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您的检索式：作者名="Francesca Beolchini"
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| 1 | Roasting and chlorine leaching of gold-bearing refractory concentrate:Experimental and process analysis显示文摘This paper deals with gold extraction from a refractory concentrate by chlorine leaching.The process considers a pre-treatment of refractory materials by low temperature oxidation carried out with low oxygen concentration.The oxidized material is treated by leaching with brine.After gold adsorption/reduction onto activated carbon,iron and base metals can be precipitated by NaOH.Roasting tests show the necessity to carry out a thermal pre-treatment at least at 550°C to obtain a reduction of sulfur and mercury in the material(50%and 90%,respectively).Highest gold extraction yield(around 93%)is obtained in the leaching test performed with material sample treated at 650°C.This result confrms the necessity to optimize the thermal pre-treatment to improve Au recovery and to reduce chlorine consumption.A comparison with conventional cyanidation confrms that chlorination could be an useful alternative:in fact,gold extraction yield is quite low:57%in non-pre-treated material and 25%in pre-treatment material. | Ida De Michelis Agostino Olivieri Stefano Ubaldini Francesco Ferella Francesca Beolchini Francesco Vegliò | 2013 | International Journal of Mining Science and Technology2013，23，5： | 10 |
| 2 | Extraction of Zincand Manganese from Alkaline and Zinc-Carbon Spent Batter-ies by Citric-Sulphuric Acid Solution显示文摘 | Francesco Ferella Ida De Michelis Francesca Beolchini Valentina Innocenzi Francesco Veglid | 2010 | International Jour-nal of Chemical Engineering2010，3，： | 1 |
| 3 | Auto- and heterotrophic acidophilic bacteria enhance the bioremediation efficiency of sediments contaminated by heavy metals显示文摘 | Francesca Beolchini Antonio Dell’Anno Luciano De Propris Stefano Ubaldini Federico Cerrone Roberto Danovaro | 2008 | Chemosphere2008，，10： | 1 |
| 4 | Non-toxic, high selectivity process for the extraction of precious metals from waste printed circuit boards显示文摘The work presented here focused on the extraction of gold (Au), silver (Ag) and palladium (Pd) from electronic waste using a solution of ammonium thiosulfate. Thiosulfate was used as a valid alternative to cyanide for precious metal extractions, due to its non-toxicity and high selectivity. The interactions between sodium thiosulfate, total ammonia/ammonium, precious metal concentrations and the particle size of the waste printed circuit boards (WPCBs) were studied by the response surface methodology (RSM) and the principal component analysis (PCA) to maximize precious metal mobilization. Au extraction reached a high efficiency with a granulometry of less than 0.25 mm, but the consumption of reagents was high. On the other hand, Ag extraction depended neither on thiosulfate/ammonia concentration nor granulometry of WPCBs and it showed efficiency of 90% also with the biggest particle size (0.50 < Ø < 1.00 mm). Pd extraction, similarly to Au, showed the best efficiency with the smallest and the medium WPCB sizes, but required less reagents compared to Au. The results showed that precious metal leaching is a complex process (mainly for Au, which requires more severe conditions in order to achieve high extraction efficiencies) correlated with reagent concentrations, precious metal concentrations and WPCB particle sizes. These results have great potentiality, suggesting the possibility of a more selective recovery of precious metals based on the different granulometry of the WPCBs. Furthermore, the high extraction efficiencies obtained for all the metals bode well in the perspective of large-scale applications. | Giulia Merli Alessandro Becci Alessia Amato Francesca Beolchini | 2023 | Frontiers of Environmental Science & Engineering2023，17，10： | 0 |
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