Microflow precipitation of barium sulfate nanoparticles from mineral barium sulfide black ash

Abstract

Microflow precipitation reaction is an effectively method for preparing high quality nanoparticles. In this study, BaSO4 nanoparticles were successfully prepared from BaS black ash in a simple capillary microreactor. Two important microflow parameters, feed flow velocity and residence time, on morphology, structure, component, average particle size (dav) and coefficient of variation (CV) of the as-synthesized product are investigated. The results show that well-dispersed ellipsoidal nanoparticles of BaSO4 with purity >99 wt% can be prepared using this novel method. High flow velocity is beneficial for producing small particles with low CV, and short residence time is also good for slightly small particles but with high CV. The dav and CV values are in the range of 33.8∼53.5 nm and 0.32∼0.39, respectively. In addition, the preparation of the BaSO4 product by this new method is compared with those by precipitation in other typical reactors. Combined with the simplicity of the microchannel structure, continuity of process operation and atomic economy of the raw materials, this proposed method is effective for preparing high quality BaSO4 nanoparticles with narrow particle size distribution.