The problem of high rate electrodeposition of metals such as copper during electrowinning operations or high rate charging of lithium or zinc electrodes for rechargeable battery applications while avoiding the adverse effects of dendrite formation such as causing short-circuiting and/or poor deposit morphology is solved by pulse reverse current electrodeposition or charging whereby the forward cathodic (electrodeposition or charging) pulse current is “tuned” to minimize dendrite formation for example by creating a smaller pulsating boundary layer and thereby minimizing mass transport effects leading to surface asperities and the subsequent reverse anodic (electropolishing) pulse current is “tuned” to eliminate the micro- and macro-asperities leading to dendrites.

The problem of high rate electrodeposition of metals such as copper during electrowinning operations or high rate charging of lithium or zinc electrodes for rechargeable battery applications while avoiding the adverse effects of dendrite formation such as causing short-circuiting and/or poor deposit morphology is solved by pulse reverse current electrodeposition or charging whereby the forward cathodic (electrodeposition or charging) pulse current is “tuned” to minimize dendrite formation for example by creating a smaller pulsating boundary layer and thereby minimizing mass transport effects leading to surface asperities and the subsequent reverse anodic (electropolishing) pulse current is “tuned” to eliminate the micro- and macro-asperities leading to dendrites.

The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

The present application relates to methods for leaching and extraction of precious metals. For example, the present application relates to methods of leaching gold, palladium and/or platinum from a substance comprising gold, palladium and/or platinum (such as a gold-containing ore or a platinum group metal (PGM) concentrate) using an organic solvent that is water-miscible or partially water-miscible.

It is disclosed a system and process for starting up an electrolytic cell. The system and process are particularly adapted for preheating an electrolytic cell or pot having cathodes before installing preheated anodes in the cell, for the production of a metal (e.g. aluminum). The system comprises one or more electrical heaters installed in the cell in place of the anode assemblies and can be used with a dry bath or a liquid melted bath (e.g. cryolite). The cell is preferably preheated by as many cell preheaters as there are anode assemblies. The cell preheater is preferably powered by current available in the pot's busbar. The invention is environmentally friendly as being preferably adapted for preheating a cell working with inert or oxygen-evolving anodes. Furthermore, the starting up process allows optimizing/reducing the time necessary for starting up the electrolytic cell, while securing the materials located inside the cell.

The invention relates to a process that allows electrolytic copper cathodes to be produced, using the pregnant leach solution (PLS) directly in the electrowinning, avoiding the step of mineral concentration by solvent extraction. Furthermore, this process has a modular structure and the full process can be mobilised depending on the requirements of the process itself. The invention also relates to the system that operates with the previously described process.

The invention relates to a process that allows electrolytic copper cathodes to be produced, using the pregnant leach solution (PLS) directly in the electrowinning, avoiding the step of mineral concentration by solvent extraction. Furthermore, this process has a modular structure and the full process can be mobilised depending on the requirements of the process itself. The invention also relates to the system that operates with the previously described process.

A marine cathodic protection system configured to protect a metal structure exposed to seawater from corrosion. The system includes a first anode provided on or adjacent the protected metal structure at a first position. The first anode is exposed to seawater, is electrically insulated from the protected metal structure, and is formed of a metal having a greater negative potential than the protected metal. The system further includes a second anode provided on or adjacent the protected metal structure at a second position. The second anode is electrically connected to the first anode. The first position is preferably substantially submerged in said seawater such that the protected metal and the first anode cooperate to define a seawater battery configured to apply an electrical current to the second anode, the second anode thus being an impressed current anode.

A marine cathodic protection system configured to protect a metal structure exposed to seawater from corrosion. The system includes a first anode provided on or adjacent the protected metal structure at a first position. The first anode is exposed to seawater, is electrically insulated from the protected metal structure, and is formed of a metal having a greater negative potential than the protected metal. The system further includes a second anode provided on or adjacent the protected metal structure at a second position. The second anode is electrically connected to the first anode. The first position is preferably substantially submerged in said seawater such that the protected metal and the first anode cooperate to define a seawater battery configured to apply an electrical current to the second anode, the second anode thus being an impressed current anode.

An apparatus for use in the electro-production of metals, comprising a plurality of anodes and a plurality of cathodes in an interleaved configuration, wherein each anode and cathode pair forms a cell; a plurality of power supplies, each cell associated with one or more respective power supplies; and the power supplies are arranged to control a direct current in the one or more cells to a predetermined value.