Sulfur emission in the form of SO2 in flue gas is the most serious pollutant associated with coal combustion. Calcium carbonate sulfur scrubbing, the process most commonly in use today, is costly, produces a large amount of waste and leaves a considerable amount of SO2 in the gas. The carbonate eutectic method for removing SO2 from flue gas at 450-650 °C was initially proposed in the 1970’s but despite its great efficiency could not be used due to the complexity of the carbonate melt regeneration stage. We propose a simple way to remove sulfur from the carbonate eutectic melt by purging it with CO.
Platinum group metals (PGM) recovery process
Various methods for recovering precious metals from used catalysts by chlorination with elemental chlorine were known. There methods allow extracting the precious metals in the form of chlorides in the sintering stage at a temperature of 1000-1100oC. Disadvantages are as follows:
- very aggressive and hazardous chlorine gas at very high temperature.
- expensive special furnace equipment for chlorine treatment.
- formation of large amounts of extremely aggressive off-gas, containing chlorine.
We offer volatilization method for selective extraction of precious and rare metals using chlorides of metals (salts) as chlorinating agent at relatively low temperatures (900C) without hazardous waste. We use safe metal chlorides instead a very dangerous chlorine gas. Extraction of the PGM to sublimates is more than 95%.