Method for preparing gaseous mercury absorbing and purifying agent

The present invention relates to a preparation of an absorbent for absorbing and purifying the gaseous elementary mercury, which is made from the vermiculite which is modified by hydrochloric acid, namely, mixing 2-6 mol/L hydrochloric acid and the vermiculite as the solid-to-liquid ratio of 1:2-4,laying for 6-8 hours, putting the mixture into the mill furnace at the temperature of 105-110 degreeC, activating for 20-24 hours, taking out and grinding to less than 200 meshes, drying in the mill furnace until the water ratio is less than 5%, and then the modified vermiculite adsorption is obtained. The absorption effect of the sorbent of the present invention is better than the active carbon for trace gaseity elementary mercury in the coom smoke gas or the other industrial tail gas. When purifying the tail gas containing elementary mercury less than 100ug/m , the absorption capability of the elementary mercury can reach 3.2ug/g-6.0ug/g. The preparation of the present invention is especially used for occasions ne