Allocation of precious metals from catalytic oxidation of ammonia, raw materials and devices installed in the nitric acid in moving gases and fluids
It's established experimentally that the precious metals: gold, silver, platinum, rhodium, palladium, iridium and ruthenium are contained in the gas and liquids moving in nonconcentrated nitric acid plants, working by W. Ostwald (1902) technology on platinum, rhodium-palladium catalyst with the formation of nitrous gases. It is established that noble metals are allocated to nitrous gases, condensation of nitric acid and nitric acid due to loss of catalyst and ammonia-air mixture and the water feed to the stage of absorption of nitrogen oxides, as well as from the materials of units devices. The precious metals are nanoparticles in feed and unit materials, thay pass into the nitrous gas, condensate and nitric acid. It is noted that the total mass of noble metals in the condensate of nitric acid and nitric acid, much higher than the total mass of platinum, rhodium and palladium, the catalyst lost to the condensate, for example, in approximately three times. At pilot plant the experiments to allocate the concentrate containing 92-95 % precious metals, from the condensation of nitric acid and nitric acid were carried out. There are technology and key equipment for the unit to select a precious metals from nitric acid by the domestic non-concentrated nitric acid unit type UKL-7 capacity of 120000 tonnes per year, based on 100 % HNO3. There are approximate technical and economic indices of the node in the unit UKL-7 JSC «Dorogobuzh». It's shown that the timing of cost recovery unit will not exceed 7 and 10 months at 100 % and 70 % feed loading of the unit.