| 摘要 |
Process for producing pellets for cleaning flue gas or industrial gases, the pollutants after a quasi-catalytic reaction being deposited or chemically reacted on metal oxides, which process involves admixing the active composition, which contains at least 10% by weight of CaO, with (quartz) sand having a particle-size distribution curve entirely below 0.3 mm, in an amount of up to 10% by weight based on the total weight, and with an amount of water sufficient for complete hydration of the metal oxides, and then, after complete hydration, first wet-pelletising it at room temperature with the addition of water, and then thermally treating the pellets at temperatures increasing stepwise over a period of at least two hours at each step. The composition is admixed with lime and kaolin as well as, if required, cement as a binder. The pelletising fluid is fed in at the final pelletising stage either directly as a vapour, or indirectly in the form of saturated warm air, the air being circulated and during its circulation outside the pelletising mixer being heated to the working temperature in each case and being enriched with water up to the saturation limit. The thermal treatment is carried out in temperature steps of from 25 DEG to 125 DEG C, up to 500 DEG C and can be carried out in the target installation, for example in a (waste) incinerator. |
