GB1350494A - Process for producing coke product - Google Patents

Abstract

1350494 Coking coal PULLMAN Inc 24 Aug 1971 [26 Jan 1971] 39751/71 Heading C5E A process for coking a dried, ground, natural coal comprises blending 75 to 91% by weight of the ground coal with a binder comprising a pyrolysis residue of a gas oil, briquetting the blend at a pressure of at least 800 p.s.i.g. and coking the briquettes, optionally after curing, by heating them to at least 1450‹ F., during which heating the rate of temperature rise is controlled to lie in the range 150‹ F. to 625‹ F. per hour between the temperatures of 700‹ F. and 1100‹ F. The residue should have an I.B.P. in the range 650‹ F. to 1100‹ F., and in an example is obtained by steam cracking a gas oil at between 1300‹ F. and 2800‹ F. for from 0-25 to 5 seconds. In the example, a blend of 75% lignite and 25% bituminous coals is dried and ground and the binder sprayed on to the ground coal in a pug mill at a temperature in the range 350‹ F. to 500‹ F., after which briquetting at that temperature and at a pressure of 3200 p.s.i.g. is performed, prior to coking in an inert atmosphere. The product has a specific density of 1À1 and a flexure strength of about 4000 p.s.i.g. In modifications, the binder may be dissolved or dispersed in steam, CCl 4 or benzene, and curing, if performed, is at from 350‹ F. to 700‹ F. Volatiles given off during coking may be condensed and distilled to yield a pitch which may be used in the binder in amounts ranging from 10 to 40% by weight. The process is applicable to coals of high and/or low rank, e.g. weakly coking or non-coking coals having a fixed carbon content below 80%.