AU662949B2 - Process for the colour stripping and bleaching of coloured waste paper - Google Patents
Process for the colour stripping and bleaching of coloured waste paper Download PDFInfo
- Publication number
- AU662949B2 AU662949B2 AU32801/93A AU3280193A AU662949B2 AU 662949 B2 AU662949 B2 AU 662949B2 AU 32801/93 A AU32801/93 A AU 32801/93A AU 3280193 A AU3280193 A AU 3280193A AU 662949 B2 AU662949 B2 AU 662949B2
- Authority
- AU
- Australia
- Prior art keywords
- waste paper
- treatment
- acid
- coloured
- bleaching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- 239000010893 paper waste Substances 0.000 title claims description 43
- 238000000034 method Methods 0.000 title claims description 26
- 238000004061 bleaching Methods 0.000 title claims description 14
- 239000002253 acid Substances 0.000 claims description 25
- 238000011282 treatment Methods 0.000 claims description 25
- 150000003839 salts Chemical class 0.000 claims description 23
- -1 halide ion Chemical class 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 12
- 239000000376 reactant Substances 0.000 claims description 10
- 238000004537 pulping Methods 0.000 claims description 9
- 150000001875 compounds Chemical class 0.000 claims description 7
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 5
- 230000002378 acidificating effect Effects 0.000 claims description 5
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 5
- 239000007864 aqueous solution Substances 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 4
- JZBWUTVDIDNCMW-UHFFFAOYSA-L dipotassium;oxido sulfate Chemical compound [K+].[K+].[O-]OS([O-])(=O)=O JZBWUTVDIDNCMW-UHFFFAOYSA-L 0.000 claims description 4
- 238000005188 flotation Methods 0.000 claims description 4
- 150000002500 ions Chemical class 0.000 claims description 4
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 3
- 238000005406 washing Methods 0.000 claims description 3
- CPELXLSAUQHCOX-UHFFFAOYSA-M Bromide Chemical compound [Br-] CPELXLSAUQHCOX-UHFFFAOYSA-M 0.000 claims description 2
- 239000003513 alkali Substances 0.000 claims description 2
- 150000004820 halides Chemical class 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 claims description 2
- 239000000123 paper Substances 0.000 description 16
- 229920003043 Cellulose fiber Polymers 0.000 description 9
- 239000000976 ink Substances 0.000 description 7
- 238000000746 purification Methods 0.000 description 4
- 229920001131 Pulp (paper) Polymers 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 150000001340 alkali metals Chemical class 0.000 description 3
- 239000000975 dye Substances 0.000 description 3
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Inorganic materials Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- FHHJDRFHHWUPDG-UHFFFAOYSA-N peroxysulfuric acid Chemical compound OOS(O)(=O)=O FHHJDRFHHWUPDG-UHFFFAOYSA-N 0.000 description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 229910052783 alkali metal Inorganic materials 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 229910052801 chlorine Inorganic materials 0.000 description 2
- 238000004040 coloring Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000002023 wood Substances 0.000 description 2
- ORWQBKPSGDRPPA-UHFFFAOYSA-N 3-[2-[ethyl(methyl)amino]ethyl]-1h-indol-4-ol Chemical compound C1=CC(O)=C2C(CCN(C)CC)=CNC2=C1 ORWQBKPSGDRPPA-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- 229910001508 alkali metal halide Inorganic materials 0.000 description 1
- 229910001615 alkaline earth metal halide Inorganic materials 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000008346 aqueous phase Substances 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 239000011111 cardboard Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 239000002761 deinking Substances 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 229910000039 hydrogen halide Inorganic materials 0.000 description 1
- 239000012433 hydrogen halide Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000011087 paperboard Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 229910052911 sodium silicate Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000001117 sulphuric acid Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/64—Paper recycling
Landscapes
- Paper (AREA)
Description
AUSTRALIA
Patents Act 662949 COMPLETE SPECIFICATION
(ORIGINAL)
Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: Solvay Interox (Societe Anonyme) Actual Inventor(s): Anthony J. Nugent John E. Skinner Address for Service: PHILLIPS ORMONDE FITZPATRICK S* Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: PROCESS FOR THE COLOUR STRIPPING AND BLEACHING OF COLOURED WASTE PAPER Our Ref: 318094 POF Code: 1659/194952 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 600-1- 6006 Process for the colour stripping and bleaching of coloured waste paper.
The invention relates to a process for the colour stripping and bleaching of waste paper with a view to its recycling. It is more particularly concerned with coloured waste paper.
The papermaking industry employs cellulose fibres originating from wood as a principal source of raw materials. Among these, fibres originating from recycled waste paper constitute an increasingly important source. This waste paper is usually disintegrated in an aqueous phase, in most cases in a pulper, so as to obtain a pulp which is generally employed as such or as a mixture with unrecycled cellulose pulp for the manufacture of packaging paper and cardboard and of newsprint. Since the proportion of recovered cellulose fibres frequently reaches a high level which it is very difficult to exceed, other outlets have also been envisaged for waste paper, namely its incorporation in pulps intended for the manufacture of printing and writing paper and of tissue paper. In this case it is important to have available pulp which exhibits a high brightness level.
*This high brightness level can usually be achieved by means of deinking and/or bleaching treatments.
20 Recycling of waste paper encounters a considerable obstacle in the presence, in a high proportion thereof, of dyes of various kinds. These prove very difficult to neutralise, given that they remain solidly attached to the cellulose fibres and can be stripped only under operating conditions which are very frequently damaging to the cellulose fibres themselves.
In the case of some categories of waste paper such as, for example, waste paper from carbonless copy paper (CCP), it has been possible to strip it by subjecting it to a treatment by means of a peroxide compound in an alkaline medium (US Patent 30 4 381 969 in the name of INTEROX).
el• 8 69i h nm fINEO) A treatment capable of permitting the colour stripping of coloured waste paper from all sources consists in pulping this paper and next subjecting it to a treatment by means of an alkali metal or alkaline-earth metal hypochlorite (Pulp and Paper Manufacture, 3rd Edition, Vol. 3, Secondary Fibers and Non-Wood Pulping, F. Hamilton, B. Leopold and M.J. Kocurek, 1987, The Joint Textbook Committee of The Paper Industry TAPPI CPPA, Atlanta and Montreal, page 234, 3rd paragraph, R.P. Singh A. Color Stripping).
In many cases, waste paper cannot be stripped sufficiently completely for a treatment by means of a peroxide compound in an alkaline medium and it is quite frequently necessary to resort to additional treatments which are often detrimental to the cellulosic matter.
The stripping of pulps originating from waste paper by means of hypochlorite, for its part, is responsible for a considerable degradation of cellulose fibres and limits the use of paper stripped in this way to lower quality paper grades.
stripping coloured waste paper which does not make use of reactant cuataining active chlorine and which maintains he intrinsic qualities of the cellulose fibres.
To this end, the invention relates to a pro ss for colour stripping and bleaching coloured waste paper in which the 25 coloured waste paper is treated by means an oxidising reactant essentially comprising an aqueous so ion of at least one peroxygen compound and of a halide io the peroxygen compound being selected from the group consi ing of monoperoxysulphuric acid, any one of the salts of t i acid, mixtures of two or more salts 30 of this acid and mixtu s of monoperoxysulphuric acid with at least one of its s ts.
Coloured ste paper is intended to denote wood-free paper, paper cont a ing a high proportion of mechanical pulp or mixtures S.of thos papers which have been subjected to a bulk-colouring tre ment using a dye for cellulose fibres. This waste paper may E E r, I q It would be advantageous to provide a process for stripping coloured waste paper which does not make use of a reactant containing active chlorine and which maintains the intrinsic qualities of the cellulose fibres.
According to this invention there is provided a process for colour stripping and bleaching of coloured waste paper, wherein the coloured waste paper is treated by means of an oxidizing reactant including an aqueous solution of at least one peroxygen compound and of a halide ion, the peroxygen compound being selected from the group consisting of monoperoxysulfuric acid, any one of the salts of this acid, mixtures of two or more salts of this acid and mixtures of monoperoxysulfuric acid with at least one of its salts.
Coloured waste paper is intended to denote wood-free paper, paper containing a high proportion of mechanical pulp or mixtures of those papers which have been subjected to a bulk-colouring treatment using a dye for cellulose fibres.
This waste paper may originate from coloured broke as well as from waste paper
S
:0.
2a- 2a collections. Wood-free waste paper gave good results.
In the process according to the invention, the treatment with monoperoxysulphuric acid or one of its salts consists in treating the waste paper with the inorganic acid corresponding to the formula H 2 S0 5 (also called Caro's acid) or one of its alkali metal, alkaline-earth metal or ammonium salts, or with a mixture of a number of these salts or of monoperoxysulphuric acid with one or more of these salts. Potassium monoperoxysulphate gave good results.
In an advantageous alternative form of the process according to the invention, the monoperoxysulphuric acid or the salts which are used may have been prepared immediately before being used by reaction of a concentrated aqueous solution of sulphuric acid or of its salts with a concentrated aqueous solution of a peroxygen compound, for example hydrogen peroxide. Concentrated solutions are intended to denote solutions of H 2 S0 4 with a concentration of at least approximately 10 moles per litre and of H202 with a concentration of at least approximately 20 by weight, respectively.
According to the invention the treatment of coloured waste paper by means of monoperoxysulphuric acid is performed in the presence of a halide ion. A halide ion is intended to denote any anion belonging to the class of the halogens or a mixture of at least two of these ions in any proportions. The halide ion will preferably be chosen from chloride, bromide and iodide ions or mixtures of at least two of these ions. The chloride ion is particularly preferred.
The halide ions are advantageously used in the form of alkali metal or alkaline-earth metal halides. All the alkali or 30 alkaline-earth metals are suitable, because of their good solubility in water. Alternatively, an aqueous solution of a hydrogen halide may also be employed.
The quantity of monoperoxysulphuric acid or of one of its salts used in the process according to the invention is generally at least approximately 0.3 g per 100 g of dry pulp and, preferably, at least approximately 0.5 g per 100 g of dry pulp. It is also appropriate that this quantity of monoperoxysulphuric acid or of one of its salts should not exceed approximately 3 g per 100 g of dry pulp and, preferably, approximately 2.8 g per 100 g of dry pulp.
The quantity of halide ions to be used depends on that of the peroxymonosuphuric acid or of one of its salts. In general, a quantity of halide ions of at least approximately 25 of the weight of peroxymonosulphuric acid or of one of its salts and, preferably, of at least approximately 50 of this weight, is suitable. It is also advantageous that this quantity of halide ions should not exceed approximately 150 of the weight of peroxymonosulphuric acid and, preferably, approximately 130 X of this weight.
In a first alternative form of the process according to the invention, which is preferred, the treatment is performed using monoperoxysulphuric acid or one of its salts in a bleaching stage following the preliminary stage of pulping of the coloured waste paper.
In this alternative form, the waste paper is first of all pulped, in most cases in a pulper in the presence of chemical reactants. The reactants most commonly employed in the pulper are alkaline reactants such as sodium or calcium hydroxide or sodium carbonate.
At the end of this preliminary stage of treatment with 25 chemical reactants, the waste paper takes the form of a pulp o* which can then, according to the invention, be subjected to a S• bleaching treatment by means of monoperoxysulphuric acid or one of its salts.
In another alternative form of the process according to the 30 invention the treatment of the coloured waste paper by means of monoperoxysulphuric acid or one of its salts is performed in the pulper during the pulping of this waste paper.
The stage of pulping the coloared waste paper may optionally be followed by a stage of purification of the pulp, in order to rid it of a good proportion of the inks which it may contain.
This purification stage is generally performed according to one of the well-known techniques for removing inks by washing or by flotation. The paper stripping stage according to the invention advantageously follows this ink removal stage.
When the pulp is subjected to a purification treatment after its pulping it may be advantageous to incorporate into the pulper at the pulping stage certain additives which will facilitate ink removal. If the purification is performed by washing, these additives may, for example, consist of dispersing agents intended for better removal of the ink particles in the washes. On the other hand, in the case where the inks are removed by a flotation treatment, these additives will preferably be chosen from collecting agents, foaming agents and sodium silicate, to assist in the debinding and separation of the ink particles in the foam which accumulates at the surface of the flotation cells.
The invention may be performed at very different pHs. The treatment of coloured waste paper by means of monoperoxysulphuric acid or one of its salts according to the invention is preferably perforsed at an acidic pH. An acidic pH is intended to denote a pH not exceeding approximately 3.5, and preferably 3. However, it is appropriate that the pH should not be exaggeratedly acidic, values of at least approximately 0.5, and preferably 1.5, being u suitable.
25 In a variant it is possible, however, in an alternative but not preferred manner, to perform the treatment of the waste paper according to the invention by means of monoperoxysulphuric acid or one of its salts at higher pHs and even at a pH close to neutrality. In general, a pH of 8 will not be exceeded. This pH 30 will in most cases lie below 7.5 and preferably below 7, for example at pH 6.
The examples which follow are given for the purpose of illustrating the invention without, however, limiting its scope.
Example 2 was carried out according to the invention and example IR was carried out, by way of comparison, under operating conditions using a colour stripping/bleaching reactant not in accordance with the invention.
Example 1R (not in accordance with the invention) A sample of blue coloured paper from dyed broke was pulped and washed. The pulp obtained was then treated with 5 g of potassium monoperoxysulphate (KMPS) per 100 g of dry pulp at a temperature of 23 °C and for 120 minutes at an initial pH and at a consistency of 10 as dry pulp.
After treatment, the chromatic characteristics of the pulp according to the Hunter L,a,b colorimetric system (TAPPI standard T524) were measured.
The results of the measurements were as follows Untreated pulp KMPS treated pulp L 83.93 84.18 a -6.07 -5.44 b -9.65 -9.37 These results indicate that no discolouration has occured.
Example 2 (in accordance with the invention) The same sample of washed blue coloured paper pulp as that employed in Example 1R was treated for 120 minutes at 23 OC, at an initial pH of 4.0, with 5 g of potassium monoperoxysulphate (KMPS) and with 0.1 g of hydrochloric acid per 100 g of solids content and at a consistency of 10 as dry pulp.
At the end of the test, the same measurements as in test 1R were performed on the treated pulp. The results of these measurements were as follows 25 Untreated pulp KMPS treated pulp L 83.93 88.32 a -6.07 -4.31 b -9.65 -2.25 It can be seen from these results that the KMPS/C1- treated S 30 pulp has been discolourised to a considerable extent.
Claims (9)
1. A process for colour stripping and bleaching of coloured waste paper, wherein the coloured waste paper is treated by means of an oxidizing reactant including an aqueous solution of at least one peroxygen compound and of a halide ion, the peroxygen compound being selected from the group consisting of monoperoxysulfuric acid, any one of the salts of this acid, mixtures of two or more salts of this acid and mixtures of monoperoxysulfuric acid with at least one of its salts.
2. A process as claimed in Claim 1, wherein the coloured waste paper is first of all pulped in a preliminary stage and is then treated in a bleaching stage following the preliminary stage of pulping of the coloured waste paper.
3. A process as claimed in Claim 1, wherein the treatment is performed in a pulper during the preliminary stage of pulping of the coloured waste paper.
4. A process as claimed .in any one of Claims 1 to 3, wherein the 15 treatment is performed in an acidic medium at a pH not exceeding approximately A process as claimed in any one of Claims 1 to 3, wherein the treatment is performed at an acidic pH close to neutrality of between 6 and
6. A process as claimed in any one of Claims I to 5, wherein the treatment is performed by means of potassium monoperoxysulphate.
7. A process as claimed in any one of Claims 1 to 6, wherein the halide ion is used in the form of a halide of at least one alkali or alkaline-earth metal.
8. A process as claimed in any one of Claims 1 to 6, wherein the halide ion is selected from chloride, bromide and iodide ions and mixtures of these ions.
9. A process as claimed in Claim 8, wherein the halide ion is a chloride ion. A process as claimed in any one of Claims 1 to 9, wherein the treatment of waste paper is applied to a pulp which has previously been subjected to an operation of ink removal chosen from washing and flotation. K 4 -7-
11. A process as claimed in Claim 1 substantially as hereinbefore described with reference to Example 2. DATED: 12 July, 1995 PHILLIPS ORMONDE FITZPATRICK Attorneys for: SOLVAY INTEROX (SOCIETE ANONYME) 6 0 *0.4. A BS T RAC T Process for the colour stripping and bleaching of coloured waste paper. Process for colour stripping and bleaching of coloured waste paper by treatment by means of monoperoxysulphuric acid or of one of its salts, according to which the treatment is performed in the presence of a halide ion. No figure. te C. CC fl C. C .1 C. CC CC CC 8. C C.. C C CC C CC CC PCC *C CC C DC** C CC *CCC CC C CC C a. C *CCE
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU32801/93A AU662949B2 (en) | 1993-02-04 | 1993-02-04 | Process for the colour stripping and bleaching of coloured waste paper |
| DE69312127T DE69312127T2 (en) | 1992-03-09 | 1993-02-25 | Process for decolorizing and bleaching waste paper |
| AT93200529T ATE155542T1 (en) | 1992-03-09 | 1993-02-25 | METHOD FOR DECOLORING AND BLEACHING WASTE PAPER |
| EP19930200529 EP0560421B1 (en) | 1992-03-09 | 1993-02-25 | Process for the discolouration and bleaching of waste paper |
| CA 2091224 CA2091224A1 (en) | 1992-03-09 | 1993-03-08 | Process for removing colour and bleaching used coloured papers |
| JP4684893A JPH0641889A (en) | 1992-03-09 | 1993-03-08 | Decolorization and bleaching method for colored waste paper |
| BR9300787A BR9300787A (en) | 1992-03-09 | 1993-03-08 | PROCESS FOR COLORING AND WHITENING COLORFUL OLD PAPERS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU32801/93A AU662949B2 (en) | 1993-02-04 | 1993-02-04 | Process for the colour stripping and bleaching of coloured waste paper |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU3280193A AU3280193A (en) | 1994-09-08 |
| AU662949B2 true AU662949B2 (en) | 1995-09-21 |
Family
ID=3720264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU32801/93A Ceased AU662949B2 (en) | 1992-03-09 | 1993-02-04 | Process for the colour stripping and bleaching of coloured waste paper |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU662949B2 (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4264912A (en) * | 1979-04-30 | 1981-04-28 | Kcr, Inc. | Image formation and development apparatus |
| US4548674A (en) * | 1983-08-08 | 1985-10-22 | Interox (Societe Anonyme) | Process for the regeneration of waste paper |
-
1993
- 1993-02-04 AU AU32801/93A patent/AU662949B2/en not_active Ceased
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4264912A (en) * | 1979-04-30 | 1981-04-28 | Kcr, Inc. | Image formation and development apparatus |
| US4548674A (en) * | 1983-08-08 | 1985-10-22 | Interox (Societe Anonyme) | Process for the regeneration of waste paper |
Also Published As
| Publication number | Publication date |
|---|---|
| AU3280193A (en) | 1994-09-08 |
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