Dust in the manufacture of silicon carbide

There are many operating points for generating dust in the silicon carbide manufacturing process. The biggest working point of dust is smelting dry method, classification and so on.
The particle size of the suspended dust in the air of the granulation workshop is as follows: particles below 5 μm account for 66.6% to 92.5%, and those above 10 μm account for 4.8% to 22%. SiC accounts for more than 95% in dust and SiO2 content ranges from 0.35% to 3.58%. Technical transformation of the silicon carbide workshop. The coke processing and granulation process is carried out by a closed dust removal method, and the furnace loading process adopts a wet material operation method to obtain a extreme payment effect (Table 2-11-5).

Table 2-11-5 Typical data of dust concentration in silicon carbide workshop (mg/m3)
Working point coke processing furnace crystal block classification granulation before technical transformation 240 290 - 138~600
After technical transformation 10 12.83 76.1 3.5~17

The silicon carbide dust meets the "other dust" condition in TJ36-79, that is, the free silica content is below 10%, so the concentration standard can be set at 10 mg/m3.

Table 2-11-6 Maximum allowable concentration of productive dust in the air of the workshop (TJ36-79)
Hazardous substance name maximum allowable concentration (mg/m3)
Dust containing more than 10% free silica (quartz, quartzite, etc.) 1 2.0`
Asbestos dust and dust containing more than 10% asbestos 2.0
Talc dust containing less than 10% free silica 4.0
Glass wool and slag cotton dust 5.0
Cement dust containing less than 10% free silica
Tobacco and Tea Dust 3.0
Coal dust 10 containing less than 10% free silica
Other dust 2 10
Aluminum, alumina, aluminum alloy dust 4.0
Table: 1 Production dust containing more than 80% free silica, preferably not exceeding 1 mg/m3.
2 Other dusts refer to mineral and animal and plant dusts with free silica content below 10% and no toxic substances.

The 13 categories of hazardous substances emission standards of the "Three-waste emission test standards for industrial" GBJ4-73 stipulate that the second type of productive dust emission concentration is 150 mg/m3. Dust emission standards for silicon carbide manufacturing processes are generally considered as such.

Reflective Customized Key Chain

Reflective Customized Key Chain,Custom Reflective Key Chain,Promotion Reflective Key Chain

Reflective Material Car Number Plate Co.,Ltd , http://www.nsreflectivematerial.com