ORALS

SESSION: NanomaterialsSatPM3-R11	6th Intl. Symp. on Synthesis and Properties of Nanomaterials for Future Energy Demands
Sat Oct, 26 2019 / Room: Coralino
Session Chairs: Chun Li; Session Monitor: TBA

17:50: [NanomaterialsSatPM313]
The Applicability of Combustion Synthesis Process to the Fabrication of MoSi2-SiC Composites
Manadana Adeli¹ ; Amir Tayebi Pak² ; ¹School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran; ²Iran University of Science and Technology, Tehran, Iran;
Paper Id: 278 [Abstract]

Combustion synthesis is a novel low-cost, rapid, and energy-saving method for the production of high-temperature materials. The synthesis of products via this method is based on the formation of the desired compounds by making use of the exothermic reactions between the starting elemental powders. In this study, the synthesis of MoSi₂-SiC composites from the starting powder mixture of Mo+2Si and Si+C has been investigated. XRD, SEM-EDS, and Vickers microhardness tests have been used to characterize the products. The effect of Mo+2Si/Si+C weight ratio on the intensity of the reaction, as well as the formation of the products, was studied. It was found out that the desired products were formed in Mo+2Si powder mixtures containing 10wt.%Si+C samples. Using higher amounts of Si+C resulted in incomplete reactions which gave rise to remains of unreacted powder particles in the product microstructure. The MoSi₂-10wt.%SiC composite showed the highest values of mircrohardness

References:
1. M. Panneerselvam, Ankur Agrawal, K.J. Rao, "Microwave sintering of MoSi2-SiC composites", Materials Science and Engineering A356 (2003) 267-273.
2. Jianguang Xu, Huiqiang Li, Haijiang Wu, Fangling Lei, Preparation of MoSi₂/SiC composite by mechanical-assistant combustion synthesis method, Journal of Alloys and Compounds, 487 (2009) 326-330.
3. Subrahmanyam Jandhyala, "Thermochemical Evaluation of Combustion Synthesis of
MoSi,-Sic Composites" J. of the American Ceramic Society, vol. 76 (1993) 226-228.

SESSION: RecyclingSatPM2-R4	Kozlov International Symposium on Sustainable Materials Recycling Processes and Products (7th Intl. Symp. on Sustainable Materials Recycling Processes and Products)
Sat Oct, 26 2019 / Room: Adonis
Session Chairs: Stefan Steinlechner; Eva Gerold; Session Monitor: TBA

17:10: [RecyclingSatPM212]
An Investigation on the Pyrometallurgical Recovery of Gold from Jewellery Workshop Wastes Using a Mixture of Fluxes
Pouria Zakeri Ketabi¹ ; Hossein Astaraki¹ ; Manadana Adeli² ; ¹Iran Unicersity of Science & Technology, Tehran, Iran; ²School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran;
Paper Id: 277 [Abstract]

Precious metals such as gold and silver are a priority in recycling processes due to their economic values. In particular, jewellery workshop wastes which contain free gold and silver particles are considered a very valuable waste. These metals are usually extracted from jewellery wastes via the cupellation method using metallic lead. In this study, a pyrometallurgical method using a mixture of fluxes has been considered to recover gold from floor wastes of jewellery workshops. The process yields a relatively high efficiency in recovery, as well as savings in time and energy with the use of non-contaminating chemicals. The effect of type and flux-to-waste weight ratio on the properties of slag and recovery of gold has been studied. XRD, XRF, and DTA analyses have been used to characterize the wastes and the formed slag and to investigate the effect of slag properties on the recovery. A maximum value of 63.26wt.% was obtained for the recovery of gold without using dangerous chemical such as lead or contaminating processes such as cyanide leaching.

References:
1. C. W. Corti, "Recovery and Refining of Gold Jewellery Scraps and Wastes," no. May, pp. 1-22, 2002
2. S. Syed, "Recovery of gold from secondary sources-A review," Hydrometallurgy, vol. 115-116, pp. 30-51, 2012
3. M. Delfini, A. Manni, and P. Massacci, "Gold recovery from jewellery waste," Miner. Eng., vol. 13, no. 6, pp. 663-666, 2000