US3091579A - Electrochemical process and apparatus with purification of mercury - Google Patents

Electrochemical process and apparatus with purification of mercury Download PDF

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Publication number
US3091579A
US3091579A US12417A US1241760A US3091579A US 3091579 A US3091579 A US 3091579A US 12417 A US12417 A US 12417A US 1241760 A US1241760 A US 1241760A US 3091579 A US3091579 A US 3091579A
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mercury
cell
electrolysis
centrifuge
amalgam
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US12417A
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Alexis G Basilevsky
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ELECTROCHEMICAL PROCESSES Inc
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ELECTROCHEMICAL PROCESSES Inc
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Priority to NL133158D priority Critical patent/NL133158C/xx
Priority to NL261847D priority patent/NL261847A/xx
Application filed by ELECTROCHEMICAL PROCESSES Inc filed Critical ELECTROCHEMICAL PROCESSES Inc
Priority to US12417A priority patent/US3091579A/en
Priority to DEE20432A priority patent/DE1240836B/de
Priority to FI0026/61A priority patent/FI41270B/fi
Priority to ES0263917A priority patent/ES263917A1/es
Priority to CH116861A priority patent/CH396857A/de
Priority to FR854337A priority patent/FR1288964A/fr
Priority to BE600842A priority patent/BE600842A/fr
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Publication of US3091579A publication Critical patent/US3091579A/en
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
    • C25B1/36—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in mercury cathode cells

Definitions

  • the electrolysis of sodium chloride in aqueous solutions to liberate chlorine and sodium is carried out in various types of electrolysis apparatus.
  • the mercury cathode electrolytic cell has been found particularly effective for carrying out this reaction and is extensively used in commercial electrolysis installations.
  • a stream of metallic mercury is caused to flow through the cell, generally over the bottom thereof, in contact with the brine.
  • the anodes of the electrolysis cell are generally formed from graphite and are electrically connected to a source of electrical current.
  • the most dangerous impurities are metals such as vanadium, chromium, molybdenum and titanium. Other metals such as nickel and iron are also dangerous, but to a lesser degree. Apparently the most dangerous metals are those which can exist in a form which is not readily soluble in the mercury or amalgam. The mechanism of their adverse action is not fully understood, their action has long been known.
  • the amount of impurities of the character indicated above which are deposited, along with the alkali metal, on the mercury cathode at any one time is extremely small and this amount does not adversely affect the electrolytic process to any significant extent and can be readily tolerated.
  • the precipitated impurities remain with the flowing mercury cathode throughout its cycle in the apparatus and they gradually accumulate in quantity as additional amounts are precipitated, during continuous operation of the electrolysis cell, until they reach a concentration which does seriously affect the electrolytic reaction and the adverse reactions referred to above begin to take place. It is necessary, therefore, either to discard the mercury when the impurity concentration reaches a dangerous value or it is necessary to separate the impurities from the mercury and restart the mercury cycle through the apparatus with purified mercury.
  • an object of the present invention to provide an improved process for removing impurities from the mercury cathode of a mercury cathode electrolytic installation.
  • the electrolytic process involving an electrolysis step in the presence of a moving mercury stream, and a decomposition step wherein the amalgam formed in the electrolysis step is decomposed to release the mercury for recycling to the electrolysis step, is combined with a purification operation which comprises the steps of centrifuging the liquid mercury stream, at at least one point in its closed circuit between the electrolysis step and the decomposing step, to remove a light fractional portion containing substantially all of the impurities contained in the mercury, returning the heavy substantially impurity-free mercury to the liquid mercury stream, separating the impurities from the light portion by settling, and returning the thuspurified fraction of the light portion to the centrifuging step.
  • a purification operation which comprises the steps of centrifuging the liquid mercury stream, at at least one point in its closed circuit between the electrolysis step and the decomposing step, to remove a light fractional portion containing substantially all of the impurities contained in the mercury, returning the heavy substantially impurity-free mercury to the liquid mercury stream, separating the impurities from the light
  • the mercury which serves as the cathode in the electrolysis step and then flows as an amalgam to the decomposing step, to be subsequently returned as freed mercury to the electrolysis step to repeat the cycle is referred to as the mercury stream although it will be appreciated that it is actually free mercury only during part of its cycle.
  • the electrolysis system for carrying out this process is defined by an electrolysis cell, a decomposing cell, a conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in at least one of these conduits, and a settling unit connected with each centrifuge.
  • purification of the circulating mercury stream is effected by treatment of only a very minor fraction of the total volume of the mercury circulating in the system.
  • the purification operation is effected substantially automatically with a minimum of supervision.
  • FIG. 1 shows an electrolysis system embodying the features of the present invention and illustrating a typical assembly of units by means of which the process of the invention can be effectively carried out;
  • FIG. 2 shows a modified form of the system illustrated in FIG. 1;
  • FIG. 3 shows another modified form of the system of FIG. 1.
  • FIG. 1 of the drawings there is shown at 10 an electrolysis cell of the mercury cathode type having an electrolyte inlet 12, an electrolyte outlet 14, a mercury inlet 16 and an amalgam outlet 18.
  • a decomposing cell having an amalgam inlet 22 and a mercury outlet 24 with a water inlet 26- and an alkali outlet 28.
  • the amalgam outlet 18 of the cell 10 is connected to the amalgam inlet 22 of the cell 20 by a conduit 30.
  • the mercury outlet 24 of the cell 20 is connected by a conduit 32 with the mercury inlet 16 of the cell 10 to keep the circuit for the moving mercury cathode.
  • a pump 34 to effect the necessary raising of the liberated mercury to the mercury inlet of the electrolysis cell 10*.
  • a centrifuge connected to a settling unit is interposed in at least one of the conduits 30 and 32.
  • the centrifuge is shown at 38 in the conduit 32 and it will be seen that all of the liberated mercury issuing from the decomposing cell 20 passes into the centrifuge 38 wherein the mercury is separated into a lighter fraction containing the impurities and a heavier fraction consisting of substantially pure mercury, the heavier fraction continuing on through conduit 32 for return to the electrolysis cell 32 under the action of the pump 34.
  • a branch conduit 40 for the lighter fraction of the mercury separated in the centrifuge 38 passes to a gravity settler 42. In the settler the impurities rise to the surface and are readily skimmed off from time to time.
  • the impurityfree mercury settles and flows through a return conduit 46 back to the conduit 32. It will be observed that the return conduit 46 discharges into the conduit 32 between the decomposing cell 20 and the centrifuge 38, i.e. upstream of the centrifuge. As a result, if any impurities still remain in the mercury they will again be subjected to centrifugation and the mercury flowing on to pump 34 will be essentially impurity-free.
  • the settler illustrated at 42 comprises an outer tank 50, which is suitably circular, and an inner concentric circular bafiie 52 which extends downwardly 'to a level slightly above the bottom- 54 of the tank 50.
  • the conduit 40 carrying the lighter fraction separated in the centrifuge 38 discharges into an inlet tube 56 which extends centrally through the bottom 54 and rises into the baffle 52 to a level substantially above the level of the lower edge of the baffle.
  • the level of mercury in the tank 42 is determined by an overflow out let 58 which communicates with conduit 46 to lead the settled mercury back to the main conduit 32 of the mercury circuit.
  • mercury has a very high specific gravity.
  • the impurities however, have a substan tially lower specific gravity so that they tend to rise to the surface of the mercury when they are" given the opportunity.
  • the impurity-rich mercury fraction As the impurity-rich mercury fraction enters through the conduit, it is discharged into the chamber defined within the baffle 52.
  • the impurities gradually move to the surface of the mercury body in this chamber and the mercury gradually moves downwardly and escapes below the baffie into the annular pool between the baffle and the tank wall and overflows through the outlet 58.
  • the impurities collect on the surface of the mercury interiorly of the bafiie and are readily skimmed off at intervals.
  • other settler constructions may be employed in this phase of my process and the process is not limited by the particular construction of the settler or of the other apparatus units in the system shown in the drawing.
  • the electrolysis cell 10, the decomposing cell 20, the centrifuge 38 and the pump 34 may be of known construction.
  • the electrolysis cell may be of the construction shown in the patent of Charles Deprez and Alexis Basilevsky No. 2,550,231 or it may have the construction shown in the patent to Charles Deprez No. 2,704,743.
  • the decomposing cell on the other hand, may be of the vertical type and have the construction set forth in my Patent No. 2,588,469 or it may be of the horizontal type and have the construction set forth in the patent of Charles Deprez and Alexis Basilevsky No. 2,610,908.
  • the decomposing cell 30 is shown as a vertical unit but this may be readily replaced by a horizontal unit of any knovm construction.
  • the centrifuge is suitably of the liquid-liquid separator type illustrated, for example, on page 1000 of The Chemical Engineers Handbook by John H. Perry, 3rd ed.
  • the mercury and amalgam in the cathode cycle flow in the usual manner through the electrolysis cell 10, wherein the mercury is formed into an alkali metal amalgam, through the decomposing cell 20 wherein the amalgam is decomposed to liberate the mercury and to form alkali metal hydroxide, and through the conduits 30 and 32.
  • the mercury and amalgam flow through the electrolysis cell 10, the conduit 30 and the decomposing cell 20 by gravity and the decomposed mercury is then elevated by the pump 34 to the level of the mercury inlet of the cell 10.
  • the amalgam enters the centrifuge 38 which is continuously in operation and the heavy portion of the two-phases separated in the centrifuge leaves the outlet of the centrifuge and continues in conduit 30.
  • the impurities separated in the settler will float on the top of the mercury body in the settler and can be removed from time to time, e.g. once a day, without any problem.
  • These impurities can be stored and, if desired, later distilled in known manner to recover the small amount of mercury which they generally contain.
  • the amount of impurities thus separated will depend solely on the amount of impurities introduced into the system with the salt to be electrolyzed, the graphite anodes, and the water which is introduced into the decomposer and, therefore, can vary very much from one plant to the other.
  • the electrolysis cell and the decomposing cell are suitably operated in conventional manner to elfect eflicient electrolysis and subsequent denuding of the amalgam formed during electrolysis.
  • Flow rates, current densities, proportions and temperatures are those conventionally employed in this art in plants which do not contain the purification system which characterizes the present invention.
  • centrifuge and the pump have been shown as separate units. However, the functions of the pumps and the centrifuge may be combined, if desired, and the mercury stream may be propelled back to the electrolysis cell by the force provide in the combined unit.
  • the centrifuge 38 may be interposed in the conduit 32, rather than in the conduit 30', so that the decomposed mercury rather than the newlyformed amalgam is treated, or two centrifuges may be employed, one being provided in the conduit 30 and the other being provided in the conduit 32.
  • the centrifuge 38 is interposed in the line 30 leading from the electrolytic cell outlet 18 to the decomposing cell inlet 22.
  • the lighter fraction passes to the settler 42 and the settled fraction returns through line 46 to the line 30 upstream of the centrifuge 38.
  • a centrifuge 38 is interposed in the line 30 and a second centrifuge 38 is interposed in the line 32 leading from the decomposing cell 20.
  • Each centrifuge is connected to a settler 42 in an assembly such as shown in FIGS. 1 and 2.
  • the first centrifuge is connected in line 30 in the same manner as shown in FIG. 2 and the second centrifuge is connected in line 32 in the same manner as shown in FIG. 1.
  • amalgam formed in the cell which contains about 0.5% sodium by weight, is removed from the cell through amalgam outlet 18 at the rate of about 900 lbs. per minute and is introduced into a decomposing cell 20 such as, for instance, the one shown in my Patent No. 2,558,469.
  • the mercury In the centrifuge the mercury is separated into two portions, viz. a lighter portion and a heavier portion.
  • the lighter portion flows at a rate of 47.5 lbs. per minute and contains substantially all the impurities present in the incoming mercury, as well as those impurities not completely separated in the settler. These impurities will be present in the lighter fraction in a concentration somewhat above p.p.m.
  • the heavier portion or fraction, substantially free of impurities, is directed to the inlet of the mercury pump 34 at a rate of 895.5 pounds per minute and is pumped back into the electrolytic cell 10 through the inlet 16.
  • the lighter fraction separated in the centrifuge enters settling tank 42 in which the impurities, which are much lighter than mercury, will separate from the mercury and accumulate on the surface of the mercury body in the settler.
  • the mercury substantially freed from its impurities, returns as mentioned, at a rate of about 47.5 lbs. per minute and is mixed with the mercury coming from the decomposer 20 and the mixed mercury is introduced into the centrifuge.
  • the introduction of the efiiuent from the settler into the mercury stream upstream of the centrifuge compensates for the fact that the settler may not effect a complete separation of impurities and thus impurities which might not have been separated in the settler are prevented from being reintroduced into the electrolytic cell 10.
  • the amount of impurities removed from the cell in the present example is about 8.2 lbs. per day.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in at least one of said conduits for receiving the fluid flowing therethrough, and a settling unit connected With each centrifuge for receiving a fraction of said fluid, said centrifuge being effective to separate the fluid which it receives into a heavier fraction and into a lighter fraction, and said settling unit being connected with the centrifuge to receive the lighter fraction therefrom.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in at least one of said conduits for receiving the fluid flowing therethrough, and a settling unit connected with each centrifuge for receiving a fraction of said fluid, said settling unit being connected to receive the lighter fraction from the centrifuge and to return said fraction after settling to the inlet side of said centrifuge.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a first conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in said first conduit for receiving the fluid flowing therethrough, and a settling uni-t connected With said centrifuge for receiving a fraction of said fluid, said centrifuge being effective to separate the fluid which it receives into a heavier fraction and into a lighter fraction, and said settling unit being connected with the centrifuge to receive the lighter fraction therefrom.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a first conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet .end of the electrolysis cell, a centrifuge connected in said first conduit for receiving the fluid flowing therethrough, and a settling unit connected with said centrifuge for receiving a fraction of said fluid, said settling unit being connected to receive the lighter fraction from the centrifuge and to return said fraction after settling to the inlet side of said centrifuge.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a first conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in said second conduit for receiving the fluid flowing therethrough, and a settling unit connected with said centrifuge for receiving a fraction of said fluid, said centrifuge being effective to separate the fluid which it receives into a heavier fraction and into a lighter fraction, and said settling unit being connected with the centrifuge to receive the lighter fraction therefrom.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a firstconduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in said second conduit for receiving the fluid flowing therethrough, and a settling unit connected with said centrifuge for receiving a fraction of said fluid, said settling unit being connected toreceive the lighter fraction from the centrifuge and to return said fraction after settling to the inlet side of said centrifuge.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam With mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a first conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in each of said conduits for receiving the fluid flowing therethrough, and a settling unit connected with each centrifuge for receiving a fraction of said fluid, said centrifuge being effective to separate the fluid which it receives into a heavier fraction and into a lighter fraction, and said settling unit being connected with the centrifuge to receive the lighter fraction therefrom.
  • An electrolysis system of the mercury cathode type for continuous electrolysis of a salt of a metal forming an amalgam with mercury with continuous purification of the mercury cathode which comprises, in combination, an electrolysis cell, a decomposing cell, a first conduit connecting the amalgam discharge end of the electrolysis cell with the amalgam inlet end of the decomposition cell, a second conduit connecting the mercury discharge end of the decomposing cell with the mercury inlet end of the electrolysis cell, a centrifuge connected in each of said conduits for receiving the fluid flowing therethrough, and a settling unit connected with each centrifuge for receiving a fraction of said fluid, said settling unit being connected to receive the lighter fraction from the centrifuge and to return said fraction after settling to the inlet side of said centrifuge.
  • a purification operation to separate from said stream metallic impurities selected from the group consisting of vanadium, chromium, molybdenum, titanium, nickel and iron which comprises the steps of centrifuging the steps of centrifuging the liquid mercury stream at at least one point in its circuit between the electrolysis step and the decomposing step, removing in said centrifuging step a lighter fractional portion of said stream containing substantially all of the impurities in said stream subjected to centrifuging, directing the heavier substantially impurity-free fractional portion from said centrifuging step into the liquid mercury stream, separating the impurities from the lighter portion by settling, and returning the thus-purified fraction of the lighter portion to the centrifuging step.
  • a purification operation to separate from said stream metallic impurities selected from the group consisting of vanadium, chromium, molybdenum, titanium, nickel and iron which comprises the steps of centrifuging the liquid mercury stream as it flows from said electrolysis step to said decomposing step, removing in said centrifuging step a lighter fractional portion of said stream containing substantially all of the impurities in said stream subjected to centrifuging, directing the heavier substantially impurity-free fractional portion from said centrifuging step into the liquid mercury stream, separating the impurities from the lighter portion by settling, and returning the thus-purified fraction of the lighter portion to the centrifuging step.
  • a purification operation to separate from said stream metallic impurities selected from the group consisting of vanadium, chromium, molybdenum, titanium, nickel and iron which comprises the steps of centrifuging the liquid mercury stream as it flows from said decomposing step to said electrolysis step, removing in said centrifuging step a lighter fractional portion of said stream containing substantially all of the impurities in said stream subjected to centrifuging, directing the heavier substantially impurity-free fractional portion from said centrifuging step into the liquid mercury stream, separating the impurities from the lighter portion by settling, and returning the thus-purified fraction of the lighter portion to the centrifuging step.
  • a purification operation to separate from said stream metallic impurities selected [from the group consisting of vanadium, chromium, molybdenum, titanium, nickel and iron which comprises the steps of centrifuging the liquid mercury stream as it flows from said electrolysis step to said decomposing step, removing in said centrifuging step a lighter fractional portion of said stream containing substantially all of the impurities in said stream subjected to centrifuging, directing the heavier substantially impurity-free fractional portion from said centrifuging step to the liquid mercury stream, separating the impurities from the lighter portion by settling, and returning the thus-purified fraction of the lighter portion to the centrifuging step, centrifuging the liquid mercury stream as it flows between said decomposing step and said electrolysis step, removing

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)
US12417A 1960-03-02 1960-03-02 Electrochemical process and apparatus with purification of mercury Expired - Lifetime US3091579A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL133158D NL133158C (de) 1960-03-02
NL261847D NL261847A (de) 1960-03-02
US12417A US3091579A (en) 1960-03-02 1960-03-02 Electrochemical process and apparatus with purification of mercury
DEE20432A DE1240836B (de) 1960-03-02 1961-01-10 Anordnung zur Elektrolyse von Alkali-salzloesungen nach dem Amalgamverfahren und zurZersetzung des Amalgams
FI0026/61A FI41270B (de) 1960-03-02 1961-01-11
ES0263917A ES263917A1 (es) 1960-03-02 1961-01-11 Nuevo proceso electroquimica y aparato para su realizaciën
CH116861A CH396857A (de) 1960-03-02 1961-02-01 Elektrolysesystem und Verwendung desselben
FR854337A FR1288964A (fr) 1960-03-02 1961-03-02 Procédé et appareil électrochimique
BE600842A BE600842A (fr) 1960-03-02 1961-03-02 Procédé et appareil électrochimique.

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US12417A US3091579A (en) 1960-03-02 1960-03-02 Electrochemical process and apparatus with purification of mercury

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US3091579A true US3091579A (en) 1963-05-28

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US12417A Expired - Lifetime US3091579A (en) 1960-03-02 1960-03-02 Electrochemical process and apparatus with purification of mercury

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US (1) US3091579A (de)
BE (1) BE600842A (de)
CH (1) CH396857A (de)
DE (1) DE1240836B (de)
ES (1) ES263917A1 (de)
FI (1) FI41270B (de)
NL (2) NL261847A (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3410763A (en) * 1963-08-08 1968-11-12 Union Carbide Corp Continuous polarographic method
US3497432A (en) * 1966-10-10 1970-02-24 Dynamit Nobel Ag Process for reducing the hydrogen content in chlorine gas produced by alkali-metal chloride electrolysis
US3663385A (en) * 1968-08-30 1972-05-16 Kureha Chemical Ind Co Ltd Alkali salt electrolysis by mercury process
US20090032407A1 (en) * 2006-04-12 2009-02-05 Industrie De Nora S.P.A. Device for the Separation of Mercury from Caustic Soda in Chlor-Alkali Plants

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1707471A (en) * 1924-10-11 1929-04-02 Savage De Remer Corp Art of purifying mercury
GB396041A (en) * 1931-05-01 1933-07-18 Knut Wilhelm Palmaer Improved method of purifying mercury which has been used as a cathode in electrolysis
US2128444A (en) * 1933-10-25 1938-08-30 Vroonen Emile Process for the purification of molten metals
US2224814A (en) * 1938-08-25 1940-12-10 Du Pont Electrolytic production of metals
US2504095A (en) * 1947-01-10 1950-04-11 Pacific Bridge Company Electrolyzing of chrome solutions to recover chrome
US2534210A (en) * 1946-02-28 1950-12-12 Lummus Co Centrifugal separation
US2628021A (en) * 1949-05-03 1953-02-10 Separator Ab Centrifuge with auxiliary feed arrangement
US2866703A (en) * 1956-05-28 1958-12-30 Diamond Alkali Co Treated molten metal
US2949212A (en) * 1958-08-11 1960-08-16 Orla E Watson Liquid feeder

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH288422A (de) * 1950-08-28 1953-01-31 Krebs International Engineerin Verfahren zur Reinigung des bei der Chloralkali-Elektrolyse nach dem Amalgam-Verfahren verwendeten Quecksilbers.

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1707471A (en) * 1924-10-11 1929-04-02 Savage De Remer Corp Art of purifying mercury
GB396041A (en) * 1931-05-01 1933-07-18 Knut Wilhelm Palmaer Improved method of purifying mercury which has been used as a cathode in electrolysis
US2128444A (en) * 1933-10-25 1938-08-30 Vroonen Emile Process for the purification of molten metals
US2224814A (en) * 1938-08-25 1940-12-10 Du Pont Electrolytic production of metals
US2534210A (en) * 1946-02-28 1950-12-12 Lummus Co Centrifugal separation
US2504095A (en) * 1947-01-10 1950-04-11 Pacific Bridge Company Electrolyzing of chrome solutions to recover chrome
US2628021A (en) * 1949-05-03 1953-02-10 Separator Ab Centrifuge with auxiliary feed arrangement
US2866703A (en) * 1956-05-28 1958-12-30 Diamond Alkali Co Treated molten metal
US2949212A (en) * 1958-08-11 1960-08-16 Orla E Watson Liquid feeder

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3410763A (en) * 1963-08-08 1968-11-12 Union Carbide Corp Continuous polarographic method
US3497432A (en) * 1966-10-10 1970-02-24 Dynamit Nobel Ag Process for reducing the hydrogen content in chlorine gas produced by alkali-metal chloride electrolysis
US3663385A (en) * 1968-08-30 1972-05-16 Kureha Chemical Ind Co Ltd Alkali salt electrolysis by mercury process
US20090032407A1 (en) * 2006-04-12 2009-02-05 Industrie De Nora S.P.A. Device for the Separation of Mercury from Caustic Soda in Chlor-Alkali Plants
US8216444B2 (en) * 2006-04-12 2012-07-10 Industrie De Nora S.P.A. Device for the separation of mercury from caustic soda in chlor-alkali plants

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DE1240836B (de) 1967-05-24
CH396857A (de) 1965-08-15
BE600842A (fr) 1961-09-04
NL133158C (de)
ES263917A1 (es) 1961-03-16
FI41270B (de) 1969-06-30
NL261847A (de)

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