Method for reducing sulfur content of coke

Abstract

The invention relates to the technical field of coking, and provides a method for reducing the sulfur content of coke, which comprises the following steps: S1, crushing raw coal, and carrying out flotation to obtain coal powder; s2, uniformly mixing the pulverized coal with a catalyst, and coking in a reducing gas atmosphere to obtain red hot coke; s3, quenching the red hot coke to obtain coke; the catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; the reducing gas includes carbon monoxide. According to the technical scheme, the problem of low sulfur removal rate in the coking process in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coking, and specifically, to a method for reducing the sulfur content of coke. Background Art

[0002] In today's steel industry, coke, as a key raw material, its quality has a profound impact on the efficiency, cost, and product quality of steel production. With the booming development of the steel industry and the increasingly stringent environmental protection requirements, the control of coke quality has become more and more important, and the sulfur content has become one of the core indicators.

[0003] From the perspective of the production process, in the traditional coking process, a large amount of sulfur elements in coal will be transferred to coke. Coal has a wide range of sources and complex compositions, and the sulfur content includes various types, including organic sulfur and inorganic sulfur, which makes it difficult to accurately control the sulfur content of coke. Excessive sulfur content will not only reduce the reactivity and strength of coke, affecting its use effect in processes such as blast furnace ironmaking, but also increase sulfur impurities in steel products, seriously affecting the performance of steel, such as reducing its toughness, ductility, and corrosion resistance.

[0004] At the environmental protection level, during the combustion or use of coke, sulfur elements will be converted into harmful gases such as sulfur dioxide and emitted into the atmosphere, becoming an important inducement for environmental pollution problems such as acid rain. Countries have successively introduced strict environmental protection regulations to limit the emission concentration and total amount of sulfur oxides in industrial waste gases. If steel enterprises want to achieve sustainable development, they must actively address the problem of excessive sulfur content in coke.

[0005] At present, although there are some methods for reducing the sulfur content of coke, such as coal washing pretreatment, optimizing the coal blending scheme, and improving the coking process, these methods generally have limitations. The coal washing technology has poor desulfurization effects on certain forms of sulfur and high costs; the optimization of coal blending is limited by coal types and cost constraints and is difficult to achieve deep desulfurization; the improvement of the existing coking process has a limited desulfurization range and cannot meet the growing demand for low-sulfur coke.

[0006] Under this background, it is urgent to develop an efficient method for improving the sulfur removal rate in the coking process, which has important practical significance for enhancing the overall competitiveness of the steel industry and promoting the realization of environmental protection goals. Summary of the Invention

[0007] The present invention proposes a method for reducing the sulfur content of coke, which solves the problem of low sulfur removal rate in the coking process in the related art.

[0008] The technical solution of the present invention is as follows: The present invention proposes a method for reducing the sulfur content of coke, including the following steps: S1. Crush raw coal and perform flotation to obtain coal powder; S2. Mix the pulverized coal and the catalyst evenly and carry out coking under a reducing gas atmosphere to obtain red-hot coke; S3. Quench the red-hot coke to obtain the coke; The catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The reducing gas includes carbon monoxide.

[0009] As a further technical solution, the raw materials of the titanium dioxide loaded with manganese sulfate and vanadium pentoxide include manganese sulfate, vanadium pentoxide and titanium dioxide; The mass ratio of the pulverized coal to the catalyst is 100:1 to 3.

[0010] As a further technical solution, the preparation method of the titanium dioxide loaded with manganese sulfate and vanadium pentoxide includes the following steps: A1. Mix manganese sulfate and vanadium pentoxide and carry out ball milling to obtain a mixture; A2. Mix the mixture with titanium dioxide, calcine and cool to obtain titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The temperature of the calcination is 420 to 460 °C and the time is 4 to 5 h.

[0011] As a further technical solution, the mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide is 2 to 3:5:36.

[0012] In the present invention, by adjusting the mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide to 2 to 3:5:12, the desulfurization rate in the coking process is further improved.

[0013] As a further technical solution, the particle size of the mixture is 50 to 100 nm.

[0014] As a further technical solution, the reducing gas further includes ammonia and methane.

[0015] As a further technical solution, the volume ratio of carbon monoxide, ammonia and methane is 7:1:2 to 3.

[0016] In the present invention, by adjusting the volume ratio of carbon monoxide, ammonia and methane to 7:1:2 to 3, the desulfurization rate in the coking process is further improved.

[0017] As a further technical solution, during the coking, the temperature is 1100 to 1250 °C and the time is 24 to 26 h.

[0018] As a further technical solution, during the flotation, sodium diisobutyl dithiophosphate is used as a collector, sec-octanol is used as a foaming agent, the temperature is 20 to 30 °C, and the flotation time is 0.5 to 1.5 h; The mass ratio of the raw coal to the collector is 1t: 0.5 - 1kg; The mass ratio of the raw coal to the foaming agent is 1t: 0.05 - 0.1kg.

[0019] As a further technical solution, the flow rate of the reducing gas is 1.5 - 2m / s.

[0020] As a further technical solution, the coke quenching is dry coke quenching; The dry coke quenching includes the following steps: using nitrogen to cool the red-hot coke to room temperature.

[0021] The working principle and beneficial effects of the present invention are as follows: In the present invention, the catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide. Manganese ions in manganese sulfate undergo a coordination reaction with sulfur during the coking process. Sulfur weakens the sulfur bond, making it easier to transform into gaseous sulfur. Vanadium pentoxide provides oxygen active sites during the coking process to promote sulfur oxidation. The two are loaded on titanium dioxide and, under the catalytic action of titanium dioxide, the three work together to improve the desulfurization rate during the coking process, reduce the coke quality problems caused by sulfur impurities, and ensure the quality stability and reliability of subsequent products. Specific Embodiments

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present invention.

[0023] In the following embodiments and comparative examples, the content of manganese sulfate is 99wt%, the content of vanadium pentoxide is 99wt%, the content of titanium dioxide is 99.9wt%, and the particle size is 1250 mesh.

[0024] Example 1 A method for reducing the sulfur content of coke, including the following steps: S1. Crush the raw coal and perform flotation to obtain coal powder; S2. Mix the coal powder and the catalyst evenly and coke in a reducing gas atmosphere to obtain red-hot coke; S3. Quench the red-hot coke by dry coke quenching to obtain coke; The catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The raw materials of titanium dioxide loaded with manganese sulfate and vanadium pentoxide include manganese sulfate, vanadium pentoxide, and titanium dioxide with a mass ratio of 5:5:36; The reducing gas is carbon monoxide; The flow rate of the reducing gas is 2 m / s; The mass ratio of pulverized coal to the catalyst is 100:3; The preparation method of titanium dioxide loaded with manganese sulfate and vanadium pentoxide comprises the following steps: A1. Mix manganese sulfate and vanadium pentoxide and ball-mill them to obtain a mixed material; A2. Mix the mixed material with titanium dioxide, calcine it, and then cool it to obtain titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The calcination temperature is 460 °C and the time is 4 h; The particle size of the mixed material is 100 nm; During coking, the temperature is 1250 °C and the time is 26 h; During flotation, sodium diisobutyl dithiophosphate is used as a collector, sec-octanol is used as a frother, the temperature is 30 °C, and the flotation time is 0.5 h; The mass ratio of raw coal to the collector is 1 t:1 kg; The mass ratio of raw coal to the frother is 1 t:0.1 kg; Dry quenching of coke comprises the following steps: using nitrogen to cool the red-hot coke to room temperature.

[0025] Example 2 A method for reducing the sulfur content of coke, comprising the following steps: S1. Crush raw coal and perform flotation to obtain pulverized coal; S2. Mix the pulverized coal and the catalyst evenly and carry out coking in a reducing gas atmosphere to obtain red-hot coke; S3. Carry out dry quenching on the red-hot coke to obtain coke; The catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The raw materials of titanium dioxide loaded with manganese sulfate and vanadium pentoxide include manganese sulfate, vanadium pentoxide and titanium dioxide with a mass ratio of 0.5:5:36; The reducing gas is carbon monoxide; The flow rate of the reducing gas is 1.5 m / s; The mass ratio of pulverized coal to the catalyst is 100:1; The preparation method of titanium dioxide loaded with manganese sulfate and vanadium pentoxide comprises the following steps: A1. Mix manganese sulfate and vanadium pentoxide and ball-mill them to obtain a mixed material; A2. Mix the mixed material with titanium dioxide, calcine it, and then cool it to obtain titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The calcination temperature is 420 °C and the time is 5 h; The particle size of the mixed material is 50 nm; During coking, the temperature is 1100 °C and the time is 26 h; During flotation, sodium di-n-butyldithiophosphate is used as a collector, and sec-octanol is used as a frother. The temperature is 20 °C and the flotation time is 1.5 h; The mass ratio of raw coal to the collector is 1 t: 0.5 kg; The mass ratio of raw coal to the frother is 1 t: 0.05 kg; Dry quenching of coke includes the following steps: using nitrogen to cool the red-hot coke to room temperature.

[0026] Example 3 A method for reducing the sulfur content of coke includes the following steps: S1. Crushing the raw coal and performing flotation to obtain pulverized coal; S2. Mixing the pulverized coal and the catalyst evenly and coking in a reducing gas atmosphere to obtain red-hot coke; S3. Performing dry quenching on the red-hot coke to obtain coke; The catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The raw materials of titanium dioxide loaded with manganese sulfate and vanadium pentoxide include manganese sulfate, vanadium pentoxide and titanium dioxide with a mass ratio of 1:5:36; The reducing gas is carbon monoxide; The flow rate of the reducing gas is 1.5 m / s; The mass ratio of pulverized coal to the catalyst is 50:1; The preparation method of titanium dioxide loaded with manganese sulfate and vanadium pentoxide includes the following steps: A1. Mixing manganese sulfate and vanadium pentoxide and ball milling to obtain a mixture; A2. Mixing the mixture and titanium dioxide, calcining and cooling to obtain titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The calcination temperature is 440 °C and the time is 4.5 h; The particle size of the mixture is 75 nm; During coking, the temperature is 1200 °C and the time is 25 h; During flotation, sodium di-n-butyldithiophosphate is used as a collector, and sec-octanol is used as a frother. The temperature is 25 °C and the flotation time is 1 h; The mass ratio of raw coal to the collector is 1 t: 0.7 kg; The mass ratio of raw coal to the frother is 1 t: 0.07 kg; Dry quenching of coke includes the following steps: using nitrogen to cool the red-hot coke to room temperature.

[0027] Example 4 The difference between this example and Example 3 is only that the mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide in this example is 4:5:12.

[0028] Example 5 The difference between this example and Example 3 is only that the mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide in this example is 2:5:12.

[0029] Example 6 The difference between this example and Example 3 is only that the mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide in this example is 3:5:12.

[0030] Example 7 The difference between this example and Example 6 is only that the reducing gas in this example includes carbon monoxide, ammonia and methane with a volume ratio of 7:1:4.

[0031] Example 8 The difference between this example and Example 7 is only that the volume ratio of carbon monoxide, ammonia and methane in this example is 7:1:1.

[0032] Example 9 The difference between this example and Example 7 is only that the volume ratio of carbon monoxide, ammonia and methane in this example is 7:1:2.

[0033] Example 10 The difference between this example and Example 7 is only that the volume ratio of carbon monoxide, ammonia and methane in this example is 7:1:3.

[0034] Comparative Example 1 The difference between this example and Example 3 is only that the catalyst in this comparative example is titanium dioxide loaded with manganese sulfate; The raw materials of titanium dioxide loaded with manganese sulfate include manganese sulfate and titanium dioxide with a mass ratio of 1:6; The preparation method of titanium dioxide loaded with manganese sulfate includes the following steps: Ball-mill manganese sulfate to a particle size of 75 nm, mix it with titanium dioxide, calcine it, and cool it to obtain titanium dioxide loaded with manganese sulfate; The calcination temperature is 440 °C and the time is 4.5 h.

[0035] Comparative Example 2 The difference between this example and Example 3 is only that the catalyst in this comparative example is titanium dioxide loaded with vanadium pentoxide; The raw materials of titanium dioxide loaded with vanadium pentoxide include vanadium pentoxide and titanium dioxide with a mass ratio of 1:6; The preparation method of titanium dioxide loaded with vanadium pentoxide includes the following steps: Milling vanadium pentoxide to a particle size of 75 nm, mixing it with titanium dioxide, calcining, and cooling to obtain titanium dioxide supported with vanadium pentoxide; The calcination temperature is 440 °C and the time is 4.5 h.

[0036] Comparative Example 3 The difference between this comparative example and Example 3 is only that the catalyst in this comparative example is titanium dioxide.

[0037] Comparative Example 4 The difference between this comparative example and Example 3 is only that this comparative example has no catalyst.

[0038] Experimental Example 1 Testing the desulfurization rate of the methods for reducing the sulfur content in coke in Examples 1 - 10 and Comparative Examples 1 - 4. The testing method is as follows: Testing the sulfur mass m in raw coal according to the Eschka method in GB / T 214 - 2007 "Methods for the Determination of Total Sulfur in Coal" 1 and testing the sulfur mass m in coke according to the Eschka method in GB / T 2286 - 2017 "Methods for the Determination of Total Sulfur Content in Coke" 2 The desulfurization rate A = (m 1 - m 2 ) / m 1 ; The test results are shown in Table 1.

[0039] Table 1 Test Results of Desulfurization Rate

[0040] Comparing Example 3 with Comparative Examples 1 - 4 shows that using titanium dioxide supported with manganese sulfate and vanadium pentoxide as a catalyst in the present invention improves the desulfurization rate in the coking process.

[0041] Comparing Examples 7 - 10 with Example 6 shows that when the reducing gas is carbon monoxide, ammonia, and methane in the present invention, the desulfurization rate in the coking process is further improved.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for reducing the sulfur content of coke, characterized in that: The following steps are involved: S1, crushing the raw coal and flotation to obtain coal powder; S2, uniformly mixing the pulverized coal and the catalyst, and coking in a reducing gas atmosphere to obtain red-hot coke; S3, quenching the red-hot coke to obtain the coke; The catalyst is titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The reducing gas includes carbon monoxide.

2. A method for reducing sulfur content in coke according to claim 1, characterized in that: The raw materials of the titanium dioxide loaded with manganese sulfate and vanadium pentoxide include manganese sulfate, vanadium pentoxide and titanium dioxide; The mass ratio of the coal powder to the catalyst is 100:1-3.

3. A method for reducing the sulfur content of coke according to any one of claims 1 to 2, characterized in that: The method for preparing titanium dioxide loaded with manganese sulfate and vanadium pentoxide comprises the following steps: A1. Mix manganese sulfate and vanadium pentoxide, and ball-mill to obtain a mixture; A2, mixing the mixed material with titanium dioxide, calcining, and cooling to obtain titanium dioxide loaded with manganese sulfate and vanadium pentoxide; The calcination temperature is 420-460° C. and the calcination time is 4-5 hours.

4. A method for reducing the sulfur content of coke according to claim 2, characterized in that: The mass ratio of manganese sulfate, vanadium pentoxide and titanium dioxide is 2-3:5:

36.

5. A method for reducing the sulfur content of coke according to claim 3, characterized in that: The particle size of the mixture is 50-100 nm.

6. A method for reducing sulfur content in coke according to claim 1, characterized in that: The reducing gas also includes ammonia and methane.

7. A method for reducing sulfur content in coke according to claim 6, characterized in that: The volume ratio of carbon monoxide, ammonia and methane is 7:1:2-3.

8. The method for reducing the sulfur content of coke according to claim 1, characterized in that: During the coking, the temperature is 1100-1250° C. and the time is 24-26 hours.

9. The method for reducing sulfur content in coke according to claim 1, characterized in that: During the flotation, sodium dibutyl dithiophosphate is used as a collector, octanol is used as a frother, the temperature is 20-30° C., and the flotation time is 0.5-1.5 h; The mass ratio of the raw coal to the collector is 1t:0.5~1kg; The mass ratio of the raw coal to the foaming agent is 1t:0.05~0.1kg.

10. The method for reducing sulfur content in coke according to claim 1, characterized in that: The flow rate of the reducing gas is 1.5-2 m / s.

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