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  2. Merrill–Crowe process - Wikipedia

    en.wikipedia.org/wiki/Merrill–Crowe_process

    The gold precipitate (mixed with zinc dust) is then filtered out of the solution, and the zinc dust and gold are mixed with sulfuric acid to dissolve the zinc. The solution is filtered, and the remaining solids are smelted to a gold dore bar. These bars are sent to a refinery to remove the copper and silver, the specific process used depending ...

  3. Hydrometallurgy - Wikipedia

    en.wikipedia.org/wiki/Hydrometallurgy

    Precipitation is the selective removal of a compound of the targeted metal or removal of a major impurity by precipitation of one of its compounds. Copper is precipitated as its sulfide as a means to purify nickel leachates. Cementation is the conversion of the metal ion to the metal by a redox reaction. A typical application involves addition ...

  4. Cementation (metallurgy) - Wikipedia

    en.wikipedia.org/wiki/Cementation_(metallurgy)

    Cementation is a type of precipitation, a heterogeneous process in which ions are reduced to zero valence at a solid metallic interface. The process is often used to refine leach solutions. Cementation of copper is a common example. Copper ions in solution, often from an ore leaching process, are precipitated out of solution in the presence of ...

  5. Precipitation (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Precipitation_(chemistry)

    Copper from a wire is displaced by silver from a silver nitrate solution it is dipped into, and metallic silver crystals precipitate onto the copper wire. The Walden reductor is an illustration of a reduction reaction directly accompanied by the precipitation of a less soluble compound because of its lower chemical valence: Cu + 2 Ag + → Cu 2 ...

  6. Gravimetric analysis - Wikipedia

    en.wikipedia.org/wiki/Gravimetric_analysis

    Gravimetric analysis describes a set of methods used in analytical chemistry for the quantitative determination of an analyte (the ion being analyzed) based on its mass. The principle of this type of analysis is that once an ion's mass has been determined as a unique compound, that known measurement can then be used to determine the same analyte's mass in a mixture, as long as the relative ...

  7. Copper tubing - Wikipedia

    en.wikipedia.org/wiki/Copper_tubing

    While pipe sizes in Australia are inch-based, they are classified by outside rather than inside diameter (e.g., a nominal 3 ⁄ 4 inch copper pipe in Australia has measured diameters of 0.750 inches outside and 0.638 inches inside, whereas a nominal 3 ⁄ 4 inch copper pipe in the U.S. and Canada has measured diameters of 0.875 inch outside and ...

  8. Coprecipitation - Wikipedia

    en.wikipedia.org/wiki/Coprecipitation

    In chemistry, coprecipitation (CPT) or co-precipitation is the carrying down by a precipitate of substances normally soluble under the conditions employed. [1] Analogously, in medicine, coprecipitation (referred to as immunoprecipitation) is specifically "an assay designed to purify a single antigen from a complex mixture using a specific antibody attached to a beaded support".

  9. Gold extraction - Wikipedia

    en.wikipedia.org/wiki/Gold_extraction

    Gold extraction is the extraction of gold from dilute ores using a combination of chemical processes. Gold mining produces about 3600 tons annually, [1] and another 300 tons is produced from recycling. [2] Since the 20th century, gold has been principally extracted in a cyanide process by leaching the ore with cyanide solution.