Atık çinko karbon pillerdeki metalik çinkonun hidrometalurjik yöntemle kazanılması
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Dosyalar
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, atık çinko-karbon pillerdeki metalik çinkonun nitrik asit çözeltilerindeki çözünürlüğü, çözünme kinetiği ve optimum çözünme koşulları belirlenmiştir. Metalik çinkonun nitrik asit çözeltilerindeki çözünürlüğü üzerine deney parametrelerinin etkileri incelenmiş ve çözünme kinetiğini temsil etmek üzere bir matematiksel model önerilmiştir. Çözünme prosesi üzerine nitrik asit derişimi, metalik çinko miktarı (katı/sıvı oranı), reaksiyon sıcaklığı ve karıştırma hızının etkileri araştırılmıştır. Nitrik asit derişimi, karıştırma hızı ve reaksiyon sıcaklığının artması, katı/sıvı oranının ise azalmasıyla çinkonun çözünme hızının arttığı gözlenmiştir. Çözünme deneylerinden elde edilen veriler kullanılarak kinetik analiz yapılmış ve çözünme hızının yalancı birinci mertebe kinetiğe uyduğu bulunmuştur. Çözünme işlemi için aktivasyon enerjisi 12.89 kJ/mol olarak bulunmuş ve çözünme işleminin difüzyon kontrollü olduğu belirlenmiştir. Metalik çinkonun çözünmesinden sonra elde edilen çözeltideki çinko iyonları çöktürme metodu ile kazanılmıştır. Bu amaç için sodyum bikarbonat çözeltisi kullanılmış ve çöktürme işlemi neticesinde çinko iyonlarının çinko hidroksi karbonat bileşiği olarak çöktürüldüğü belirlenmiştir. Çöktürme işleminde pH, çinko/sodyum bikarbonat mol oranı, reaksiyon süresi ve reaksiyon sıcaklığı sırasıyla 8, 1/2.5, 240 dakika ve 60 °C olarak alınmıştır. Bu koşullarda çözeltideki çinko iyonlarının tamamının geri kazanıldığı belirlenmiştir. Elde edilen hidroksi karbonat bileşiği 300 °C sıcaklıkta 4 saat süreyle kalsinasyon işlemine tabi tutularak çinko oksit üretilmiştir. Optimum çözünme koşullarını belirlenmek için yapılan deneylerde, bağımsız değişkenler olarak nitrik asit derişimi, reaksiyon süresi ve çinko miktarı seçilmiştir. Metalik çinkonun çözünürlüğüne etki eden parametre değerlerini optimize etmek için yanıt yüzey yöntemi (YYY) kullanılmıştır. Proses parametrelerinin etkilerini görebilmek için deneysel bulgulara çoklu regresyon analizi yapılmış ve model denklemi türetilmiştir. Deneyler sonucunda nitrik asit derişimi ve reaksiyon süresinde bir artma ve çinko miktarında ise bir azalma olmasıyla çözünme veriminin arttığı bulunmuştur.
In this study, the dissolution and kinetics, and the optimal dissolution conditions of metallic zinc in waste zinc-carbon batteries were determined in nitric acid solution. The effects of the experimental parameters on the dissolution of metallic zinc in nitric acid solutions were examined, and a mathematical model to represent the dissolution kinetics was purposed. The effects of the concentration of nitric acid, amount of metallic zinc (solid to liquid ratio), reaction temperature and stirring speed on the dissolution process were investigated. It was observed that the dissolution rate of zinc increased with increasing nitric acid concentration, stirring speed and reaction temperature and with decreasing solid to liquid ratio. A kinetic analysis using data obtained from the dissolution experiments was made, and it was found that the dissolution rate fit to the pseudo-first order kinetic. The activation energy for the dissolution process was found to be 12.89 kJ/mol, and it was determined that it was controlled by diffusion. Zinc ions in the resulting solution after the dissolution of metallic zinc was recovered by precipitation method. For this aim, sodium bicarbonate solution was used, and it was determined that zinc ions was precipitated as zinc hydroxy carbonate compound. In the precipitation process, pH, molar ratio of zinc/sodium bicarbonate, reaction time, and reaction temperature were taken to be 8, 1/2.5, 240 min, and 60 °C, respectively. Under these conditions, it was determined that zinc ions in the solution were fully recovered. Hydroxy carbonate compound obtained was subjected to the calcination process at a temperature of 300 °C for 4 h, and zinc oxide was produced. In the experiments performed to determine the optimal dissolution conditions, the concentration of nitric acid, reaction time, and zinc amount were selected as independent variables. The response surface method (RSM) was utilized to optimize the parameter values that have an effect on the dissolution of metallic zinc. To see the interactive effects of process variables, the multiple regression analysis to the experimental findings was performed, and a model equation was derived. At the end of the tests, it was found that the dissolution efficiency increased with an increase in the concentration of nitric acid and reaction time, and with a decrease in the amount of zinc.
In this study, the dissolution and kinetics, and the optimal dissolution conditions of metallic zinc in waste zinc-carbon batteries were determined in nitric acid solution. The effects of the experimental parameters on the dissolution of metallic zinc in nitric acid solutions were examined, and a mathematical model to represent the dissolution kinetics was purposed. The effects of the concentration of nitric acid, amount of metallic zinc (solid to liquid ratio), reaction temperature and stirring speed on the dissolution process were investigated. It was observed that the dissolution rate of zinc increased with increasing nitric acid concentration, stirring speed and reaction temperature and with decreasing solid to liquid ratio. A kinetic analysis using data obtained from the dissolution experiments was made, and it was found that the dissolution rate fit to the pseudo-first order kinetic. The activation energy for the dissolution process was found to be 12.89 kJ/mol, and it was determined that it was controlled by diffusion. Zinc ions in the resulting solution after the dissolution of metallic zinc was recovered by precipitation method. For this aim, sodium bicarbonate solution was used, and it was determined that zinc ions was precipitated as zinc hydroxy carbonate compound. In the precipitation process, pH, molar ratio of zinc/sodium bicarbonate, reaction time, and reaction temperature were taken to be 8, 1/2.5, 240 min, and 60 °C, respectively. Under these conditions, it was determined that zinc ions in the solution were fully recovered. Hydroxy carbonate compound obtained was subjected to the calcination process at a temperature of 300 °C for 4 h, and zinc oxide was produced. In the experiments performed to determine the optimal dissolution conditions, the concentration of nitric acid, reaction time, and zinc amount were selected as independent variables. The response surface method (RSM) was utilized to optimize the parameter values that have an effect on the dissolution of metallic zinc. To see the interactive effects of process variables, the multiple regression analysis to the experimental findings was performed, and a model equation was derived. At the end of the tests, it was found that the dissolution efficiency increased with an increase in the concentration of nitric acid and reaction time, and with a decrease in the amount of zinc.
Açıklama
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Şenel, M. (2019). Atık çinko karbon pillerdeki metalik çinkonun hidrometalurjik yöntemle kazanılması
