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Encyclopedia > Crucible
Crucibles used in Czochralski method
Crucibles used in Czochralski method

A crucible is a cup-shaped piece of laboratory equipment used to contain chemical compounds when heating them to very high temperatures. The receptacle is usually made of porcelain or an inert metal. Crucible can mean: A cup shaped piece of labratoratory equipment, a crucible. ... ImageMetadata File history File links Download high resolution version (2048x1536, 604 KB) Summary Title: Crucibles used in Czochralski method Desc: Two unused crucibles - smaller one is placed in the big crucible, which is not the case during the crystal growth process. ... ImageMetadata File history File links Download high resolution version (2048x1536, 604 KB) Summary Title: Crucibles used in Czochralski method Desc: Two unused crucibles - smaller one is placed in the big crucible, which is not the case during the crystal growth process. ... The Czochralski process is a method of crystal growth used to obtain single crystals of semiconductors (e. ... This article does not cite any references or sources. ... A chemical compound is a chemical substance of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... Fig. ... “Fine China” redirects here. ... In English, to be inert is to be in a state of doing little or nothing. ... It has been suggested that Properties and uses of metals be merged into this article or section. ...

Contents

Crucible materials and description

One of the earliest uses of platinum was to make crucibles. More recently, metals such as nickel and zirconium have been used. Crucibles are commonly used with a high temperature-resistant crucible cover (or lid) made of a similar material. The lids are typically loose-fitting to allow gases to escape during heating of a sample inside. Crucibles and their lids can come in high form and low form shapes (see Ext. Link 2 below) and in various sizes, but rather small 10–15 ml size porcelain crucibles are commonly used for gravimetric chemical analysis. These small size crucibles and their covers made of porcelain are quite cheap when sold in quantity to laboratories, and the crucibles are sometimes disposed of after use in precise quantitative chemical analysis. There is usually a large mark-up when they are sold individually in hobby shops. General Name, Symbol, Number platinum, Pt, 78 Chemical series transition metals Group, Period, Block 10, 6, d Appearance grayish white Standard atomic weight 195. ... General Name, symbol, number nickel, Ni, 28 Chemical series transition metals Group, period, block 10, 4, d Appearance lustrous, metallic and silvery with a gold tinge Standard atomic weight 58. ... General Name, Symbol, Number zirconium, Zr, 40 Chemical series transition metals Group, Period, Block 4, 5, d Appearance silvery white Standard atomic weight 91. ... LID is an abbreviation for: Light-Weight Identity, a system that allows individuals to claim and own their digital identity on the Internet League for Industrial Democracy Library Interchange Definition This is a disambiguation page — a list of pages that otherwise might share the same title. ... The millilitre (ml or mL, also spelt milliliter) is a metric unit of volume that is equal to one thousandth of a litre. ... Analytical chemistry is the analysis of material samples to gain an understanding of their chemical composition and structure. ... A hobby store is a place dedicated to the selling of things that people usually employ for their personal satisfaction. ...

Crucible after being used
Crucible after being used
Melting gold in a graphite crucible
Melting gold in a graphite crucible
Several graphite crucibles of different sizes
Several graphite crucibles of different sizes

A crucible is also a container in which metals are melted, usually for temperatures above 500 °C. These crucibles are usually made of graphite with clay as a binder. These crucibles are very durable and resist temperatures to over 1600 °C. A crucible is placed into a furnace and, after the melting, the liquid metal is taken out of the furnace and poured into the mold. Some furnaces (usually electric or induction) have an embedded crucible and are tilted when the metal is poured out. ImageMetadata File history File links Download high resolution version (1536x2048, 904 KB) Summary Title: Crucible used in Czochralski method Desc: This crucible was used to pull a silicon crystal by Czochralski method. ... ImageMetadata File history File links Download high resolution version (1536x2048, 904 KB) Summary Title: Crucible used in Czochralski method Desc: This crucible was used to pull a silicon crystal by Czochralski method. ... Image File history File linksMetadata Melting_crucible. ... Image File history File linksMetadata Melting_crucible. ... General Name, Symbol, Number gold, Au, 79 Chemical series transition metals Group, Period, Block 11, 6, d Appearance metallic yellow Standard atomic weight 196. ... Image File history File linksMetadata Download high-resolution version (1008x858, 146 KB) Graphite crucibles of different sizes , the largest has about 500ml content. ... Image File history File linksMetadata Download high-resolution version (1008x858, 146 KB) Graphite crucibles of different sizes , the largest has about 500ml content. ... It has been suggested that Properties and uses of metals be merged into this article or section. ... Graphite (named by Abraham Gottlob Werner in 1789 from the Greek γραφειν (graphein): to draw/write, for its use in pencils) is one of the allotropes of carbon. ... The Gay Head cliffs in Marthas Vineyard are made almost entirely of clay. ... A furnace is a device for heating air or any other fluid. ... One half of a bronze mould for casting a socketed spear head dated to the period 1400-1000 BC. There are no known parallels for this mould. ...


The term crucible is occasionally used for unrelated activities that are very difficult, but act as a refining or hardening process.


Use in chemical analysis

In the area of chemical analysis, crucibles are used in quantitative gravimetric chemical analysis (analysis by measuring mass of an analyte). Common crucible use may be as follows. A residue or precipitate in a chemical analysis method can be collected or filtered from some sample or solution on special "ashless" filter paper. The crucible and lid to be used are pre-weighed very accurately on an analytical balance. After some possible washing and/or pre-drying of this filtrate, the residue on the filter paper can be placed in the crucible and fired (heated at very high temperature) until all the volatiles and moisture are driven out of the sample residue in the crucible. The "ashless" filter paper is completely burned up in this process. The crucible with the sample and lid is allowed to cool in a desiccator. The crucible and lid with the sample inside is weighed very accurately again only after it has completely cooled to room temperature (higher temperature would cause air currents around the balance giving inaccurate results). The mass of the empty, pre-weighed crucible and lid is subtracted from this result to yield the mass of the completely dried residue in the crucible. This article or section is in need of attention from an expert on the subject. ... An Analyte is the substance or chemical constituent that is undergoing analysis. ... Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid flow and is used to separate fine solids from liquids. ... An analytical balance is an instrument used to measure mass to a very high degree of precision. ... In chemistry and common usage, a filter is device (usually a membrane or layer) that is designed to block certain objects or substances whilst letting others through. ... The ability of a liquid to evaporate quickly and at relatively low temperatures. ... Dew on a spider web Moldy bread Moisture generally refers to the presence of water, often in trace amounts. ... Desiccation is the state of extreme dryness, or the process of extreme drying. ...


A crucible with a bottom perforated with small holes which is designed specifically for use in filtration, especially for gravimetric analysis as just described, is called a Gooch crucible after its inventor, Frank Austen Gooch. Frank Austen Gooch (1852 – 1929) was a chemist and engineer. ...


For completely accurate results, the crucible is handled with clean tongs because fingerprints can add weighable mass to the crucible. Porcelain crucibles are hygroscopic, i. e. they absorb a bit of weighable moisture from the air. For this reason, the porcelain crucible and lid is also pre-fired (pre-heating to high temperature) to constant mass before the pre-weighing. This determines the mass of the completely dry crucible and lid. At least two firings, coolings, and weighings resulting in exactly the same mass are needed to confirm constant (completely dry) mass of the crucible and lid and similarly again for the crucible, lid, and sample residue inside. Since the mass of every crucible and lid is different, the pre-firing/pre-weighing must be done for every new crucible/lid used. The desiccator contains desiccant to absorb moisture from the air inside, so the air inside will be completely dry. Tong could refer to :- Tong, a village in Shropshire, England Tong, a village in West Yorkshire, England Tong, pronunciation of several Chinese characters The Chinese surnames Tang (唐 and 湯/汤) transliterated based on Cantonese This is a disambiguation page: a list of articles associated with the same title. ... A hygroscopic substance is a substance that absorbs water readily from its surroundings. ... A dessicant is a hygroscopic substance that induces or sustains a state of dryness (desiccation) in its local vicinity in a moderately-well sealed container. ...


Use in Ash Content Determination

Ash is the completely unburnable inorganic salts in a sample. A crucible can be similarly used to determine the percentage of ash contained in an otherwise burnable sample of material such as coal, wood, or oil. A crucible and its lid are pre-weighed at constant mass as described above. 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 crucible, lid, and sample are then fired to constant mass to completely burn up the sample, leaving behind only the completely unburnable ash. After cooling in dryness, the crucible, lid, and remaining ash are weighed to find the mass of the ash from the sample by difference. The fraction of ash (by mass) in the sample is determined by the dividing the mass of the ash by the mass of the sample before burning, which is done by subtracting the weight of the crucible and lid from the figure of the container, lid, and sample. One of the components in the proximate analysis of biological materials, consisting mainly of carbonates and bicarbonates of metals. ... Inorganic chemistry is the branch of chemistry concerned with the properties and reactions of inorganic compounds. ... For other uses, see Salt (disambiguation). ... Coal Coal (IPA: ) is a fossil fuel formed in swamp ecosystems where plant remains were saved by water and mud from oxidization and biodegradation. ... Trunks A tree trunk as found at the Veluwe, The Netherlands Wood is a solid material derived from woody plants, notably trees but also shrubs. ... Synthetic motor oil An oil is any substance that is in a viscous liquid state (oily) at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water, literally water fearing) and lipophilic (miscible with other oils, literally fat loving). This general definition includes compound classes with otherwise unrelated...


External links

  • Momentive Performance Quartz, Inc - Manufacturer of Quartz Crucibles
  • Intellect Associates - Manufacturers & Exporters of Graphite Crucibles
  • Metal Technology - a manufacturer of crucibles
  • CR-Scientific: Catalog: Porcelain ware & accessories: Crucibles shows picture of 10 ml high form and 15 ml low form porcelain crucibles and lids.

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In the area of chemical analysis, crucibles are used in quantitative gravimetric chemical analysis (analysis by measuring mass of an analyte).
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