Search results
Results from the WOW.Com Content Network
A modern crucible used in the production of silicon ingots via the Czochralski process Smaller clay graphite crucibles for copper alloy melting. A crucible is a container in which metals or other substances may be melted or subjected to very high temperatures.
Crucible An evaporating dish is a piece of laboratory glassware used for the evaporation of solutions and supernatant liquids, [ a ] and sometimes to their melting point . Evaporating dishes are used to evaporate excess solvents – most commonly water – to produce a concentrated solution or a solid precipitate of the dissolved substance.
Since crucible tongs work with the crucible, one must know the safety procedures of the crucible. Before using the crucible, make sure that it is dry; Fill the crucible with sample chemicals to only 1/2 or 2/3, do not fill until it is full; If the user used the crucible to fuse the glass, waiting for the crucible to cool down before cleaning it
A crucible and its lid are pre-weighed after thorough drying. The sample is added to the completely dry crucible and lid and together they are weighed to determine the mass of the sample by difference. The sample is placed in the hot furnace long enough so that complete combustion of the sample occurs. The crucible, lid and ash then are re-weighed.
This cylinder, referred to as an electrode is then put into a large cylindrical enclosed crucible and brought to a metallurgical vacuum (0.001–0.1 mmHg or 0.1–13.3 Pa). At the bottom of the crucible is a small amount of the alloy to be remelted, which the top electrode is brought close to prior to starting the melt.
The safer way is to use a crucible, which is specified for the desired temperatures and does not react with the sample material (e.g. alumina, gold or platinum crucibles). If the sample is likely to evolve volatiles or is in the liquid state, the crucible should be sealed to prevent contamination.
A pipeclay triangle is a piece of laboratory apparatus that is used to support a crucible being heated by a Bunsen burner or other heat source. It is made of wires strung in an equilateral triangle on which are strung hollow ceramic, normally fire clay, tubes. The triangle is usually supported on a tripod or iron ring.
A watch glass is a circular concave piece of glass used in chemistry as a surface to evaporate a liquid, to hold solids while being weighed, for heating a small amount of substance, and as a cover for a beaker. When used to cover beakers, the purpose is generally to prevent dust or other particles from entering the beaker; the watch glass does ...