Alkali liçing çözeltilerinden uranyum kazanılmasında dowex 1x4'ün kullanılabilirliğinin incelenmesi
Küçük Resim Yok
Tarih
1994
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
ÖZET Bu çalışmada, nükleer yakıt çevriminde önemli yeri olan iyon değiştirme tekniği ile kuvvetli bazik anyon değiştirici Dowex 1x4 reçinesi laboratuvar şartlarında incelenmiş ve uranyum kazanımı amacıyla alkali liç çözeltilerine uygulanabilirliği araştırılmaya çalışılmıştır. Reçinenin optimum koşullarını belirlemek amacıyla yapılan denemelerde hazırlanan standart çözeltiler kullanılarak sırasıyla reçinenin adsoıpsiyon eğrisinin oluşturulması, adsorpsiyona uranyum çözeltisinin pH ve konsantrasyonunun etkisi, reçine yatak yüksekliğinin etkisi parametreleri incelenmiştir. Adsoıpsiyon eğrisinin oluşturulması denemelerinde çözelti hacmi arttıkça reçinede tutulan uranyum miktarının azaldığı gözlenmiştir. Çözeninin pil ve konsantrasyonu denemelerinde pH 7 ile 10 aralığında reçinede tutulan uranyum miktarında fazla bir değişiklik olmadığı gözlenmiş, 40 ile 72 ppm 'lik konsantrasyon aralığında yapılan denemeler sonucunda ise % 95 'in üzerinde adsoıpsiyon verimi bulunmuştur. Ayrıca reçinenin kolon yatak yüksekliğinin artmasıyla adsorpsiyon veriminin yükseldiği gözlenmiştir. Reçinenin optimum koşulları belirlendikten sonra, çalışmada kullanılan liçing çözeltisi karbonat içeriği yüksek olan Sarıcaoğlu (Bergama) bölgesi örneklerinden elde edilmiştir. Yavuz ve Eral tarafından Sarıcaoğlu (Bergama) Bölgesi toprak örnekleriyle daha önce yapılmış olan çalışmalarda belirlenen optimum liçing koşullarına (K/S = 3/10 pulp yoğunluğu, (240 + 60) g/I NaıCOı + NallCCb alkali miktarı, 50 °C liçing sıcaklığı ve 4 saat liçing süresi ) uyularak liçing çözeltisi elde edilmiştir Elde edilen liç çözeltisinin uranyum içeriği Arsenazo III metodu ile belirlenmiş ve 72,92 mg/1 olarak bulunmuştur. Elde edilen liç çözeltisi 250 mi 'lik kısımlar halinde, reçinenin optimum koşulları göz önünde bulundurularak dört özdeş iyon değiştirici kolon sistemindeki Dowex 1x4 reçinesinden geçirilmiş ve % 80-90 'lik adsoıpsiyon verimi bulunmuştur. 23Elüsyon aşamasında dört ayrı elüsyon reaktifı ( HC1,H2SÜ4, (NH4 )2SO<4. NH4CI ) denenmiş ve yaklaşık % 40'lık bir elüsyon verimi sağlanmıştır. Bu çalışmanın sonucunda, Dowex 1x4 reçinesinin alkali liç çözeltilerine uygulanabileceği, fakat elüsyon basamağının yeniden incelenip, elüsyon veriminin farklı reaktifler kullanılarak arttırılabileceği kanısına varılmıştır. 24
SUMMARY in this study, strong basic anion exchange resin Dowex 1x4 wasexamined under the laboratory conditions by the ion exchange technique which has an important place in nuclear fuel cycle and its applicability to alkaline leach solutions was studied for recovering uranium. The following parameters were examined by using the standard solutions prepared in the trials which were done to determine the optimum conditions of the resin; formation of the adsorption curve of the resin; the effect of pH and concentration of the uranium on the adsorption; and the effect of the resin bed height. In the trials for the formation of the adsorption curve it was observed that the amount of uranium adsorbed in the resin decreased while the volume of the solution increased. In the pH and concentration trials when the pll was between 7 and 10, it was seen that no significant change occured in the amount of uranium adsorbed by the resin, wherests 95% adsoiption efficiency was observed as a result of the trials withirr. the range of concentration of 40-72 ppm. Moreover, it was found that the adsoiption efficiency increased while the column bed height of the resin increased. After the optimum conditions of the resin were determined, the leaching solution used in the study was obtained from the samples of Sancaoğlu (Bergama) area which had a high carbonate content. The leaching solution was obtained using the same optimum conditions as the ones determined in the study done with the Sancaoğlu area samples by Yavuz and Eral (Solid / Liquid : 3/10 pulp density, 240 + 60 g/1 Na2COi » NaH CO.i alkaline amount, 50 ° C and 4 hours of retention ). The uranium content of the leach solution obtained was determined by Arsenazo III method and calculated as 72,92 mg/1. By considering the optimum conditions of the resin, the leach solution was passed through the Dowex 1x4 resin in the four equal ion exchange column system, as 250 ml portions. And the adsoiption efficiency was found to be 80 - 90 %. In the elution stage, four elution reagents were investigated (HC1, I-I2SO1, (NH4) 2SO4, NH4CI ) and the elution efficiency of approximately 40 % was obtained. 25As a result of this study, it was accepted that Dowcx 1x4 resin could be applied to alkaline leach solutions but the edition efficiency could be increased by using different reactives after examining the elution stage again. 26
SUMMARY in this study, strong basic anion exchange resin Dowex 1x4 wasexamined under the laboratory conditions by the ion exchange technique which has an important place in nuclear fuel cycle and its applicability to alkaline leach solutions was studied for recovering uranium. The following parameters were examined by using the standard solutions prepared in the trials which were done to determine the optimum conditions of the resin; formation of the adsorption curve of the resin; the effect of pH and concentration of the uranium on the adsorption; and the effect of the resin bed height. In the trials for the formation of the adsorption curve it was observed that the amount of uranium adsorbed in the resin decreased while the volume of the solution increased. In the pH and concentration trials when the pll was between 7 and 10, it was seen that no significant change occured in the amount of uranium adsorbed by the resin, wherests 95% adsoiption efficiency was observed as a result of the trials withirr. the range of concentration of 40-72 ppm. Moreover, it was found that the adsoiption efficiency increased while the column bed height of the resin increased. After the optimum conditions of the resin were determined, the leaching solution used in the study was obtained from the samples of Sancaoğlu (Bergama) area which had a high carbonate content. The leaching solution was obtained using the same optimum conditions as the ones determined in the study done with the Sancaoğlu area samples by Yavuz and Eral (Solid / Liquid : 3/10 pulp density, 240 + 60 g/1 Na2COi » NaH CO.i alkaline amount, 50 ° C and 4 hours of retention ). The uranium content of the leach solution obtained was determined by Arsenazo III method and calculated as 72,92 mg/1. By considering the optimum conditions of the resin, the leach solution was passed through the Dowex 1x4 resin in the four equal ion exchange column system, as 250 ml portions. And the adsoiption efficiency was found to be 80 - 90 %. In the elution stage, four elution reagents were investigated (HC1, I-I2SO1, (NH4) 2SO4, NH4CI ) and the elution efficiency of approximately 40 % was obtained. 25As a result of this study, it was accepted that Dowcx 1x4 resin could be applied to alkaline leach solutions but the edition efficiency could be increased by using different reactives after examining the elution stage again. 26
Açıklama
Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.
Anahtar Kelimeler
Nükleer Mühendislik, Nuclear Engineering, Baz değişimleri, Base changes, Liçing, Leaching, Uranyum, Uranium, Çözeltiler, Solutions
