Coking inhibitor and preparation method thereof

Abstract

The invention discloses a coking inhibitor and a preparation method thereof. The coking inhibitor comprises a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance, and the valence of the sulfur element in the sulfur-containing substance is negative bivalence or zero valence. Therefore, by adopting the coking inhibitor provided by the invention, the melting point of the coking body can be reduced, the coking body is promoted to be melted, and the occurrence of a coking phenomenon is favorably inhibited.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical material production, and in particular relates to a coking inhibitor and a preparation method thereof. Background Art

[0002] Coking refers to the deposition of ash in a molten state on the heating surface, which usually occurs in smelting boilers. Taking the copper smelting furnace as an example, as the copper smelting matte smelting proceeds, coking will occur on the ascending flue of the copper smelting furnace and the inner wall of the boiler. In particular, thick and large coking bodies are easily formed inside the ascending flue of the copper smelting furnace. These coking bodies will destroy normal combustion conditions, reduce boiler output, and cause pipe burst accidents. In severe cases, the furnace outlet will be blocked and the furnace will be forced to shut down.

[0003] However, the existing methods are not effective in inhibiting coking. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present application provides a coking inhibitor and a preparation method thereof, wherein the coking inhibitor can effectively inhibit the occurrence of coking.

[0005] In a first aspect of the present invention, a coking inhibitor is provided, which includes a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero.

[0006] According to the coking inhibitor of the above embodiment of the present invention, the addition of the reducing agent can reduce the high melting point compound in the coke body to a low melting point compound, and the valence of the sulfur element in the sulfur-containing substance is negative divalent and zero valence, so the sulfur-containing substance has both a sulfurizing effect and can combine with the impurities in the coke body, and a reducing effect that can further promote the conversion of the high melting point compound in the coke body to a low melting point compound, and the silicon-containing substance and the calcium-containing substance have a slag-forming effect and can combine with the reduced low melting point compound to promote the melting of the coke body. Therefore, the coking inhibitor provided by the present invention can reduce the melting point of the coke body, promote the melting of the coke body, and help inhibit the occurrence of coking.

[0007] In addition, the coking inhibitor according to the above embodiment of the present invention may also have the following additional technical features:

[0008] In some embodiments of the present invention, based on the total mass of the coking inhibitor, the mass percentages of the components in the coking inhibitor are: 20%-60% of reducing agent, 6%-30% of sulfur-containing substance, 20%-40% of silicon-containing substance and 10%-15% of calcium-containing substance. This is beneficial to lower the melting point of the coking body, thereby promoting the melting of the coking body.

[0009] In some embodiments of the present invention, the reducing agent includes at least one of carbon, graphite and coal, thereby facilitating the reduction of high melting point compounds in the coke body into low melting point compounds, thereby facilitating the reduction of the melting point of the coke body.

[0010] In some embodiments of the present invention, the sulfur-containing substance includes at least one of pyrite, chalcopyrite and matte. Thus, the high melting point compounds in the coke body can be promoted to transform into low melting point compounds, which is beneficial to lowering the melting point of the coke body.

[0011] In some embodiments of the present invention, the sulfur-containing substances include pyrite, chalcopyrite and matte. Thus, the melting point of the coke body can be further reduced.

[0012] In some embodiments of the present invention, the sulfur-containing substance includes pyrite, chalcopyrite and matte, and based on the total mass of the coking inhibitor, the mass percentage of each component in the sulfur-containing reducing agent is: 2%-10% of pyrite, 2%-10% of chalcopyrite and 2%-10% of matte. This is conducive to lowering the melting point of the coked body and promoting the melting of the coked body.

[0013] In some embodiments of the present invention, based on the total mass of the coking inhibitor, the mass percentages of the components in the coking inhibitor are: 40%-50% reducing agent, 3%-6% pyrite, 3%-6% chalcopyrite, 3%-6% matte, 25%-30% silicon-containing material, and 11%-12% calcium-containing material. Thus, the melting of the coking body can be further promoted, which is beneficial to inhibiting the occurrence of coking.

[0014] In some embodiments of the present invention, the silicon-containing material includes at least one of quartz, silicic acid, and silicate, so that it can be combined with the reduced low-melting-point compound, which is beneficial to promote the melting of the coke body.

[0015] In some embodiments of the present invention, the calcium-containing substance includes at least one of lime, quicklime and soda lime, so that it can be combined with the reduced low-melting-point compound, which is beneficial to promote the melting of the coke body.

[0016] In some embodiments of the present invention, the average particle size of the coking inhibitor is 80-1100 mesh, and can be 200-800 mesh, thereby increasing the contact area between the coking inhibitor and the coke body, which is beneficial to lowering the melting point of the coke body.

[0017] In a second aspect of the present invention, the present invention provides a method for preparing the above-mentioned coking inhibitor. According to an embodiment of the present invention, the method comprises mixing a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance to obtain the coking inhibitor, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero valent. Thus, by adopting the method provided by the present invention, a coking inhibitor with good uniformity can be obtained, which is conducive to reducing the melting point of the coked body.

[0018] In some embodiments of the present invention, the mixing time is not less than 60 minutes, which is conducive to obtaining a uniformly mixed coking inhibitor, and further conducive to reducing the melting point of the coked body.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 A graph showing the change of coke mass with temperature when no coke inhibitor is used;

[0022] Figure 2 The graph shows the change of the coking body with temperature after the coking inhibitor provided by the present invention is used. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0024] Coking refers to the deposition of ash in a molten state on the heating surface, which usually occurs in smelting boilers. Taking the copper smelting furnace as an example, as the copper smelting matte smelting proceeds, coking will occur on the ascending flue of the copper smelting furnace and the inner wall of the boiler. In particular, thick and large coking bodies are easily formed inside the ascending flue of the copper smelting furnace. These coking bodies will destroy normal combustion conditions, reduce boiler output, and cause pipe burst accidents. In severe cases, the furnace outlet will be blocked and the furnace will be forced to shut down.

[0025] The main reason for the formation of coking in the ascending flue of a copper smelting furnace is that the ascending flue temperature is high (1200℃), and there are molten or semi-molten oxides of metals such as lead, zinc, and iron, as well as compounds such as silicates and sulfates in the flue gas. As the flue gas moves, it collides and adheres to the flue wall, and gradually increases, leading to the occurrence of coking.

[0026] At present, the industry mainly alleviates the impact of coking on production by adding coking inhibitors or adding decoking equipment. Specifically, (1) adding coking inhibitors: by adding inhibitors that increase the melting point of the coke body, the coke body is no longer in a molten / semi-molten state with high adhesion, thereby reducing its adsorption of fine particles in the smoke and reducing the coke body. Although this method can inhibit the occurrence of coking to a certain extent, it can only prolong the time of coking formation, and it is difficult to fundamentally inhibit the accumulation and growth of the coking layer, and it is impossible to eliminate larger coke bodies; (2) Equipment modification method: usually add secondary anthracite or natural gas and oxygen-enriched air injection pipelines in the ascending flue area, use the heat released by combustion to increase the flue ambient temperature, and reduce the condensation and coking of molten or semi-molten particles in the flue gas on the flue wall. However, this method usually requires the modification of the original furnace body, and the subsequent maintenance cost and continuous use stability are poor, and the application effect is poor.

[0027] In short, the coke bodies cannot be effectively removed either by adding coking inhibitors to increase the melting point of the coke bodies or by upgrading the equipment.

[0028] In view of this, in one aspect of the present invention, a coking inhibitor is proposed, which includes a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero.

[0029] According to the coking inhibitor of the above embodiment of the present invention, the addition of the reducing agent can reduce the high melting point compound in the coke body to a low melting point compound, and the valence of the sulfur element in the sulfur-containing substance is negative divalent and zero valence, so the sulfur-containing substance has both a sulfurizing effect and can combine with the impurities in the coke body, and a reducing effect that can further promote the conversion of the high melting point compound in the coke body to a low melting point compound, and the silicon-containing substance and the calcium-containing substance have a slag-forming effect and can combine with the reduced low melting point compound to promote the melting of the coke body. Therefore, the coking inhibitor provided by the present invention can reduce the melting point of the coke body, promote the melting of the coke body, and help inhibit the occurrence of coking.

[0030] It should be noted that, in a specific embodiment of the present invention, after phase analysis and high-temperature melting characteristics analysis of coke bodies in the ascending flue of various copper smelting furnaces, it was found that the coke bodies all contained a large amount of magnetite spinel and cuprous ferrite phases with a melting point exceeding 1500°C. This is mainly due to the relatively high oxygen potential in the ascending flue, which causes the low-valent iron oxides in the soot and splashes above the furnace to be oxidized to form trivalent iron compounds, which increases their melting temperature to form a solid-liquid coexistence state, and the adhesion is sharply enhanced, thereby forming a hard and difficult-to-peel off coke layer on the inner wall of the ascending flue and accumulating to form ultra-large blocks of refractory coke bodies.

[0031] In some embodiments of the present invention, based on the total mass of the coking inhibitor, the mass percentage of each component in the coking inhibitor is 20%-60% of the reducing agent, 6%-30% of the sulfur-containing substance, 20%-40% of the silicon-containing substance and 10%-15% of the calcium-containing substance. For example, the reducing agent can be 20%, 30%, 40%, 50%, 60%, etc.; the sulfur-containing substance can be 6%, 10%, 15%, 20%, 25%, 30%, etc.; the silicon-containing substance can be 20%, 25%, 30%, 35%, 40%, etc.; the calcium-containing substance can be 10%, 11%, 12%, 13%, 14%, 15%, etc. Therefore, limiting the mass percentage of each component in the coking inhibitor within the above range can further reduce the melting point of the coking body, promote the melting of the coking body, effectively remove the coking body and inhibit the occurrence of coking. The reducing agent can be selected as 40%-50%, the silicon-containing substance can be selected as 25%-30%, and the calcium-containing substance can be selected as 11%-12%.

[0032] In some embodiments of the present invention, the reducing agent includes at least one of carbon, graphite and coal. The above reducing agent can reduce the high melting point magnetite spinel phase to low melting point ferrous oxide (FeO), thereby reducing the melting point of the coke body. FeO can also combine with silicon-containing substances or calcium-containing substances to form a low melting point slag system of FeO-SiO2 or FeO-CaO-SiO2, which promotes the melting of the coke body. In addition, when the above carbon is used as a reducing agent, it can partially burn and release heat during the decoking reaction, which can increase the local temperature of the coke body, maintain the thermal balance of the ascending flue, and enhance the stability of decoking. Moreover, the above substances are common and easily available reducing agents with good reduction effect and fast rate.

[0033] In some embodiments of the present invention, the sulfur-containing substance includes at least one of pyrite, chalcopyrite and matte. The above-mentioned sulfur-containing substance contains negative divalent sulfur element, has strong reducing property, can be used as a supplement to the above-mentioned reducing agent, and is conducive to cost saving. In addition, the sulfur-containing substance also has a sulfurizing effect, and can form a sulfide with a low melting point with the reduced divalent iron, which promotes the melting of the coke body to fall into the molten pool, accelerates the melting and removal of the coke, and can also realize the sulfurization recovery of the copper mixed in the coke body. Therefore, the selection of the above-mentioned sulfur-containing substance can promote the melting of the coke body, effectively remove the coke body and inhibit the occurrence of coking phenomenon.

[0034] In some embodiments of the present invention, the sulfur-containing substances include pyrite, chalcopyrite and matte. The above-mentioned sulfides are all common raw materials and intermediate products of the copper smelting system, which are cheap and easy to obtain, and the constituent elements of the sulfides (iron, copper, etc.) are all common substances of the copper smelting system, which can form iron-silicon compounds with the coke body and melt into the slag layer of the molten pool. The formed sulfides can penetrate the slag layer and melt into the matte phase, without the introduction of new impurities, and will not affect the original smelting system. Moreover, the above-mentioned sulfur-containing substances can partially burn and release heat during the decoking reaction, which can increase the local temperature of the coke body, maintain the thermal balance of the ascending flue, and enhance the stability of decoking. Therefore, the selection of the above-mentioned substances as sulfur-containing substances can promote the melting of the coke body and effectively remove the coke body, and can also reduce the cost of coking inhibitor production.

[0035] In some embodiments of the present invention, the sulfur-containing substances include pyrite, chalcopyrite and matte. Based on the total mass of the coking inhibitor, the mass percentage of each component in the sulfur-containing substances is 2%-10% of pyrite, 2%-10% of chalcopyrite and 2%-10% of matte. For example, pyrite can be 2%, 5%, 7%, 8%, 10%, etc.; chalcopyrite can be 2%, 4%, 6%, 8%, 10%, etc.; matte can be 2%, 4%, 6%, 8%, 10%, etc. The above sulfides are all common raw materials and intermediate products of the copper smelting system, cheap and easy to obtain, and the constituent elements of sulfides (iron, copper, etc.) are all common substances of the copper smelting system, which can form iron-silicon compounds with the coking body and melt into the slag layer of the molten pool. The formed sulfides can penetrate the slag layer and melt into the matte phase, without the introduction of new impurities, and will not affect the original smelting system. In addition, limiting the mass percentage of each component in the sulfur-containing substance to the above range is conducive to further combining with the ferrous oxide produced by reduction in the coke body to form iron-silicon compounds that melt into the molten pool slag layer, thereby promoting the melting of the coke body. The pyrite can be selected at 3%-6%, the chalcopyrite can be selected at 3%-6%, and the matte can be selected at 3%-6%.

[0036] In some embodiments of the present invention, the silicon-containing material includes at least one of quartz, silicic acid, and silicate. The silicon-containing material can combine with non-copper impurity element oxides (such as FeO, CaO) in the coke body to form a slag system (FeO-SiO2 or FeO-CaO-SiO2) with low melting point and low viscosity, so as to separate the crude copper from the impurities in the coke body, and then recover the copper in the coke body, wherein quartz is a common slag-forming flux in pyrometallurgy. Therefore, the selection of the above-mentioned silicon-containing material can effectively promote the melting of the coke body and also reduce costs.

[0037] In some embodiments of the present invention, the calcium-containing substance includes at least one of lime, quicklime and soda lime. The calcium-containing substance can cooperate with the silicon-containing substance to promote the formation of a low-melting-point slag system of FeO-CaO-SiO2 after the reduction of FeO, thereby melting the coke body in the ascending flue. Therefore, the selection of the above-mentioned calcium-containing substance can effectively promote the melting of the coke body.

[0038] In some embodiments of the present invention, the average particle size of the coking inhibitor is 80-1100 mesh, for example, the average particle size can be 80 mesh, 100 mesh, 300 mesh, 500 mesh, 600 mesh, 800 mesh, 1100 mesh, etc. The appropriate average particle size is conducive to the coking inhibitor and the coking body to fully contact, so that the coking body can be melted to form small droplets, which drip into the molten pool, eliminating the influence of coking on the flue gas channel and the molten pool system. Further, the average particle size of the coking inhibitor can be selected to be 200 mesh-800 mesh.

[0039] It should be noted that average particle size refers to the general term for particle size. For example, the particle size of spherical particles is expressed by its diameter and is called "particle size". Non-spherical particles have no diameter, so the concept of "equivalent particle size" is used to describe their particle size. Different equivalent particle sizes have different physical meanings. Therefore, particle size is a general term.

[0040] In a second aspect of the present invention, the present invention provides a method for preparing the coking inhibitor described in the first aspect. According to an embodiment of the present invention, the method comprises mixing a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance to obtain the coking inhibitor, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero valent.

[0041] According to the method for preparing a coking inhibitor according to an embodiment of the present invention, the method provided by the present invention is simple and easy to operate. When the prepared coking inhibitor is combined with the coke body, the melting point of the coke body can be reduced, and the coke body will be melted to form small molten droplets, which will drip into the molten pool, eliminating the influence of coking on the flue gas channel and the molten pool system. Specifically, the coking inhibitor contains reducing substances (carbon powder and sulfur-containing substances, etc.) and slag-forming fluxes (silicon-containing substances and calcium-containing substances, etc.). After the coking inhibitor contacts and reacts with the high-melting-point component magnetite spinel in the coke body, it is reduced and forms a low-melting-point (<1200°C) compound, and then the soft molten flow drips into the molten pool and merges with the slag layer, eliminating the influence of the violent fluctuation of the molten pool slag surface and the furnace body temperature caused by the fall of the coke body. In addition, the carbon powder and sulfide can also partially burn and release heat during the decoking reaction, increase the local temperature of the coke body, maintain the thermal balance of the ascending flue, enhance the stability of decoking, and increase the life of the furnace lining. Therefore, the coking inhibitor of the present invention can reduce the melting point of the coked body, promote the melting of the coked body, and help inhibit the occurrence of coking.

[0042] In some embodiments of the present invention, the mixing time is not less than 60 minutes. For example, the mixing time can be 60 minutes, 70 minutes, 75 minutes, 80 minutes, 90 minutes, etc. Therefore, limiting the mixing time within the above range can promote uniform mixing of the components of the coking inhibitor, which is beneficial to reducing the melting point of the coked body.

[0043] The scheme of the present disclosure will be explained below in conjunction with the examples. Those skilled in the art will appreciate that the following examples are only used to illustrate the present disclosure and should not be considered to limit the scope of the present disclosure. Where specific techniques or conditions are not indicated in the examples, the techniques or conditions described in the literature in this area or the product instructions are used. Where the manufacturers of reagents or instruments are not indicated, they are all conventional products that can be obtained commercially.

[0044] Example 1

[0045] (1) mixing carbon, quartz, lime, pyrite, chalcopyrite and matte in a certain proportion for 60 minutes, and grinding to obtain a coking inhibitor with an average particle size of 300 meshes, wherein the mass percentage of each component in the coking inhibitor is 40% of carbon powder, 30% of quartz sand, 12% of lime, 6% of pyrite, 6% of chalcopyrite and 6% of matte;

[0046] (2) The prepared coking inhibitor is applied to a top-blown smelting furnace. Specifically, a conventional powder injection gun is used to spray the coking inhibitor provided in the present application into the coking-prone part of the ascending flue.

[0047] The coking inhibitors of Examples 2-33 and Comparative Examples 1-6 are the same as Example 1 except for different experimental parameters (see Table 1).

[0048] The experimental parameters of the coking inhibitors of Examples 1-33 and Comparative Examples 1-9 of the present application are shown in Table 1.

[0049] Table 1 Experimental parameters of Examples 1-33 and Comparative Examples 1-9

[0050]

[0051]

[0052] “ / ” means none.

[0053] Testing and analysis

[0054] Under the same conditions, the coking inhibitor obtained in Examples 1-33 was used in different types of copper smelting furnaces to solve the coking problem of the original ascending flue. After 20 consecutive days of use, the coking condition of the ascending flue and the blockage of the weir were observed. Figure 1The figure shows the change of the coke body with temperature when no coking inhibitor is used. It can be seen from the figure that when the temperature reaches above 1500℃, the volume of the coke body is reduced to a certain extent, but the reduction is not obvious. Figure 2 The graph of the coke body changing with temperature after the coke inhibitor provided by the present invention is used is shown. It can be seen from the figure that the volume of the coke body gradually decreases with the increase of temperature. When the temperature reaches about 1200°C, the coke body basically melts into slag. Therefore, the coke inhibitor provided by the present invention can greatly reduce the melting point of the coke body, from more than 1500°C to about 1200°C, while the normal flue gas temperature of the ascending flue is about 1250°C. Therefore, by adding the coke inhibitor of the present invention, it can be achieved that the coke material is difficult to form a block, and after falling, it melts in the molten pool slag, which will not cause the weir to be blocked in production and cause safety accidents. Among them, the indicators for evaluating the effect are: excellent: no coke layer, no non-coke body is found; good: no obvious coke layer, no non-melting large coke body is found, but there is a small amount of non-melting small coke body; medium: no coke layer, and the unmelted large coke body is significantly reduced; poor: an obvious coke layer is observed in the ascending flue, and there are large unmelted tumors in the molten pool.

[0055] The observation results are shown in Table 2.

[0056] 2 Observation results of Examples 1-33 and Comparative Examples 1-9

[0057]

[0058]

[0059] Combined with Table 2, it can be found that after using the coking inhibitor obtained in Examples 1-33, it can be found that there is no obvious coking layer in the ascending flue of the copper smelting furnace body, and no large unmelted coking bodies are found, while in Comparative Examples 1-9, no coking inhibitor provided by the present application is used, and an obvious coking layer is observed in the ascending flue, and there are large unmelted lumps in the molten pool. Therefore, the present invention adds a coking inhibitor that reduces the melting point of the large coking body to promote the large coking body to melt and drip slowly into the molten pool, thereby fundamentally eliminating the violent fluctuations of the melt and furnace ore caused by the huge coking body falling into the molten pool.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", "some implementation schemes" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0061] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A coking inhibitor, characterized in that: include: A reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero.

2. The coking inhibitor according to claim 1, characterized in that Based on the total mass of the coking inhibitor, the mass percentages of the components in the coking inhibitor are: 20%-60% of reducing agent, 6%-30% of sulfur-containing substance, 20%-40% of silicon-containing substance and 10%-15% of calcium-containing substance.

3. The coking inhibitor according to claim 1 or 2, characterized in that: The reducing agent comprises at least one of carbon, graphite and coal; and / or, The sulfur-containing substance includes at least one of pyrite, chalcopyrite and matte.

4. The coking inhibitor according to claim 1 or 2, characterized in that: The sulfur-containing substances include pyrite, chalcopyrite and matte.

5. The coking inhibitor according to claim 2, characterized in that: The sulfur-containing substances include pyrite, chalcopyrite and matte. Based on the total mass of the coking inhibitor, the mass percentage of each component in the sulfur-containing reducing agent is: 2%-10% of pyrite, 2%-10% of chalcopyrite and 2%-10% of matte.

6. The coking inhibitor according to claim 5, characterized in that Based on the total mass of the coking inhibitor, the mass percentages of the components in the coking inhibitor are: reducing agent 40%-50%, pyrite 3%-6%, chalcopyrite 3%-6%, matte 3%-6%, silicon-containing material 25%-30%, and calcium-containing material 11%-12%.

7. The coking inhibitor according to claim 1 or 2, characterized in that: The silicon-containing material includes at least one of quartz, silicic acid and silicate; and / or, The calcium-containing substance includes at least one of lime, quicklime and soda lime.

8. The coking inhibitor according to claim 1 or 2, characterized in that: The average particle size of the coking inhibitor is 80 meshes to 1100 meshes, and can be optionally 200 meshes to 800 meshes.

9. A method for preparing the association inhibitor according to claims 1-8, characterized in that: include: The coking inhibitor is obtained by mixing a reducing agent, a sulfur-containing substance, a silicon-containing substance and a calcium-containing substance, wherein the valence of the sulfur element in the sulfur-containing substance is negative divalent or zero valent.

10. The method according to claim 9, characterized in that The mixing time is not less than 60 minutes.

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