Studies On Separation And Recycle Of Vanadium And Aluminum From Wastewater With Sedimentated Vanadium

The sink vanadium wastewater containing more than environmental capacity of metal ions will produce very serious pollution to the environment, if not treated directly discharged into the nature.In order to protect the environment, prevent and control pollution, we must vigorously develop vanadium industry production technology and the improvement of pollution control technology, to recycle the metal ions from wastewater.It not only has a certain economic significance,but also for maintaining the health of the water and the ecological environment has important significance.Using the sink vanadium wastewater from some factory, This paper facused on the treatment to discharged of the wastewater and recovery of the high concentrations of aluminum and vanadium.This experiment uses the three-stage method to deal with the sink vanadium wastewater,optimizing the parameters of each process, improving the treatment effect, reducing the process of processing cost, in order to maximize the recovery of valuable metals from the sink vanadium wastewater. First, components of the sink vanadium wastewater were analyzed and then different treaments of the sink vanadium wastewater were studied in detail, the results were very good. The main study of this subject can be drawn as follows:(1) Considering the acid sink vanadium wastewater containing high the concentration of iron,aluminum and vanadium, Through the analysis of the contrast experiment many times, finally coming up with a best experimental methods: Alkaline precipitation in addition to iron- Heavy aluminium- Vanadium ammonium salt sink- Fiber exchange(low solubility vanadium).The experimental results show that the iron removal rate reaching 99.4%, aluminium dissolution rate above 92.1%, vanadium dissolution rate above 90% Under the condition of solution pH to 13. When pH of heavy aluminiumthe is 5 ~ 9, The precipitation rate of aluminum is 97.8%. Due to the aluminum hydroxide adsorption vanadium ion easily, At the same time the best condition of purification of aluminum hydroxide are discussed, including ammonia concentration, reaction temperature, reaction time. The experimental results show Under this condition of ammonia is 25 g/L, 40 ℃, 30 min. The aluminum hydroxide purity as high as 97.3%. and the dispersion of Aluminum hydroxide was studied, The optimum dispersion conditions are Sodium polyacrylate as dispersant and concentration 1.6wt%, ultrasonic power 300 W.(2) The precipitation conditions of vanadium with NH4 Cl from the wasterwater containing of vanadium were investigated. The results show that the optimal conditions of vanadium ammonium salt sink are pH=2, plus ammonium K=2.5, temperature of 90 ℃, heating reaction 120 min and stiring speed 250 r/min especially, under the process conditions, the precipitation rate of vanadium is about 98.5%.(3) The exchange of V(V) on the PAN based polyamine fibers was studied. In the static adsorption experiment, effects of the pH, fiber type, temperature and time on fiber saturated exchange amount were investigated in detail, meanwhile the optimal concentration of sodium hydroxide for desorption the fiber is discussed. The results indicated that the fiber saturated exchange amount is 294 mg/g and the remove of V(V) was more than 98.1% under the condition of chlorine fibrous, 25℃, t=3h, pH=6~8. The desorption rate of the fiber is above 98.02%, when the concentration of desorption solution(sodium hydroxide) is 0.5 mol/L. Effects of the temperature and flow rate on the dynamic adsorption for saturated exchange amount had been examined, The results showed that lower rate and higher temperature wae beneficial for exchange.