Study On The Enrichment Of Vanadium And Purification Technology Of Waste Water

The application, distribution and reserves of vanadium were described in this paper. Basing on the two steps of purification of vanadium from stone coal:roasting and enrichment, the advantages and disadvantages of the various methods and new technology were discussed. Optimized process was: roasting with compound additive-leaching with water- leaching with hydrogen peroxide-ion exchange-precipitation, which was proved to be environmentally friendly and economical, and the enrichment and purification of vanadium were studied.1. Screening out D301 anion exchange resins:styrene, macroporous, weak alkaline, using static adsorption, taking adsorption amount of vanadium as the standard.2. Through static and dynamic adsorption, factors having influences on adsorption amount of vanadium were discussed, Such as concentration and flow rate of vanadium solution, time, temperature, resin amount, chloride ion concentration of vanadium solution, etc. The results show that concentration of chloride ion has a little effect on adsorption of vanadium, the adsorption amount of vanadium goes up with the increase of the temperature and resin loadage, while the adsorption amount of vanadium on resin(unit weight)reduces. Adsorption capacity expands with time,20g resin reached equilibrium after 90h, saturated adsorption was 148mg/g.The particle diffusion plays a central role on the adsorption of vanadium, low concentration(4.1537g/L), low flow rate(0.25mL/min) was helpful to the adsorption of vanadium.3. Toxic ions was treated by reduction, neutralization and precipitation. Those influencing the removal effects of Cr6+,Cu2+,Zn2+,Ni2+,Cd2+,such as the amount of Na2S and Na2SO3, time, pH value were discussed. The results show:the removal of all ion increases with the increasing of the amount of Na2S and Na2SO3. For 100mL solution, the better amount of Na2S and Na2SO3 are 74.8038mg and 147.5208mg. Aicd promotes removal of Cr6+, When pH is 2.07, its concentration is the smallest, Alkaline helps the removal of Cu2+,Zn2+,Ni2+,Cd2+,when pH is 8.35,it shows a better removal. The reaction time longer, the lower of ion concentration. After 15min, the removal of harmful ions almost achieves emission standards.4. Finally, with dynamic adsorption, the different sectors on desorption were investigated.4% NaOH and 6% NaCl have better capability of desorption. The peak of liquid desorption is up to 112g/L, the average desorption concentration was 50g/L～90g/L, enrichment impact was 10 to 20 times, the optimum amount of desorption agent is 3-4 times of the resin by volume, the better flow rate is 0.7mL/min.