Patiented Nov. 6, 1923. 43.5 ( UNE TEED STATES PATENT OFFICE. CSARLEs E. PARSOENS, OF ENGLEWOOD, NEW JERSISY. PRO Class OS PRODUCING CARSEDES OF SOLOURE AND 230,0R. To osswig. Application filed April 10, 1928. Serial So. 88,214. To all whom it may concern. Be it known that I, CHARLEs E. PARSoNs, dium carbide Na,C, will in contact with the a citizen of the United States, residing at air be burned to sodium carbonate. It is Englewood, in the county of Bergen and also essential that the sublimed sodium car State of New Jersey, have invented certain bide be condensed and cooled out of contact new and useful improvements in Processes with the air. 60 of Producing Carbides of Sodium and The boron carbide BC can be tapped out Boron; and I do hereby declare the follow of the furnace in the usual manner. It is ing to be a full, clear, and exact description important that the carbon be not added to of the invention, such as will enable others the molten borate until the latter has been skilled in the art to which it appertains to heated several hundred degrees above its 65 make and use the same. melting point for otherwise elemental so This invention relates to a process of dium is liable to be driven of and the lower simultaneously producing sodium and boron carbide BC instead of the higher carbide carbides from sodium tetraborate, NaBO B.C. is liable to be produced. , and carbon, and has for its object to provide That is, the higher boron carbide B.C. a procedure which will be more efficient in does not dissociate while in the molten bath action and less costly to carry out than under the hydrostatic pressure of the fusion, those heretofore proposed. and the latter also prevents elemental so With these and other objects in view, the dium from leaving the borate and escaping invention consists in the novel steps and carbon.as a sublimate before uniting with the 75 combinations of steps constituting the proc It is of course possible to dissociate the ess, all as will be more fully hereinafter boron carbide B.C. without removal from claims.disclosed and particularly pointed out in the the furnace chamber by raising the tempera In carrying out this invention, one may ture of said carbide to say about 100° C. 80 take any suitable quantity of sodium tetra after the sodium carbide has been removed borate, NaBO, heat the same to about by sublimation. By this means, the boron 880° C., or until it is melted, and then raise carbide BC may be broken back to the the molten mass to a temperature above lower carbide B.C. 1000° C., or better still to about 1200° C., What is claimed is: or to a point just safely under its dissocia 1. The process of making a boron carbide tion temperature. To the superheated melt which consists in melting sodium tetrabo thus had, one now adds an excess of finely rate, NaB.O.; raising the temperature of the divided carbon, such as anthracite coal, coke molten bath to a point above 1000°C; add or charcoal, which is thoroughly admixed ing sufficient carbon to said bath to produce 90 with the melted borate and the temperature the desired boron carbide; and recovering raised until substantially all the sodium the product. present sublimes off in the form of a car 2. The process of simultaneously produc bide leaving boron carbide behind in accord ing sodium carbide and boron carbide from ance with the following equation: sodium tetraborate, which consists in melt 95 raisinging said the borate temperature out of contact to a point with betweenthe air; The lower boron carbide BC is not di 1000° C. and the point of dissociation of said rectly made by this process so long as a borate; adding sufficient carbon to produce state of fusion exists unless the temperature the desired sodium and boron carbides; and 00 exceeds 1700° C. It is preferred to make recovering said carbides. the higher carbide BC by the above dis 3. The process of simultaneously making closed fusion process and to then convert sodium carbide Na,C, and boron carbide it into the hard dissociation product BC B,C, which consists in melting in a closed system sodium tetra-borate NaBO, rais OS by a separate procedure. ing the temperature of the molten baththus Of course, the operation of producing produced to a point below that at which simultaneously sodium and boron carbides said borate will decompose; adding suffi in the manner above stated must be carried cient carbon to the bath to produce the de out in a closed system; otherwise the so sired sodium carbide and boron carbide; and 1478,510 segregating and recovering said carbide duce a higher carbide of boron; still further products out of contact with the air. raising the temperature until said higher 4. The process of producing a boron car- carbide dissociates into a lower carbide; and 10 bide which consists in melting sodium tetra- recovering the latter. borate; raising the temperature of the melt In testimony whereof I affix my signature. toperature; a point belowadding that sufficient of its dissociation carbon to tempro- CHARLES E. PARSONS.