PROCESS FOR THE PRODUCTION OF NITRIC ACID WITH A CONCENTRATION OF OVER 70 PERCENT BY WEIGHT

摘要

Process of preparing nitric acid (having a concentration of over 70 percent by weight) by catalytically oxidizing ammonia with air to form NO2, absorbing the NO2 in water or aqueous nitric acid, increasing the partial pressure of the NO2 partly by compression and partly by passage through the absorption stage, washing out the residual NO2 with 60-70 percent nitric acid and recycling the same into the absorption stage, and blowing out the NO2 through the nitrous gas products of the ammonia oxidation in a degasification stage arranged ahead of the absorption stage.