Document 2gBoNL78ovKeBKJg7Z44ZVDa

IN THE UNITEC STATES PATENT OFFICE In ra application of GUNNARD E. JOHNSON, REGINALD G. BOWMAN and WILLIAM J. KNOX, JR. Serial No. 178,352 Filed December 6, 1937 Dir, 56 - Room 4725 : ; : METHOD OF PRODUCING : WHITE LEAD i : AFFIDAVIT STATE OF INDIANA COUNTY OF LAKE ) : as: ) William J. Knox, Jr., being duly sworn deposes and says: I am one of the applicants in the above-mentioned application. 1 am employed by the International Smelting end Refining Company, and I am thoroughly familiar with the White Lead Plant of that Company at East Chicago, Indiana, where white lead is produced eleotrolytioally. 1 am and hare been for the past 15 years Superintendent in charge of this White Lead Plant. I am one of the patentees of the Patent to Johnson et al No. 1,645,713. I am thoroughly familiar with the prooess therein described and with tha work leading to the development of that prooess. The Johnson et al patent reoognizes the Importance of controlling the bicarbonate ion concentration of the anolyte in electrolytic processes for the manufacture of pC00006`25 N11216 white lead, and mentions several methods for effecting such ' control. Jne such method la to maintain the supply of C0a to the catholyte constant end to add aoetlo cold to the i. anolyte at the point outside the cell (this is procedure (2) of the Johnson et al patent, page 1, lines 39-42), Another such method is to maintain the supply of COg to the catholyte constant and to supply sodium bicarbonate as such to the anolyte at. a point outside the oell (this is procedure (4) jof the Johnson et al patent, page 1, lines 47-50), Prior to malting the invention disoloaed and claimed in the present application Serial No. 178,352, filed December 6, 1937, the only commercially feasible method for controlling bicarbonate ion concentration in the anolyte known to me was the method referred to in procedure (1) of the aforesaid Johnson et al patent No. 1,845,713 (page 1, lines 37-39). The above-mentioned methods of control (procedures (2) and (4) of the Johnson et al patent) were never carried beyond the preliminary development stage because, while these methods of control are effective to control the bloarbonate ion concentration of the anolyte and henoe the composition of the white lead product, neither of these methods is commercially feasible. With these above-mentioned methods of control the acetate ions in the case of procedure (2) and sodium ions in the case of procedure (4) must be added in substantial excess of the normal operating loss of these substances in order to seoure effective control of the bi carbonate ion concentration in the anolyte. Consequently, the concentration of these added ions Increases to such an extent that it becomes neoessary continuously to disoard a 2. PNYC00008*26 >! :| portion of the electrolyte to which they ware added in order ! to permit lowering the concentration of these Iona in the !| remaining eleotrolyte by dilution with water. Discarding a ! portion of the electrolyte is required in order to permit :j | dilution of the remaining electrolyte, because without dieii ;! cording such portion, the volume of the electrolyte la in- i j |i creased by dilution to beyond the capacity of the plant j ! equipment. The coat of the reagents present in the electro- i lyte thus required to be discarded ia so great that the methods ! of oontrol requiring auoh diaoarding of electrolyte {procedures (2) and {4} of the aforeaaid Johnson et al patent) can not be employed in commercial operations. ! In addition to myself, the patentees of the afore- jj |j aaid Johnson et al patent No, 1,845,713 are Gunnard E, Johnson | and Reginald G. Bowman, the same Gunnard E. Johnson and J 1! !; Reginald G. Bowman who are co-applicants with me in the matter i 1 of the present application. The said Gunnard E. Johnson and i the said Reginald G. Bowman are and have been continuously I ) employed in the aforesaid East Chicago Plant of the International jSmelting and Refining Company ainoe prior to the development of the prooeaa described in the aforesaid Johnson et al patent, J '1 land the nature of their employment has been continuously, during | that time, such that they have each been at all times fer.iliarj jwith details of operation of the White Lead Flant. From the j time of the development of the process described in the said ! . ' , .. i Johnson et al patent No. 1,845,713 until development of the , process described end olaimed in the present application, I jdiscussed the operations and oonduct of the White Lead Plant with each of these men almost daily. At no time prior to the 3. PNYC00008427 development of the Invention described and olaimed in the present application did either of these men suggest to me the possibility of controlling the bicarbonate ion oonsentra tion of the anolyte in the manner described in the present application. Had this method of control been known or apparent to either Gunnard h. Johnson or Reginald G. Bowman, the duties of their employment would have required them promptly to acquaint me therewith. William J*2 Knox, Jr. Notary Public 4. PNVC00008428