Index denomination | Characteristics and norms for grades
| Methods of analysis | |||||||
| 60 | 90 | 120 | 150 | 175 | 200 | 300 | 380 | |
1. Appearance: noncompacted*) |
Loose blue-white powder | visually | |||||||
compacted | White mass in the form of porous pieces | - | visually | ||||||
2. Mass part of silicone dioxide (SiO₂) in recalculation on burnt substance, %, not less | 99,9 | 99,9 | 99,9 | 99,9 | 99,9 | 99,9 | 99,9 | 99,9 | GOST 14922 |
3. Mass part of Fe₂O₃, %, not more | 0,003 | 0,003 | 0,003 | 0,003 | 0,003 | 0,003 | 0,003 | 0,003 | GOST 14922 |
4. Mass part of Al₂O₃, %, not more | 0,05 | 0,05 | 0,05 | 0,05 | 0,05 | 0,05 | 0,05 | 0,05 | GOST 14922 |
5. Mass part of TiO₂, %, not more | 0,03 | 0,03 | 0,03 | 0,03 | 0,03 | 0,03 | 0,02 | 0,02 | GOST 14922 |
6. pH of suspension | 3,8 -4,5 | 3,8 -4,5 | 3,8 -4,5 | 3,8 -4,5 | 3,8 -4,5 | 3,7 -4,5 | 3,6 -4,5 | 3,6 -4,5 | GOST 14922 |
7. Mass part of moisture, %, not more**) | 1 | 1 | 1 | 1 | 1,5 | 1,5 | 1,5 | 1,5 | GOST 14922 |
8. Mass loses at burning, %, not more | 1 | 1 | 1 | 1 | 1 | 1 | 2 | 2 | GOST 14922 |
9.Bulk density, gr/dm³: |
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| GOST 14922 |
noncompacted | 40-60 | 40-60 | 40-60 | 40-60 | 40-60 | 40-60 | 40-60 | 40-60
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compacted | 120-140 | 120-140 | 120-140 | 120-140 | 120-140 | 120-140 | 110-140 | Is not to be compacted | |
10. Specific surface, m2/gr by BET method | 60±20 | 90±20 | 120±20 | 150±20 | 175±25 | 200±25 | 300±30 | 380±40 | GOST 14922 |
11. Mass part of big particles (grit), %, not more | 0,04 | 0,04 | 0,04 | 0,04 | 0,04 | 0,04 | 0,04 | 0,05 | GOST 14922 |
*) In noncompacted silica there can be easily decomposable/breakable loose pieces **) Increase of moisture mass part is allowed for grades 60, 90, 120, 150, 175 and 200, not more than up to 2%; for grades 300 and 380 not more than up to 3 and 4% accordingly, during the shelf life at relative air humidity of not more than 60%.
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