PROCESS FOR THE PRODUCTION OF GRANULAR MINERAL MATERIAL FROM COAL-BURNING RESIDUES

摘要

1. Method for production of granular additive materials from coal combustion products from fluidized bed apparatus with a bed temperature less than 900 degrees C and with the addition of lime, characterized by the following measures a) the use of fuel particle accretions with low proportion of fine particles ; b) control of the dwell time of the coarser particles in the fluid bed until they are burned up and up to the point where the mineral clay has been dehydrated ; c) repeated recycling of the finer particles fully treated in the gaseous stream into the fluidized bed until they are burned up and up to the point where the mineral clay has been dehydrated ; d) dispensing the lime-containing additive according to its sulphur content (twice the stoichiometric amount) ; e) selecting the fuel particle accretions and additive with the result that the granular mineral substance falling as ash comprises - a glue content =< 4% by weight - a sulphate content =< 3% by weight - a burnt lime content =< 3% by weight - a chloride content =< 0.1% by weight.