| Titre : |
Chromium recovery or reuse |
| Type de document : |
texte imprimé |
| Auteurs : |
Karl Flowers, Auteur |
| Année de publication : |
2019 |
| Article en page(s) : |
p. 52-56 |
| Langues : |
Anglais (eng) |
| Catégories : |
Chrome -- Recyclage
Récupération (Déchets, etc.)
Tannage au chrome
|
| Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
| Résumé : |
Chromium tanning is a highly inefficient chemical process if allowed. For the last 130 years, tanners have learnt progressively how to make this process more efficient. There are a few significant methods that allow the process to go from a low yield process into a more efficient method :
- Effective chromium and collagen masking allowing deeper penetration.
- Lower float use, increases the concentration of chromium and this drives penetration.
- pH at the higher end of basifying range.
- Temperature at the end of basifying.
- Masking agents that help with chromium binding (chrome savers).
- Chase pickle type tannages.
Many of these have driven the process towards efficiencies that are in the 80-90% range. Some tannages have even claimed 95-99% efficiencies. For those levels of efficiencies, the residual levels of chromium may be too insignificant to financially motivate for the reuse or recycling of the chromium salts.
For a tannery that has a 65% uptake of the chromium salts, the amount of remaining chromium salts will be in the order of 35% (350 g/L) chromium that could be used in the next iteration of the process. A tannery having 5% (50 g/L) chromium could use the liquor remaining from the tannage (after pH correction) and could directly apply it into the pickle, the sait and residual chromium (and water of course) would mean significant reductions in chemicals and water used at this processing step. |
| Note de contenu : |
- Waste hierarchy
- Chromium efficiency
- Recycling/reuse
- Recovery
- Circularity
- Fig. 1 : The waste hierarchy
- Fig. 2 : The chromium recycle system
- Fig. 3 : The chromium recovery system |
| En ligne : |
https://drive.google.com/file/d/1QCSUQSP7K8PMiZbsw8Deh4eDFqHdspoC/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33141 |
in INTERNATIONAL LEATHER MAKER (ILM) > N° 38 (11-12/2019) . - p. 52-56
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Chromium recovery or reuse in INTERNATIONAL LEATHER MAKER (ILM), N° 38 (11-12/2019)
