Difference between revisions of "Coating oxide (chemical blacking) in surface industry"
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+ | | align="center" style="background:#2266CC;"|'''Process''' | ||
+ | | align="center" style="background:#2266CC;"|'''Temperature [°C]''' | ||
+ | | align="center" style="background:#2266CC;"|'''Heat transfer medium''' | ||
+ | | align="center" style="background:#2266CC;"|'''Residence time''' | ||
+ | | align="center" style="background:#2266CC;"|'''Chemicals''' | ||
+ | | align="center" style="background:#2266CC;"|'''Concentration''' | ||
+ | | align="center" style="background:#2266CC;"|'''Details''' | ||
+ | | align="center" style="background:#2266CC;"|'''Literature''' | ||
+ | |- | ||
+ | | style="background:#AACCEE;"| Chemical blacking of steel|| align="center"| 121-149|| align="center"| || align=”center”| || align=”center”| Sodium hydroxide and sodium nitrate or a mixture of sodium nitrate and sodium nitrite || align="center"| Sodium hydroxide: 75 wt% and sodium nitrate: 25 wt%; sodium nitrate: 12 wt% and sodium nitrite: 13 wt%|| align="center"| || rowspan="6" align="center"| BAT for the surface treatment of metals and plastics, August 2006 | ||
+ | |- | ||
+ | | rowspan="3" style="background:#AACCEE;"| Chemical blacking of stainless steel|| align="center"| 370|| align="center"| || align=”center”| || align=”center”| Molten sodium/porassium dichromate|| align="center"| || align="center"| | ||
+ | |- | ||
+ | | align="center"| 60-90|| align="center"| || align=”center”| || align=”center”| Chromic acid and sulphate|| align="center"| || align="center"| "Inox" process | ||
+ | |- | ||
+ | | align="center"| 125-130|| align="center"| || align=”center”| || align=”center”| NaOH/NaNO2|| align="center"| || align="center"| Black colouring of chromium nickel steel | ||
+ | |- | ||
+ | | style="background:#AACCEE;"| Chemical blacking of copper|| align="center"| 93-100|| align="center"| || align=”center”| || align=”center”| Sodium hydroxide and sodium chlorite|| align="center"| Sodium hydroxide: 75 wt% and sodium chlorite: 25 wt%|| align="center"| | ||
+ | |- | ||
+ | | style="background:#AACCEE;"| Chemical blacking of brass|| align="center"| 93-100|| align="center"| || align=”center”| 5-10 min|| align=”center”| Sodium hydroxide and sodium chlorite|| align="center"| Sodium hydroxide: 85 wt% and sodium chlorite: 15 wt%|| align="center"| | ||
+ | |} | ||
+ | |||
Revision as of 14:25, 1 December 2010
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- Chemical blacking flowsheet
General flowsheet for the surface treatment of metals & plastics:
Literature: BAT for the surface treatment of metals & plastics, 2006
- Typical parameters of the process
Process | Temperature [°C] | Heat transfer medium | Residence time | Chemicals | Concentration | Details | Literature |
Chemical blacking of steel | 121-149 | Sodium hydroxide and sodium nitrate or a mixture of sodium nitrate and sodium nitrite | Sodium hydroxide: 75 wt% and sodium nitrate: 25 wt%; sodium nitrate: 12 wt% and sodium nitrite: 13 wt% | BAT for the surface treatment of metals and plastics, August 2006 | |||
Chemical blacking of stainless steel | 370 | Molten sodium/porassium dichromate | |||||
60-90 | Chromic acid and sulphate | "Inox" process | |||||
125-130 | NaOH/NaNO2 | Black colouring of chromium nickel steel | |||||
Chemical blacking of copper | 93-100 | Sodium hydroxide and sodium chlorite | Sodium hydroxide: 75 wt% and sodium chlorite: 25 wt% | ||||
Chemical blacking of brass | 93-100 | 5-10 min | Sodium hydroxide and sodium chlorite | Sodium hydroxide: 85 wt% and sodium chlorite: 15 wt% |
- Energy losses from the surface area of heated process solutions
LITERATURE: BAT for the Surface Treatment of Metals and Plastics, May 2005