NO127834B - - Google Patents
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- Publication number
- NO127834B NO127834B NO16900767A NO16900767A NO127834B NO 127834 B NO127834 B NO 127834B NO 16900767 A NO16900767 A NO 16900767A NO 16900767 A NO16900767 A NO 16900767A NO 127834 B NO127834 B NO 127834B
- Authority
- NO
- Norway
- Prior art keywords
- bleaching
- pulp
- resin
- alkaline
- mass
- Prior art date
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- 238000004061 bleaching Methods 0.000 claims description 23
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 claims description 20
- 239000004155 Chlorine dioxide Substances 0.000 claims description 10
- 235000019398 chlorine dioxide Nutrition 0.000 claims description 10
- 230000020477 pH reduction Effects 0.000 claims description 8
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 6
- 239000002736 nonionic surfactant Substances 0.000 claims description 5
- 150000002978 peroxides Chemical class 0.000 claims description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 4
- -1 alkylphenols Chemical class 0.000 claims description 4
- 239000003945 anionic surfactant Substances 0.000 claims description 4
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 4
- 239000000194 fatty acid Substances 0.000 claims description 4
- 229930195729 fatty acid Natural products 0.000 claims description 4
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 claims description 3
- 229910052791 calcium Inorganic materials 0.000 claims description 3
- 239000011575 calcium Substances 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 150000004665 fatty acids Chemical class 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 238000010306 acid treatment Methods 0.000 claims description 2
- 150000001412 amines Chemical class 0.000 claims description 2
- 150000002191 fatty alcohols Chemical class 0.000 claims description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims 1
- 150000001450 anions Chemical class 0.000 claims 1
- 239000007859 condensation product Substances 0.000 claims 1
- 239000002563 ionic surfactant Substances 0.000 claims 1
- 238000009898 sodium hypochlorite bleaching Methods 0.000 claims 1
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 claims 1
- 239000011347 resin Substances 0.000 description 20
- 229920005989 resin Polymers 0.000 description 20
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 12
- 239000004094 surface-active agent Substances 0.000 description 9
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 8
- 238000005406 washing Methods 0.000 description 8
- 230000002378 acidificating effect Effects 0.000 description 6
- 239000003513 alkali Substances 0.000 description 6
- 239000007844 bleaching agent Substances 0.000 description 6
- ZKQDCIXGCQPQNV-UHFFFAOYSA-N Calcium hypochlorite Chemical compound [Ca+2].Cl[O-].Cl[O-] ZKQDCIXGCQPQNV-UHFFFAOYSA-N 0.000 description 4
- 125000000129 anionic group Chemical group 0.000 description 4
- 238000005660 chlorination reaction Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- RSWGJHLUYNHPMX-UHFFFAOYSA-N 1,4a-dimethyl-7-propan-2-yl-2,3,4,4b,5,6,10,10a-octahydrophenanthrene-1-carboxylic acid Chemical compound C12CCC(C(C)C)=CC2=CCC2C1(C)CCCC2(C)C(O)=O RSWGJHLUYNHPMX-UHFFFAOYSA-N 0.000 description 2
- 239000005708 Sodium hypochlorite Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 1
- 229920001131 Pulp (paper) Polymers 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 150000008055 alkyl aryl sulfonates Chemical class 0.000 description 1
- 150000008051 alkyl sulfates Chemical class 0.000 description 1
- 125000002947 alkylene group Chemical group 0.000 description 1
- 150000003868 ammonium compounds Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000003278 mimic effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000004076 pulp bleaching Methods 0.000 description 1
- 238000004537 pulping Methods 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/082—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer for immersion
Description
Fremgangsmåte ved flertrinnsbleking av sulfitmasse. Procedure for multi-stage bleaching of sulphite pulp.
Det er kjent at en vesentlig del av de forstyrrende smussflekker i 'blekt sulfitmasse består av harpiksprikker. Disse harpiksflekker dannes ofte ved bestemte be-handllngstrinn av massen, f. eks. ofte i forbindelse med visse bleketrinn eller føl-ger av bleketrinn. Dette følges da vanlig-vis av harpiksavsettelser i massesystemet. Det er f. eks. kjent at særlig -besværlige harpiksflekker dannes ved et kalsiumhypokloritbleketrinn som følger etter en alkali-behandlimg. It is known that a significant part of the disturbing dirt spots in 'bleached sulphite mass' consists of resin dots. These resin stains are often formed during certain treatment steps of the mass, e.g. often in connection with certain bleaching steps or following bleaching steps. This is usually followed by resin deposits in the pulp system. It is e.g. known that particularly troublesome resin stains are formed by a calcium hypochlorite bleaching step that follows an alkali treatment.
Harpiksvanskeligheter og forstyrrende Resin difficulties and disturbing
harpiksflekker forekommer også som følge ved flere andre bleketrinn. Det har vist seg at stor risiko for slike vanskeligheter alltid foreligger, når en sur massebehand-ling følger etter en alkalisk massebehand-ling, enten direkte eller etter at ytterligere et eller flere mere eller mindre alkaliske behandlinigstrinn er skutt inn mellom dem. Vanskelighetene opptrer, det være seg om alkaliet stammer ifra alkalimetall-, j ordalkallmetall- eller ammoniumforbin-delser, såsnart 'behandlingen er blitt utført ved en pH-verdi tilstrekkelig høy, f. eks. 8, for at en påtagelig koagulering av harpiks- og fettsyreforbindelser skal inntreffe ved den etterfølgende sur gjøring. resin stains also occur as a result of several other bleaching steps. It has been shown that there is always a high risk of such difficulties when an acidic pulp treatment follows an alkaline pulp treatment, either directly or after one or more more or less alkaline treatment steps have been inserted between them. The difficulties arise, whether the alkali originates from alkali metal, alkaline earth metal or ammonium compounds, as soon as the treatment has been carried out at a sufficiently high pH value, e.g. 8, for a noticeable coagulation of resin and fatty acid compounds to occur during the subsequent acidification.
Som eksempel skal nevnes en bleke-metode med klorerinigstrinn, 'alkalitrinn, hypoklorittrinn og surt klordioksydtrinn. Ved denne holdes normalt hypokloritbleke-trinnet relativt alkalisk, f. eks. med en slutt pH på over 9,0 eller 9,5. I det sure klordioksydtrinn synker derpå pH-verdien f. eks. til 4,5—6,5. Anvendes kalsium som base i hypokloritbleketrlnnet kan en del av harpiksprikkene dannes i dette trinnet. Når massen etter vaskning ikommer inn i klordioksydtrinnet skjer her dog på ny en påtagelig dannelse av forstyrrende harpiksprikker, spesielt hvis man, slik som ønsket fra varmeøkonomisk synspunkt, holder relativt lukket toakvannssystem med påfølgende fortynning og vasketrinn. As an example, a bleaching method with a chlorination step, an alkali step, a hypochlorite step and an acidic chlorine dioxide step should be mentioned. In this case, the hypochlorite bleaching step is normally kept relatively alkaline, e.g. with a final pH above 9.0 or 9.5. In the acidic chlorine dioxide step, the pH value then drops, e.g. to 4.5-6.5. If calcium is used as a base in the hypochlorite bleach solution, some of the resin dots may be formed in this step. When the pulp after washing enters the chlorine dioxide step, a noticeable formation of disturbing resin dots occurs here again, especially if, as desired from a heat economy point of view, a relatively closed two-water system with subsequent dilution and washing step is kept.
Lignende risiko for dannelse av harpiksflekker finnes når man gjør massen sur med svoveldioksyd eililer et inatrlumhy-poklorittrinn eller etter et kalsiumhypokloritbleketrinn med en relativ høy slutt pH, enten direkte eller etter først å ha skutt inn ennu en svak alkalisk behandling f. eks. en peroksydblekning. A similar risk for the formation of resin stains exists when the pulp is acidified with sulfur dioxide before an inatrlum hypochlorite step or after a calcium hypochlorite bleaching step with a relatively high final pH, either directly or after first introducing another weak alkaline treatment, e.g. a peroxide bleach.
Lignende vanskeligheter forekommer også når et surt kloreringstrinn følger på en alkalisk behandling, særlig når massen ikke senere gjennomgår noen ytterligere alkalisk behandling, hvor koagulerte har-pikspartikler ipå ny kan dispergeres. Similar difficulties also occur when an acid chlorination step follows an alkaline treatment, particularly when the pulp does not later undergo any further alkaline treatment, where coagulated resin particles can be dispersed again.
Hensikten med nærværende oppfinnelse er at ved tilsetning av små kjemika-liemengder å øke renheten hos den frem-stilte masse, hva angår forstyrrende, lett synlige harpiksprikker. Samtidig skal mas-sesystem og vaskefilter holdes fri for harpiksavsettelser og mengden av utskudds-masse fra sitøriet bringes ned. Oppfinnel-sen har sin hovedsakelige interesse ved fremstilling av sulfitmasse, hvor der legges størst vekt på renheten, som f. eks. blekt papir masse. The purpose of the present invention is to increase the purity of the produced mass, with regard to disturbing, easily visible resin dots, by adding small amounts of chemicals. At the same time, the pulping system and washing filter must be kept free of resin deposits and the amount of waste pulp from the sieve must be reduced. The invention has its main interest in the production of sulphite pulp, where the greatest emphasis is placed on purity, such as e.g. bleached paper pulp.
Foreliggende oppfinnelse angår en fremgangsmåte ved flertrinnsbleking av sulfitmasse, hvor en sur behandling utføres etter en alkalisk behandling som består av en alkalisk kalsium- eller natriumhypo-klorittbleklnig eller en peroksydbleking, og karakteristisk er at man straks før eller under sur gjøringen av massen tilsetter den et eller flere anioniske eller ikke-ioniske overflateaktive midler i en mengde av 0,003 til 0,03 vektspst., og fortrinnsvis 0,005 til 0,015 vektspst., beregnet på tørr masse. Tilsetningen av det overflateaktive middel til massen skjer helst før surgjøringen, f. eks. når massen har forlatt vaske-filtret, slik at det overflateaktive middel er nærværende når syren eller det sure blekemiddel blandes inn i massen. Det er også mulig å tilføre det overflateaktive middel sammen med blekemidlet. The present invention relates to a method for multi-stage bleaching of sulphite pulp, where an acid treatment is carried out after an alkaline treatment consisting of an alkaline calcium or sodium hypochlorite bleach or a peroxide bleach, and it is characteristic that immediately before or during the acidification of the pulp, a or more anionic or nonionic surfactants in an amount of 0.003 to 0.03 wt.%, and preferably 0.005 to 0.015 wt.%, calculated on dry mass. The addition of the surface-active agent to the mass preferably takes place before the acidification, e.g. when the pulp has left the washing filter, so that the surfactant is present when the acid or acidic bleach is mixed into the pulp. It is also possible to add the surface-active agent together with the bleaching agent.
Den nødvendige mengde anioniske og/ eller ikke-ioniske midler har vist seg å være avhengig av flere faktorer. Viktigst blant disse er konsentrasjonen oppløst harpikssyre- og fettsyreanloner i den masse som kommer inn i trinnet, hvilken kon-sentrasjon på sin side er avhengig blant annet av den iforangående alkaliske behandlingen, av virkningsgraden hos mel-lomliggende vasketrinn, av massekonsen-trasjonen, massens opprinnelige harpiks-innhold og harplksets kjemiske sammen-setning. Viktige faktorer er ennvidere pH-verdien og konsentrasjonen av flervexdige metaOiMoraeir i isuingj ørinigsitrininet, så vel som temperatur, oppholdstid, omrøring og luft-innsugning i dette trinn. Det har vist seg at en tilsetning av overflateaktive midler fra 0,003 og opp til 0,03 vektsprosent, beregnet på tørt cellulosemateriale, er tilstrekkelig, og at i de fleste tilfeller gir en mengde på 0,005—0,015 vektsprosent det beste resultat. The required amount of anionic and/or nonionic agents has been shown to depend on several factors. Most important among these is the concentration of dissolved resin acid and fatty acid anlons in the mass entering the step, which concentration in turn depends on, among other things, the previous alkaline treatment, on the effectiveness of intermediate washing steps, on the mass concentration, the mass's original resin content and the chemical composition of the resin. Important factors are furthermore the pH value and the concentration of multi-vegetable metaOiMoraeir in the isuingj ørinigcitrinin, as well as temperature, residence time, agitation and air entrainment in this step. It has been shown that an addition of surfactants from 0.003 and up to 0.03% by weight, calculated on dry cellulose material, is sufficient, and that in most cases an amount of 0.005-0.015% by weight gives the best result.
Såvel anioniske som ikke-ioniske overflateaktive midler har vist seg egnet for foreliggende oppfinnelse. Blant anioniske overflateaktive midler har særlig alkylsul-fater og alkylarylsulfonater og Mant ikke-ionaktive alkylenoksydaddukter, særlig med fettalkoholer, alkylfenoler, fettsyrer eller aminer eller en blanding av sådanne midler, vist særlig god effekt. Both anionic and non-ionic surfactants have proven suitable for the present invention. Among anionic surfactants, particularly alkyl sulfates and alkyl aryl sulfonates and Mant non-ionic alkylene oxide adducts, especially with fatty alcohols, alkyl phenols, fatty acids or amines or a mixture of such agents, have shown particularly good effect.
Tilsetningen av det overflateaktive midlet gir godt resultat f. eks. hvis den ut-føres når vanlig alkaMbehandling eller alkalisk kajlisdumhypokloribblJekiniing, natai-umhypokloritblekning og/eller peroksyd-bleknlng følges av f. eks. surgj øring med svoveldioksyd eller svovelsyre eller sur klordioksydblekning. The addition of the surfactant gives good results, e.g. if it is carried out when normal alkaline treatment or alkaline kajlisdum hypochloribljekiniing, natural hypochlorite bleaching and/or peroxide bleaching is followed by e.g. acidification with sulfur dioxide or sulfuric acid or acid chlorine dioxide bleaching.
Tilsetningen av overflateaktivt middel ved surgj øringen etter en alkalisk mas-sebehandling ifølge foreliggende oppfinnelse har til eneste oppgave å forhindre fremkomsten av harpikskonglomerater av sådan størrelse at de er lett synlige og der-for påvirker en visuell bedømmelse av massens renhet. Den har ingen harpiks-utløsende effekt. , The addition of surfactant during acidification after an alkaline pulp treatment according to the present invention has the sole task of preventing the appearance of resin conglomerates of such a size that they are easily visible and therefore affect a visual assessment of the purity of the pulp. It has no resin-dissolving effect. ,
Den kj ente utløsning av harpiks og lignende inkruster fra trecellulose (norsk patent nr. 81 667 og amerikansk patent nr. 2 716 058) krever betydelig større meng-der overflateaktive midler og kan med for-del baire skje ved alkalliske foehandltogs-trlnn. Av omkostningsgrunner anvendes slik harpiksutløsning bare ved fremstilling av høyt foredlede sulfitmasser, som derivatmasse. The known release of resin and similar incrustations from wood cellulose (Norwegian patent no. 81 667 and American patent no. 2 716 058) requires significantly larger amounts of surface-active agents and can advantageously be carried out with alkaline commercial solutions. For reasons of cost, such resin release is only used in the production of highly refined sulphite pulps, as derivative pulps.
Eksempel 1. Example 1.
Et sulfitblefeeri på 150 tonn pr. døgn har et kloreringstrinn, et alkalitrinn, et kalsiumhypokloritbleketrinn og to tårn og eit surt klordiioksydblieketrinn med vandig A sulphite refinery of 150 tonnes per day has a chlorination stage, an alkali stage, a calcium hypochlorite bleaching stage and two towers and an acidic chlorine dioxide bleaching stage with aqueous
filtervask mellom hvert trinn. Foran mas-seblekningen foregikk ikke noen mekanisk avhartsing. Alkalltårnet kjøres med 1,5 vektsprosent NaOH, iberegnet på tørr masse ved 40° C og 15 pst. massekonseaitrasjon, hvoretter kalslumhypokloritblekningen skjedde ved 7 pst. massekonsentrasjon, 35° C og en slutt pH på 10,0 Det sure klordioksydbleketrinnet utførtes ved 70°, 18 pst. massekonstrasjon og en pH på 4,5. En tilsetning på totalt 0,03 vektsprosent, beregnet på tørr masse, av et etylenoksydaddukt ved hypokloritblekningen begrenset antallet harpiksflekker i massen, overstigende 0,7 mm2 flekkflate til 25—30 stykker pr. m2. En ytterligere tilsetning av 0,01 vektsprosent av samme ikke-ioniske overflateaktive middel til klordioksydbleketrinnet, bragte ned antallet av slike harpiksflekker til 5—10 stykker pr. m<2>. For ytterligere å kunne lukke bakvannsystemet for fortynning og vaskning etter 'klordioksydbleketrinnet ved dette flekkantall, øket dog behovet av overflateaktivt middel i klordioksydtrinnet til 0,02 vektsprosent. filter wash between each step. Before pulp bleaching, no mechanical deresining took place. The alkali tower is run with 1.5% by weight NaOH, calculated on dry pulp at 40°C and 15% pulp concentration, after which the calcium hypochlorite bleaching took place at 7% pulp concentration, 35°C and a final pH of 10.0. The acidic chlorine dioxide bleaching step was carried out at 70° , 18 percent mass concentration and a pH of 4.5. An addition of a total of 0.03% by weight, calculated on dry pulp, of an ethylene oxide adduct during the hypochlorite bleaching limited the number of resin stains in the pulp, exceeding 0.7 mm2 stain surface to 25-30 pieces per m2. A further addition of 0.01% by weight of the same nonionic surfactant to the chlorine dioxide bleaching step reduced the number of such resin stains to 5-10 pieces per m<2>. In order to be able to further close the backwater system for dilution and washing after the chlorine dioxide bleaching step at this stain count, the need for surfactant in the chlorine dioxide step increased to 0.02% by weight.
Eksempel 2. Example 2.
En laboratorieblekning av sulfitmasse utføres med et kloreringstrinn, et alkalitrinn, et nlatriumhypoklorittrlnin, et alkalisk sluttbleketrinn med peroksyd og ende-lig en surgjøring med svoveldioksyd. Vask-ningen mellom trinnene skjedde på et glassfilter med en begrenset vannmengde for å etterligne fatøibksvaskniingefn. Ved surgj øringen deltes massen i to satser og til den ene ble tilsatt sammen med S02-vannoppløsningen 0,01 vektsprosent av et A laboratory bleaching of sulphite pulp is carried out with a chlorination step, an alkali step, a sodium hypochlorite solution, a final alkaline bleaching step with peroxide and finally an acidification with sulfur dioxide. The washing between the steps took place on a glass filter with a limited amount of water to mimic barrel washing conditions. During acidification, the mass was divided into two batches and to one was added together with the SO2 water solution 0.01% by weight of a
hovedsakelig sekundært alkylsulfat, beregnet på tørr masse. Ark tole formet av begge mainly secondary alkyl sulphate, calculated on dry mass. Sheet tole shaped by both
massene for å sammenligne renheten,. Det the masses to compare the purity,. The
viste seg, at tilsetningen av det anioniske turned out, that the addition of the anionic
overflateaktive middel hadde minsket det surfactant had reduced it
totale antall prikker, overstigende 0,7 mm^, total number of dots, exceeding 0.7 mm^,
med 20 pst. with 20 percent
Claims (3)
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US56684766A | 1966-07-21 | 1966-07-21 | |
US566944A US3393663A (en) | 1966-07-21 | 1966-07-21 | Fluidizing electrode development apparatus |
US566842A US3380437A (en) | 1966-07-21 | 1966-07-21 | Transversely reciprocating fluidized bed development apparatus |
US566841A US3357399A (en) | 1966-07-21 | 1966-07-21 | Combined fluidized bed and inverted cascade development apparatus |
Publications (1)
Publication Number | Publication Date |
---|---|
NO127834B true NO127834B (en) | 1973-08-20 |
Family
ID=27504853
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO16900767A NO127834B (en) | 1966-07-21 | 1967-07-12 |
Country Status (11)
Country | Link |
---|---|
BE (1) | BE701467A (en) |
CH (1) | CH481406A (en) |
CS (1) | CS157025B2 (en) |
DE (1) | DE1597873A1 (en) |
DK (1) | DK123998B (en) |
GB (1) | GB1193443A (en) |
IL (1) | IL28298A (en) |
LU (1) | LU54062A1 (en) |
NL (1) | NL159204B (en) |
NO (1) | NO127834B (en) |
SE (1) | SE322414B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3115294C2 (en) * | 1981-04-15 | 1983-02-03 | Siemens AG, 1000 Berlin und 8000 München | Process for regenerating the carrier particles of a two-component developer consisting of carrier particles and toner |
-
1967
- 1967-07-10 LU LU54062D patent/LU54062A1/xx unknown
- 1967-07-11 IL IL2829867A patent/IL28298A/en unknown
- 1967-07-12 SE SE1047967A patent/SE322414B/xx unknown
- 1967-07-12 NO NO16900767A patent/NO127834B/no unknown
- 1967-07-17 DK DK368767A patent/DK123998B/en unknown
- 1967-07-17 BE BE701467D patent/BE701467A/xx unknown
- 1967-07-18 GB GB3286867A patent/GB1193443A/en not_active Expired
- 1967-07-18 CH CH1026767A patent/CH481406A/en not_active IP Right Cessation
- 1967-07-18 NL NL6709924A patent/NL159204B/en not_active IP Right Cessation
- 1967-07-18 DE DE19671597873 patent/DE1597873A1/en active Pending
- 1967-07-21 CS CS537067A patent/CS157025B2/cs unknown
Also Published As
Publication number | Publication date |
---|---|
NL159204B (en) | 1979-01-15 |
NL6709924A (en) | 1968-01-22 |
CH481406A (en) | 1969-11-15 |
DK123998B (en) | 1972-08-28 |
DE1597873A1 (en) | 1970-09-17 |
LU54062A1 (en) | 1968-03-12 |
SE322414B (en) | 1970-04-06 |
IL28298A (en) | 1971-04-28 |
CS157025B2 (en) | 1974-08-23 |
BE701467A (en) | 1968-01-17 |
GB1193443A (en) | 1970-06-03 |
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