Method for extracting sodium thiocyanate from coking desulfurization waste liquid

[0007] Take the coking desulfurization waste liquid provided by Tongling Xinyaxing Coking Co., Ltd. After analysis, the main components of the waste liquid are: NH 4 SCN 183g / L, (NH 4 ) 2 S 2 o 3 155g / L, (NH 4 ) 2 SO 4 47g / L, take 1 liter of the waste liquid, add 60g of activated carbon in a beaker, heat to 70°C and keep stirring for 1 hour, filter; add 60mL of 98% concentrated sulfuric acid to the filtrate in a closed container to pH = 3.5, heat to 80°C and Keep stirring for 1 hour, the evolved SO 2 The gas is drawn out with a catheter and absorbed with dilute ammonia water; after the reaction is completed, filter, and add NaOH96g and Ca(OH) to the filtrate in a closed container 2 110g, heated to 70°C and kept stirring for 1 hour, the escaping ammonia gas was drawn out with a catheter and absorbed into dilute ammonia water; after the reaction was completed, it was filtered, and the filtrate was evaporated and crystallized to obtain 178g of sodium thiocyanate product...

[0009] Take the coking desulfurization waste liquid provided by Huahao Coking Co., Ltd. in Changyi City, Shandong Province. After analysis, the main components of the waste liquid are: NH 4 SCN 136g / L, (NH 4 ) 2 S 2 o 3 107g / L, (NH 4 ) 2 SO 4 31g / L, take 1 liter of the waste liquid, add 20g of activated carbon to a beaker, heat to 90°C and keep stirring for 2 hours, filter; add 55mL of 70% concentrated sulfuric acid to the filtrate in a closed container to pH = 4.5, heat to 60°C and keep After stirring for 2 hours, the evolved SO 2 The gas is drawn out with a catheter and absorbed with dilute ammonia water; after the reaction is completed, filter, and add NaOH 72g and Ca(OH) to the filtrate in a closed container 2 75g, heated to 50°C and kept stirring for 1 hour, the escaping ammonia gas was drawn out with a catheter and absorbed into dilute ammonia water; after the reaction was completed, it was filtered, and the filtrate was evaporated and crystallized to obtain 12...