Abstract: Various systems and methods for protecting electrowinning anodes having electrocatalytically active coatings in a bank of electrolytic cells from being damaged by reverse currents. In the first embodiment, one or more auxiliary power sources are provided that, when triggered by one or more predetermined conditions being met, keep the bank of electrolytic cells in an electrical state that is relatively harmless to the anodes having electrocatalytically active coatings. In a second embodiment, the invention is directed to a method of maintaining the polarization of anodes in an electrowinning cell positive of the cathodes (i.e. in a potential region where the anode coating is not susceptible to significant damage). In a final embodiment, the invention is directed to various methods for the installation of replacement anodes and maintenance of electrowinning cells.

Abstract: A method of preparing organic acids (fulvic, humic, and ulmic) for use as an electrolyte for producing high ionizations of precious metals (such as silver) which entails leaching out the organic acid from its source, stabilizing the organic acid first with ascorbic acid followed by sodium benzoate, removing cations, and using the organic acid as an electrolyte. A precious metal (such as silver) is used as a sacrificial electrode in this electrolyte. A non-sacrificial electrode could either be the same precious metal or an inert non-precious metal (titanium or graphite carbons). If the same material is used for the non-sacrificial electrode as for the sacrificial electrode, the size of each electrode may be about the same. If different material is used for the non-sacrificial electrode, its size should be larger that of the sacrificial electrode. Current at about 2 or more volts is applied to the electrodes and the ionization process begins yielding high concentrations of ionized precious metals.

Abstract: A process for purifying and refining platinum group metals such as platinum, iridium, palladium, rhodium and the like by an electrochemical process using ammonium chloride as the electrolyte to form ammonium chloride platinum group salts as a "slime" followed by the use of ammonia hydroxide to dissolve and separate said salts from other materials in the slime. A further step to precipitate the platinum metals from the ammonia hydroxide may be employed.