified, and the method has obvious lifting effect on the subsequent carbon ash separation in the primary or secondary airflow classification, because the modifier changes the surface electrical property, contact angle and activation degree of the gasified slag, and can reduce the phenomenon that the agglomeration of gasified slag particles in the airflow classification affects the separation. Meanwhile, the modifier adopted by the application is solid, and in the solid-solid grinding process of the gas slag and the modifier, the active surface exposed by grinding and crushing the gas slag can be timely contacted with the modifier for modification, and the condition is mild, so that a better modification effect is achieved.

Therefore, the application fully modifies the gas slag directly in the grinding process, realizes high-efficiency quality classification according to the grain grade and the carbon residue content in the primary or secondary airflow classification to obtain modified lean carbon slag and modified superfine carbon-rich slag, and can be applied to white carbon black and carbon black substitute products in rubber reinforcing filler respectively based on the carbon content and the ash content of the modified slag, thereby realizing high-value full-component utilization of the coal gasification slag.

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

Drawings

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

FIG. 1 is a flow chart of a modified separation and utilization method for gas slag in an example of the application.

Fig. 2 is a schematic diagram of a modified gas slag separation and utilization system according to an example of the application.

Fig. 3 is a schematic view of a guide vane according to an example of the present application.

The marks are as follows: the device comprises a power supply 1, an air source 2, a screw feeder 3, an air flow mill 4, a primary air flow classifier 5, a secondary air flow classifier 6, a cyclone separator 7, a bag-type dust collector 8 and an induced draft fan 9.

Detailed Description

The following describes specific embodiments of the present application in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the application, are not intended to limit the application.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Wherein the terms "first position" and "second position" are two different positions.

Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, and may be, for example, either fixed or removable; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Referring to fig. 1, the first aspect of the present application provides a modified gas slag sorting and utilizing method, comprising the following steps:

Preferably, in the step 1), the solid modifier adopts one or a combination of more of a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, stearic acid, an alkali activator and the like.

In the application, the adding proportion of the modifier in the coal gasification fine slag can be determined through a pre-experiment. In some embodiments, the pre-experiment comprises: and uniformly sampling the gas slag, and drying the obtained representative gas slag to obtain the residual carbon content of the gas slag. The dried gas slag and the modifier are modified in a small grinding device, and the addition proportion of the modifier is confirmed by the surface characteristics of the modified slag sample and the characteristics of the modified slag sample in the rubber filler. The representative gas slag is sampled by a quarter method according to national standards, and the selected gas slag can represent an integral slag pile, so that the problem that the measured components cannot represent the integral performance of the gasification slag due to uneven sampling is avoided.

In the application, the gas slag comprises gasified fine slag and gasified coarse slag, the particle diameter of the gasified fine slag is generally smaller, and the gasified fine slag can be directly fed generally; the gasification coarse slag contains large particles in a molten state, and is preferably crushed and fed, for example, the particle size of the gasification slag is preferably controlled to 3mm or less.

Preferably, in step 1), the solid modifier is added in an amount of 0.1% to 15%, preferably 6% to 12%, for example 6%,7%,8%,9%,10%,11%,12% or other values within this range of the mass of the gas slag to be modified.

Preferably, in the step 1), the grinding is an air flow grinding, the material is driven by high-pressure air flow to circularly move, the particles and the walls of the cavity body are mutually impacted, collided and rubbed to be crushed into a certain particle size, the carbon residue and the ash are dissociated, and the surfaces of the particles are modified. Further, the feeding speed and the gas flow rate can be adjusted, and the modified gas slag can be prepared by fully grinding and modifying.

In some embodiments, the feed rates of the gas slag and the solid modifier are adjusted to be between 0.5 and 2 kg per minute, and the gas flow rate is between 5 and 50 m/s. Grinding until the particle size of the material is no more than 0.15mm.

In the application, in the step 2), the particle size of the coarse material is larger than the reference particle size, the particle size of the fine material is smaller than the reference particle size, and the reference particle size can be determined according to the appearance properties of carbon and ash in gasified slag, for example: the reference particle size ranges from 5 to 74 μm.

In some embodiments, in step 2), the reference particle size is 10 μm, the particle size of the coarse material is ∈10μm, and the particle size of the fine material is < 10μm.

Preferably, step 2) further comprises returning the coarse material to step 1) for regrinding.

In the application, the carbon content of the obtained modified superfine carbon-rich slag is more than 60 percent, and the carbon content of the modified carbon-poor slag is less than 20 percent. The modified superfine carbon-rich slag can be used as a substitute product of carbon black in rubber reinforcing filler, and the modified carbon-lean slag product can be used as a substitute product of white carbon black in rubber reinforcing filler. In addition, the modified carbon-rich slag and the modified carbon-poor slag obtained by the application have nonpolar characteristics, and have good dispersing effect when being filled into nonpolar rubber.

Referring to fig. 2, a second aspect of the present application provides a modified gas slag separation and utilization system, comprising:

Preferably, the mill is an air flow mill, and it is understood that the gas slag and modifier are mixed and then fed into the air flow mill through a feed pipe, and the gas provided by an external gas source also enters the air flow mill. According to the application, the high-speed gas is used for carrying material particles to grind and modify the tank body, and the material particles are scattered by the gas in the grinding process, so that the phenomenon of uneven modification effect caused by particle aggregation can be well avoided. In addition, the elutriation area passing through the primary or secondary air classifier also has the processes of breaking, grinding and modifying and separating quality, thus being capable of greatly improving the uneven modifying effect.

In some embodiments, a screw feeder is provided for effecting proportional mixing of the gas-slag and modifier and feeding both into the mill via a material conveying device (e.g., conveyor belt, conveyor pipe, etc.).

In some examples, the interior of the primary air classifier or the secondary air classifier is a elutriation zone and a classification zone in sequence from bottom to top.

Preferably, the material inlet of the primary air classifier or the secondary air classifier is below the side face of the primary air classifier or the secondary air classifier body. So as to fully improve the material floating height, increase the dispersity of the material in the elutriation area and strengthen the secondary separation, and fully disperse and secondarily separate the material in the elutriation area, thereby improving the particle size and the ash grade efficiency of the carbon.

Preferably, the guide vane is arranged in the tangential direction of the air flow of the air material inlet of the primary air classifier or the secondary air classifier. The guide vane with the optimized design shown in the figure 3 can enable the airflow field in the grading machine to be relatively stable, reduce the generation of vortex and ensure the material to be fully dispersed and secondarily separated in the elutriation area, thereby improving the grading efficiency. In some examples, the guide vanes are perpendicular to the lower wall or base of the primary or secondary air classifier, at an angle of 20 ° -60 °, and the number of vanes is 5-40.

In the application, in the diversion area formed by the diversion blades of the primary air classifier, fine particles are further crushed and elutriated between particles, particles and the wall of the diversion area under the action of gravity and centrifugal force, and coarse materials collected under the primary air classifier can be preferably returned into a grinder for grinding and modifying again according to different particle size properties. The residual fine materials are entrained with high-speed gas and enter a secondary gas flow classifier.

In the application, in a diversion area formed by the guide vanes of the secondary air classifier, high-speed gas with ultrafine particles is crushed and elutriated to further finish the dissociation of carbon ash, and modified lean carbon slag is collected below the secondary air classifier according to different carbon content and ash content and density difference of the carbon ash by adjusting parameters of the air classifier.

In some embodiments, the gas-solid separator includes a cyclone separator and a dust collector (e.g., a bag-type dust collector) connected with the cyclone separator, and the specific structure is not described in detail even if it is referred to in the prior art. The high-speed gas carries ultrafine particles to enter a cyclone separator, and modified ultrafine carbon-rich slag is collected below the cyclone separator and a bag-type dust collector.

The application is further illustrated by the following examples:

example 1

The application provides a method for preparing a rubber reinforcing filler by modifying and sorting coal gasification slag, which comprises the following steps of:

(1) The mass addition proportion of the aluminate coupling agent in the Xinjiang coal gasification fine slag is determined to be 8% through a pre-experiment.

(2) And (3) feeding the gasified fine slag and 8% of aluminate coupling agent into an air flow mill through a material conveying device, wherein the feeding speed of the gasified fine slag and the solid modifying agent (aluminate coupling agent) is 0.6kg/min, the air flow speed is 20m/s, and the gasified fine slag and the solid modifying agent are fully ground and modified to the grain size of no more than 12.44 mu m, so that the modified slag is prepared.

(3) Sending the modified slag material processed in the step (2) into a primary air classifier (with the frequency of 170 Hz), collecting coarse materials (with the particle size of more than or equal to 10 mu m) and fine materials with the particle size of less than 10 mu m below the primary air classifier according to the properties of different particle sizes, and refluxing the coarse materials to a grinder for modification again;

(4) The high-speed gas entrains fine materials (particle size is less than 10 mu m) and enters a secondary air flow classifier (frequency is 100 Hz), and modified lean carbon slag is collected and obtained below the secondary air flow classifier according to different carbon content and ash content;

(5) The high-speed gas entrains ultrafine particles to enter a cyclone separator, modified ultrafine carbon-rich slag is collected below the cyclone separator and a bag-type dust collector, and the parameter of a draught fan connected with the bag-type dust collector is 30Hz. The product performance data are shown in tables 1-2.

TABLE 1 preparation of rubber reinforcing filler by Xinjiang slag separation

The formula comprises the following components: NR 100, a filler 20, zinc oxide 5, stearic acid 2, a promoter CZ 0.8, an anti-aging agent RD 1 and sulfur 2.5; the formula is the rubber formula adopted in the embodiment, and the modified superfine carbon-rich slag and the modified carbon-poor slag obtained in the embodiment are used as rubber fillers.

Table 2 filled natural rubber composite properties

Example 2

The application provides a method for preparing rubber reinforcing filler by modifying and sorting coal gasification slag, which comprises the following steps of:

(1) The mass adding proportion of the aluminate coupling agent in the elm coal gasification coarse slag is determined to be 10% through a pre-experiment.

(2) Feeding the elm gasification coarse slag and 10% of aluminate coupling agent into an air flow mill through a material conveying device, wherein the feeding speed of gasification fine slag and solid modifying agent (aluminate coupling agent) is 0.6kg/min, the gas flow speed is 20m/s, and the mixture is fully ground and modified until the particle size is no more than 11.25 mu m, so as to prepare modified slag.

(3) Sending the modified slag material processed in the step (2) into a primary air classifier (frequency is 160 Hz), collecting coarse materials (particle size is more than or equal to 10 mu m) and fine materials with particle size less than 10 mu m below the primary air classifier according to different particle size properties, and refluxing the coarse materials to a grinder for modification again;

(5) The high-speed gas entrains ultrafine particles to enter a cyclone separator, and modified ultrafine carbon-rich slag is collected below the cyclone separator and a bag-type dust collector. The induced draft fan connected with the bag-type dust collector has the parameter of 30Hz. The product performance data are shown in tables 3-4. The rubber formulation was the same as in example 1, and the modified ultrafine carbon-rich slag and modified carbon-lean slag obtained in this example were used as rubber fillers.

Table 3 preparation of rubber reinforcing filler by separation of elm coarse slag

Table 4 filled natural rubber composite properties

Example 3

(1) The mass addition proportion of the aluminate coupling agent in the Xinjiang coal gasification fine slag is determined to be 3% through a pre-experiment.

(2) And (3) feeding the gasified fine slag and 3% of aluminate coupling agent into an air flow mill through a material conveying device, adjusting the feeding speed to be 1kg/min, and the air flow speed to be 5m/s, and fully grinding and modifying until the grain size is no more than 35 mu m, so as to obtain modified slag.

(3) Sending the modified slag material processed in the step (2) into a primary air classifier, collecting coarse materials (the particle size is more than or equal to 20 mu m) and fine materials with the particle size less than 20 mu m below the primary air classifier (the frequency is 130 Hz) according to the properties of different particle sizes, and refluxing the coarse materials to a grinder for modification again;

(4) The high-speed gas entrains fine materials (particle size is less than 20 mu m) and enters a secondary air flow classifier (frequency is 125 Hz), and modified lean carbon slag is collected and obtained below the secondary air flow classifier according to different carbon content and ash content;

(5) The high-speed gas entrains ultrafine particles to enter a cyclone separator, and modified ultrafine carbon-rich slag is collected below the cyclone separator and a bag-type dust collector. The product performance data are shown in tables 5-6. The rubber formulation was the same as in example 1, and the modified ultrafine carbon-rich slag and modified carbon-lean slag obtained in this example were used as rubber fillers.

TABLE 5 preparation of rubber reinforcing filler by Xinjiang slag separation

Table 6 filled natural rubber composite Properties

The two filler particle sizes obtained in example 3 are larger than the filler particle size obtained in example 1; meanwhile, the addition amount of the aluminate coupling agent in the embodiment 3 is 3%, the addition amount is slightly low, the contact angle is smaller, the surface of the filler cannot be changed from polarity to non-polarity, the compatibility of the filler and a natural rubber matrix is poor due to the two reasons, and the rubber is finally poor in mechanical property.

Comparative example 1 (without modifier)

(1) And feeding the gasified coarse slag into an air flow mill through a material conveying device, adjusting the feeding speed to be 0.6kg/min and the air flow speed to be 20m/s, and fully grinding the modified grain size to be no more than 12 mu m to prepare slag.

(2) Feeding the slag material processed in the step (1) into a primary air classifier (frequency is 160 Hz), collecting coarse materials (particle size is more than or equal to 10 mu m) and fine materials (particle size is less than 10 mu m) below the primary air classifier according to different particle size properties, and refluxing the coarse materials to a grinder for grinding again;

(3) The high-speed gas entrains fine materials (particle size is less than 10 mu m) and enters a secondary air flow classifier (frequency is 100 Hz), and lean carbon slag is collected and obtained below the secondary air flow classifier according to different carbon content and ash content;

(4) The high-speed gas entrains ultrafine particles to enter a cyclone separator, and ultrafine carbon-rich slag is collected below the cyclone separator and a bag-type dust collector. The product performance data are shown in tables 7-8. The rubber formulation was the same as in example 1, and the ultra-fine carbon-rich slag and the carbon-poor slag obtained in this comparative example were used as rubber fillers.

Table 7 preparation of rubber reinforcing filler by separation of elm coarse slag

Table 8 filled natural rubber composite properties

Comparative example 1 has a similar particle size to that of example 1, but comparative example 1 does not add an aluminate coupling agent and does not change the surface of the filler from polar to non-polar. The filler and the natural rubber matrix have poor compatibility, and finally the rubber has poor mechanical properties.

In summary, the application carries out grinding modification on the gas slag, realizes the particle size classification and the carbon ash separation by adopting gravity separation in the airflow separation process, and fully recycles the raw gas slag, thus preparing the modified superfine carbon-rich slag (carbon content is more than 60 percent) and the modified lean carbon slag (carbon content is less than 20 percent). The particle size is an important index for rubber filler, the gasified slag is firstly ground and modified, and then the subsequent air flow classification procedure is carried out, so that the difficulty of modification of the superfine powder is overcome, and the whole preparation process is simple and efficient. Finally, according to the density/granularity difference of the carbon ash, the modified superfine gasification slag is subjected to high-efficiency carbon ash separation in an optimized and improved air classifier (for example, guide vanes are additionally arranged at a material inlet of the air classifier along the tangential direction of air flow, or a vertical air classifier is adopted, the inclination angle of the vanes and the number of the vanes are optimized in the embodiment 1 shown in fig. 3, the inclination angle is 35 degrees, and the number of the vanes is 8), so that modified superfine carbon-rich slag and modified lean carbon slag products are obtained. The modified superfine carbon-rich slag can be used as a substitute product of carbon black in rubber reinforcing filler, and the modified carbon-lean slag product can be used as a substitute product of white carbon black in rubber reinforcing filler, so that the aim of utilizing the gas slag in a large scale is fulfilled.

It is to be understood that the above examples of the present application are provided by way of illustration only and not by way of limitation of the embodiments of the present application. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. Not all embodiments are exhaustive. All obvious variations or modifications which come within the spirit of the application are desired to be protected.

Claims

1. The modified separation and utilization method for the gas slag is characterized by comprising the following steps of:

2. The method for modifying and sorting the gas slag according to claim 1, wherein in the step 1), the solid modifier is one or a combination of a plurality of silane coupling agents, aluminate coupling agents, titanate coupling agents, stearic acid and alkali activating agents.

3. The method for modifying and sorting and utilizing the gas slag according to claim 1 or 2, wherein in the step 1), the addition amount of the solid modifier is 0.1% -15%, preferably 6% -12% of the mass of the gas slag to be modified.

4. The modified gas slag separation and utilization method according to any one of claims 1-3, wherein in the step 1), the grinding is an air flow mill, and the grinding is carried out until the particle size of the material is no more than 0.15mm.

5. The modified separation and utilization method of the gas slag according to claim 1, wherein in the step 2), the particle size of the coarse material is larger than the reference particle size, the particle size of the fine material is smaller than the reference particle size, and the reference particle size is 5-74 μm; preferably, the reference particle size is 10 μm, the particle size of the coarse material is not less than 10 μm, and the particle size of the fine material is less than 10 μm.

6. The method for modified separation and utilization of gas slag according to claim 1, wherein the step 2) further comprises the step of returning the coarse material to the step 1) for grinding again.

7. The utility model provides a modified separation utilization system of coal gas slag which characterized in that includes:

8. The system of claim 1, wherein the material inlet of the primary air classifier or the secondary air classifier is below the side of the primary air classifier or the secondary air classifier body.

9. The modified and sorting utilization system of the gas slag according to claim 8, wherein guide vanes are arranged in the tangential direction of the gas flow of the gas material inlet of the primary gas flow classifier or the secondary gas flow classifier; preferably, the guide vanes are perpendicular to the base of the primary air classifier or the secondary air classifier, the inclination angle is 20-60 degrees, and the number of the vanes is 5-40.

10. The system of claim 1, wherein the gas-solid separator comprises a cyclone separator and a dust separator.