of the product gas stream and particles in a quench zone coated or lined internally with silicon nitride application_number US 22044888 A description the partial combustion of coal to produce synthesis gas which is substantially carbon monoxide and hydrogen and particulate flyslag is well known and a survey of known processes is given in 34 ullmanns enzyklopadie der technischen chemie 34 vol 10 1958 pp 360 458 several such processes for the preparation of hydrogen and carbon monoxide flyslag gases are currently being developed accordingly details of the gasification process are related only insofar as is necessary for understanding of the present invention in general the gasification is carried out by partially combusting the coal with a limited volume of oxygen at a temperature normally between about 1050 u00b0 c and about 2000 u00b0 c if a temperature of between 1050 u00b0 c and 2000 u00b0 c is employed the product gas may contain very small amounts of side products such as tars phenols and condensable hydrocarbons as well as the molten or sticky particles mentioned suitable coals include lignite bituminous coal subbituminous coal anthracite coal and brown coal in order to achieve a more rapid and complete gasification initial pulverization of the coal is preferred particle size is preferably selected so that 70 of the solid coal feed can pass a 200 mesh sieve the gasification is preferably carried out in the presence of oxygen and steam the purity of the oxygen preferably being at least 90 by volume nitrogen carbon dioxide and argon being.