Review of research results of zinc powder electrolytic production from alkaline solutions

The purpose of this work is to form specific approaches and directions in the field of producing zinc powders with desired properties from alkaline electrolytes. The analysis is given to the research results of many authors (86 sources) on the influence of various conditions of zinc powder electroextraction from alkaline electrolytes. Still there is no comprehensive theoretical explanation of the mechanism of powder formation in zinc electrolysis from alkaline solutions. Despite the multiplicity and diversity of published data, it is impossible to determine the production conditions of zinc powders with desired properties from zinc electrolytes without carrying on one’s own systematic studies. Consideration is given to the research methods of zinc electrodeposition in the solutions of sodium hydroxide on the stainless steel cathode using cyclic volmperometry, chronoamperometry and chronopotentiometry. In the conditions of laboratory electrolysis the influence of electrolyte composition, impurity concentration, current density, temperature, introduction of additives on the current output and morphology of the obtained powders is studied. It has been revealed that there is no consensus on the impact of electrolysis conditions in terms of current efficiency and power consumption among the authors. It is found out that the advantages of the electrolysis of alkaline zincate solutions are: high purity of the resulting metal, possibility of obtaining the powders of the specified size, good compressibility and sintering, possibility of using non-acid-resistant structural materials.

electroextraction, zinc powders, alkaline electrolytes, current density, current output, cyclic volmperometry