This standard specifies the principle, sample preparation, instruments and reagents, test procedures, test results and precision of the determination of silicon carbide in corundum. This standard is applicable to the determination of silicon carbide content in corundum, a by-product of graphitization production process. YB/T 175-2000 Determination of Silicon Carbide in Corundum YB/T175-2000 Standard download decompression password: www.bzxz.net

YB/T175—2000
Based on the characteristics of carborundum, a by-product of the graphitization production process, this standard selects a chemical analysis method for the determination of silicon carbide using hydrochloric acid as a solvent.
This standard is proposed and managed by the Metallurgical Industry Information Standards Research Institute. The drafting unit of this standard: Jilin Carbon Group Co., Ltd. The main drafters of this standard: Zhang Xifen, Park Wenge, Sun Quan. 337
7 Scope
Ferrous Metallurgical Industry Standard of the People's Republic of China Determination of Silicon Carbide in Carborundum
The determination of silicon carbide in carborundumYB/T 175—-2000
This standard specifies the principle, sample preparation, instruments and reagents, test procedures, test results and precision of the determination of silicon carbide in carborundum. This standard is applicable to the determination of silicon carbide content in carborundum, a by-product of the graphitization production process. 2 Referenced standards
The clauses contained in the following standards constitute the clauses of this standard by being referenced in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1997-1989 Collection and preparation of coke samples 3 Principle
The sample is first burned to remove free carbon, and the residue is treated with hydrofluoric acid, nitric acid and sulfuric acid to allow free silicon and silicon dioxide to generate volatile silicon tetrafluoride to escape. Impurities are dissolved with hydrochloric acid, filtered and washed, and the residue is measured to obtain the silicon carbide content. 4 Samples
4.1 The collection of samples shall be carried out in accordance with the provisions of GB/T1997. 4.2 First, place the sample in a drying oven at 105±5℃ and dry for 2h~3h, take it out and cool it, then use a hammer to break the sample on a steel plate until it is less than 2.5mm, mix it thoroughly and take 1kg of the sample by quartering, use a double-grinding crusher to crush all the samples to less than 1mm, mix the sample thoroughly and evenly, take 100g by quartering, crush it with a steel mortar until it passes through a 0.15mm standard sieve, take 25g by quartering, use a magnet to absorb the iron filings brought in during the crushing, put them into a sample bag, and place them in a dryer for use. 5 Instruments and reagents
5.1 Instruments
5.1.1 High temperature furnace: (850±20)℃.
5.1.2 Adjustable electric furnace: not less than 2000W. 5.1.3 Sand bath: not less than 3000W.
5.1.4 Platinum crucible: 30mL (height less than 30mm). 5.1.5 Beaker: 300mL.
5.1.6 Glass funnel: 80mm diameter.
Plastic volumetric precipitator: 20mL, graduation value is 0.4mL. 5. 1.7
5.1.8 Filter paper: $125mm medium-speed quantitative filter paper. 5.1.9 Balance: sensitivity 0.0001g.
Dryer: internal desiccant (color-changing silica gel). 5.1.10
State Metallurgical Industry Bureau approved 338 on 2000-07-26
Implementation on 2000-12-01
5.1.11 Pipette: 2mL.
5. 1.12 pH test paper.
5.2 Reagents
5.2.1 Hydrofluoric acid; analytical grade.
5.2.2 Nitric acid; analytical grade.
5.2.3 Sulfuric acid: analytical grade (1+1).
Hydrochloric acid: analytical grade (1+1).
5.2.5 Hydrochloric acid: analytical grade (5+95).
6 Analysis steps
YB/T 175—2000
6.1 Weigh 0.5g of the sample to the nearest 0.0001g, place it in a platinum bath that has been burned to constant weight, and burn it in a high-temperature furnace at (850±20)℃ for 2h.
6.2 After the sample cools naturally, add 10mL of hydrofluoric acid, 1mL of concentrated nitric acid, and 3-5 drops of (1+1) sulfuric acid, place it in a sand bath and heat until all the white smoke disappears.
6.3 Add 20mL (1+1) hydrochloric acid to platinum and heat it on a sand bath for 20min~25min to completely dissolve the impurities. Filter with medium-speed quantitative filter paper. Wash with (5+95) hot hydrochloric acid 3~4 times, and then wash with hot distilled water until the pH test paper turns yellow. Place the filter paper and residue in the original platinum crucible, ash the filter paper on an electric furnace, and then place it in a muffle furnace at (850±20)℃ and burn it for 40min. Take it out, cool it in the air for about 5min, then move it into a dryer and cool it to room temperature before weighing. 7 Test results www.bzxz.net
The content of silicon carbide is calculated according to formula (1):
SiC(%) =
Where: SiC-a percentage of silicon carbide, %.
m Mass of empty crucible, g.
Mass of crucible and residue, g.
The result is the arithmetic mean of two tests, and the test result is rounded to two decimal places. 8 Precision
Repeatability r: not more than 0.60%.
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