阅读说明：本技术 一种利用密封环保式碳化硅冶炼炉冶炼碳化硅的方法 (Method for smelting silicon carbide by utilizing sealed environment-friendly silicon carbide smelting furnace ) 是由 夏开展 于 2021-11-08 设计创作，主要内容包括：本发明提供了一种利用密封环保式碳化硅冶炼炉冶炼碳化硅的方法,在密封环保式碳化硅冶炼炉炉进行碳化硅冶炼,冶炼过程为首先配置反应原料并混料：将硅质原料和碳质原料按照1.17～1.19：1的比例进行配置并混合均匀；再进行装炉：将配置混合的反应原料装炉；最后进行冶炼：对装好的炉通电冶炼32～36小时,通电过程中,前85％～95％的时间段送电变压器功率为额定功率,后5％～15％的时间段的送电变压器功率为额定功率的2/3,冶炼完成后冷却3天后出炉,分级获得碳化硅。本发明应用在密封式碳化硅冶炼炉中,将下部炉料的粒度变粗,碳质原料的粒度为1mm～3mm,硅质原料的粒度为3～10mm,使料隙增加,有效改善炉料的透气性,提高炉内热量及硅质炉料的传送,有利于提高产品一级品率。(The invention provides a method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace, wherein silicon carbide smelting is carried out in the sealed environment-friendly silicon carbide smelting furnace, and the smelting process comprises the following steps of firstly preparing reaction raw materials and mixing the materials: mixing a siliceous raw material and a carbonaceous raw material according to the weight ratio of 1.17-1.19: 1, and mixing uniformly; and then furnace charging is carried out: charging the prepared and mixed reaction raw materials into a furnace; and finally, smelting: and (3) electrifying the assembled furnace for smelting for 32-36 hours, wherein in the electrifying process, the power of the power transmission transformer in the first 85-95% time period is the rated power, the power of the power transmission transformer in the later 5-15% time period is 2/3 of the rated power, cooling for 3 days after smelting is finished, discharging, and grading to obtain the silicon carbide. The invention is applied to a sealed silicon carbide smelting furnace, coarsens the granularity of furnace charge at the lower part, the granularity of carbonaceous raw material is 1 mm-3 mm, and the granularity of siliceous raw material is 3-10 mm, increases the material gap, effectively improves the air permeability of the furnace charge, improves the heat in the furnace and the transmission of the siliceous furnace charge, and is beneficial to improving the first-grade product rate of products.)

1. The method for smelting silicon carbide by using the sealed environment-friendly silicon carbide smelting furnace is characterized by comprising the following steps of:

s1 preparing reaction raw materials and mixing: mixing a siliceous raw material and a carbonaceous raw material according to the weight ratio of 1.17-1.19: 1, and mixing uniformly;

s2 furnace charging: charging the S1 prepared and mixed reaction raw materials into a furnace;

s3 smelting: and (3) electrifying the furnace loaded in S2 for smelting for 32-36 hours, wherein in the electrifying process, the power of the power transmission transformer in the first 85-95% time period is the rated power of the silicon carbide smelting furnace, the power of the power transmission transformer in the later 5-15% time period is 3/5-3/4 of the rated power of the silicon carbide smelting furnace, cooling after smelting, discharging, and grading to obtain the silicon carbide.

2. The method of claim 1 for smelting silicon carbide using a sealed, environmentally friendly silicon carbide smelting furnace, wherein: the granularity of the charging material carbon raw material below the height 1/3 of the silicon carbide smelting furnace is 1 mm-3 mm, the granularity of the siliceous raw material is 3 mm-10 mm, the granularity of the charging material carbon raw material above the height 1/3 of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm.

3. The method of claim 1 for smelting silicon carbide using a sealed, environmentally friendly silicon carbide smelting furnace, wherein: the siliceous raw material is quartz sand, and the carbonaceous raw material is one of anthracite or taixi coal.

4. The method of claim 1 for smelting silicon carbide using a sealed, environmentally friendly silicon carbide smelting furnace, wherein: the silicon content of the siliceous raw material is more than or equal to 98 percent, the fixed carbon of the carbonaceous raw material is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent.

5. The method of claim 1 for smelting silicon carbide using a sealed, environmentally friendly silicon carbide smelting furnace, wherein: after the furnace is charged in the step S2, the bulk density of the furnace burden below the 1/3 height position of the silicon carbide smelting furnace is 250kg/m³～300kg/m³。

6. The method of smelting silicon carbide using a closed-loop, environmentally-friendly silicon carbide smelting furnace of claim 2, wherein: the granularity of the charging material carbon raw material below the height 1/3 of the silicon carbide smelting furnace is 1 mm-3 mm, and the granularity of the siliceous raw material is 4 mm-10 mm.

7. The method of claim 1 for smelting silicon carbide using a sealed, environmentally friendly silicon carbide smelting furnace, wherein: in the step S3, the rated power of the silicon carbide smelting furnace is 125000 KVA-51000 KVA.

Technical Field

The invention belongs to the technical field of silicon carbide smelting, relates to a method for smelting silicon carbide, and particularly relates to a method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace.

Background

The traditional silicon carbide smelting furnace consists of a furnace bottom, an end wall and a side wall, wherein the furnace bottom is a ground plane; the end wall is a material blocking body which is fixed on the furnace bottom and is provided with a power-on electrode; according to different capacities of furnace bodies, the side walls are tens of or even tens of movable bodies, when the smelting furnace is charged, the side walls are assembled on the bottom of the smelting furnace in sequence and used as blocking bodies of furnace materials, and after the smelting furnace is completed, the side walls are disassembled and assembled on another smelting furnace and used as the blocking bodies of the furnace materials, so that the side walls can be recycled. Therefore, the side wall is assembled when the furnace is charged, the side wall is disassembled for facilitating the discharging operation after the smelting is finished, and the disassembly process of the side wall causes that a large amount of high-temperature furnace burden suddenly blows out of the furnace and deflagration generates a large amount of dust to seriously pollute the environment after being mixed with air, and on the other hand, in the smelting process, because the gaps among the side walls and between the side walls and the bottom of the furnace are difficult to seal, the treatment difficulty of the smoke of a furnace surface and the tail gas of a furnace is larger.

In order to respond to the national environment-friendly working requirement and improve the working environment of staff, the side wall is poured into an integral structure, so that the side wall, the furnace bottom and the end wall form an integral structure, the original movable side wall is changed into a fixed side wall of integral concrete, thus, the smelting furnace is a uncovered box body with a U-shaped section, the sealing performance of the smelting furnace with the fixed side wall is greatly improved, on one hand, the smelting furnace is favorable for collecting and treating the tail gas of the smelting furnace, on the other hand, the side wall is not required to be disassembled in the working process, the dust is thoroughly treated, the tail gas and the dust are treated, the working environment is clean and orderly, the production requirement is met, and a good effect is achieved. The formation of silicon carbide is carried out at high temperature, while convection is the main form of heat transfer in the furnace, and the poor air permeability is not favorable for the convection heat transfer; the gas convection process is also the conveying process of the siliceous raw material, and the poor air permeability is not favorable for the conveying of the siliceous raw material and is extremely unfavorable for the formation of silicon carbide products.

Disclosure of Invention

In order to solve the technical problems caused by the traditional method for smelting silicon carbide by using the sealed environment-friendly silicon carbide smelting furnace, the invention provides a method for smelting silicon carbide by using the sealed environment-friendly silicon carbide smelting furnace, which comprises the following specific steps:

s1 preparing reaction raw materials and mixing: preparing a siliceous raw material and a carbonaceous raw material according to the proportion of 1.16-1.20, and uniformly mixing;

s2 furnace charging: charging the S1 prepared and mixed reaction raw materials into a furnace;

s3 smelting: and (3) electrifying the furnace loaded in S2 for smelting for 32-36 hours, wherein in the electrifying process, the power of the power transmission transformer in the first 85-95% time period is the rated power of the silicon carbide smelting furnace, the power of the power transmission transformer in the later 5-15% time period is 3/5-3/4 of the rated power of the silicon carbide smelting furnace, cooling after smelting, discharging, and grading to obtain the silicon carbide.

In the step S3, the rated power of the silicon carbide smelting furnace is 125000 KVA-51000 KVA.

Furthermore, the granularity of the carbonaceous raw material of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 1 mm-3 mm, the granularity of the siliceous raw material is 3 mm-10 mm, the granularity of the carbonaceous raw material of the furnace charge above the height 1/3 of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm.

The furnace wall of the silicon carbide smelting furnace is a fixed furnace wall, the smelting furnace is a sealed environment-friendly silicon carbide smelting furnace, and specifically, the furnace wall of the silicon carbide smelting furnace is disclosed in the patents of 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A) and 'a side wall of the silicon carbide smelting furnace' (CN211261772U) which are applied by the applicant. Compared with the traditional furnace type, the sealed ring-protection type silicon carbide smelting furnace has poor air permeability, is not beneficial to the transmission of heat in the furnace and siliceous furnace burden and is not beneficial to the formation of products.

However, the improvement of the air permeability increases the possibility that the crystallization cylinder burns out the furnace bottom, and a corresponding power transmission process needs to be established for the improvement, the power transmission process is adjusted to prevent the crystallization cylinder from sinking too fast, and the power transmission process is 2/3 for reducing the input load to be normal smelting power when the furnace is shut down.

The siliceous raw material is quartz sand, and the carbonaceous raw material is one of anthracite or taixi coal.

The silicon content of the siliceous raw material is more than or equal to 98 percent, the fixed carbon of the carbonaceous raw material is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent.

Further, after charging in the step S2, the bulk density of the burden below the 1/3 height of the silicon carbide smelting furnace is 250-300 kg/m³(ii) a The bulk density is small, which is beneficial to improving the air permeability of the lower part of the smelting furnace, and the bulk density is closely related to the grain diameter of the furnace burden. Good air permeability, and is beneficial to the flow of the generated SiO steam, Si steam and Si steam generated by the decomposition of silicon carbide.

Furthermore, in order to increase the air permeability of the charge at the lower part of the smelting furnace, the particle size of the carbonaceous raw material of the charge below the 1/3 position of the silicon carbide smelting furnace is 1 mm-3 mm, and the particle size of the siliceous raw material is 4 mm-10 mm.

The invention has the outstanding technical effects that:

1. the invention is applied to a sealed silicon carbide smelting furnace, coarsens the granularity of furnace charge at the lower part, the granularity of carbonaceous raw material is 1 mm-3 mm, and the granularity of siliceous raw material is 3-10 mm, increases the material gap, effectively improves the air permeability of the furnace charge, improves the heat in the furnace and the transmission of the siliceous furnace charge, and is beneficial to improving the first-grade product rate of products.

2. According to the invention, the silicon carbide smelting power transmission process is set as uniform load input of the main smelting process, and the input load is reduced when the furnace is shut down, so that the smelting power when the furnace is shut down is 2/3 of the normal smelting power, the possibility that the bottom of the furnace is burned out by the crystallization cylinder after the air permeability of furnace materials of the silicon carbide smelting furnace is improved is solved, and the crystallization cylinder is prevented from sinking too fast to influence the stable operation of the smelting process, and further influence the product percent of pass.

Drawings

FIG. 1 is a process diagram of a method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace.

Detailed Description

Embodiments of the present invention will be described below.

Example one

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 807 tons of quartz sand with the granularity of 4 mm-10 mm and 680 tons of taixi coal with the granularity of 1 mm-3 mm are prepared and uniformly mixed, marked as material A, and 1613 tons of quartz sand with the granularity of less than 1mm and 1360 tons of taixi coal with the granularity of less than 2mm are prepared and uniformly mixed, marked as material B; the quartz sand and the Taixi coal are prepared and mixed according to the proportion of 1.186: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the reaction raw material mixed with the S1, charging the material A, and charging the material B to ensure that the granularity of the carbonaceous raw material of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 1-3 mm, the granularity of the siliceous raw material is 4-10 mm, and the bulk density of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 250kg/m³～290kg/m³(ii) a The granularity of the charging material carbon raw material above the 1/3-height position of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm;

s3 smelting: and (3) electrifying the furnace assembled in the S2 for smelting for 34 hours, wherein in the electrifying process, the power of the power transmission transformer in the 0 th-30.6 th hour time period is 51000KVA, the power of the power transmission transformer in the 30.6 th-34 th hour time period is 34000KVA, cooling for 3 days after smelting is completed, discharging, and grading to obtain the silicon carbide.

After the smelting furnace is taken out, the first-grade yield of the silicon carbide is 65%, the crystallization cylinder in the smelting furnace is relatively complete, and the crystallization cylinder does not obviously sink.

Example two

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 704.43 tons of quartz sand with the granularity of 3 mm-10 mm and 607.26 tons of taixi coal with the granularity of 1 mm-3 mm are prepared and uniformly mixed, marked as material A, 1408.85 tons of quartz sand with the granularity of less than 1mm and 1214.52 tons of taixi coal with the granularity of less than 2mm are prepared and uniformly mixed, and marked as material B; the quartz sand and the Taixi coal are prepared and mixed according to the proportion of 1.16: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the reaction raw material mixed with the S1, charging the material A, and charging the material B to ensure that the granularity of the carbonaceous raw material of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 1-3 mm, the granularity of the siliceous raw material is 3-10 mm, and the bulk density of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 260kg/m³～300kg/m³(ii) a The granularity of the charging material carbon raw material above the 1/3-height position of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm;

s3 smelting: and (3) electrifying the furnace assembled in the S2 for smelting for 32 hours, wherein in the electrifying process, the power of the power transmission transformer in the 0 th-30.4 th hour time period is 45000KVA, the power of the power transmission transformer in the 30.4 th-32 th hour time period is 27000KVA, cooling for 3 days after smelting is completed, discharging, and grading to obtain the silicon carbide.

After the smelting furnace is discharged, the first-grade yield of the silicon carbide is 72%, the crystallization cylinder in the smelting furnace is relatively complete, and the crystallization cylinder does not obviously sink.

EXAMPLE III

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 810.91 tons of quartz sand with the granularity of 3 mm-10 mm and 675.76 tons of taixi coal with the granularity of 1 mm-3 mm are prepared and uniformly mixed, marked as material A, 1621.82 tons of quartz sand with the granularity of less than 1mm and 1351.52 tons of taixi coal with the granularity of less than 2mm are prepared and uniformly mixed, and marked as material B; the quartz sand and the Taixi coal are prepared and mixed according to the proportion of 1.20: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the reaction raw material mixed with the S1, charging the material A, and charging the material B to ensure that the granularity of the carbonaceous raw material of the furnace burden below the 1/3 position of the silicon carbide smelting furnace is 1 mm-3 mm, the particle size of the siliceous raw material is 3 mm-10 mm, and the bulk density of the burden below the height 1/3 of the silicon carbide smelting furnace is 260kg/m³～300kg/m³(ii) a The granularity of the charging material carbon raw material above the 1/3-height position of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm;

s3 smelting: and (3) electrifying the furnace assembled in the S2 for smelting for 36 hours, wherein in the electrifying process, the power of the power transmission transformer in the 0 th-30.6 th hour time period is 51000KVA, the power of the power transmission transformer in the 30.6 th-36 th hour time period is 38000KVA, cooling for 3 days after smelting is completed, discharging, and grading to obtain the silicon carbide.

After the smelting furnace is taken out, the first-grade yield of the silicon carbide is 63 percent, the crystallization cylinder in the smelting furnace is relatively complete, and the crystallization cylinder does not obviously sink.

Example four

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 125.17 tons of quartz sand with the granularity of 3 mm-10 mm and 165.56 tons of taixi coal with the granularity of 1 mm-3 mm are prepared and uniformly mixed, marked as material A, 397.35 tons of quartz sand with the granularity of less than 1mm and 331.12 tons of taixi coal with the granularity of less than 2mm are prepared and uniformly mixed, and marked as material B; the quartz sand and the Taixi coal are prepared and mixed according to the proportion of 1.20: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the reaction raw material mixed with the S1, charging the material A, and charging the material B to ensure that the granularity of the carbonaceous raw material of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 1-3 mm, the granularity of the siliceous raw material is 3-10 mm, and the bulk density of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 260kg/m³～300kg/m³(ii) a The granularity of the charging material carbon raw material above the 1/3-height position of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm;

s3 smelting: and (3) electrifying the furnace assembled in S2 for smelting for 36 hours, wherein in the electrifying process, the power of the power transmission transformer in the 0 th-30.6 th hour time period is 12500KVA, the power of the power transmission transformer in the 30.6 th-36 th hour time period is 8300KVA, cooling for 3 days after smelting is completed, discharging, and grading to obtain the silicon carbide.

After the smelting furnace is taken out, the first-grade yield of the silicon carbide is 60%, the crystallization cylinder in the smelting furnace is relatively complete, and the crystallization cylinder does not obviously sink.

Comparative example 1

The method for smelting silicon carbide by using the sealed environment-friendly silicon carbide smelting furnace is characterized by comprising the following steps of:

s1 preparing reaction raw materials and mixing: 2420 tons of quartz sand with the granularity of less than 2mm and 2040 tons of taixi coal with the granularity of less than 1mm are prepared and mixed uniformly, and the quartz sand and the taixi coal are prepared and mixed according to the proportion of 1.186: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the S1 mixed reaction raw materials, wherein the bulk density of the charge is 350kg/m³～450kg/m³；

S3 smelting: and (3) electrifying the furnace assembled in the S2 for smelting for 34 hours, wherein in the electrifying process, the power of the power transmission transformer in the 0 th-30.4 th hour time period is 51000KVA, the power of the power transmission transformer in the 30.4 th-34 th hour time period is 34000KVA, cooling for 3 days after smelting is completed, discharging, and grading to obtain the silicon carbide.

After the silicon carbide is discharged from the furnace, the first-grade yield of the silicon carbide is 50 percent, and the crystallization cylinder is relatively complete.

Comparative example No. two

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 807 tons of quartz sand with the granularity of 4 mm-10 mm and 680 tons of taixi coal with the granularity of 1 mm-3 mm are prepared and uniformly mixed, marked as material A, and 1613 tons of quartz sand with the granularity of less than 1mm and 1360 tons of taixi coal with the granularity of less than 2mm are prepared and uniformly mixed, marked as material B; the quartz sand and the Taixi coal are prepared and mixed according to the proportion of 1.186: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the reaction raw material mixed with the S1, charging the material A, and charging the material B to ensure that the granularity of the carbonaceous raw material of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 1-3 mm, the granularity of the siliceous raw material is 4-10 mm, and the bulk density of the furnace charge below the height 1/3 of the silicon carbide smelting furnace is 250kg/m³～290kg/m³(ii) a The granularity of the charging material carbon raw material above the 1/3-height position of the silicon carbide smelting furnace is less than 2mm, and the granularity of the siliceous raw material is less than 1 mm;

s3 smelting: and (3) electrifying the furnace loaded in the S2 for smelting for 34 hours, setting the power of the power transmission transformer to be 9000KVA, cooling for 3 days after smelting, discharging, and grading to obtain the silicon carbide.

After the silicon carbide is discharged from the furnace, the first-grade yield of the silicon carbide is 59%, and the crystallization cylinder is burnt out and sinks obviously.

Comparative example No. three

A method for smelting silicon carbide by using a sealed environment-friendly silicon carbide smelting furnace is used for smelting silicon carbide in the sealed environment-friendly silicon carbide smelting furnace disclosed by 'a high-efficiency environment-friendly silicon carbide smelting furnace' (CN110849151A), and the smelting comprises the following steps:

s1 preparing reaction raw materials and mixing: 2420 tons of quartz sand with the granularity of less than 2mm and 2040 tons of taixi coal with the granularity of less than 1mm are prepared and mixed uniformly, and the quartz sand and the taixi coal are prepared and mixed according to the proportion of 1.186: 1; the silicon content of the quartz sand is more than or equal to 98.5 percent, the fixed carbon of the anthracite is more than 83 percent, the ash content is 2 to 7 percent, and the volatile matter is 7 to 9.5 percent;

s2 furnace charging: charging the S1 mixed reaction raw materials, wherein the bulk density of the charge is 350kg/m³～450kg/m³；

S3 smelting: and (3) electrifying the furnace loaded with S2 for smelting for 34 hours, setting the power of the power transmission transformer to be 51000KVA, cooling for 3 days after smelting, discharging, and grading to obtain the silicon carbide.

After the silicon carbide is discharged from the furnace, the first-grade yield of the silicon carbide is 48%, and the crystallization cylinder is burnt out and sinks obviously.

TABLE 1 comparative examples and different processes of silicon carbide smelting conditions in the examples

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.