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Layer Growth
Published in Gerard F. Arkenbout, Melt Crystallization Technology, 2021
The principle of zone melting is given in Figure 6.4(a) (Pfann, 1966; Zief and Wilcox, 1967; Sloan and McGhie, 1988; Bollen, 1972). Zone melting can be characterized as a physical separation method by which a molten zone of limited length is gradually moved from one end of an ingot towards the other. As a result, impurities are concentrated at one, or both, end(s) of the ingot in case distribution coefficients of both lower and higher than unity are involved.
A Review on Germanium Resources and its Extraction by Hydrometallurgical Method
Published in Mineral Processing and Extractive Metallurgy Review, 2021
Thi Hong Nguyen, Man Seung Lee
Figure 5 shows flowsheet for the production of Ge from zinc refinery residues and scraps. The production of Ge from ores and scraps can be divided into two main steps: (i) production of Ge(II/IV) concentrate (30% content of Ge(II/IV)) from Ge-bearing ores, coals, flue dust by physical separation or pyro and hydrometallurgical processes and (ii) production of Ge(IV) such as pure GeCl4, GeO2 and Ge metal from germanium concentrate and Ge-bearing scraps (Curtolo, Friedrich and Friedrich 2017; Depuydt et al. 2007; Melcher and Buchholz 2012; Ruiz, Sola and Palmerola 2018). Germanium concentrate is chlorinated, distilled and purified to pure GeCl4 (99.9999%) which is used in fiber optics (Curtolo, Friedrich and Friedrich 2017; Melcher and Buchholz 2012). Consequently, pure GeCl4 can be hydrolyzed and dried to form pure GeO2 (99.9999%). GeO2 is reduced in hydrogen atmosphere into metallic form. The Ge metal thus produced is then heated and the molten Ge is refined by zone melting to produce intrinsic Ge metal and single-crystal Ge (Melcher and Buchholz 2012).
For creating layered composite materials based on monocrystalline silicone for gradient heat measurement based by diffusion welding method
Published in Welding International, 2019
O. A. Barabanova, S. V. Nabatchikov, S. Z. Sapozhnikov
Studies [11–13] have shown that for selecting a method for producing a silicon single crystal for the creation of LCMs by DW, the method of zone melting without alloying with nitrogen is the most preferred, this will make it possible to lower the temperature of the threshold of the start of macroscopic deformation of silicon and thereby increase its degree of activation.