Ultra-gravity Enhanced Lye Absorption Of Copper Sulphuric Acid System Associated With H 2 S Experimental Study

There is a great quantity of acid wastewater discharged from the production process of copper smelting.Due to its high acidity,smelting enterprises generally referred to as"contaminated acid".The sulfide precipitation methods have widely been used in treatment of coppering smelting contaminated acid at present because of simple operation and high-efficient.The only fly in the ointment is S2-would react with the H+from the contaminated acid to produce the secondary contaminants H2S gas,which belongs to one of the air pollutants.The removal of H2S from copper smelting contaminated acid by sodium hydroxide(NaOH)solution as absorption liquid was investigated in a RPB reactor in this paper.the main contents are as follows:(1)The influences of experimental factors on the removal efficiency of H2S were analyzed comparatively.The optimum conditions for H2S absorption in the RPB were identified to be high gravity factor was 80,gas flow rate was 3m3/h1,liquid flow ratio was 55L/h,concentration of sodium hydroxide was 1.2mol/L,mass concentration of H2S in feed gas was 1500mg/m3,and absorption liquid temperature was 298K,under which condition the mass concentration of H2S in outlet gas decline sensitively and H2S removal efficiency is about 95.2%.(2)Based on the basic mass transfer model and mass transfer equation,the influences of experimental factors on the overall volumetric gas side mass transfer coefficient were analyzed comparatively.The results illustrated that gas side mass transfer coefficient increased as the high gravity factor,gas flow rate,liquid flow rate and concentration of sodium hydroxide was increased,and decreased with an increasing mass concentration of H2S in feed gas.Besides,gas side mass transfer coefficient was insensitive to temperature of absorption liquid.Further,gas side mass transfer coefficient in the rotating packed bed reactor was about 1 orders of magnitude higher than which in conventional tower reactor at similar operating conditions of QG/QL ratio.The results illustrated that high gravity technology shows a significant enhancement in the gas-liquid mass transfer.(3)The removal process of H2S was optimized by response surface methodology on the basis of single factor experiment,and the optimal experimental conditions were obtained.Under the experimental conditions,the predicted value is 96.62%,the actual value is 96.8%and the absolute error is very small,which indicates that the removal process of H2S can be optimized by fitting model.