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Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point. At the melting point, the ordering of ions or ...
Smelting. Electric phosphate smelting furnace in a TVA chemical plant (1942) Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. [1] It is a form of extractive metallurgy that is used to obtain many metals such as iron, copper, silver, tin, lead and zinc.
Partial melting is the phenomenon that occurs when a rock is subjected to temperatures high enough to cause certain minerals to melt, but not all of them. Partial melting is an important part of the formation of all igneous rocks and some metamorphic rocks (e.g., migmatites), as evidenced by a multitude of geochemical, geophysical and petrological studies.
At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point or crystallization point.
Vacuum arc remelting. Vacuum arc remelting (VAR) is a secondary melting process for production of metal ingots with elevated chemical and mechanical homogeneity for highly demanding applications. [1] The VAR process has revolutionized the specialty traditional metallurgical techniques industry, and has made possible tightly-controlled materials ...
Zone melting (or zone refining, or floating-zone method, or floating-zone technique) is a group of similar methods of purifying crystals, in which a narrow region of a crystal is melted, and this molten zone is moved along the crystal. The molten region melts impure solid at its forward edge and leaves a wake of purer material solidified behind ...
Surface area is the key when it comes to forcing melt more rapidly. “The speed depends on the contact surface area,” Viswanathan says. “If there is more surface in contact, the ice will melt ...
The process was initially developed to refine certain special metals such as cobalt and nickel. As these metals and alloys became more common, the vacuum induction melting (VIM) process became more widely adopted. [4] VIM now helps to melt a variety of metals for aircraft and nuclear applications. [4]