Radioactive tracer such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production. Radioactive tracers form the basis of a variety of imaging systems, such as, PET scans, SPECT scans and technetium scans. Radiocarbon dating uses the naturally occurring carbon-14 isotope as an isotopic label. Isotopes of a chemical element differ only in the mass number. For example, the isotopes of hydrogen can be written as H, H and H, with the mass number at top left. When the
Hydrochloric acid regeneration Hydrochloric acid regeneration Hydrochloric acid regeneration or HCl regeneration refers to a chemical process for the reclamation of bound and unbound HCl from metal chloride solutions such as hydrochloric acid. The commercially most relevant field of application for HCl regeneration processes is the recovery of HCl from waste pickle liquors from carbon-steel pickling lines. Other applications include the production of metal oxides such as, but not limited, to AlO and MgO, as well as rare-earth oxides, by pyrohydrolysis of aqueous metal chloride or rare-earth chloride solutions. A number of different process routes are available. The most widely used is based