Platinum Metals Catalvtic Systems J J in Nitric Acid Production SYSTEM OPTIMISATION IN NON-CONCENTRATED ACID PLANTS

paper gives a brief overview of the main results of work carried out by GIAP alone and in co-operation with other organisations over the past 50 years on the optimisation ofthe production of non-concentrated nitric acid. In partic-ular developments to reduce the amounts of platinum group metals used in ammonia oxidation and waste gas cleaing, and ways to reduce platinum group metal losses are discussed. At present the states of the former U.S.S.R. (CIS) produce about half of the total world out-put of non-concentrated nitric acid, and have in use at all times approximately 6 tonnes of plat-inumrrhodium-palladium alloys as catalysts for the conversion of ammonia to nitrous oxide, and about 8 tonnes of palladium in catalysts for the removal of residual nitrogen oxide Erom the waste gas. Annually the non-recoverable loss of plat