Conditions for Production of Copper Powder in a Pipe Reactor

"Copper(II) can be recovered or removed from acidic copper sulfate solutions as cuprite or metallic copper powder by reduction with carbohydrates (van der Weijden et al., 2001, 2002). In order to make this process suitable for a commercial scale pipe reactor, process conditions and reactor configuration need to guarantee proper throughput of the dilute suspension. This is where crystal engineering also comes into view. Copper powder characteristics, such as size and shape of particles, influence the tendency to adhere to reactor walls and to agglomerate, which in turn influence the throughput. Furthermore, separation, drying, packaging and product quality, are dependent on the powder characteristics.In this paper the effect of both chemical and physical parameters on the shape and size of particles were systematically studied in a number of autoclave experiments. These parameters include mixing, Cu(II) concentration, pH, temperature, seeding, use of additives and reactor materials. Additionally, Monte Carlo simulations of copper growth inside a Kenics static mixer were made. Results show that the use of additives, and the use of static mixers influence particle characteristics the most."