BACKGROUND TECHNOLOGY FOR PURIFICATION OF POLLUTED AQUATIC ENVIRONMENT AND REGENERATION OF CONCENTRATED WASTE NITRATE-CHLORIDE-SULFATE INDUSTRIAL SOLUTIONS
Background. Recently, the problem of recycling and regeneration of concentrated waste technological solutions containing non-ferrous metal ions, in particular copper, has become acute. The particular complexity of processing such type of solutions is caused by the presence of nitrates and chlorides in their composition, causing their chemical aggressiveness. There is a great number of works devoted to electrodeposition of copper from nitrate-containing solutions. However, the background technology for the regeneration of nitrate-containing solutions by electrowinning method is poorly developed.
Objective. The aim of the investigation is to develop background technology for the purification of contaminated aquatic environment and to study the process of regeneration of concentrated nitrate-containing solutions by the method of copper electrowinning with establishing the influence of the cathodic current density and solution composition on the efficiency of copper extraction and the quality of cathode deposits.
Methods. The effect of the solution composition on the polarization and limiting current density of copper deposition was determined by voltammetry. The influence of current density and inter-electrode distance on the cathodic copper current efficiency and the quality of the cathode sediments were determined on the basis of gravimetric studies. The quantitative and qualitative composition of copper cathode deposits was investigated by X-ray fluorescence analysis.
Results. The possibility of compact copper obtaining in the solution with copper content of 2 M at the current densities of 15–25 A/dm2 with the current efficiency of about 100 % was shown. It was established that for current densities less than 10 A/dm2 the copper current efficiency exceeds 100 %, which is due to the precipitation of basic copper salts in the cathode layer. On the basis of current-voltage measurements it was established that the electrodeposition of copper from the investigated nitrate-chloride-sulfate solutions occurs with diffusion limitations.Conclusions.As a result of the conducted research the main technological parameters of the copper electrowinning process from concentrated nitrate-sulfate-chloride solutions are established. The obtained data are not indispensable for solving the important environmental problems of removing the concentrated metal-containing industrial waste. Further investigations will focus on optimization of the current mode of copper electrowinning process and development of semi-industrial plant for copper electrowinning from nitrate-contain solutions.
J.Y. Choi and D.S. Kim, “Production of ultrahigh purity copper using waste copper nitrate solution”, J. Hazard. Mater., vol. 99, no. 2, рр. 147–158, 2003. doi: 10.1016/s0304-3894(02)00312-6
Kekki et al., “Copper deposition on stainless steel sheets in copper nitrate solution”, Physicochem. Probl. Miner. Process., vol. 51, no. 1, рр. 247−256, 2015. doi: 10.5277/ppmp150122
A.A. Pravda et al., “Features of the discharge-ionization of copper from low concentrated nitrate solutions”, Naukovi Pratsi Do-netskoho Natsionalnoho Tekhnichnoho Universytetu, vol. 1, no. 20, pp. 82–89, 2013.
A.A. Pravda et al., “The effect of complexation on the electrodeposition of copper from solutions of nitric acid salt”, Ukr. Khim. Zhurn., vol. 75, no. 6, pp. 101–105, 2009.
A.O. Pravda et al., “The patterns of copper electrochemical behavior in nitrate solutions with impurities of different nature”, Naukovyj Visnyk Chernivetsʹkoho Universytetu, vol. 399, pp. 140–142, 2008.
R.K. Rosenene and S.P. Pilite, “Investigation of the effect of quinone on the process of electrodeposition of copper from nitrate solutions”, in Proc. XIV Conf. Studies in the Field of Metal Deposition, Vil'nyus, 1976, pp. 26–30.
D.A. Rogozhnikov et al., “Optimum parameters of the electroextraction of copper from nitrate-bearing solutions”, Metallurgist, vol. 59, рр. 7–8, 2015. doi: 10.1007/s11015-015-0163-9
M.N. Bobrov, “The technology of extracting copper in a compact form from concentrated copper-containing salt waste”, Ph.D. thesis, Vyatka State University, Kazan, 2011.
J.-M. Mermet et al., Analytical Chemistry. Problems and Approaches, vol. 1. Moscow, Russia: Mir, AST, 2004, pp.425–427.
O.V. Linyucheva et al., “Development of highly productive current modes for copper electrowinning as a dense metal”, Eastern-European Journal of Enterprise Technologies, vol. 6, no. 72, pp. 48–55, 2014. doi: 10.15587/1729-4061.2014.30660
D.Yu. Ushchapovskiy et al., “Method of controlling the morphology of cathode deposit by determining electrochemical re-sistance for copper electrodeposition process”, Naukovi Visti NTUU KPI, no. 2, pp. 114–121, 2005. doi: 10.20535/1810-0546.2016.2.60951
GOST Style Citations
- There are currently no refbacks.
Copyright (c) 2019 The Author(s)
This work is licensed under a Creative Commons Attribution 4.0 International License.