阅读说明：本技术 一种石油焦制氢灰渣的处理办法及介孔硅材料 (Method for treating petroleum coke hydrogen production ash and mesoporous silicon material ) 是由 吕灵灵 王沿森 叶阑珊 张立萍 张贝贝 于维钊 张新功 于 2020-12-16 设计创作，主要内容包括：本申请提供一种石油焦制氢灰渣的处理办法及介孔硅材料,属于石油焦制氢灰渣的处理技术领域。该处理方法包括碱处理：将石油焦制氢灰渣和碱液混合后进行碱处理,增大了灰渣的比表面积,固液分离后得到碱溶渣。酸处理：将碱溶渣和酸液混合后进行酸处理,使碱溶渣中的金属离子溶出。该方法中,碱处理可以破坏灰渣的玻璃体结构,使渣具有一定的比表面积,为后续的酸处理提供反应孔道,以便酸处理时碱溶渣中的金属离子溶出,以去除灰渣中的重金属离子。(The application provides a method for treating petroleum coke hydrogen production ash and a mesoporous silicon material, belonging to the technical field of treatment of petroleum coke hydrogen production ash. The treatment method comprises the following steps: mixing the petroleum coke hydrogen production ash with alkali liquor, then carrying out alkali treatment, increasing the specific surface area of the ash, and carrying out solid-liquid separation to obtain alkali dissolving slag. Acid treatment: mixing the alkali dissolving slag and the acid liquor, and then carrying out acid treatment to dissolve out metal ions in the alkali dissolving slag. In the method, the alkali treatment can destroy the vitreous body structure of the ash slag, so that the slag has a certain specific surface area, and a reaction pore channel is provided for subsequent acid treatment, so that metal ions in the alkali-dissolved slag are dissolved out during the acid treatment, and the heavy metal ions in the ash slag are removed.)

1. A method for treating petroleum coke hydrogen production ash is characterized by comprising the following steps:

alkali treatment: mixing the petroleum coke hydrogen production ash with alkali liquor and then carrying out alkali treatment, so that the specific surface area of the ash is increased, and carrying out solid-liquid separation to obtain alkali dissolving slag;

acid treatment: and mixing the alkali soluble slag and an acid solution, and then carrying out acid treatment to dissolve out metal ions in the alkali soluble slag.

2. The method of claim 1, wherein the alkaline treatment conditions include: treating for 1-3h under the conditions of 100-180 ℃, wherein the mass concentration of the alkali liquor is 1-10%.

3. The method of claim 2, wherein the alkaline treatment conditions include: treating for 1-3h at the temperature of 100-145 ℃, wherein the alkali liquor is strong alkali solution, and the mass concentration of the alkali liquor is 3-7%.

4. The process according to claim 3, characterized in that the strong alkaline solution is a sodium hydroxide solution or/and a potassium hydroxide solution.

5. The process of claim 1, wherein the acid treatment conditions comprise: treating at 110-160 ℃ for 0.5-3h, wherein the mass concentration of the acid solution is 5-50%.

6. The process of claim 5, wherein the acid treatment conditions comprise: treating for 0.5-3h at the temperature of 110-145 ℃, wherein the acid solution is a strong acid solution, and the mass concentration of the acid solution is 5-30%.

7. The method according to claim 6, wherein the strong acid solution is one or more of a sulfuric acid solution, a hydrochloric acid solution and a nitric acid solution.

8. The process of any one of claims 1 to 7, further comprising, before the alkali treatment, a step of subjecting the ash to a char treatment.

9. The method according to claim 8, wherein the method further comprises the step of pulverizing the ash into 50-150 μm before the step of burning the coal.

10. A mesoporous silicon material, characterized by being obtained by the treatment method of claim 8;

optionally, the specific surface area of the mesoporous silicon is 280-502m²(ii)/g, the average pore diameter is 3-10 nm.

Technical Field

The application relates to the technical field of treatment of petroleum coke hydrogen production ash, in particular to a treatment method of petroleum coke hydrogen production ash and a mesoporous silicon material.

Background

For coal gasification ash or other ash with similar properties, the main treatment mode is secondary utilization after stabilization. The main components of the coal gasification ash comprise carbon, silicon oxide, aluminum oxide, calcium oxide and the like, and heavy metals of vanadium and nickel are not contained in the coal gasification ash; although the hydrogen production process of petroleum coke is the same as the hydrogen production process of coal, the main components of the ash slag for hydrogen production of petroleum coke comprise compounds such as carbon, silicon oxide, aluminum oxide, calcium oxide, vanadium oxide, nickel oxide, iron oxide, sodium oxide and the like, wherein heavy metals such as vanadium and nickel are contained. If the stabilizing treatment is directly carried out, vanadium and nickel in the ash can not be removed.

Disclosure of Invention

The first purpose of the application is to provide a method for treating petroleum coke hydrogen production ash, which can remove heavy metals of vanadium and nickel in the petroleum coke hydrogen production ash.

The second objective of the present application is to provide a mesoporous silicon material, which is obtained by processing petroleum coke hydrogen production ash.

In a first aspect, the application provides a method for treating petroleum coke hydrogen production ash, which comprises the following steps: alkali treatment: mixing the ash and alkali liquor, carrying out alkali treatment, increasing the specific surface area of the ash, and carrying out solid-liquid separation to obtain alkali dissolving slag. Acid treatment: mixing the alkali dissolving slag and the acid liquor, and then carrying out acid treatment to dissolve out metal ions in the alkali dissolving slag.

The alkali treatment can destroy the vitreous structure of ash slag, so that the slag has a certain specific surface area, a reaction pore channel is provided for subsequent acid treatment, so that metal ions in the alkali-soluble slag are dissolved out during the acid treatment to remove heavy metal ions in the alkali-soluble slag, and after solid-liquid separation, a solid material with reduced content of the heavy metal ions or even without the heavy metal ions is obtained, and the solid material can be used as a building material raw material.

In one possible embodiment, the conditions of the alkali treatment include: treating for 1-3h at the temperature of 100-180 ℃, wherein the mass concentration of the alkali liquor is 1-10%. Under the condition, the glass structure of ash slag is easier to damage, the dissolution of silicon can be reduced to a certain degree, and the caking of alkali-soluble slag can be avoided.

In one possible embodiment, the conditions of the alkali treatment include: treating for 1-3h at the temperature of 100-145 ℃, wherein the alkali liquor is strong alkali solution, and the mass concentration of the alkali liquor is 3-7%. The strong alkaline solution can make the treatment conditions more easily accessible, so as to reduce the treatment cost.

In one possible embodiment, the strong alkaline solution is a sodium hydroxide solution or/and a potassium hydroxide solution.

In one possible embodiment, the acid treatment conditions include: treating at 110-160 deg.C for 0.5-3h, wherein the acid solution has a mass concentration of 5-50%. Under the condition, the heavy metal ions in the alkali slag can be removed more thoroughly.

In one possible embodiment, the acid treatment conditions include: treating at 110-145 ℃ for 0.5-3h, wherein the acid solution is a strong acid solution, and the mass concentration of the acid solution is 5-30%. The strong acid solution can make the treatment condition easier to reach so as to reduce the treatment cost.

In one possible embodiment, the strong acid solution is one or more of a sulfuric acid solution, a hydrochloric acid solution, and a nitric acid solution.

In a possible embodiment, before the alkali treatment, the method further comprises the step of performing a charcoal burning treatment on the ash. The carbon component in the ash can be removed by burning the ash, and the nickel sulfide in the ash can be converted into nickel oxide, and the vanadium ion oxide with low valence state (the vanadium ion oxide with less than 5 valence state) is converted into the vanadium ion oxide with high valence state (the vanadium ion oxide with 5 valence state). The carbon does not wrap the glass body after the carbon burning treatment, so that the mass transfer of alkali is facilitated, the structure of the glass body is easy to break during the alkali treatment, more than 90% of vanadium in the burnt ash can be dissolved out, and most or even all metal ions in the alkali-dissolved slag are removed through the acid treatment to obtain the mesoporous silicon material which is a high-value byproduct and is beneficial to resource utilization of the ash.

In a possible embodiment, before the charcoal burning, the method also comprises the step of crushing the ash into the particle size of 50-150 μm.

After crushing, the efficiency of the carbon burning, alkali treatment and acid treatment is higher, and the mesoporous silicon material with high specific surface area can be obtained.

In a second aspect, the present application provides a mesoporous silicon material obtained by the above treatment method.

In one possible embodiment, the specific surface area of the mesoporous silicon is 280-502m²(ii)/g, the average pore diameter is 3-10 nm. The mesoporous silicon material has large specific surface area and small average pore diameter, and the obtained mesoporous silicon material is not easy to collapse and is beneficial to subsequent use.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments are briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive efforts and also belong to the protection scope of the present application.

Fig. 1 is a flowchart of a method for preparing a mesoporous silica material using petroleum coke hydrogen production ash provided by the present application;

FIG. 2 is a flow diagram of a process for treating petroleum coke hydrogen production ash provided herein;

FIG. 3 is a scanning electron microscope photograph of ash particles after burning before alkali treatment in Experimental example 1;

FIG. 4 is a scanning electron microscope photograph of the burned ash after alkali treatment in Experimental example 1;

FIG. 5 is an XRD pattern of a burned ash before and after an alkali treatment in Experimental example 1;

FIG. 6 is a scanning electron microscope image of mesoporous silicon material in Experimental example 1;

FIG. 7 is a graph showing the distribution of pore diameters of mesoporous silicon material in Experimental example 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

Main part of petroleum coke gasification ashThe main components are compounds such as carbon, silicon oxide, aluminum oxide, calcium oxide, vanadium oxide, nickel sulfide, iron oxide and the like, the carbon in the ash accounts for the main part and contains heavy metals nickel and vanadium, and the ash belongs to hazardous waste solid wastes and needs to be treated. Due to the special process of ash slag in the generation process (molten slurry enters a water cooling system at the high temperature of 1400 ℃), the ash slag has a vitreous body structure (a silicon-aluminum ceramic structure coated by carbon), and the specific surface area of the petroleum coke hydrogen production ash slag is less than 5m²/g。

The application provides a method for preparing a mesoporous silicon material by using petroleum coke hydrogen production ash. Wherein, fig. 1 is a flow chart of a method for preparing mesoporous silicon material by using petroleum coke hydrogen production ash. Referring to fig. 1, the method includes the following steps:

s10, crushing the petroleum coke hydrogen production ash into ash particles with the particle size of 50-150 mu m, which is beneficial to subsequent treatment. Wherein, wet grinding, dry grinding and other means can be adopted for processing. Alternatively, the particle size of the ash particles may be 50-80 μm, 80-110 μm, 110-.

S20, charring the ash particles to obtain burnt ash. On the one hand, the carbon component in the ash particles can be removed, the carbon does not wrap a vitreous body structure (a silicon-aluminum structure), nickel sulfide in the ash can be converted into nickel oxide, and vanadium ion oxide with a low valence state (vanadium ion oxide with a lower valence state than 5) is converted into vanadium ion oxide with a high valence state (vanadium ion oxide with a valence state of 5).

And S30, performing alkali treatment on the burned ash. Optionally, mixing the ash and the alkali liquor and then carrying out alkali treatment, so that the specific surface area of the ash is increased, and carrying out solid-liquid separation to obtain alkali dissolving slag and an alkali solution.

Because of the carbon burning treatment, on one hand, the carbon can not wrap the glass body, which is beneficial to the mass transfer of alkali, and the glass body structure is easy to be damaged during the alkali treatment; on the other hand, the low-valence vanadium ion oxide is converted into high-valence vanadium ion oxide, and more than 90% of vanadium in the burnt ash can be dissolved out in the alkali treatment process. And in the process of destroying the vitreous body structure and dissolving out vanadium ions, the specific surface area of ash can be increased, and a reaction pore channel is provided, so that the subsequent acid treatment is facilitated.

Alternatively, the conditions of the alkali treatment include: treating for 1-3h at the temperature of 100-180 ℃, wherein the mass concentration of the alkali liquor is 1-10%. Under the condition, the glass body structure of ash slag is easier to destroy, so that the purpose of pore forming is achieved, the dissolution of silicon can be reduced to a certain extent, and the caking of alkali-soluble slag can be avoided.

In some possible embodiments, the temperature of the alkali treatment may be 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃ or 180 ℃; the time of the alkali treatment can be 1h, 1.5h, 2h, 2.5h or 3 h; the mass concentration of the alkali liquor can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

Further, the conditions of the alkali treatment include: treating for 1-3h at the temperature of 100-145 ℃, wherein the alkali liquor is strong alkali solution, and the mass concentration of the alkali liquor is 3-7%. The strong alkali solution can enable the treatment condition to be more easily achieved so as to reduce the treatment cost, and the strong alkali solution with low mass concentration is not easy to dissolve silicon (the silicon dissolution rate is less than 5 percent) so as to improve the yield of the mesoporous silicon material.

In the embodiment of the application, the strong alkali solution is sodium hydroxide solution or/and potassium hydroxide solution. For example: the strong alkali solution is sodium hydroxide solution, or the strong alkali solution is potassium hydroxide solution, or the strong alkali solution is a mixture of the sodium hydroxide solution and the potassium hydroxide solution.

In other embodiments, the lye may also be a solution of potassium carbonate or/and sodium carbonate, but not as effective as a solution of a strong base.

And S40, carrying out acid treatment on the alkali dissolving slag. Optionally, the alkali slag and the acid solution are mixed and then subjected to acid treatment, so that metal ions (especially aluminum ions) in the alkali slag are dissolved out, and the mesoporous silicon material is obtained after solid-liquid separation.

And then, most or even all metal ions in the alkali slag are removed through acid treatment, so that the specific surface area of the material is further increased, and the mesoporous silicon material is obtained, is a high-value byproduct and is beneficial to resource utilization of ash slag.

Alternatively, the acid treatment conditions include: treating at 110-160 deg.C for 0.5-3h, wherein the acid solution has a mass concentration of 5-50%. Under the condition, the heavy metal ions in the alkali slag can be removed more thoroughly.

In some possible embodiments, the temperature of the acid treatment is 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃ or 160 ℃; the treatment time is 0.5h, 1h, 1.5h, 2h, 2.5h or 3 h; the acid solution has a mass concentration of 5%, 10%, 20%, 30%, 40% or 50%.

The acid treatment conditions include: treating at 110-145 ℃ for 0.5-3h, wherein the acid solution is a strong acid solution, and the mass concentration of the acid solution is 10-15%. Under the condition, the removal rate of heavy metal ions in the alkali slag is higher (the dissolution rates of aluminum, iron, nickel and the like are all over 90 percent), and the collapse of a mesoporous structure can be avoided, so that the mesoporous silicon material with high specific surface area is obtained.

In the embodiment of the application, the strong acid solution is one or more of a sulfuric acid solution, a hydrochloric acid solution and a nitric acid solution. For example: the strong acid solution is a sulfuric acid solution; or the strong acid solution is hydrochloric acid solution; or the strong acid solution is a nitric acid solution; or the strong acid solution is a mixture of a sulfuric acid solution and a nitric acid solution, and the like.

Fig. 2 is a flow chart of a treatment method of petroleum coke hydrogen production ash provided by the application. Referring to fig. 2, in this embodiment, the hydrogen production ash from petroleum coke is not subjected to a carbon burning treatment, and the main purpose is not to obtain mesoporous silicon material, but to remove metal ions (especially heavy metal ions) in the ash.

In this example, no charcoal-burning treatment was performed before the alkali treatment. In the alkali treatment (the conditions of the alkali treatment are the same as those described above), the vanadium ions in the ash are not substantially eluted, but the vitreous structure of the ash is still destroyed, and the purpose of forming pores is achieved, so that the metal ions (particularly, the heavy metal vanadium ions and nickel ions) in the ash are eluted in the subsequent acid treatment (the conditions of the acid treatment are the same as those described above) to obtain a solid material containing a carbon-silica-alumina structure, which can be used as a building material.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Experimental example 1 preparation of mesoporous silicon

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 3%, treating for 1h at the temperature of 90 ℃, carrying out solid-liquid separation to obtain alkali dissolving slag, and dissolving the alkali dissolving slag. Mixing the alkali slag with a sulfuric acid solution with the mass concentration of 10%, treating for 1h at the temperature of 135 ℃, and carrying out solid-liquid separation to obtain the mesoporous silicon material. The contents of the respective components in the ash before and after the alkali treatment and the specific surface area of the ash were measured as shown in Table 1. The detection method of the content of each component is as follows: firstly, respectively carrying out microwave digestion on the ash before and after acid treatment, then detecting the ion content in the ash by an inductively coupled plasma emission spectrometer, and then calculating the dissolution rate. And the specific surface area of the ash was measured by a micromeritics ASAP 2460 specific surface analyzer.

TABLE 1 content of each component in ash before and after alkali treatment and specific surface area

Principal Components	SiO2	Al2O3	Na2O	V2O5	Specific surface area
						Before alkali dissolution	50.26	17.65	1.23	4.83	3m2/g
After alkali dissolution	46.35	17.50	12.15	1.07	87m2/g
						Dissolution rate	7.78％	0.85％	/	77.85％	/

As can be seen from table 1, after the alkali treatment, the vanadium elution rate of the ash subjected to the charring was high, the silicon elution rate was low, aluminum was hardly eluted, and the specific surface area of the ash was increased.

FIG. 3 is a scanning electron microscope picture of burned ash particles before alkali treatment, and FIG. 4 is a scanning electron microscope picture of burned ash particles after alkali treatment. As can be seen from the comparison between fig. 3 and 4, the specific surface area of the alkali slag increases after the alkali treatment.

FIG. 5 is an XRD pattern of the burned ash before and after the alkali treatment. As can be seen from fig. 5, after the alkali treatment, a sodium aluminosilicate diffraction peak appeared, indicating the formation of crystalline aluminosilicate. After crystalline aluminosilicate is formed, aluminum is removed through subsequent acid treatment, and the mesoporous silicon material can be obtained.

The contents of the respective components in the ash before and after the acid treatment were measured and the dissolution rate was calculated, and the specific surface areas of the ash before and after the acid treatment were measured as shown in table 2.

TABLE 2 content of each component in ash before and after acid treatment and specific surface area

Principal Components	Aluminium	Iron	Nickel (II)	Vanadium oxide	Specific surface area
						Before acid dissolution/%)	16.44	8.83	1.23	1.07	87m2/g
After acid dissolution/%)	1.28	2.95	0.09	0.19	487m2/g
						Dissolution rate/%)	96.1	83.3	96.4	91.1

As can be seen from Table 2, after the acid treatment, most of Al, Ni, Fe and V in the ash are dissolved out, and the mesoporous silicon material with larger specific surface area is obtained.

Fig. 6 is a scanning electron microscope picture of the mesoporous silicon material, and fig. 7 is a distribution diagram of the pore diameter of the mesoporous silicon material. As can be seen from fig. 6 and 7, the mesoporous silicon material has rich pores, a large specific surface area, and an average pore diameter of about 4.4 nm.

Experimental example 2 conditions of alkali treatment

Pulverizing the hydrogen-making ash of petroleum coke into ash particles with particle size of 50-70 μm, performing charring treatment (or not), and burning the ash (specific surface area of 2-3 m)²/g) is mixed with sodium hydroxide solution with the mass concentration of 1-9 percent, the mixture is treated for 2 hours at the temperature of 90 ℃, and alkali dissolving slag is obtained after solid-liquid separation. The vanadium leaching rate in the ash before and after the alkali treatment and the specific surface area of the ash were measured and calculated as shown in table 3.

TABLE 3 vanadium leaching rate and specific surface area of ash before and after alkali treatment (different alkali concentrations)

As can be seen from Table 3, the vanadium leaching rate of the ash can be increased and the specific surface area of the alkali leaching slag can be increased by performing the coke-burning treatment and then performing the alkali treatment. And when the mass concentration of the sodium hydroxide solution is 3-7%, the alkali treatment effect is better.

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 5%, treating for 2h at the temperature of 30-180 ℃, and carrying out solid-liquid separation to obtain alkali dissolving slag. The leaching rate of vanadium in the ash before and after the alkali treatment and the specific surface area of the ash were measured and calculated as shown in table 4.

TABLE 4 dissolution rate of vanadium in ash before and after alkali treatment (different alkali treatment temperature)

As can be seen from Table 4, when the temperature of the alkali treatment is 90-150 ℃, the dissolution rate of vanadium in the ash can be higher, and the specific surface area of the alkali-dissolved slag is larger. The temperature is too low, the alkali dissolution treatment effect is poor, the vanadium dissolution rate is low, and the specific surface area is small; the excessive high temperature can cause excessive structural damage of the vitreous body and collapse of the structure, and the specific surface area is reduced.

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 5%, treating for 1-3h at the temperature of 120 ℃, and carrying out solid-liquid separation to obtain alkali dissolving slag. The leaching rate of vanadium in the ash before and after the alkali treatment and the specific surface area of the ash were measured and calculated as shown in table 5.

TABLE 5 dissolution rate of vanadium in ash before and after alkali treatment (different alkali treatment time)

Time of alkali treatment	1	2	3
				Dissolution rate of vanadium	73％	87％	90.4％
Specific surface area after alkali treatment	14m2/g	77m2/g	81m2/g

As can be seen from Table 5, when the alkali treatment time is 2-3h, the dissolution rate of vanadium in the ash can be higher, and the specific surface area of the alkali-dissolved slag is larger.

Experimental example 3 conditions of acid treatment

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 3%, treating for 1h at the temperature of 90 ℃, carrying out solid-liquid separation to obtain alkali dissolving slag, and dissolving the alkali dissolving slag. Mixing the alkali dissolving slag with a sulfuric acid solution with the mass concentration of 10-20%, treating for 1h at the temperature of 135 ℃, and carrying out solid-liquid separation to obtain the mesoporous silicon material. The silicon content in the ash before and after the acid treatment was measured, the silicon dissolution rate during the acid treatment was calculated, and the mesoporous silicon specific surface area was measured as shown in table 6.

TABLE 6 silicon content in ash before and after acid treatment, silicon leaching rate, and mesoporous silicon specific surface area (different acid solution concentrations)

Acid liquor concentration	5％	10％	15％	20％
					Silicon content before acid dissolution/%)	46.35	46.35	46.35	46.35
Silicon content after acid dissolution/%)	89.6	91.31	93.56	95.47
					Silicon dissolution rate/%)	0.04	0.03	0.05	0.02
Specific surface area of mesoporous silicon	256m2/g	394m2/g	356m2/g	312m2/g

As can be seen from Table 6, almost no silicon was lost during the acid treatment. When the concentration of the acid liquid is 10-20%, the specific surface area of the mesoporous silicon material is larger.

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 3%, treating for 1h at the temperature of 90 ℃, carrying out solid-liquid separation to obtain alkali dissolving slag, and dissolving the alkali dissolving slag. Mixing the alkali slag with a sulfuric acid solution with the mass concentration of 10%, treating for 1h at the temperature of 25-160 ℃, and carrying out solid-liquid separation to obtain the mesoporous silicon material. The silicon dissolution rate during acid treatment and the specific surface area of the mesoporous silicon after acid treatment were measured and calculated as shown in table 7.

TABLE 7 silicon elution Rate and mesoporous silicon specific surface area for acid treatment (different acid treatment temperature)

As can be seen from Table 7, if the acid treatment temperature is too low, the dissolution rate of silicon is high, and silicon is hardly lost at the acid treatment temperature of 110 ℃ and 160 ℃. When the temperature of the acid treatment is 120-160 ℃, the specific surface area of the mesoporous silicon is larger.

Crushing petroleum coke hydrogen production ash into ash particles with the particle size of 50-70 mu m, carrying out charcoal burning treatment on the ash particles, then mixing the ash particles with a sodium hydroxide solution with the mass concentration of 3%, treating for 1h at the temperature of 90 ℃, carrying out solid-liquid separation to obtain alkali dissolving slag, and dissolving the alkali dissolving slag. Mixing the alkali slag with a sulfuric acid solution with the mass concentration of 10%, treating for 0.5-3h at the temperature of 135 ℃, and carrying out solid-liquid separation to obtain the mesoporous silicon material. The silicon dissolution rate during acid treatment and the specific surface area of the mesoporous silicon after acid treatment were measured and calculated as shown in table 8.

TABLE 8 silicon elution Rate and mesoporous silicon specific surface area for acid treatment (different acid treatment time)

Acid treatment time	0.5h	1h	2h	3h
					Silicon dissolution rate/%)	0.02	0.02	0.03	0.03
Specific surface area of mesoporous silicon	487m2/g	394m2/g	286m2/g	255m2/g

As can be seen from Table 8, if the acid treatment time is too long, the specific surface area of the mesoporous silicon is rather decreased, and when the acid treatment time is 0.5 to 1 hour, the specific surface area of the mesoporous silicon is large.

The embodiments described above are some, but not all embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.