scholarly journals Experiments on Rare-Earth Element Extractions from Umber Ores for Optimizing the Grinding Process

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 239
Author(s):  
Takaya ◽  
Wang ◽  
Fujinaga ◽  
Uchida ◽  
Nozaki ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Rare Earth ◽  
Physical Properties ◽  
Rare Earth Element ◽  
Propagation Velocity ◽  
Earth Element ◽  
Extraction Process ◽  
P Wave ◽  
Grinding Process ◽  
Wave Propagation Velocity

Ancient hydrothermal metalliferous sediments (umber) have recently attracted attention as a new rare-earth element resource. We conducted chemical leaching experiments on three different umber ores to optimize the hydrometallurgical extraction process, especially regarding the grinding process. The three umber ore samples, which were collected from Japanese accretionary complexes (Kuminiyama and Aki umber) and Troodos ophiolite (Cyprus umber), had different chemical, mineral, and physical properties, and showed different leaching behaviors. The experimental results revealed that the physical properties (density and P-wave propagation velocity) principally controlled the extent of REY (lanthanides and yttrium) extraction from the umber ore samples, and REY extraction from umber samples clearly increased with the decrease in the density and P-wave propagation velocity. The differences in physical properties of the umber samples are attributable to the pressure and thermal history of each ore sample, and it was revealed that umber samples which underwent strong metamorphism are not suitable for actual development. The results also suggested that the optimum particle size (optimum grinding level) of umber samples is simply predictable based on the physical properties. The results of this study should be valuable for future efforts to procure these important mineral resources.

Microstructure and physical properties of superionic eutectic composites of the LiF–RF3 (R=rare earth element) system

1999 ◽  
Vol 119 (1-4) ◽  
pp. 173-180 ◽  
Author(s):  
V Trnovcová ◽  
P.P Fedorov ◽  
Č Bárta ◽  
V Labaš ◽  
V.A Meleshina ◽  
...  
Keyword(s):  
Rare Earth ◽  
Physical Properties ◽  
Rare Earth Element ◽  
Earth Element ◽  
Element System

RA 353 MA ALLOY

Alloy Digest ◽  
1996 ◽  
Vol 45 (3) ◽  
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Physical Properties ◽  
Oxidation Resistance ◽  
Rare Earth Element ◽  
Earth Element ◽  
High Temperature Strength

Abstract RA 353 MA is a 25Cr-35Ni alloy designed with oxidation resistance and applications above 1800 deg F in mind. It is fortified with a rare earth element and silicon for oxidation resistance and nitrogen for stability and high temperature strength. Typical applications include radiant tubes and furnace components. This datasheet provides information on composition, physical properties, and elasticity as well as creep. It also includes information on joining. Filing Code: SS-634. Producer or source: Rolled Alloys Inc.

Automatic Classification of Impact-Echo Spectra II

2011 ◽  
pp. 199-205
Author(s):  
Addisson Salazar ◽  
Arturo Serrano
Keyword(s):  
Neural Networks ◽  
Wave Propagation ◽  
Propagation Velocity ◽  
Sampling Frequency ◽  
P Wave ◽  
Material Surface ◽  
S Wave ◽  
Wave Propagation Velocity ◽  
Impact Echo

We study the application of artificial neural networks (ANNs) to the classification of spectra from impact-echo signals. In this paper we focus on analyses from experiments. Simulation results are covered in paper I. Impact-echo is a procedure from Non-Destructive Evaluation where a material is excited by a hammer impact which produces a response from the material microstructure. This response is sensed by a set of transducers located on material surface. Measured signals contain backscattering from grain microstructure and information of flaws in the material inspected (Sansalone & Street, 1997). The physical phenomenon of impact-echo corresponds to wave propagation in solids. When a disturbance (stress or displacement) is applied suddenly at a point on the surface of a solid, such as by impact, the disturbance propagates through the solid as three different types of stress waves: a P-wave, an S-wave, and an R-wave. The P-wave is associated with the propagation of normal stress and the S-wave is associated with shear stress, both of them propagate into the solid along spherical wave fronts. In addition, a surface wave, or Rayleigh wave (R-wave) travels throughout a circular wave front along the material surface (Carino, 2001). After a transient period where the first waves arrive, wave propagation becomes stationary in resonant modes of the material that vary depending on the defects inside the material. In defective materials propagated waves have to surround the defects and their energy decreases, and multiple reflections and diffraction with the defect borders become reflected waves (Sansalone, Carino, & Hsu, 1998). Depending on the observation time and the sampling frequency used in the experiments we may be interested in analyzing the transient or the stationary stage of the wave propagation in impact- echo tests. Usually with high resolution in time, analyzes of wave propagation velocity can give useful information, for instance, to build a tomography of a material inspected from different locations. Considering the sampling frequency that we used in the experiments (100 kHz), a feature extracted from the signal as the wave propagation velocity is not accurate enough to discern between homogeneous and different kind of defective materials. The data set for this research consists of sonic and ultrasonic impact-echo signal (1-27 kHz) spectra obtained from 84 parallelepiped-shape (7x5x22cm. width, height and length) lab specimens of aluminium alloy series 2000. These spectra, along with a categorization of the quality of materials among homogeneous, one-defect and multiple-defect classes were used to develop supervised neural network classifiers. We show that neural networks yield good classifications (

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