Weathered coal-based potassium iron humate fire coal catalyst as well as preparation and application thereof

Abstract

The invention relates to the technical field of catalysts, in particular to a preparation method of a weathered coal-based potassium iron humate fire coal catalyst, which comprises the following steps of: adding the following components in percentage by mass into a reactor: 4-8% of weathered coal, 1-2% of potassium hydroxide, 0.01-0.05% of ferrous sulfate, 0.3-0.5% of ferric sulfate and the balance of water, stirring and reacting for 2 hours, centrifuging, reserving supernate, adjusting the pH value to 1.0-2.0, and filtering to obtain the weathered coal-based potassium iron humate fire coal catalyst. Filtering and drying to obtain the potassium iron humate. And then preparing the weathered coal-based potassium iron humate fire coal catalyst from 28%-32% of potassium iron humate, 4%-6% of potassium chloride, 2%-4% of calcium chloride, 1%-3% of nickel nitrate hexahydrate, 4%-6% of sodium nitrate, 0.4%-0.6% of copper nitrate and the balance of water. The addition amount of the catalyst is 0.05-0.15% of the mass of raw coal, the flue gas emission sulfur of fire coal is reduced, and the combustion efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coal-fired catalysts, and in particular to a weathered coal-based humic acid iron potassium coal-fired catalyst and a preparation method and application thereof. Background Art

[0002] Coal is one of the main fossil energy sources in my country, and the coal used for direct combustion accounts for 84% of the total coal consumption each year. Due to the non-renewable nature of coal resources and the serious environmental problems caused by incomplete combustion, it is particularly important to improve the combustion efficiency of coal to achieve the goal of full utilization of coal resources and energy conservation and emission reduction. The current coal-saving technology mainly increases the combustion rate of coal and reduces the ash and carbon residue by adding coal-burning catalysts to the coal. There are still some problems with the existing coal-saving catalysts in coal burning, such as: complex composition; expensive raw materials; containing heavy metals; there is a risk of environmental pollution; the coal-saving effect is not obvious, etc.

[0003] Therefore, improving coal combustion efficiency through coal-saving catalysts still has extremely high research significance. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a weathered coal-based humic acid iron potassium coal-fired catalyst, so as to significantly improve the combustion efficiency of coal and solve the problems existing in the above-mentioned prior art.

[0005] The technical solution of the present invention is as follows:

[0006] The first aspect of the present invention provides a method for preparing a humic acid potassium iron catalyst, the method comprising the following process steps:

[0007] (1) Preparation of potassium iron humate: In a reactor, add the following composition in percentage by mass: weathered coal: 4% to 8%, potassium hydroxide: 1% to 2%, ferrous sulfate: 0.01% to 0.05%, ferric sulfate: 0.3% to 0.5%, and the balance is water. Stir the reaction for 1 to 4 hours, centrifuge, take the supernatant, adjust the pH to 1.0 to 2.0 with 0.5 to 4 M hydrochloric acid, filter the precipitate, and dry to obtain potassium iron humate.

[0008] (2) In step (1): the weathered coal particles are no larger than 100 mesh; after ferrous sulfate and ferric sulfate are dissolved in the aqueous solution, they are slowly added during stirring.

[0009] In step (2): water is added to a compounding container, and potassium iron humate, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate are added in sequence; the time interval between the addition of each component is 3-5 minutes.

[0010] The amount of the catalyst added is 0.05% to 0.15% of the mass of the raw coal. The sulfur content of the flue gas emitted by the coal combustion is reduced, which has a significant environmental protection effect and can significantly improve the combustion efficiency.

[0011] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0012] (1) The present invention prepares potassium iron humate, the main component of coal-fired catalyst, from Xinjiang weathered coal, thus developing a new use for Xinjiang coal. At the same time, the raw material is used as the catalyst material, thereby reducing the components of the coal-fired catalyst.

[0013] (2) Potassium iron humate is relatively easy to obtain and prepare, so the cost of adding this component is relatively low, and potassium iron humate is not likely to cause harm to the ecological environment during the catalytic reaction.

[0014] (3) The present invention obtains a catalyst combination with a high-efficiency coal-burning catalytic effect through the selection of coal-burning catalyst components and the experiment of component ratio. The synergistic effect of potassium iron humate, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate and copper nitrate can improve the maximum combustion temperature of coal and increase the average combustion rate of coal.

[0015] (4) The raw materials of the coal-fired catalyst are easily available, the preparation is simple, the catalyst is environmentally friendly and has high coal-saving efficiency. DETAILED DESCRIPTION

[0016] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0017] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0018] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0019] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0020] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0021] Example 1

[0022] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 6%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0023] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0024] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 30%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0025] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0026] Example 2

[0027] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 4%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0028] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0029] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 30%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0030] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0031] Example 3

[0032] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 8%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0033] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0034] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 30%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0035] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0036] Example 4

[0037] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 6%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0038] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0039] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 28%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0040] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0041] Example 5

[0042] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 4%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0043] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0044] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 28%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0045] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0046] Example 6

[0047] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 8%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0048] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0049] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 28%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0050] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0051] Example 7

[0052] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 6%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0053] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0054] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 32%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0055] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0056] Example 8

[0057] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 4%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0058] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0059] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 32%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0060] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0061] Example 9

[0062] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 8%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0063] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0064] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 32%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0065] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0066] Example 10

[0067] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 6%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.5%, and the balance is water.

[0068] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0069] (2) The mass percentage composition of the humic acid potassium iron catalyst is as follows: humic acid potassium iron: 30%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water.

[0070] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0071] Embodiment 11

[0072] (1) Preparation of potassium iron humate: In a reactor, the following composition percentages by mass are added: weathered coal with a particle size of 20-80 mesh: 6%, potassium hydroxide: 1.5%, ferrous sulfate: 0.03%, ferric sulfate: 0.4%, and the balance is water.

[0073] In the reactor, water, weathered coal and potassium hydroxide are first added, and then an aqueous solution of ferrous sulfate and ferric sulfate is added during stirring. After the addition is completed, the reaction is stirred for 2 hours, centrifuged, and the supernatant is retained. The pH is adjusted to 1-2 with 2M hydrochloric acid, and the precipitate is filtered and dried to obtain potassium iron humate.

[0074] (2) The mass percentage composition of the potassium iron humate catalyst is as follows: potassium iron humate: 30%, potassium chloride: 6%, calcium chloride: 4%, nickel nitrate hexahydrate: 3%, sodium nitrate: 6%, copper nitrate: 0.6%, and the balance is water.

[0075] Add water into the compounding container according to the mass percentage of the humic acid potassium iron catalyst, and then add humic acid potassium iron, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate, and copper nitrate in sequence; stir and dissolve to obtain the weathered coal-based humic acid potassium iron coal-fired catalyst. The time interval for adding each component is controlled to be 4 minutes.

[0076] Comparative Example 1

[0077] The coal is burned directly without using any catalyst.

[0078] Comparative Example 2

[0079] Potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, the balance is water. (The amount added is 0.10% of the original coal mass)

[0080] Comparative Example 3

[0081] Humic acid (the amount added is 0.10% of the raw coal mass)

[0082] Comparative Example 4

[0083] Humic acid: 32%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, the balance is water. (The amount added is 0.10% of the mass of the raw coal) Comparative Example 5

[0084] Humic acid: 28%, potassium chloride: 5%, calcium chloride: 3%, nickel nitrate hexahydrate: 2%, sodium nitrate: 5%, copper nitrate: 0.5%, and the balance is water. (The amount added is 0.10% of the mass of the raw coal) The coal-fired catalyst samples prepared in Examples 1 to 11 and Comparative Examples 1 to 5 were uniformly mixed with the same amount of coal at a weight ratio of 0.1% of the coal-fired catalyst to coal for combustion experiments (the ignition point, net burn rate and average combustion rate of the samples were analyzed according to the thermogravimetric curve. Ignition point: The intersection of the tangent line at the horizontal position before the TG step and the tangent line at the inflection point of the curve is the ignition point of the sample. Net burn rate: It is expressed by the ratio of the remaining mass after combustion to the initial mass. Average combustion rate: By analyzing the TG curve, the mass change of the sample in different temperature ranges can be obtained, and the average combustion rate can be calculated; thermogravimetric analysis conditions: starting temperature: 30°C; end temperature: 900°C; heating rate: 10°C / min, air atmosphere, flow rate of 100 mL / min, thermogravimetric analysis sample amount: 10.0-15.0 mg.), and the results are as follows:

[0085]

[0086] 1. Reduce the ignition point of combustion and improve the net combustion rate.

[0087] 2. Improved the average burning rate.

[0088] 3. Reduce sulfur emissions in exhaust gas.

[0089] The obtained results further confirmed that the humic acid potassium iron coal-fired catalyst of the present invention significantly improved the utilization rate of coal and had better environmental friendliness compared with comparative example 1.

[0090] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A weathered coal-based humic acid iron potassium coal-fired catalyst, characterized in that: The composition thereof is calculated by mass percentage as follows: potassium iron humate: 28% to 32% (preferably 30-31%), potassium chloride: 4% to 6% (preferably 4.5-5.5%), calcium chloride: 2% to 4% (preferably 2.5-3.5%), nickel nitrate hexahydrate: 1% to 3% (preferably 1.8-2.2%), sodium nitrate: 4% to 6% (preferably 4.5-5.5%), copper nitrate: 0.4% to 0.6% (preferably 0.45-0.55%), and the balance is water.

2. The weathered coal-based humic acid potassium iron coal-fired catalyst according to claim 1, characterized in that: in, The preparation process of potassium iron humate is as follows: in a reactor, add the required balance of water according to the following composition mass percentages (the sum of the masses of each component is 100%), weathered coal: 4% to 8% (preferably 5-7%), potassium hydroxide: 1% to 2% (preferably 1.5-1.6%), ferrous sulfate: 0.01% to 0.05% (preferably 0.02-0.04%), ferric sulfate: 0.3% to 0.5% (preferably 0.35-0.45%), stir the reaction for 1-4h, centrifuge, take the supernatant, adjust the pH to 1.0 to 2.0 with 0.5-4M hydrochloric acid, precipitate, filter and dry to obtain potassium iron humate.

3. The weathered coal-based humic acid potassium iron coal-fired catalyst according to claim 2, characterized in that: The particle size of the weathered coal is not greater than (less than or equal to) 100 mesh (preferably 20-80 mesh).

4. A method for preparing a weathered coal-based humic acid potassium iron coal-fired catalyst according to claim 1, 2 or 3, characterized in that: Water is added into a compounding container according to the mass percentage composition of the potassium iron humate catalyst, and the remaining required components potassium iron humate, potassium chloride, calcium chloride, nickel nitrate hexahydrate, sodium nitrate and copper nitrate are added in sequence during stirring; stirring and dissolving, a weathered coal-based potassium iron humate coal-fired catalyst is obtained.

5. The preparation method according to claim 4, characterized in that: When adding the remaining required components during the stirring process: the time interval between adding each component is 3-5 minutes.

6. Use of the weathered coal-based humic acid iron potassium coal-fired catalyst according to claim 1, 2 or 3 in a catalytic coal combustion process.

7. The use according to claim 6, characterized in that: The coal-fired catalyst or a water dilution of the coal-fired catalyst (the dilution ratio of the coal-fired catalyst to water is 1:5-8) is added to coal for combustion, and the amount of the coal-fired catalyst is 0.05% to 0.15% of the weight of the coal, preferably 0.09% to 0.11%.

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