Case Study #270
1. Headline: Process modification in a crystal and glass
works reduces discharge
2. Background: The Art de Vianne crystal and glass works
produces glass and crystal lighting by blowing. A
technical feasibility study on the fluoridated bath
recycling for the satin finish for glass was carried out
in 1993.
3. Cleaner Production Principle: process modification
4. Description of Cleaner Production Application:
Information about the process and wastes
The glass is given a satin finish and frosted by soaking
in a fluorhydric acid and ammonium bifluoride bath. The
rinsing waters contain hexafluorosilicic acid, ammonia,
silica and fluorohydric acid. The factory did not have any
waste treatment.
The technique normally used by the glass workers consists
of precipitation-settling-filtration with lime milk which
generates sludge, costly to discharge. The sanitary land
filling of such sludge will be forbidden in the future.
The study was concerned with a regeneration process for
effluent solutes to obtain fluorohydric acid, satin finish
recycling and recycling of treated rinsing water.
The process is based on electrodialysis and
electrometathesis.
Decomposition of hexafluorosilicic acid by strong
alkaline.
Elimination of the silica achieved by filtration.
Preconcentration of ammonium fluoride achieved in a
preliminary electrodialysis module.
Concentration of fluorohydric acid in a second
electrodialysis module.
Recycling of the thinned solution, towards the rinsing,
and of the solution concentrated in fluorohydric acid
towards the satin-finish bath.
Stage of development
Study started on a pilot unit of 1 m3/h to validate the
concluding results obtained in the laboratory.
Material / energy balance and substitution
Recuperation forecast of 30 tons of fluoride per year.
Recuperation forecast of 5 kg of fining products per year.
5. Economics:
Cost of direct investment
Technical study 656 000
Financial study 144 000
Total 800 000
FF (1993)
6. Advantages:
Discharges suppression.
Reduction of pollution tax.
Conformity of the factory to environmental regulations.
Products saving.
7. Constraints: No information provided.
8. Contacts:
Agence de l'Eau Adour-Garonne
M. GARIADOR
TEL: 33 61.36.37.38
M. PARENT
S.A. Cristalleries et Verreries d'Art de Vianne
Le Bourg
47230 VIANNE - France
TEL: 33 53.97.55.05
FAX: 33 53.97.50.28
M. Maton
M. Chatenet
Office International de l'Eau
Direction de la Formation et des Etudes
rue Edouard Chamberland
87065 Limoges Cedex, France
TEL: 33 55114770
FAX: 33 55777115
9. Keywords: France, crystal and glass, lighting, process
modification, fluoridated bath, electrometathesis, ISIC
3620, electrodialysis
10. This case study was submitted to UNEP IE in 1994 by the
French Office International de l'Eau. It has not undergone
a formal technical review.