PROCESS OF MAKING CARBON ELECTRODES

• Main Authors: SHAO, RICHARD, LIICHANG, LEWIS, IRWIN, CHARLES, LEWIS, RICHARD, THOMAS, PIRRO, TERRENCE A, KORTOVICH, JAMES, WILLIAM
• Format: Patent
• Language: English; French; German
• Published: 12.11.2008
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; APPARATUS THEREFOR; ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; COMPOUNDS THEREOF; CONCRETE; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTIONOF COMPOUNDS OR NON-METALS; INORGANIC CHEMISTRY; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIME, MAGNESIA; METALLURGY; NON-METALLIC ELEMENTS; PERFORMING OPERATIONS; REFRACTORIES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; SLAG; TRANSPORTING; TREATMENT OF NATURAL STONE; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A new process for preparing a graphite article such as a graphite electrode or cathode is described. The process comprises (a) mixing (i) a particulate fraction comprising at least about 35 weight percent coke, coal or mixtures thereof having a diameter such that a major fraction passes through a 25 mm mesh screen but not a 0.25 mm mesh screen, and (ii) a pitch binder, to form a stock blend; (b) extruding the stock blend to form a green stock; (c) baking the green stock to form a carbonized stock; and (d) graphitizing the carbonized stock by maintaining the carbonized stock at a temperature of at least about 2500 degree C. A graphite electrode column made using the new process has sufficient strength to maintain the integrity of the graphite electrode column without use of a pin, has increased resistance to cracking and has reduced brittleness, when plural such graphite electrode columns are used to form a graphite electrode.