The influence of the rate of selenium crystallization from aqueous solutions on its morphology
| Autor: | I. Harañczyk, B. Szafirska, K. Fitzner |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
aqueous solutions
lcsh:TN1-997 Aqueous solution Morphology (linguistics) crystallization Inorganic chemistry Metals and Alloys chemistry.chemical_element reduction Geotechnical Engineering and Engineering Geology law.invention Degree (temperature) Volumetric flow rate Reaction rate constant chemistry Mechanics of Materials law morphology Materials Chemistry Crystallization selenium Constant (mathematics) lcsh:Mining engineering. Metallurgy Selenium |
| Zdroj: | Journal of Mining and Metallurgy. Section B: Metallurgy, Vol 38, Iss 1-2, Pp 33-48 (2002) |
| ISSN: | 2217-7175 1450-5339 |
| DOI: | 10.2298/jmmb0202033h |
| Popis: | Selenium crystallization process from aqueous solutions was investigated at constant temperature of 357 K. Two different reducers were used, namely dissolved NaHSO3 and gaseous SO2. Experiments were conducted for solutions with different initial selenium concentration and different pH. The degree of conversion was determined as a function of time from the weight of the sediment, and can be described by Avrami-type equation of the following form: - ln ( 1 - ?) = (6.95 . 10 -3 . t )1.52 valid at constant temperature of 357 K for NaHSO3 reducer, rate constant k = 6.95.10-3 min-1, and t in minutes. When the reduction was carried out in SO2 stream, the rate constant k was found to be strongly dependent on the flow rate. Possible mechanism of the reduction process and the influence of the rate of the reduction on the morphology of the product were suggested. |
| Databáze: | OpenAIRE |
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