Содержание журнала №3 за 2016 год
Информация о статье:
| Раздел/Section | Экология и ресурсосбережение | Environment and Resources Saving |
| Страницы/Pages | 39-45 | |
| Заглавие/Title | Анализ причин разложения и утилизации цианидных электролитов серебрения | Analysis of the Causes of Destruction of Silver Cyanide Baths and the Utilization of Spent Baths |
| Авторы/Authors | Калинкина А.А., Аснис Н.А., Спешилов И.О., Ваграмян Т.А. | Kalinkina A.A., Asnis N.A., Speshilov I.O., Vagramyan T.A. |
| Ключевые слова Keywords | потери цианидов; накопление цианидов; регенерация серебра; обезвреживание цианидов; cyanide loss; carbonate built-up; silver recovery; cyanide disposal | |
| Аннотация Description | Проанализированы причины потерь цианид-ионов и накопления карбонатов в цианидных электролитах серебрения. Проведена утилизация отработанного цианидного электролита серебрения. Применение электрохимического метода с последующим хлорированием позволило практически полностью извлечь серебро из отработанного цианидного электролита серебрения и обезвредить цианид-ионы. | Causes of the deterioration of silver coatings quality resulting from the accumulation of carbonate and destruction cyanides were studied. Utilization of silver plating solutions was performed in two stages: 1. cathodic deposition of silver at room temperature using 12X18H9 steel cathodes and different anodes ((12Х18Н9, 03ХН28МД, 03Х18Н10Т, hastalloy С-276) using current source with stabilized voltage. Silver was obtained as compact deposit, easily removed from the cathode surface. At least 98% of silver was recovered after passing ≥25 А•h/l (Table 1). At the second stage the spent silver-free solution was diluted by 20 times and was treated by gradual addition of alkaline NaClO solution with active chlorine concentration of 190 g/l to agitated solution. Fig.1 demonstrates the time-dependence of the Pt/Ag/AgCl electrode potentials vs. time. After the addition of stoichiometric amount of NaClO ([CN-]:[ClO-]=1:2,5) the potential reached 600 mV in 4 min, which corresponds to a complete oxidation of cyanide into cyanate. Further addition of NaClO solution (triple excess [CN-]:[ClO-]=1:7,5) did not change the electrode potential. Utilization process was stopped, when the potential did not change its value by more than by 3 mV after 10 min. The use of electrochemical method allowed to recover all silver and to destruct cyanide ions. |
| Текст/Text | http://elibrary.ru/item.asp?id=26494130 | |