Copper is not easy to oxidize in the air, but in humid […]
Copper is not easy to oxidize in the air, but in humid air containing SO2 and CO2, a combination of basic copper sulfate and basic copper carbonate (alias verdigris) will be slowly produced on the surface. The patina structure is delicate and inseparable from the fusion of the copper base material, and thus has the maintenance effect of avoiding the air oxidation of the base material again, so the copper has excellent corrosion resistance in the air.
The ionization potential of copper in water is +0.52 (Cu+), and it is not easy to exchange electronic devices with H+ in water to produce charge and discharge reactions; only when it is oxidized into positive ions, copper will react with H+, so copper is resistant to water in water. corrosion. The ancient coins dug at the bottom of West Lake in Hangzhou thousands of years ago are intact, and the copper water pipes used for a hundred years are still bright, which fully proves the problem. Copper also has excellent sulfate corrosion resistance and corrosion resistance in the sea. It is unmatched by stainless steel plates.
Because copper is resistant to corrosion in both gas and water, it has excellent remanufacturing properties. Except for very few positive ions implanted into foreign countries, basically all of them can be acquired. The demand for recycled copper in industrial production capitalist countries has reached 55% of the copper sales market, and it has reached 45% in my country. In addition, this proportion will increase again in the future. It can be conceived that after decades or even hundreds of years, recycled copper will become the key source of the sales market, becoming an emerald green copper resource that does not need to be mined, has extremely high composition and very low energy consumption. This is of vital importance to countries that lack copper resources.