One of the most important chemicals in the gold leaching process is cyanide. Cyanide acts as a complexant that reacts with the gold to create a unique complex in the water. The main byproduct of the process is a family of cyanide contaminants that are related to free cyanide (CN-Free), weak acid dissociation (CN-WAD), strong acid dissociation (CN-SAD) and the SUM of those species which is the CN-Total. The CN levels in the different regulation can range between 0.05 to 0.2ppm and can reach even higher levels for the WAD and the TOTAL types of cyanide.
The patented electrolytic process is based on the known total oxidation pathways of the cyanide CO2 and N2. P2W designs and constructs a unique structure of reactors- high performance electrodes with high surface area and an appropriate electrical current required for the oxidation process.
The cyanide oxidation process occurs and takes place inside the reactor, on the electrode surface and within the flowing water media. The reactors contain several individual electrolytic cells that combine modular cathodes and anodes of various types. These anodes and cathodes are defined according to the type and the level of the contaminants in the wastewater.
The electrolytic reactor unit includes a set of coated commercial electrodes. The electrodes are configured in an alternating manner, such that each cell is different from the one that is next to it. Parts of the inner electrolytic cells are working in series and parts of them are working in parallel. When connected to an external power source, the anode material will electrochemically corrode due to oxidation, while the cathode will be subjected to passivation. For this reason we use bi-polar electrodes that automatically change polarity and totally eliminate the passivisation problems. The current densities are controlled by a central system that controls the current and the volt according to the influent parameters of the water (mainly the conductivity) and is automatically adjusting the electrical parameters according to the changes in the water quality.