Specialized metallurgical processes – compositions for use therei – Processes – Free metal or alloy reductant contains magnesium
Reexamination Certificate
1999-02-23
2001-01-30
King, Roy V. (Department: 1742)
Specialized metallurgical processes, compositions for use therei
Processes
Free metal or alloy reductant contains magnesium
C423S024000, C428S391000, C428S405000, C528S030000
Reexamination Certificate
active
06179898
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a new aluminosilicate organic-inorganic polymer and its use in effluent treatment processes, in particular for the treatment of photographic effluents.
BACKGROUND OF THE INVENTION
Many manufacturing and processing methods generate effluents which, on the one hand, cannot be directly disposed of via the sewers because of their composition and, on the other hand, contain substances the recovery and reuse of which would be economically gainful. One example is the photographic processing industry, in which exposed silver halide photographic films and papers are treated in successive processing baths that are rich in chemicals. Such photographic film processing methods are well known (see for example, Chimie et Physique Photographiques; Pierre Glafkides, Vol. 2, Chap XL, pages 947-967).
In general photographic processing comprises several processing baths and one or more wash and/or stabilization baths. The build-up in the wash and/or stabilization baths of substances carried over from the preceding processing steps is especially detrimental not only to the stability of developed photographic images and to the good keeping of sensitometric characteristics, but also to the possibility of recycling these wash and stabilization baths, or discharging them to the sewers. After processing, the wash and stabilization baths are found to contain inorganic compounds, such as iron, silver, thiosulfate, and sulfate ions, or organic compounds which are, either substances used for development, or products coming from the reaction of these substances during development, or from the step of fixing or bleach-fixing.
The problem of discharging silver to the sewers is especially important because of new standards that apply to photographic processing methods. There are notably standards that set the maximum volume of water that should be used for washing 1 m
2
of photographic material. In particular, for processing X-radiographs, the current French standard permits the use of 15 liters of water per m
2
of single-coated radiographic product to be processed and 30 liters of water per m
2
of double-coated radiographic product, with discharge to the sewers of water containing a maximum of 1 ppm of silver. Reducing the permissible volume of water produces wash baths that are more concentrated in silver and thus more difficult to decontaminate. Therefore it is necessary to have a processing method that is both efficient and complies with the standards. It is also useful to have a method that is easy to apply and economic.
SUMMARY OF THE INVENTION
The objective of the present invention is to provide a new organic-inorganic polymer and the use of this polymer for the treatment of effluents containing silver in ionic form so as to reduce significantly the quantity of silver discharged with these effluents. This organic-inorganic polymer can be included as part of a device for treating effluent containing silver in the ionic form.
This objective is achieved according to the present invention, which relates to an aluminosilicate having grafted thereon an organic radical having a —SH or —S(—CH
2
)
n
—S— group wherein n is from 0 to 4.
The present invention further relates to a method for obtaining such a polymer, method which comprises hydrolysing an alkylalkoxysilane having the formula RSiR
1
x
(OR
2
)
3−x
wherein R is an alkyl group comprising a —SH or —S(—CH
2
)
n
—S— function wherein n is from 0 to 4, R
1
and R
2
are independently a methyl or ethyl group, x is 0 or 1, in the presence of an aluminosilicate inorganic polymer comprising active hydroxyl groups on the surface. “Active hydroxyl groups” are groups capable of reacting with alkylalkoxysilane.
The present invention further relates to a process for treating an effluent containing silver in ionic form, which comprises contacting said effluent with an organic-inorganic polymer comprising aluminosilicate having grafted thereon an organic radical having a —SH or —S(—CH
2
)
n
—S— group wherein n is from 0 to 4 in order to eliminate the silver in ionic form.
This process reduces the quantity of silver contained in the effluent substantially when the silver in the effluent is in ionic form.
The process of this invention is especially efficient for decontaminating photographic effluents, in particular for processing baths for silver halide photographic materials, for example wash baths, stabilization baths, and bleaching baths containing silver in ionic form. For photographic baths, the silver is in the form of an ionic complex.
The treatment process of the invention does not modify the properties of the effluent treated. In particular, the pH of the effluent before and after the invention treatment as well as the salt content of the effluent stay unchanged. In addition, the nature of the water making up the effluent to be treated does not modify the efficiency of the treatment.
In the scope of the invention, it is not worthwhile previously diluting the effluent to be treated.
REFERENCES:
patent: 2304427 (1942-12-01), Sibley
patent: 2726141 (1955-12-01), Appell
patent: 3547841 (1970-12-01), Overmars
patent: 3892688 (1975-07-01), Motani et al.
patent: 3892689 (1975-07-01), Motani et al.
patent: 4051026 (1977-09-01), Cremers et al.
patent: 5683826 (1997-11-01), Poncelet et al.
patent: 5756628 (1998-05-01), Tani et al.
patent: 736249 (1996-10-01), None
Mercier et al, “Access in Mesoporous Materials Advantages of a Uniform Pore Structure in the Design of a Heavy Metal Ion Adsorbent for Environmental Remediation” Advanced Materials, vol. 9, No. 6, 1997. pp. 500-503.
Derwent Publication #1992-223551 1990 JP-0275026 Oct. 12, 1990.
Poncelet Olivier J.
Rigola Jeannine
Wettling Danielle M.
Eastman Kodak Company
King Roy V.
McGuthry-Banks Tima
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