The Technology Research Of Recovering And Enriching Low Concentration Wastewater Of Rare Earth

Along with the mining of rare earths on the environment pollution problem is becoming more and more serious, the state "rare earth industrial pollution emission standards" made specific provision for rare earth industrial wastewater, waste gas and radioactive emission standard. Processing a large number of low concentration of rare earth wastewater produced in this paper, the study of rare earth resources in the process of mining and material recycling technology, for effective treatment of wastewater, achieve industrial emissions standards and recovery of useful substances.This paper using chitosan and nano Si O2 supported chitosan prepared(hereinafter referred to as the CTS/ nano Si O2), the material has the characteristics of the rare earth ion adsorption speed and high adsorption capacity etc, the adsorption and desorption performance of CTS/nano-Si O2 for low concentration of rare earth ions was studied. The optimum conditions was as follows: adsorption temperature was 25℃, p H value was 5, initial mass concentration of gadolinium, lanthanum and yttrium was 45mg/L, 37.5mg/L and 27.5mg/L, respectively, and adsorbent dosage was 40 mg. Under these conditions, the saturated adsorption capacity of CTS/nano-Si O2 for gadolinium, lanthanum and yttrium was 22.3mg/g, 17.8mg/g and 12.9mg/g, respectively. Langmuir isotherm was used to describe the adsorption behavior of rare earth ions on CTS/nano-Si O2, and the saturated adsorption capacity was 23.8mg/g(for gadolinium), 17.8mg/g(for lanthanum) and 12.9mg/g(for yttrium), respectively. Experimental results showed that adsorbent of CTS/nano-Si O2 had a strong interaction with rare earth ions with adsorption efficiency above 98%, and the rare earth ions absorbed could be desorbed with hydrochloric acid for recycling.The use of selective adsorption, catalysis and ion exchange of Na Y molecular sieve three characteristics, the material has the characteristics of the rare earth ion adsorption speed and high adsorption capacity etc, the adsorption and desorption performance of Na Y molecular sieve for low concentration of rare earth ions was studied, The optimum conditions was as follows: adsorption temperature 25℃, p H value was 5, initial mass concentration of gadolinium, yttrium and lanthanum was 96.7mg/L、93.3mg/L、90mg/L, respectively, and absorbent dosage was 40 mg, under these conditions, the saturated adsorption capacity of Na Y molecular sieve for gadolinium, yttrium and lanthanum was 71.3mg/g, 69.8mg/g and 67mg/g, respectively. Langmuir isotherm was used to describe the adsorption behavior of rare earth ions on Na Y molecular sieve, and the saturated adsorption capacity was 71.3mg/g(for gadolinium), 69.8mg/g(for yttrium) and 67mg/g(for lanthanum), respectively. Research shows that, Na Y molecular sieve adsorption strong effect of rare earth ions, the adsorption rate was as high as 99.3%, and the rare earth ions absorbed could be desorbed with sodium chloride for recycling, coexisting cations will restrain the adsorption rate of adsorbents of rare earth ions on Na Y molecular sieve.