| 摘要 |
<p>The present invention relates to a method of decomposing gypsum to sulfur dioxide, and the apparatus thereof. The apparatus comprises a set of four-stage cyclone preheater and a rotary kiln for decomposing and calcining. In the four-stage cyclone preheater, the off-gas of the kiln conducts heat-exchange with materials. By such processing, the exchange efficiency is high, and gypsum which contain 10-25 % water can be directly used for preparing crude materials. The entrance temperature of the preheated materials can be up to 600-720 °C, while the temperature of the off-gas can be decreased to 260-400 °C, so that heat utilization ratio is high, and the cost of the apparatus can be cut down. The concentration of SO2 in the off-gas may be up to 11-14 %, so that two-conversion two-adsorption process can be employed for preparing sulfuric acid.</p> |
