Document vBZz66yDkY63pODK4Rq3qVz09

In t e r n a t io n a l Sme l t in g a n d Re f in in g Co mp a n y 25 Broadway. New York Ornci or m na-Pwoen January 30, 1942 Mr, , 0. Sorer-'iae, Secretary , I nt ernati onel Smelting refining Co., Building. P.e: Johnson et al. Application, Serial No. 173,352, Jor: ELECTROCHEMICAL METHOD OF PRODUCING '"SITE LEAD Dear Sir: 1 am sending you herewith for filing, the original deed in the above mentioned application, which is assigned to the International Smelting k Refining Company, Till you kindly acknowledge receipt of this deed on the attached carbon copy and return for my files. Tours very truly KSf l&t. -J PNYC00008332 IMPORTANT NOTICE This grant of United States Letters Patent should he carefully f i tserred. It is an original document of title. All articles embodying the invention of the patent made, used - r sold by you (or anyone licensed by yon) after the date of the patent should be plainly marked with the word "Patent" together with the number of the patent. 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The language of the statute is as follows: "It Shall be the duty of all patentees, and their assign.' and legal representatives, and of all persons making or vending any patented article for or under them, to give sufficient notice to the public that the same is patented; either by fixing thereon the word `patent,' together with the number of the patent: or when, from the character of the article, this can not be done, by fixing to it, or to the package wherein one or more of them is enclosed, a label containing the like,notice: * * * and in any suit for infringement by the party failing so to ... maric,no damages shall be recovered by the plaintiff, except "y on.proof that the defendant was duly notified of the infringeBMBt and continued, after such notice, to make, use, or vend the article so patented." (U. S. Code, Title 35, Sec. 49.) Pe n s ie , Davis, Ma r v in & Ed mo n d s . PNYC00003333 N11447.01 THE UNITED SMFES OF AMERICA rn AWi TOiTOaOMlTHfiSE: P-HBSEMK; SHMili HOME:!; ^bficrcas g c t NAHD S. JOHNSON, of Hammond, R30INALD C, 30' 'AN, of G-ary, and V/ILUAM J. KNOX, JP.of Hammond, Indiana, assignors to INTZPNATIONAL 3TZLTm AND RHFININS COMPANY, of East Chicago, Indiana, a corporation of Montana, iRE9KyrF.n t o t h f . CoillnilN wlonPT of THE CHA.VT OF I,ETTE!t HVI K.VT FOR .Of ALLtCiKI) a I'KTiTro.'i p iu y i.\o i <u A.VO VSFFI L IMPRWEMt.VT IN SLSCTHOCHBCICAL mKODS 0? FRODUCirc '.7KITK 1*1 AD, A h k s c h ip t h w o f w h ic h in v e n t io n im c o n t a in e d in t h e s p e c if ic a t io n o f w h ic h A :OIY IS H KKK l.'NTt ANNEXED AN l> MADE A HAKT HEREOF. ANU COMPUKO WITH THE VAH lOt'S REQUIREMENTS OF UW IN RICH CASES MAUK AM) PROVIDED. AMU l^crcas IRON ll'E EXAM I NATION MADE THE Ha ID (XMM.VNT g AOJIDCEU TO BE J19TI.Y ENTITLED TO A PATENT I NDF.H THE L\W. NOW THEREFORE THEME LottCPN .VICE TO GRANT t'NTO THF. SAD) International Smelting and Rgfining Company, its successors OR AMNIONS SEVENTEENFOR THE TERM OF YEARS FROM THE DATE OF THIS GRANT ^THE EXCLUSIVE RIGHT TO MAKE. ISE AND VEND THE SAID INVENTION THflOlGHOlT THE IGNITED St a t e s a n d t h e Te r r it o r ie s t h e r e o f . g| 3n testinumi} ,y rf///u/t/s/s/'////.m///As.issr/(Office '//>/rs// /^' 6s/y M/.j twentieth </s/y January, s// Ms ft/t? ////'r ///// / . Ai/Ay/s/i/A/irs forty--two, *'///>//* //. sr/////</ M>' ''dr/snr/r //, /'//f A/s /h /s s ///t/tr/ sixty-sixth. r //n . '! PNYC00008334 Patented Jan. 20* 1942 2,270,783 UNITED STATES PATENT OFFICE 2.270.783 ELECTROCHEMICAL METHOD OF PRODUCING WHITE LEAD Gtmnard E. Johnson. Hammond. Reginald G. Bowman, Gary, and WUUam J. Knox. Jr.. Ham mond. Ind.. assignors to International Smelt ing' and Refining Company, East Chicago, Ind., a corporation of Montana No Drawing. December Serial No. 178,352 4 Claims. (CL 204--88) This invention relates to the production of into the catholyte which is also acted upon by white lead and has far an object the provision of the current, the acetate ions replacing a part certain improvements in processes for producing of the hydroxide and carbonate loos that migrate white lead. More particularly, the Invention con to the anolyte. This is compensated for by per- templates the provision of certain improvements ' mitting a certain amount of seepage of catholyte in processes for producing white lead by elec into anolyte through the diaphragm. The seep trolysis. age Is controlled by selecting a diaphragm fabric The present-day commercial process for pro of the desired porosity for a given hydrostatic ducing white lead electrolytically 1s carried out in solution head of catholyte of a selected composi a so-called bi-fluid cell having a lead anode and n' tion in the cathode compartment. The addition an iron cathode separated by a porous dia of relatively small amounts of anolyte to catho phragm. The anode is surrounded by an elec lyte and catholyte to anolyte permits adjusting trolyte (the anolyte) containing sodium acetate the sodium concentration of the two electrolytes and a very small amount of sodium carbonate. and the conservation of chemicals, since all The cathode is surrounded by an electrolyte (the t > make-up solution can then be added to the catholyte) containing sodium acetate and a rela anolyte in the form of filtrate from the filters. tively large amount of sodium carbonate. Each All anolyte in the filter cakes is replaced by electrolyte is maintained In rapid circulation water by a counter current washing operation about its electrode. The circulation systems of and returned to .the anolyte circulation system. the two electrolytes are entirely independent 2n In addition, wash water filtrate is also returned and no communication exists between the cath as required to replenish the losses enumerated olyte and anolyte in the cell except through the above. As the volume of solutions transferred diaphragm in the cell. between the two electrolytes is very small the In practice, a small amount of NajCCh. not ex anolyte as previously stated is essentially free ceeding about .05 %, is added to the anolyte be 25 of the reacting salts and they are only brought fore placing the electrolytic cells in operation. into the zone where the white lead is precipitated When the current is turned on. the lead dis in electro-chemical equivalent amounts, there is solves from the surface of the anode and is Im never an excess present to alter the reaction or mediately precipitated as white lead at a slight influence the size of the panicle. distance from the anode surface. The precipitate 30 The white lead which is removed continuously is carried down through the cell by the descend from the ceil by the circulation of the anolyte. ing current of anolyte in a thick cloud without is removed from the anolyte by settling and depositing on the anode surface. Hydrogen and filtering. The filter pulp Is washed, dried, ground the hydroxide ions are liberated at the cathode. and air floated, and is then barrelled in a dry The hydroxide and carbonate ions of the hy 3.1 pulverulent form. The clear anolyte Is recircu drolyzed sodium carbonate (NasCOs) of the lated through the cell. catholyte migrate through the diaphragm to The composition of the anolyte during its pas ward the anode, replenishing the anions removed sage through the cell remains unchanged except from the anolyte by precipitation of the lead ions. for a small increase in the acetate concentration, By this electrolytic migration, the electro-chemi to This is controlled by dilution with wash water cal equivalent amount of anions required to pre from the filter. The catholyte 1s depleted in car cipitate the lead cations as they are dissolved at bonate Ions and a small percent of acetate ions, the anode are transported to the anolyte. Slight and enriched in hydroxide Ions during its passage traces of carbonate can be detected Is the anolyte through the cathode compartment of the cell. but* It is entirely free of dissolved lead salts. 4*> The excess of hydrate ions la neutralized and the However, there is no sodium carbonate (NaaCOj) loss in carbonate ions restored by passing the present in the solution film In contact with the catholyte through carbonation towers, in which anode. a stream of descending solution passes through a The foregoing outlines the major reaction. In rising stream of CGs gas from a coke burning practice, in order to replenish and conserve o0 boiler. The acetate loss Is replenished as noted chemicals and to restore the loss in volume of by running a small stream of anolyte into the catholyte due to decomposition' of water at the catholyte after it is discharged from the cells. cathode, evaporation and mechanical losses, In the United States patent to Ralph M. Har anolyte is added to the catholyte is a small con rington. No. 1,308.948, it Is recognized that the tinuous stream. This introduces sodium acetate U character and quality of the white-lead product P**C000083J5 2 2.370.783 may be controlled by regulating the amount of ide. "Excess carbonation." as used herein and carbon dioxide supplied to the catholyte, and it as understood in the art, means carbonation in is further recognized that in order to obtain excess of that required to maintain the bicar rapid carbon dioxide absorption, and at the bonate ion concentration of the anolyte at the time avoid precipitation of white lead on the 5 value necessary for the production of a white anode, it is necessary to maintain the catholyte lead product of desired composition. The alkali as compared with the anolyte relatively strongly metal hydroxide may be added to the anolyte alkaline. in any suitable manner as. for example, by dis We discovered that the composition of the solving the hydroxide in the anolyte outside the white lead produced varies directly with the 10 cell, by adding a preformed solution of the hy HCOj ion or bicarbonate content of the anolyte. droxide to the anolyte outside the cell, or by add Our investigations have indicated that the white ing catholyte high in hydroxide 'after electroly lead formation is represented by the following sis and prior to carbonation? to the anolyte out reaction equation: side the cell. Each of these procedures effects 3Pb<C2Hj03>3+4Na:C03-i-2H20= 2PbCOs Pb < OH) i - 2NaHCOs -r6NaCsH30s 18 the desired control of the bicarbonate ion con centration in the anolyte. and hence the compo1 the precipitated white lead, in a man The composition of the basic lead salt precipi ner such that the addition of ions not entering tated varies with the pH value of the solution In into the composition of the precipitated white which it is formed. It will be apparent, there- 20 lead Is not substantially greater than the loss of fore, that if only sodium carbonate 'NaaCOi) such ions in the course of normal operation of and lead acetate Pb<C2H30*>2> were supplied to the cell. The solution of hydroxide for addition the solution, the sodium bicarbonate 'NaHC03> to the anolyte may be formed by employing as content would progressively increase and the solvent the filtrate normally employed as make ratio of HCO: to OH ions in the resulting precipitated lead salt would increase until finally up solution. The invention permits simplifica tion of the carbonation operation and provides only PbCOi would be produced. In other words a simple method of maintaining a supply of the carbon dioxide rCOa> content of the precipi anoiyte of the proper concentration with respect tated white lead bears a direct relation to the to bicarbonate. Instead of controlling the car sodium bicarbonate >NaHCOi) concentration of go bonation operation to completely or partially the anolyte. This has been found to be true in neutralize the catholyte solution from the cell actual operation. In order to control the com 'depleted in carbonate ion and high in hydrox position of the white lead produced, therefore, ide' and. in the case of the partially neutralized it is necessary to control the NaHCCh content of catholyte. adding an acid or bicarbonate to the the anolyte. 30 anolyte to compensate for the incomplete neu Our discovery of the effect of the HCOj ion or tralization. the carbonation operation may be bicarbonate content of the anolyte on the com permitted to proceed to the point at which ex position of the white lead produced is described cess carbonation is effected without the necessity in our United States Patent No. 1.845.713, dated for exercising extreme caution to secure exaci February 16. 1932. which covers control of the 40 neutralization or accurate deficient carbonation bicarbonate content of the anolyte by maintain The invention simplifies the process also by elim ing a uniform and deficient carbonation of the inating the necessity for exact control of addi catholyte and adding an acid or a bicarbonate tion of catholyte to anolyte by electrolysis and by to the anolyte. seepage through the diaphragm to meet changes Our aforementioned patent also points out that 43 in operating conditions. The composition of it is desirable that the carbonate salt content of anolyte thus harmfully altered can be adjusted the anolyte be kept low--much lower than is re readily by the method of the invention. In the quired in order to avoid formation of white lead preferred method of the invention, the carbona incrustations on the anode--in order to permit tion operation is so controlled as to effect sub washing the white lead free of these salts in the 50 stantially uniform and excess carbonation of the finishing of the white lead separated from the catholyte for each particular set of operating anolyte. This is Important in the commercial conditions designed to produce a product of par production of white lead by the electrolytic ticular composition. method, since the presence of any considerable In accordance with our Invention, using a bf- amount of metal carbonate in the white 00 fiuid cell with a lead anode suspended in an lead product renders it unfit for use as paint pig anolyte capable of yielding a solvent for the lead, ment. We have found that the difficulty in e. g.. sodium acetate, and a suitable inert cath washing the white lead sufficiently free of ad ode suspended in a catholyte containing sodium sorbed salts increases with increasing concentra carbonate and separated from the anolyte by a tion of carbonate salt In the anolyte to a point so suitable diaphragm, and to which an excess of at which it is practically impossible to eliminate carbon dioxide <COa> is supplied in the carbona them. This may be explained by adsorption of the salts in the white lead particles, but it seems tion operation, the anolyte solution is sampled and analyzed at regular intervals, say every hour, more probable that a reaction may occur as fol lows: and Its bicarbonate content adjusted to and maintained at the desired figure by the addition of an alkali metal hydroxide, as pointed out 2i 2PbCOs.Fb OKU)* NajCOa+NaHCCh = 3N&Pba1CO3 > j OH 4- Ht O above. For example. In a ceil operated at a current whereby the carbonate salt becomes chemically density of 30 amperes per square loot of cathode combined and therefore very difficult or impos- TO area and producing approximately .011 pound of slble to remove. Our present invention provides for control of the biearbonate content of the anolyte by means of excess carbonation of the catholyte and the addition to the anolyte of an alkali metal hydrox- 70 white lead per ampere hour and operating at an anolyte displacement rate of 18 gallons per min ute while timing uniform and excess car bonation of the catholyte. the sodium bicarbon ate content of the anoiyte Is maintained at PNV C00C08336 ,2 270,783 3 0.0551% through adjustment by the addition of re-use of the regenerated catholyte. the compo sodium hydroxide thereto to produce a white lead sition of the precipitated white lead being con containing 11.60% of carbon dioxide <COj >. To trolled by reference to the bicarbonate ion con produce white lead of greater or smaller CO? centration in the anolyte. the improvement which content the acid carbonate content of the anolyte 5 comprises adjusting the bicarbonate ion concen may be increased or decreased by the addition of tration in the anolyte by subjecting the catholyte lesser or greater amounts, respectively, of sodium to excess carbonation and addin? to the anolyte hydroxide. The exact acid carbonate content re a sufficient amount of uncarbonated catholyte quired for the production cf a particular white containing hydroxyl ions to establish in the lead product should be determined in each in- m anolyte bicarbonate ions in the desired concen stance by experiment. The carbonate salt con tration. whereby addition of ions not entering tent af the anolyte is maintained at not exceed into the composition of the precipitated white ing about twenty-five one-hundredths of one per lead is not substantially greater than the loss of cent iO.25%). and preferably less than six one- such ions in the course of normal operation of hundredths of one percent < 0,06% '. Thesfgnifl- 1.5 cance of the limited carbonate salt contc;.- -i.e ui the process of producing white lead of anolyte specified may be appreciated by com constant particular composition by electrolysis in parison with the limitation of the carbonate salt a bifluld cell in which the white lead is precipi content of the anolyte necessary to avoid trouble tated in an anolyte capable under electrolysis of some precipitation of white lead on the anode in .to yielding a lead solvent and containing bicarbon accordance with the Harrington patent. In this ate salt, the steps which consist in determining case the carbonate salt content of the anolyte the bicarbonate ion concentration in the anolyte may run as high as six tenths of one percent corresponding to the precipitation of white lead <0.60%'. which content, however, will produce of the particular composition, and maintaining white lead containing so much carbonate salt said bicarbonate ion content in the anolyte by that It is not feasible in commercial operation to maintaining a uniform and excess carbonation wash it sufficiently free of such salt as to pro of the catholyte and by adding an alkali metal duce a first grade white lead paint pigment. hydroxide to the anolyte in such an amount that We claim: the amount of added alkali metal Ions is not sub 1. In a process cf producing white lead of con- 'to stantially in excess of the amount of alkali metal stant particular composition by electrolysis in a ions lost in the course of normal operation of bifluid cell involving the use of an anolyte ca the cell but sufficient to establish in the anolyte pable under electrolysis of yielding a lead solvent bicarbonate Ions in the desired concentration for and containing a bicarbonate and of a catholyte precipitation of white lead of the particular com containing a carbonate which is altered during '** position. the course of the process by removal of carbon 4. In a process of producing white lead of con ate ions, and involving carbonaticn of the cath stant particular composition by electrolysis in a olyte to restore carbonate ions thereto and re-use bifluid cell involving the use of <1) an anolyte of the regenerated catholyte. the composition of capable under electrolysis of yielding & lead sol the precipitated white lead being controlled by vent and containing a carbonate and a bicar reference to the bicarbonate ion concentration in bonate and '2' a catholyte containing a car the anolyte, the improvement which comprises bonate which is altered during the course of the adjusting the bicarbonate ion concentration in process by removal of carbonate Iona, and in the anolyte by subjecting the catholyte to ex volving carbonation of the catholyte to restore cess carbonatlon and by incorporating hydroxyl u carbonate ions thereto and re-use of the regen ions in the anolyte in the form of a soluble metal erated catholyte. the composition of the precipi hydroxide in such an amount that the amount tated white lead being controlled by reference to of added metal ions of said hydroxide is not sub the bicarbonate ion concentration in the anolyte. stantially m excess of the amount of metal loos the improvement which comprises maintaining lost In the course of normal operation of the cell, oO the carbonate concentration in the anolyte at or the amount of metal hydroxide incorporated In below a predetermined maximum which is sub the anolyte being sufficient to establish therein stantially less than the concentration resulting in bicarbonate ions in the desired concentration, objectionable deposition of white lead on the whereby the addition of ions not entering into anode, and adjusting the bicarbonate ion con the composition of the precipitated white lead is centration in the anolyte by subjecting a portion not substantially greater than the toss of such of the catholyte to excess carbonation and by ions in the course of normal operation of the adding to the anolyte the remaining portion of ceil. uncarbonated catholyte containing sodium hy 2. In a process of producing white lead of con droxide to establish in the anolyte bicarbonate stant particular composition by electrolysis ta s g ions in the desired concentration, whereby the bifluid cell involving the use of an anolyte ca concentration of iens not entering into the com pable under electrolysis of yielding a lead sol position of the precipitated white lead Is not in vent and containing a bicarbonate and a cath creased in the course of normal operation of the olyte containing a carbonate which is altered cell. during the course of the process by removal of w GUNNARD E. JOHNSON. carbonate ions, and involving carbonatlon of the catholyte to restore carbonate ions thereto and REGINALD G. BOWMAN. WILLIAM J. KNOX. J*. I OSPROPERTY OF Anaconda Copper Mining Company ...utiLLiju... ,.=K L'LZ.XSJh Qa^., 6-,..../ ? 3 7... PNYC0000633ti N11447.02 In t e r n a t io n a l Sme l t in g & Re f in in g Co mp a n y 25 ROADWAY P"eoeRiCK L-a is t VICE MCSiOCN' New YORK December 20, 1937 Mr. D. B. Hennessy, B u '' 1 d i n g. Re: U. 3. Patent Application of Messrs. Johnson, Bowman & Knox Serial Number 178,552 Filed December 6, 1937 For: Method of Producing White Lead Dear Sir: X am sending 70U herewith the original assignment con veying title to the invention disclosed in the above noted appli cation to the International Smelting and Refining Company. This assignment was recorded in the Transfers of Patents in the United States Patent Office under date of Dec ember 6, 1937 in XAber B173, Page 600. Will you kindly acknowledge receipt of this assign ment on the attached carbon copy and return for ray files. Tours very truly, FL 0 Qicl. PNTC00008339 N11447.03 V4947 tsBl73 mstjflO ASSIGNMENT WHEREAS, we, GUNNARD E. JOHNSON, REGINALD G. BOWMAN and WILLIAM J. KNOX, JR., citizens of the United States and residents respectively of Hamnond, County of Lake, State of Indiana, Gary, County of Lake, State of Indiana, and Hammond, County of Lake, State of Indiana, have invented certain new and useful improvements in METHOD 07 PRODUCING WHITE T.Eau for which we have executed an application for Letters Patent of the United States, of even date herewith; and WHEREAS, INTERNATIONAL SMELTING AND REPINING COMPANY, a corporation organized under the laws of the State of Montana and having a place of business at Bast Chicago, County of Lake, State of Indiana, is desirous of obtaining the entire right, title and Interest in, to and under the said improvements and the said application: NOW, THEREFORE, in consideration of the sum of One ($1.00) Dollar to us in hand paid, and other good and valuable consideration, the receipt of which is hereby acknowledged, we, the said GUNNARD E. JOHNSON, REGINALD G. BOWMAN and WILLIAM J. KNOX, JR., have sold, assigned, transferred and set over, and by these presents do hereby sell, assign, transfer and set over, unto the said INTERNATIONAL 305LTING AND REFINING COMPANY, its suooessors, legal reporesentatlves and assigns, the entire right, title end interest in, to and under the said Improvements, and the said application and all divisions, renewals and continuations thersof, and all Letters Patent of the United States which may be granted thereon and all . reissues and extensions thereof, and all applications for Letters Patent whloh may hereafter be filed for said lmprovej seats in any oountry or countries foreign to the United j States, and all Letters Pstent which may be granted for sold i improvements in any country or countries foreign to the United Statee and all extensions, renewals and reissues ' thereof; and we hereby authorize and request the Commissioner C' ' of Patents of the United States, and any Official of any oountry or countries foreign to the United States, whose duty 1 it is to issue patents on application* as aforesaid, to 4 issue all Letters Patent for said improvements to the said \ INTERNATIONAL SMELTING AND REFINING COMPANY, I its successors, legal representatives end aaalgna, in ac cordance with the terms of this instrument. AND WX HEREBY oovenant that ww have full right to oonveythe entire Interest herein assigned, and that we have ij not emmeuted, and will not execute, any agreement in conflict herewith, AND WX HEREBY further oovenant and agree that we will communicate to the said COMPANY, its successors, legal representatives and assigns, any faota known to us respecting said improvements, and testify in any legal proceeding, PNYC00008340 N11447.04 alga all lawful papers, execute all divisional, continuing and reissue applications, make all rightful oaths and <55! generally do everything possible to aid the eaid COMPANY, Sg Its successors, legal representatives and assigns, to obtain^ and enforce proper patent protection for said Improvements g in all countries. ^ m TESTIMONY aiitiffio?, X hereunto set my hand and seal *-- this ^-day of , 1937. s' fSC STATS OF INDIANA ) COUNTT OF LASS ) 9S* On this Z, 2>-~-4*y of . , 1937, before me, a Notary Public in and for the Stats and County aforesaid, appeared OTNNARD . JOHNSON, to as known and jKJknown to me to be the person of that naae, who signed and ' *"0T11 * -- - et/o%thkbeee Vhfo4israegfroe.iAnegaientstarnuJdmAde.e.n.eJt,d. and he acknowledged the f Will Notary Public. IK TESTIMONY wtusKBOl1, I berunto set my hand and seal this i i-e4ty of , 1937. STATE OF INDIANA ) County of Lake ) 88 . . Reginald o. Bowman On this vv'--^ay of , 1937, before me, a Notary Publlo in and'for the State and County aforesaid, personally appeared REGINALD 0. BOWMAN, to as known and known to me to be the person of that name, who signed and alsd the foregoing instrument, and he acknowledged the is to he his free sot and deed. "V^^^^sotary Public^. IN TESTIKON! WHEREOF, I hereunto set my hand and seal this day of 1937. 'ATE 07 INDIANA [NTT 0? LAKE On this X^^-day of ' , 1937, before me, a Notary Public in and for the State and County aforesaid, personally appeared WILLIAM J. KNOX, JR., to me known and known to'ms to he the person of that name, Wto signed and sealed the foregoing instrument, and he acknowledged the same to be his free sot and deed... V. S, Notary Public. PNVC00008341 -2