DK157360B - PROCEDURE FOR REMOVAL OF CHROMATES FROM Aqueous CHLORATE SOLUTIONS - Google Patents
PROCEDURE FOR REMOVAL OF CHROMATES FROM Aqueous CHLORATE SOLUTIONS Download PDFInfo
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- DK157360B DK157360B DK398878AA DK398878A DK157360B DK 157360 B DK157360 B DK 157360B DK 398878A A DK398878A A DK 398878AA DK 398878 A DK398878 A DK 398878A DK 157360 B DK157360 B DK 157360B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J47/00—Ion-exchange processes in general; Apparatus therefor
- B01J47/02—Column or bed processes
- B01J47/04—Mixed-bed processes
Description
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Opfindelsen angâr en fremgangsmâde til fjernelse af chro-mationer fra vandige oplosninger, der indeholder sâdanne ioner og store mængder af oploste alkalimetalchlorater, især en fremgangsmâde til fjernelse af chromationer fra vandige chloratrige chloridoplosninger, ved at fore oplosningen gennem en masse af blandede anion- og kation-bytterharpikser, der hver foreligger pâ en specificeret form.The invention relates to a process for removing chromations from aqueous solutions containing such ions and large amounts of dissolved alkali metal chlorates, in particular a method for removing chromations from aqueous chlorate-rich chloride solutions, by passing the solution through a mass of mixed anion and cation - exchange resins, each in a specified form.
USA patent nr. 3.835.001, der blev udstedt den 10. septem-ber 1974 til T.F. O’Brien, beskriver en fremgangsmâde til fjernelse af en væsentlig andel af chromationer fra en vandig alkalimetalchlorat-chlorid-oplosning, hvor oplos-ningen fores gennem en masse af stærkt basisk anionbytter-harpiks pâ chloridform ved et oprindeligt pH i oplosningen pâ under 6,5, fortrinsvis omkring 5. Selv om denne fremgangsmâde frembringer en afgorende forbedring af fjernelsen af chromationer fra sâdanne oplosninger i sammenligning med tidligere kendte metoder, er behovet for yderligere forbedring ved fjernelse af endog storre andele af chromationer évident. Dette betyder, at det er kommercielt onsk-værdigt at tilvejebringe en fremgangsmâde, der pâ okonomisk mâde vil fjerne i det væsentlige hele mængden af chromationer fra oplosninger, der indeholder sa lidt som 10 vægtdele per million, men sædvanligvis under ca. 20 g per liter oplost alkalimetalchromât, sâledes at en enkelt be-handling af oplosningen i det væsentlige vil frembringe fjernelse og fortrinsvis en i det væsentlige fuldstændig fjernelse af chromationerne fra oplosningen uden den led-sagende dannelse af farligt chlordioxid.US Patent No. 3,835,001, issued September 10, 1974, to T.F. O'Brien discloses a process for removing a substantial proportion of chromium ions from an aqueous alkali metal chlorate chloride solution, wherein the solution is passed through a mass of highly basic anion exchange resin in chloride form at an initial pH of the solution below 6, 5, preferably about 5. Although this method produces a decisive improvement in the removal of chromate ions from such solutions in comparison with previously known methods, the need for further improvement in the removal of even larger proportions of chromate ions is evident. This means that it is commercially desirable to provide a process that will economically remove substantially the entire amount of chromium ions from solutions containing as little as 10 parts by weight per million, but usually below about 10% by weight. 20 grams per liter of dissolved alkali metal chromate, so that a single treatment of the solution will substantially remove and preferably a substantially complete removal of the chromations from the solution without the associated formation of hazardous chlorine dioxide.
Fremgangsmâden ifolge opfindelsen, der er af den i indled-ningen til krav 1 angivne art, er ejendommelig ved det i den kendetegnende del af krav 1 angivne.The method according to the invention, which is of the kind set forth in the preamble of claim 1, is characterized by the characterizing part of claim 1.
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Man kender ganske vist fra US patentskrift nr. 3 972 810 en fremgangsmâde til fjernelse af chromationer fra en op-lesning, men denne oplosning indeholder i modsætning til, hvad der er tilfældet ved fremgangsmâden if0lge opfindelsen, ikke en stor koncentration af alkalimetalchlorat. Endvide-re er naturen af de anvendte ionbyttere, den procès, ved hvis hjælp chromationen genvindes, og regenerationen af ionbytterne forskellige, nâr man sammenligner den kendte procès med fremgangsmâden ifolge opfindelsen.Although US Patent No. 3,972,810 discloses a process for removing chromate ions from a solution, this solution does not contain a high concentration of alkali metal chlorate, contrary to the method of the invention. Furthermore, the nature of the ion exchangers used, the process by which the chromation is recovered, and the regeneration of the ion exchangers are different when comparing the known process with the process according to the invention.
Ved en foretrukken udforelsesform for fremgangsmâden i-folge opfindelsen foréligger kationbytterharpiksen i en mængde, der ikke er under 0,5 dele, men heller ikke over 2,0 dele pâ vægtbasis for hver del anionbytterharpiks.In a preferred embodiment of the method according to the invention, the cation exchange resin is present in an amount not less than 0.5 parts but not more than 2.0 parts by weight for each part of anion exchange resin.
I industriel praksis specificeres antallet af bytteposi-tioner sædvanligvis ved den "totale byttekapacitet" ud-trykt som milliækvivalenter/ml eller milliækvivalenter/g. Bestemmelsesmetoden for denne mængde afviger lidt blandt fabrikanterne af harpikserne. Fabrikantens tekniske bulletin (1972) for Amberlite IRC-50 angiver: "Total byttekapacitet: Den maximale kapacitet for Amberlite IRC-50 kan bekvemt bestemmes ved at ækvilibrere en repræsentativ preve pâ hydrogenform med et overskud af 0,1 N natriumhy-droxid. Harpiksen ber forblive i kontakt med et overskud af kaustisk materiale i 24 til 48 timer. Den neutralisere-de mængde natriumhydroxid betragtes som værende ækvivalent med den maximale kapacitet af ionbytteren".In industrial practice, the number of exchange positions is usually specified by the "total exchange capacity" expressed as milliequivalents / ml or milliequivalents / g. The method of determination for this quantity differs slightly among the manufacturers of the resins. Manufacturer's technical bulletin (1972) for Amberlite IRC-50 states: "Total exchange capacity: The maximum capacity of Amberlite IRC-50 can be conveniently determined by equilibrating a representative hydrogen form prev with an excess of 0.1 N sodium hydroxide. remain in contact with excess caustic material for 24 to 48 hours. The neutralized amount of sodium hydroxide is considered to be equivalent to the maximum capacity of the ion exchanger ".
Bâde kation- og anionbytterharpikser, der er anvendelige ved opfindelsen, kan enten være af geltypen eller af den makroreticulære type, men den makroreticulære type fore-trækkes pâ grund af dens sterre stabilitet under multiple cycler af ionbytteroperationer. Ionbytterharpikser af forskellige typer diskuteres f.eks. i Kirk-Othmer, Encyclope-dia of Chemical Technology, anden udgave, bind II, side 871 et seq.Both cation and anion exchange resins useful in the invention may be either the gel type or the macroreticular type, but the macroreticular type is preferred due to its steric stability during multiple cycles of ion exchange operations. Ion exchange resins of various types are discussed e.g. in Kirk-Othmer, Encyclopaedia of Chemical Technology, Second Edition, Volume II, page 871 et seq.
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Anionbytterharpiksen kan være en svag eller stærk harpiks-base, men man foretrækker en svagt basisk anionbytterhar-piks fra det standpunkt, der omfatter en mere kvantitativ udvinding under regenereringen. Nâr anionbytterharpiksen anvendes under driften eller chromatadsorptionstrinnet af ionbytterprocessen, ber anionbytterharpiksen initiait fore-ligge pâ chloridformen.The anion exchange resin may be a weak or strong resin base, but a weak basic anion exchange resin is preferred from the standpoint of a more quantitative recovery during regeneration. When the anion exchange resin is used during the operation or chromatid adsorption step of the ion exchange process, the anion exchange resin should initially be in the chloride form.
Kationbytterharpiksen ifolge opfindelsen er i det væsentlige en svagt sur kationbytter, der mâ foreligge pâ konditione-ret hydrogenform ved begyndelsen af processens driftstrin, nemlig nâr man pâbegynder chromatfjernelsen fra den chlo-ratrige oplosning.The cation exchange resin according to the invention is essentially a weakly acidic cation exchanger which must be in a conditioned hydrogen form at the beginning of the operating step of the process, namely when starting the chromate removal from the chlorate-rich solution.
Betegnelsen "konditioneret hydrogenform” betyder i denne sammenhæng en form for kationbytterharpiks, hvor en del af hydrogenionerne af kationbytterharpiksen, som initiait udelukkende forelâ pâ hydrogenform, er blevet erstattet med ioner af alkalimetal (Na+) for at forhindre overdreven syrning af den chloratrige oplosning under driftstrinene af processen. Udtrykt pâ anden mâde, for at reducere virk-ningen af ”saltspaltning” ved det som driftstrin forelig-gende chromatadsorptionstrin bliver hydrogenformen af kationharpiks skyllet (konditioneret) med en oplosning af alkalimetalchlorid, der fortrinsvis udviser et neutralt pH (6-8), for at bringe pH af udgangsmaterialetv(den udgâende brine) over 1,0, fortrinsvis op til ca. 2..The term "conditioned hydrogen form" in this context means a form of cation exchange resin, in which a portion of the hydrogen ions of the cation exchange resin, initially available exclusively in hydrogen form, has been replaced by alkali metal ions (Na +) to prevent excessive acidification of the chlorate-rich solution during the operation steps. In other words, to reduce the effect of "salt cleavage" in the chromatid adsorption step, the hydrogen form of cation resin is flushed (conditioned) with a solution of alkali metal chloride which preferably exhibits a neutral pH (6-8 ) to bring the pH of the starting material (the starting brine) above 1.0, preferably up to about 2..
Saltspaltning forekommer typisk, nâr en oplosning, der in-deholder et sait af en stærk syre og en stærk base, fores gennem en stærkt sur ionbytterharpiks eller en stærkt basisk ionbytterharpiks. Kationen af saltet udbyttes let af hydrogenet af den stærkt sure harpiks. Pâ lignende mâde udbyttes anionen af saltet let med hydroxidet af den stærkt basiske harpiks. En afgorende egenskab ved de svagt sure og de svagt basiske ionbyttere i sammenligning med de stærkt sure og stærkt basiske typer er, at denne saltspaltning sædvanligvis ikke finder sted i nogen storre udstræk-ning. At den finder sted og at den mâ kontrolleres i den 4Salt cleavage typically occurs when a solution containing a site of a strong acid and a strong base is passed through a highly acidic ion exchange resin or a strongly basic ion exchange resin. The cation of the salt is readily exchanged by the hydrogen of the highly acidic resin. Similarly, the anion of the salt is readily exchanged with the hydroxide of the highly basic resin. A crucial feature of the weakly acidic and the weakly basic ion exchangers in comparison with the highly acidic and highly basic types is that this salt cleavage usually does not occur to any great extent. That it takes place and that it must be checked in 4
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forellggen.de procès skyldes sandsynligvis de meget hoje saltkoncentrationer, som forekommer.the process is probably due to the very high salt concentrations that occur.
Fremgangsmâden ifelge opfindelsen, der med fordel gennem-f0res som en cyclisk fremgangsmâde, kan stort set beskri-ves sâledes:The process according to the invention, which is advantageously carried out as a cyclic process, can be broadly described as follows:
De udvalgte ionbytterharpikser behandles enten separat eller som en blanding med en oplosning a£ mineralsyre til tilvejebringelse af udgangsmaterialet. Derpâ behand-ler man kationharpiksen (hvis den foreligger separat) eller blandingen med en neutral brineoplosning til til-vejebringelse af en kationharpiks i den konditionerede hydrogenform. Hvis ionbytterharpikserne ikke er blandet for disse behandlinger, blandes de pâ kendt mâde, f.eks. ved at indblæse luft under vand. Derpâ begynder drifts-trinnet eller chromatadsorptionstrinnet ved at fore den chromatholdige chloratrige væske gennem den blandede har-piksmasse. Ved udtomning af ionbyttermassen, svarende til en stigning af pH til 2 og sidelobende gulfarvning af den udgâende oplosning, bliver stromningen af chromatholdig op--losning termineret, jfr. hovedkravet, og anionbytterharpik-sen behandles med henblik pâ udvinding af chromationer med eller uden forudgâende séparation af ionbytterharpikserne.The selected ion exchange resins are treated either separately or as a mixture with a solution of mineral acid to provide the starting material. Then the cation resin (if available separately) or the mixture is treated with a neutral brine solution to provide a cation resin in the conditioned hydrogen form. If the ion-exchange resins are not mixed for these treatments, they are mixed in a known manner, e.g. by injecting air under water. Then, the operation step or the chromatid adsorption step begins by passing the chromate-containing chlorate-rich liquid through the mixed resin mass. When the ion exchanger mass is depleted, corresponding to an increase of pH to 2 and parallel yellowing of the starting solution, the flow of chromate-containing solution is terminated, cf. and the anion exchange resin is processed for the purpose of recovering chromate ions with or without prior separation of the ion exchange resins.
Som forklaret i det folgende kan harpikserne om onsket se-pareres ved at fore dem opad gennem en saltoplosning gennem massen med en hastighed, der er tilstrækkelig til at frembringe séparation af de harpikser, der har en no-get forskellig massefylde.As explained below, the desired resins can be separated by passing them upwardly through a salt solution through the pulp at a rate sufficient to produce separation of the resins having a slightly different density.
Chromât bliver let og fuldstændigt fjernet (strippet) ved behandling af anionharpiksen eller -massen med en alka-lisk oplosning af alkalimetalchlorid, f.eks. ca. k% na-triumhydroxid i vandig 12-15% natriumchloridoplosning.Chromate is easily and completely removed (stripped) by treating the anion resin or mass with an alkaline solution of alkali metal chloride, e.g. ca. k% sodium hydroxide in aqueous 12-15% sodium chloride solution.
Efter fjernelse af chromatet fra anionbytterharpiksen gen-tages processen i overensstemmelse med de ovenfor angivne trin i mange eycler, indtil harpikserne ikke længere er i stand til at udvise tilstrækkelig adsorption til tilveje- ΤΎΓίτισρΙ bp a-f" on amronrlol i σ nr>nr>os 5After removal of the chromate from the anion exchange resin, the process is repeated in accordance with the above steps in many eycles until the resins are no longer able to exhibit sufficient adsorption to provide ronίτισρΙ bp a-f "on amronrlol in σ nr> nr> us 5
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For at understotte forstâelsen af de forskellige trin af processen og virkningen deraf illustrerer den folgende tabel de teoretiske ionbyttermekanismer ved fremgangs-mâden med og uden harpiksseparation.In order to support the understanding of the various steps of the process and its effect, the following table illustrates the theoretical ion exchange mechanisms of the process with and without resin separation.
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CQ ü + + Φ + Λ sCQ ü + + Φ + Λ s
P (DO - <S ®H M P 'HP (DO - <S ®H M P 'H
H| rrj H S T-P X *H | rrj H S T-P X *
Pi φ -p <H X + P + fc WPi φ -p <H X + P + fc W
M d cd H + cd <d (0 A4 OS s s o œ s Pi s « h f, C PiM d cd H + cd <d (0 A4 OS s s o œ s Pi s «h f, C Pi
W P PW P P
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<3 ♦ O X bOH o ° *2 : l* OJ l H >> (Ml «H 3 æp H ΦΑ4 PH =<3 ♦ O X bOH o ° * 2: l * OJ l H >> (Ml «H 3 ap H ΦΑ4 PH =
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M -d H a} p«H o H w HM -d H a} p «H o H w H
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77
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Stromningshastighederne for den chromatholdige opl0sning gennem harpiksbyttermassen ved fremgangsmâden if0lge op-findelsen bor ikke være over ca. 40,7 liter per minut, p fortrinsvis 30,6 liter per minut, per m , hidrorende fra udfladning af adsorptionsfronten.The flow rates of the chromate-containing solution through the resin exchanger mass in the method according to the invention should not be more than approx. 40.7 liters per minute, p preferably 30.6 liters per minute, per m, resulting from flattening of the adsorption front.
Fremgangsmâden ifolge opfindelsen er velegnet til mange vandige oplosninger, der indeholder alkalimetalchlorat i tilstrækkelig koncentration til at dekomponere ved at g0re sur til et pH pâ ca. 0,5 til 1,0. Koncentrationen af alkalimetalchlorat eller -chlorat og -chlorid b0r ikke være sâ hoj, at der fremkommer udsaltning under betingel-serne i ionbyttersojlen eller -massen. F.eks. er en accep-tabel evre grænse for koncentrationerne af en natrium-chloratrig natriumchloridoplosning ved 26,7° C ca. 120 g natriumchlorid per liter med 550 g natriumchlorat per liter.The process according to the invention is suitable for many aqueous solutions containing alkali metal chlorate in sufficient concentration to decompose by acidifying to a pH of approx. 0.5 to 1.0. The concentration of alkali metal chlorate or chlorate and chloride should not be so high as to cause salting out under the conditions of the ion exchange column or mass. Eg. is an acceptable table limit for the concentrations of a sodium chlorate-rich sodium chloride solution at 26.7 ° C. 120 g sodium chloride per liter with 550 g sodium chlorate per liter.
De folgende eksempler er angivet for at illustrere fremgangsmâden ifolge opfindelsen.The following examples are given to illustrate the process of the invention.
EKSEMPEL 1EXAMPLE 1
Lige vægtdele af en stærk anionbytterharpiks af geltypen (Amberlite IRA 400, produkt fra Rohm and Haas Company) og en svagt sur ionbytterharpiks af geltypen (Amberlite IRC 84 - produkt fra Rohm and Haas Company) blev i grundig blanding tilfort til en glassojle med en indre diameter pâ 1,25 cm. Den blandede harpiksmasse i sojlen havde en omtrentlig hojde pâ 80 cm og et volumen pâ 100 cm . Man foretog et konditioneringstrin involverende passage af 25 milliækvivalenter saltsyre gennem sojlen for at sikre, at ionbytterharpikserne delvist forelâ i henholdsvis chlorid-og hydrogenformerne. Dette trin blev efterfulgt af skyl-ninger med afioniseret vand.Equal parts by weight of a strong gel type anion exchange resin (Amberlite IRA 400, Rohm and Haas Company product) and a slightly acidic gel exchange resin (Amberlite IRC 84 - product of Rohm and Haas Company) were added in a thorough blend to an inner glass column. diameter of 1.25 cm. The mixed resin mass in the column had an approximate height of 80 cm and a volume of 100 cm. A conditioning step involving passage of 25 milliequivalents of hydrochloric acid was performed through the column to ensure that the ion exchange resins were partially present in the chloride and hydrogen forms, respectively. This step was followed by rinsing with deionized water.
En vandig væske, der skal tjene som kilde for chlorat, og som indeholder natriumchromat (600 g per liter natriumchlorat og 5,9 g natriumdichromât per liter) blev fort gennem 8An aqueous liquid to serve as a source of chlorate containing sodium chromate (600 g per liter of sodium chlorate and 5.9 g of sodium dichromate per liter) was passed through 8
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"Z"Z
sojlen i opadgâende retning med en hastighed af 2 cm/minut. Den opadgâende retning var onskværdig, fordi massefylden af ehloratoplesningen var sterre; end massefylden af har-piksen.the column in the upward direction at a speed of 2 cm / minute. The upward direction was undesirable because the density of the ehlorate solution was sterile; than the density of the har-peak.
Pâ hinanden folgende portioner (prover) af udgâende ma-teriale fra sojlen blev analyseret for pH og chromat-indhold under anvendelse af et colorimeter. Den fremad-skridende bevægelse af den opadgâende front af udveks-ling i sojlen kunne observeres ved hjælp af harpiksens farveændring. Observationer og resultater af analysen af pâ hinanden folgende portioner er angivet i den fol-gende tabel. Fuldstændig udvinding af chromatet blev op-nâet ved at fore alkalisk natriumchlorid gennem massen ved terminering af fjernelsestrinnet for chromât.Successive portions (samples) of starting material from the column were analyzed for pH and chromate content using a colorimeter. The progressive movement of the upward front of exchange in the column could be observed by the color change of the resin. Observations and results of the analysis of consecutive portions are given in the following table. Complete recovery of the chromate was achieved by passing alkaline sodium chloride through the pulp by terminating the chromate removal step.
Prove Volumen i Chromât i ud- Udgâende Hojde af udveks-massen af gâende væske, væske^ pH lingsgrænse tilfort g.p.l.Sample Volume in Chromate in Outgoing Height of Exchanger Mass of Fluid, Liquid pH pH Limit Added g.p.l.
_væske *_ 1 0,92 0,00 1,96 20 cm 2 1,72 0,00 1,20 36 cm 3 2,57 0,00 1,35 51 4 3,37 0,00 1,58 63 5 4,16 0,00 1,74 68 6 4,98 0,00 1,96 75 7 5,33 0,02 2,22 78 (top) 8 5,78 0,20 2,62 ---- 9 6,60 1,05 2,88 ---- 10 7,45 3,60 2,90 ---- 11 8,24 4,80 2,80 ----Liquid * 1.92 0.00 1.96 20 cm 2 1.72 0.00 1.20 36 cm 3 2.57 0.00 1.35 51 4 3.37 0.00 1.58 63 5 4.16 0.00 1.74 68 6 4.98 0.00 1.96 75 7 5.33 0.02 2.22 78 (top) 8 5.78 0.20 2.62 ---- 9 6.60 1.05 2.88 ---- 10 7.45 3.60 2.90 ---- 11 8.24 4.80 2.80 ----
Tilfort---- 5,90 5,50 ---- materi- ale * Massevolumen af tilfort materiale eller udgâende mate-riale er en betegnelse, der anvendes til sammenligning mellem kapaciteterne af ionbyttersojler med varierendeForced ---- 5.90 5.50 ---- Material * Mass volume of added material or starting material is a term used to compare the capacities of ion exchange columns with varying
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9 storrelse. Et massevolumen er det totale volumen, der opta-ges af harpiksmassen (tværsnittet i ni gange hojden), in-klusive det volumen/ der optages af selve ionbytterperler-ne.9 size. A mass volume is the total volume absorbed by the resin mass (the cross section at nine times the height), including the volume / volume absorbed by the ion exchange beads themselves.
EKSEMPEL 2EXAMPLE 2
En sojle med en diameter pâ 1,9 cm blev pakket til en hoj-de af 132 cm med en grundig blanding af en svag kationisk ionbytterharpiks af den makroreticulære type (Rohm & Haas Company’s Amberlite IRC 50) og en svag anionisk ionbytterharpiks af den makroreticulære type (Rohm & Haas Company’s Amberlite IRA 93) i vægtforholdet 60:40.A 1.9 cm diameter column was packed to a height of 132 cm with a thorough blend of a weak cationic ion exchange resin of the macroreticular type (Rohm & Haas Company's Amberlite IRC 50) and a weak anionic ion exchange resin of the macroreticular type (Rohm & Haas Company's Amberlite IRA 93) in the 60:40 weight ratio.
Den blandede harpiksmasse blev prækonditioneret ved forst at fore en 4% vandig natriumhydroxidoplosning i nedadgâen-de retning gennem sojlen efterfulgt af en k% vandig salt-syreoplosning, indtil pH faldt under 1,5. En sluttelig ned-adgâende vask med næsten mættet, neutral vandig natrium-chloridoplosning blev udfort for at konditionere hydrogen-formen af kationbytterharpiksen, indtil pH af det udgâende materiale steg til 1,5.The mixed resin mass was preconditioned by first passing a 4% aqueous sodium hydroxide solution downwards through the column followed by a k% aqueous hydrochloric acid solution until the pH dropped below 1.5. A final descending wash with near saturated neutral aqueous sodium chloride solution was made to condition the hydrogen form of the cation exchange resin until the pH of the starting material rose to 1.5.
Chromatadsorptionen blev gennemfort ved at fore en chlo- ratoplosning (450 g natriumchlorat per liter) indeholdende 1,02 g natriumdichromât per liter (tilforselsvæske) opad gen- 3 3 nem harpxksmassen med en hastighed af 5 cm per mmut. 1850 cm farvelost produkt blev opsamlet for det udgâende materiale blev synligt gult. pH i det udgâende materiale i dette tidsrum steg 3 regelmæssigt fra 1,6 til 2,05. Efter.150. cm . yderligere strom-ning indeholdt det udgâende materiale 24,6 ppm natriumdichromat (Na2Cr207), og pH af det udgâende materiale var 2,15.The chromatid adsorption was carried out by passing a chlorate solution (450 g sodium chlorate per liter) containing 1.02 g sodium dichromate per liter (feed liquid) up through the resin mass at a rate of 5 cm per mmut. 1850 cm colorless product was collected for the outgoing material became visibly yellow. The pH of the starting material during this period increased 3 regularly from 1.6 to 2.05. Efter.150. cm. further flow, the outgoing material contained 24.6 ppm sodium dichromate (Na 2 Cr 2 O 7) and the pH of the outgoing material was 2.15.
Som i eks. 1 udtog man pâ hinanden folgende prover af udgâende materiale, som blev analyseret for pH. Farven af hver prove blev noteret som et check for chromatindhold, idet en farvelos prove viste, at der i det væsentlige ikke DK 1573608 ίο var noget chromât tilstede. Den folgende tabel indehol-der pH og observationsdata for hver prove.As in Example 1, successive samples of starting material were taken and analyzed for pH. The color of each sample was noted as a check for chromate content, as a colorless sample showed that there was essentially no chromate present. The following table contains the pH and observation data for each sample.
TABEL IITABLE II
Prove Yolumen i Chromât i Udgâende Hojde af ud- massen af udgâende væ- væske, pH vekslings- tilfort ske (farvean- grænse (cm) væske givelse) 1 1,42 farvelos (2,3)* 20 2 1,85 farvelos 1,6 41 3 3,57 farvelos 1,67 61 4 4,28 farvelos 1,77 91 5 5j00 farvelos 1,90 ---- 6 5,28 let gui 2,05 ---- 7 5,70 tydeligt gui 2,15 ---- (24,6 ppm) jfSample Yolumen in Chromât in Outgoing Height of the outgoing mass of outgoing liquid, pH change rate (color limit (cm) liquid yield) 1 1.42 colorless (2.3) * 20 2 1.85 colorless 1 , 6 41 3 3.57 colorless 1.67 61 4 4.28 colorless 1.77 91 5 5.00 colorless 1.90 ---- 6 5.28 light gui 2.05 ---- 7 5.70 clear gui 2.15 ---- (24.6 ppm) cf.
Initiait pH er hojere for equilibrering af natriumchlo-rat med harpikser.Initial pH is higher for sodium chlorate equilibration with resins.
EKSEMPEL 3 I en sojle med diameter pâ 25,4 cm, der var specielt ud-styret med henblik pâ cyclisk gennemforelse af en kontinu-erlig ionbytterproces, fremstillede man en masse med blan-dede harpikser ved luftblanding under vand af 1 vægtdel af en svag kation harpiks (Amberlite IRC 84) med 2 vægtdele af en svag anionharpiks (Amberlite IRA 94), idet blandingen nâ-ede en total hojde af 88,9 cm i sojlen.EXAMPLE 3 In a 25.4 cm diameter column specially equipped for the cyclical performance of a continuous ion exchange process, a mass of mixed resins by air mixing under water of 1 wt. cation resin (Amberlite IRC 84) with 2 parts by weight of a weak anion resin (Amberlite IRA 94), the mixture reaching a total height of 88.9 cm in the column.
Massen blev behandlet ved at fore en k% oplosning af HCl i en NaCl-brine nedad, indtil det udgâende materiale udvis-te et pH pâ 1,5. Man gennemforte derpâ et konditionerings-trin ved at fore en mættet NaCl-oplosning (pH 9,5) nedad.The pulp was treated by running a k% solution of HCl in a NaCl brine downwards until the starting material exhibited a pH of 1.5. A conditioning step was then carried out by passing a saturated NaCl solution (pH 9.5) downwards.
Efter et initiait fald til '0,4 hidrorende fra saltspaltning steg pH over 1,0, hvorpâ man afbrod skylningen med saltvand.After an initial drop to '0.4 resulting from salt decomposition, the pH rose above 1.0, quenching the rinse with saline.
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Man pâbegyndte derpâ chromatadsorptionstrinnet med en opad-gâende str0mning med 0,95 1 per minut af en væske indehol-dende 450 g natriumchlorat per liter og 3,1 g NagCrgOy per liter. Det udgâende materiale forblev farvelost, ind-til man havde behandlet 242,3 liter. pH i det udgâende materiale var mellem 2,5 og 2,2, da den forste stromning af gui, udgâende væske kom til syne. Stripning for at de-sorbere chromât fra ionbytterharpiksen blev gennemfort ved at lade 4% NaOH i halvt mættet (12%) NaCl-oplosning passer e i nedadgaende retning.Thereafter, the chromatid adsorption step was started with an upward flow of 0.95 l per minute of a liquid containing 450 g of sodium chlorate per liter and 3.1 g of NagCrgOy per liter. The starting material remained colorless until 242.3 liters were processed. The pH of the outgoing material was between 2.5 and 2.2 when the first flow of gui outgoing fluid appeared. Stripping to dissolve chromate from the ion exchange resin was accomplished by allowing 4% NaOH in semi-saturated (12%) NaCl solution to pass in a downward direction.
TABEL IIITABLE III
Prove Volumen i mas- Chromât i ud- Udgâet væskeSample Volume in Mas- Chromât in Exhausted Liquid
sen af tilfort gâet væske pHthe pH of the liquid increased
væske (farveangivelse) 1 1,47 farvelos 2,0 2 1,90 farvel0S 1,8 3 3,50 farvel0s 1,8 4 5,08 farvel0S 1,95 5 5,93 farvelos 2,05 6 6,44 let gui 2,2 7 6,87 tydeligt gui 2,3liquid (color indication) 1 1.47 colorless 2.0 2 1.90 colorless 1.8 1.8 3.550 colorless 1.8 4 5.08 colorless 1.95 5 5.93 colorless 2.05 6 6.44 light gui 2.2 7 6.87 clearly gui 2.3
De foregâende eksempler demonstrerer fremgangsmâden ifolge opfindelsen i forhold til chromatadsorptionstrinnet. IThe foregoing examples demonstrate the process of the invention relative to the chromatid adsorption step. IN
eks. 2 og 3 efter chromatadsorptionstrinnet bliver chro-matet let strippet fra den svage basiske anionharpiks ved at fore en 4% natriumhydroxidoplosning i halvt mættet 12-15% NaCl ) saltvand gennem massen. Ma'ssen bliver derpâ re-genereret ved passage af en saltsur oplosning derigennem, og den bliver ved hjælp af en let alkalisk eller neutral oplosning (af NaCl) konditioneret til et pH pâ mellem 1 og 2. Derpâ kan man gentage chromatadsorptionstrinnet.For example, 2 and 3 after the chromatid adsorption step, the chromat is easily stripped from the weak basic anion resin by passing a 4% sodium hydroxide solution in semi-saturated 12-15% NaCl brine through the mass. The mass is then regenerated by passing a hydrochloric acid solution therethrough, and it is conditioned by a slightly alkaline or neutral solution (of NaCl) to a pH of between 1 and 2. Then the chromatid adsorption step can be repeated.
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En generel beskrivelse af en ancien udf0relsesform for op-findelsen er som folger:A general description of an exemplary embodiment of the invention is as follows:
En blandet masse af foreskreven ionbytterharpiks fremstil-les ved luftblæsning under vand af ca. 35 til ca. 65 vægt-dele af en anionbytterharpiks, som findes pâ chloridform, og ca. 65 til ca. 35 vægtdele af en svag kationbytterhar-piks, som foreligger pâ hydrogenform, i en ionbytterkolonne.A mixed mass of prescribed ion exchange resin is prepared by blowing under water with approx. 35 to approx. 65 parts by weight of an anion exchange resin present in chloride form, and approx. 65 to approx. 35 parts by weight of a weak cation exchange resin present in hydrogen form in an ion exchange column.
Efter at hâve drænet vandet fra sojlen behandles massen med en mineralsur oplosning af alkalimetalchlorid, og der- pâ konditioneres kationharpiksen ved at fore en neutral oplosning af alkalimetalchlorid gennem massen for at ind- stille pH af det udgâende materiale, som for forklaret. En vandig, alkalimetalchloratrig alkalimetalchloridvæske, der indeholder under ca. 20 g alkalimetalchromât per liter, fortrinsvis under 10 g alkalimetalchromât per liter, fores opad gennem den blandede ionbyttermasse med en hastighed 2 pâ ca. 20,3 liter per minut per m masse, mens man styrer pH af den udgâende stromning. Nâr pH stiger over ca. 2 og det udgâende materiale bliver gult, afbrydes stromningen af chloratvæsken.After draining the water from the column, the pulp is treated with a mineral acid solution of alkali metal chloride, and then the cation resin is conditioned by passing a neutral solution of alkali metal chloride through the pulp to adjust the pH of the starting material as explained. An aqueous alkali metal chlorate-rich alkali metal chloride liquid containing less than about 20 g of alkali metal chromate per liter, preferably less than 10 g of alkali metal chromate per liter, are fed upwards through the mixed ion exchange mass at a rate of 2 at approx. 20.3 liters per minute per m mass while controlling the pH of the outgoing flow. When the pH rises above approx. 2 and the outgoing material turns yellow, the flow of the chlorate liquid is interrupted.
Chloratvæsken drænes fra ionbytterharpiksmassen, og en halvt mættet (12-15%) oplosning af natriumchlorid, der. fortrinsvis udviser et neutralt pH (7-8) f0res opad gennem massen med en hastighed, der er tilstrækkelig til at separere de to ionbytterharpikser i ovre (anionharpiks) og nedre (kation-harpiks) lag. Saltvandsstrommen· afbrydes,, og man forer.· 4% natriumhydroxid i 12-15% natriumchlorid-bplosning nedad gennem anionbytterharpiks indtil den udgâende stromning bliver alkalisk, hvilket viser, at det adsorberende .chromât er fjernet fra harpiksen. Med henblik pâ regenerering forer man 4% saltsyre i en halvt mættet natriumchlorid-oplosning gennem ionbytterharpikserne, indtil pH af det udgâende materiale faider til 1,0. Konditionering af kationharpiksen.The chlorate liquid is drained from the ion exchange resin mass and a half saturated (12-15%) solution of sodium chloride which. preferably, a neutral pH (7-8) is advanced upwardly through the mass at a rate sufficient to separate the two ion exchange resins into the upper (anion resin) and lower (cation-resin) layers. The saline stream · is interrupted and fed · 4% sodium hydroxide in 12-15% sodium chloride solution downwards through anion exchange resin until the outgoing stream becomes alkaline, showing that the adsorbent chromate is removed from the resin. For regeneration, 4% hydrochloric acid in a semi-saturated sodium chloride solution is passed through the ion exchange resins until the pH of the starting material drops to 1.0. Conditioning of the cation resin.
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gennemf0res ved at f0re en halvt mættet nâtriumchlorid-. opl0sning opad eller nedad gennem harpiksen, indtil det udgâende materiale Fiar et pH pâ 1,5-2. Derpâ gentager man chromat-adsorptionstrinnet.is carried out by passing a semi-saturated sodium chloride. solution up or down through the resin until the outgoing material reaches a pH of 1.5-2. Then the chromator adsorption step is repeated.
Claims (7)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US83286677A | 1977-09-13 | 1977-09-13 | |
| US83286677 | 1977-09-13 |
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| DK398878A DK398878A (en) | 1979-03-14 |
| DK157360B true DK157360B (en) | 1989-12-27 |
| DK157360C DK157360C (en) | 1990-05-21 |
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| DK398878A DK157360C (en) | 1977-09-13 | 1978-09-11 | PROCEDURE FOR REMOVAL OF CHROMATES FROM Aqueous CHLORATE SOLUTIONS |
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| JP (1) | JPS5450488A (en) |
| AR (1) | AR219127A1 (en) |
| AU (1) | AU522562B2 (en) |
| BE (1) | BE870214A (en) |
| BR (1) | BR7805948A (en) |
| CA (1) | CA1112379A (en) |
| DD (1) | DD138303A5 (en) |
| DE (1) | DE2839894A1 (en) |
| DK (1) | DK157360C (en) |
| FI (1) | FI67494C (en) |
| FR (1) | FR2402623A1 (en) |
| GB (1) | GB2004262B (en) |
| HU (1) | HU182557B (en) |
| IT (1) | IT1107755B (en) |
| MX (1) | MX150616A (en) |
| NL (1) | NL187051C (en) |
| NO (1) | NO151999C (en) |
| PL (1) | PL112445B1 (en) |
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| YU (1) | YU216578A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US4176056A (en) * | 1978-04-27 | 1979-11-27 | Pennwalt Corporation | Cyclic operation of a bed of mixed ion exchange resins |
| US4259297A (en) * | 1979-09-04 | 1981-03-31 | Olin Corporation | Chromate removal from concentrated chlorate solution by chemical precipitation |
| US4547291A (en) * | 1983-12-13 | 1985-10-15 | The Graver Company | Method for treating aqueous solutions with weakly acidic cation exchange resins |
| CA1247761A (en) * | 1983-12-13 | 1988-12-28 | Robert Kunin | Method for treating aqueous solutions with weakly acidic cation exchange resins |
| US7907987B2 (en) | 2004-02-20 | 2011-03-15 | University Of Florida Research Foundation, Inc. | System for delivering conformal radiation therapy while simultaneously imaging soft tissue |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3835001A (en) * | 1973-04-30 | 1974-09-10 | Penn Olin Chem Co | Ion exchange removal of dichromates from electrolytically produced alkali metal chlorate-chloride solutions |
| US3972810A (en) * | 1974-07-15 | 1976-08-03 | Chemical Separations Corporation | Removal of chromium, chromate, molybdate and zinc |
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| GB760524A (en) * | 1954-05-21 | 1956-10-31 | Permutit Co Ltd | Improvements relating to the recovery of chromic or phosphoric acid |
| JPS5148563A (en) * | 1974-10-24 | 1976-04-26 | Kurita Water Ind Ltd | Kuromuganjuhaisuino shoriho |
| CA1035874A (en) * | 1974-11-20 | 1978-08-01 | Huron Chemicals Limited | Ion exchange chromate removal |
| JPS5290164A (en) * | 1976-01-23 | 1977-07-28 | Kurita Water Ind Ltd | Method for treating water containing 6 valment chromium |
-
1978
- 1978-08-11 CA CA309,206A patent/CA1112379A/en not_active Expired
- 1978-08-16 AU AU38976/78A patent/AU522562B2/en not_active Expired
- 1978-08-30 NL NLAANVRAGE7808907,A patent/NL187051C/en not_active IP Right Cessation
- 1978-08-31 AR AR273514A patent/AR219127A1/en active
- 1978-09-05 BE BE190262A patent/BE870214A/en not_active IP Right Cessation
- 1978-09-07 FI FI782748A patent/FI67494C/en not_active IP Right Cessation
- 1978-09-08 MX MX174823A patent/MX150616A/en unknown
- 1978-09-11 DD DD78207744A patent/DD138303A5/en not_active IP Right Cessation
- 1978-09-11 SE SE7809547A patent/SE431440B/en not_active IP Right Cessation
- 1978-09-11 PL PL1978209536A patent/PL112445B1/en unknown
- 1978-09-11 IT IT51044/78A patent/IT1107755B/en active
- 1978-09-11 DK DK398878A patent/DK157360C/en not_active IP Right Cessation
- 1978-09-12 BR BR7805948A patent/BR7805948A/en unknown
- 1978-09-12 JP JP11137278A patent/JPS5450488A/en active Granted
- 1978-09-12 GB GB7836518A patent/GB2004262B/en not_active Expired
- 1978-09-12 FR FR7826193A patent/FR2402623A1/en active Granted
- 1978-09-12 NO NO783088A patent/NO151999C/en unknown
- 1978-09-13 HU HU78PE1051A patent/HU182557B/en unknown
- 1978-09-13 DE DE19782839894 patent/DE2839894A1/en active Granted
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3835001A (en) * | 1973-04-30 | 1974-09-10 | Penn Olin Chem Co | Ion exchange removal of dichromates from electrolytically produced alkali metal chlorate-chloride solutions |
| US3972810A (en) * | 1974-07-15 | 1976-08-03 | Chemical Separations Corporation | Removal of chromium, chromate, molybdate and zinc |
Also Published As
| Publication number | Publication date |
|---|---|
| FI67494B (en) | 1984-12-31 |
| FI67494C (en) | 1985-04-10 |
| DD138303A5 (en) | 1979-10-24 |
| BE870214A (en) | 1979-01-02 |
| NL7808907A (en) | 1979-03-15 |
| FR2402623A1 (en) | 1979-04-06 |
| MX150616A (en) | 1984-06-11 |
| JPH0140761B2 (en) | 1989-08-31 |
| CA1112379A (en) | 1981-11-10 |
| DE2839894C2 (en) | 1988-07-21 |
| SE431440B (en) | 1984-02-06 |
| FR2402623B1 (en) | 1983-03-25 |
| NL187051C (en) | 1991-05-16 |
| PL209536A1 (en) | 1979-06-04 |
| NO151999B (en) | 1985-04-09 |
| SE7809547L (en) | 1979-03-14 |
| DK157360C (en) | 1990-05-21 |
| GB2004262A (en) | 1979-03-28 |
| IT1107755B (en) | 1985-11-25 |
| NL187051B (en) | 1990-12-17 |
| AU3897678A (en) | 1980-02-21 |
| FI782748A (en) | 1979-03-14 |
| BR7805948A (en) | 1979-05-02 |
| DE2839894A1 (en) | 1979-03-22 |
| NO783088L (en) | 1979-03-14 |
| GB2004262B (en) | 1982-03-24 |
| PL112445B1 (en) | 1980-10-31 |
| YU216578A (en) | 1982-08-31 |
| NO151999C (en) | 1985-07-17 |
| JPS5450488A (en) | 1979-04-20 |
| HU182557B (en) | 1984-02-28 |
| AU522562B2 (en) | 1982-06-17 |
| DK398878A (en) | 1979-03-14 |
| IT7851044A0 (en) | 1978-09-11 |
| AR219127A1 (en) | 1980-07-31 |
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