Document 6Raj8v0Z92LELkrGKNdmN5zp4

IN THE UNITED STATES PATENT OFFICE In re application of CUNNARD E. JOHNSON, REGINALD G. BOYrliAN and VYILLIAK J. KNOX, JR. Serial No. 178,352 Filed December 6, 1937 Dir, 56 - Room 4725 : ; : liETHQD OF PRODUCING : WHITE LEAD s : AFFIDAVIT STATE OF INDIANA COUNTY OF LAKE ) : ae: ) William J. Knox, Jr., being duly sworn depoaee 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 ia produced eleotrolytically. 1 am and have been for the peat 15 years Superintendent in charge of this White Lead Plant. I am one of the patentees of the Patent to Johnson et al No. 1,845,713. I am thoroughly familiar with the prooeas therein described and with the work leading to the development of that prooeas. The Johnson et al patent recognizes the importance of controlling the bicarbonate ion concentration of the anolyte in electrolytic processes for the manufacture of PWICOOOOWZ* white lead, and mentions several methods for effecting such ' control. One such method is to maintain the supply of C0a to the catholyte constant end to add aootlo eoid to the (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 catholyta constant and to supply sodium bicarbonate as such to the anolyte at. a point outside the oell (this is procedure (4) i of the Johnson et al patent, page 1, lines 47-50). Prior to malting the invention disclosed and claimed in the present application Serial No. 178,352, filed December 6, 1937, the only commercially feasible method for controlline 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 1(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 iona 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 discard a 2. PNYC00008*2b portion of the electrolyte to which they were added in order : to permit lowering the concentration of these ions in the ! remaining eleotrolyte by dilution with water. Discarding a j portion of the electrolyte is required in order to permit :I | dilution of the remaining electrolyte, because without dis- j! carding such portion, the volume of the electrolyte is in- j |l creased by dilution to beyond the capacity of the plant j j! I !| equipment. The cost of the reagents present in the electro- ; lyte thus required to be discarded is eo great that the methods of control requiring such discarding of electrolyte (procedures (2) and {4} of the aforesaid Johnson et al patent) can not be employed in commercial operations. In addition to myself, the petenteea of the afore\ said Johnson et al patent No. 1,845,713 are Gunnard 2. Johnson and Reginald G. Bowman, the same Gunnard E, Johnson end J Reginald G. Bowman who are co-applicants with me in the matter of the present application. The said Gunnard E. Johnson and I the said Reginald G. Bowman are and have been continuously | employed in the aforesaid East Chicago Plant of the International jSmelting and Refining Company since prior to the development of the process described in the aforesaid Johnson et al patent, end the nature of their employment has been continuously, during that time, such that they have each been at all times fer.lliar| with details of operation of the White Lead Flant. From ths 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 and claimed in the present application, I j discussed the operations and conduct 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 claimed in the present application did either of these reen suggest to me the possibility of controlling the bicarbonate ion concentre tion of the anolyte in the manner described in the present application. Had this method of oontrol been known or apparent to either Gunnard K. Johnson or Reginald G, Bowman, the duties of their employment would have required them promptly to acquaint me therewith. i y^aJL^, % ^. j William SK Knox, Jr'. j" if-*; PNYC00008428