Abstract
The pioneer work on hydrothermal reactions of interest to metallurgy was conducted in Russia at the very beginning of this century, mainly by Ipatieff and Bayer each working indepently in Saint Petersburg. Gradually industrial applications took place first in the aluminum and later in the nickel industries. Today, the technology is well established in a large numbers of industries, e. g. uranium, gold, tungsten, zinc, and titanium in addition to the aluminum and nickel.
