Abstract: The invention provides a process and an installation for producing mercury by reduction of calomel by implementing a process for preparing metallic mercury, said installation essentially comprising: a reaction vessel with an inclined base for the reduction provided with an agitator, connected by a conduit to said decanter and provided with water supply means and sulfuric acid supply means, and a mercury recovery tank connected to the lower part of the reaction vessel.

Abstract: The anodes for the electrolytic production of zinc from acid aqueous solutions of sulphate comprise a skin portion formed by conventional anode metal, lead containing from 0.25 to 1.0% silver, and a stiffening reinforcing member of titanium or zirconium. The reduction in thickness of the anodes, which is made possible by the provision of the reinforcing member, results in a substantial saving in the amount of silver-bearing lead which is immobilized, and a substantial reduction in the unit weight of the anodes. The resistance of the lead to anodic corrosion in a sulphuric acid medium is maintained and the resistance to corrosion by passivation of the reinforcing member permits the reinforcing member to be accidentally exposed, without disadvantage. To produce the anodes, the reinforcing members are clad with lead at a temperature of more than 100.degree. by rolling sheets of lead, by casting in a mould or by spraying on molten lead.