The Influences of Stirring on the Recrystallization of Ammonium Perrhenate

Junjie Tang,Yuan Sun,Dawei Fang,Li Feng,Long Wang,Yizhou Zhou,Yan Liu,Chunwei Zhang

doi:10.3390/app10020656

Abstract

Ammonium perrhenate is widely used in alloy manufacturing, powder processing, the catalytic industry, and other fields. Recrystallization can improve the specific surface area of ammonium perrhenate, reduce its particle size, and improve its particle size distribution uniformity. Therefore, recrystallized ammonium perrhenate can obtain better application benefits in the above fields. Stirring is an important factor that affects the recrystallization of ammonium perrhenate, and this paper systematically analyzes the influence of the stirring paddle types and stirring intensities on ammonium perrhenate during the homogeneous recrystallization process, ultimately revealing the relationship between the growth rate of ammonium perrhenate and the stirring process. Particle image velocimetry physical simulation results showed that the flow field in the reactor was more evenly distributed when using the disc turbine impeller, and a relatively uniform velocity liquid flow area was formed in the whole reactor, while the low-velocity liquid flow area was smaller. Therefore, this information, combined with SEM test results, suggests that under the same recrystallization time and stirring intensity, the stirring effect of a disc turbine impeller is more suitable than a propelling propeller and an Intermig impeller for the recrystallization process of ammonium perrhenate. Moreover, the XRD patterns and SEM analysis showed that if the agglomeration in the systems was too strong or too weak, the growths of the (101) crystal plane and (112) crystal plane were restrained, which caused an attenuation in the growth rates along the crystallographic directions that were orthogonal to the crystal faces. Finally, the reduction experiments show that the recrystallization of ammonium perrhenate could improve the phase parameters of rhenium powders.

Highlights

As an important strategic rare metal, Re is widely used in the metallurgy, chemical, alloy manufacturing and aerospace industries [1,2]
This study provides a theoretical basis and practical experience for optimizing the recrystallization process of ammonium perrhenate and the design of a recrystallization reactor
It can be seen that the particles that were prepared by the disc turbine impeller were regular, the crystal surfaces were smooth, morphologies of most crystal particles that were prepared by the disc turbine impeller were and a few crystal particles had rough surfaces, indicating that most crystal particle development regular, the crystal surfaces were smooth, and a few crystal particles had rough surfaces, indicating was relatively complete

Summary

Introduction

As an important strategic rare metal, Re is widely used in the metallurgy, chemical, alloy manufacturing and aerospace industries [1,2]. Sci. 2020, 10, 656 plasma methods, electrolysis methods, vapor deposition methods, and the hydrogen reduction of ammonium perrhenate [3,4]. Rhenium powders have the advantages of excellent phase parameters and uniform particle size distribution when prepared by electrolysis, vapor deposition, and plasma methods. Jurewicz et al [5] produced micro/nano rhenium powders by applying the plasma method

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