Abstract: The present invention relates to processes including the step of electrochemically treating an iron mineral. The processes are for improving the grade of iron, producing a magnetic iron mineral, or producing an iron oxide. In one aspect, the process for improving the grade of iron includes electrochemically treating a slurry including at least one iron mineral to thereby improve the grade of the iron in the slurry.

Abstract: The present invention aims to provide a zinc electrowinning anode capable of inhibiting manganese compound deposition on the anode and a cobalt electrowinning anode capable of inhibiting cobalt oxyhydroxide deposition on the anode. The zinc electrowinning anode according to the present invention is a zinc electrowinning anode having an amorphous iridium oxide-containing catalytic layer formed on a conductive substrate, and the zinc electrowinning method according to the present invention is an electrowinning method using that electrowinning anode. Also, the cobalt electrowinning anode according to the present invention is an electrowinning anode having an amorphous iridium oxide or ruthenium oxide-containing catalytic layer formed on a conductive substrate, and the cobalt electrowinning method according to the present invention is an electrowinning method using that electrowinning anode.

Abstract: An electrochemical process for the concurrent recovery of iron metal and chlorine gas from an iron-rich metal chloride solution, comprising electrolysing the iron-rich metal chloride solution in an electrolyser comprising a cathodic compartment equipped with a cathode having a hydrogen overpotential higher than that of iron and containing a catholyte having a pH below about 2, an anodic compartment equipped with an anode and containing an anolyte, and a separator allowing for anion passage, the electrolysing step comprising circulating the iron-rich metal chloride solution in a non-anodic compartment of the electrolyser, thereby causing iron to be electrodeposited at the cathode and chlorine gas to evolve at the anode, and leaving an iron-depleted solution. The iron-rich metal chloride solution may originate from carbo-chlorination wastes, spent acid leaching liquors or pickling liquors.

Abstract: This invention relates to an apparatus for producing a metal powder product using either conventional electrowinning or alternative anode reaction chemistries in a flow-through electrowinning cell. A new design for a flow-through electrowinning cell that employs both flow-through anodes and flow-through cathodes is described. The present invention enables the production of high quality metal powders, including copper powder, from metal-containing solutions using conventional electrowinning processes, direct electrowinning, or alternative anode reaction chemistry.

Abstract: Upon performing electrolysis with a solution containing nickel as the electrolytic solution, anolyte is adjusted to pH 2 to 5; impurities such as iron, cobalt and copper contained in the anolyte are eliminated by combining any one or two or more of the methods among adding an oxidizing agent and precipitating and eliminating the impurities as hydroxide, eliminating the impurities through preliminary electrolysis, or adding Ni foil and eliminating the impurities through displacement reaction; impurities are thereafter further eliminated with a filter; and the impurity-free solution is employed as catholyte to perform the electrolysis. The present invention relates to a simple method of performing electrolytic refining employing a solution containing nickel from nickel raw material containing a substantial amount of impurities, and provides technology on efficiently manufacturing high purity nickel having a purity of 5N (99.999 wt %) or more.

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 saturated solution of an alkaline earth or alkali metal halide salt is electrolyzed in a flowing mercury cathode electrolysis cell. The amalgam is added dropwise to a solution of dichlorodifluoromethane in a solution of a polar, aprotic solvent, not reducible by such amalgams. The solvent contains inhibitors of polymerization, and may contain a promoting salt of lithium or the "onium" type. Tetrafluoroethylene and unreacted dichlorodifluoromethane gases are evolved, and separated by condensing the dichlorodifluoromethane. The polar, aprotic solvent is removed from the reaction and evaporated, crystallizing the chloride salt of the alkaline earth or alkali metal. This salt is combined with the anolyte of the mercury cell to form brine. The spent mercury from the dechlorination and dimerization is also recycled to the mercury cell. The polar, aprotic solvent is condensed, and mixed with the condensed unreacted dichlorodifluoromethane for further dechlorination and dimerization.

Abstract: An electrolytic cell comprising bipolar electrodes is employed for electrochemical deposition of copper, zinc, lead, nickel or cobalt. An interior space is provided between the cathode side and the anode side of a bipolar electrode. The electrolyte can flow substantially without an obstruction through the interelectrode space between adjacent electrodes. The current densities in the interelectrode space amount to 800 to 8000 A/m.sup.2. Gas is evolved on the anode side of the bipolar electrodes and causes liquid to flow along the anode side. In the middle of the height of the anode side that liquid flow has a vertical component having a velocity of 5 to 100 cm/second. Electrolyte solution flows from the upper edge portion of the anode side to a return flow space, in which the solution flows downwardly. From the return flow space the solution is returned to the lower portion of the interelectrode space.