What Is the Problem of Refractory in Cement Kiln

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  • Topic: Chromium, Hexavalent chromium, Chromite
  • Pages : 2 (427 words )
  • Download(s) : 304
  • Published : April 3, 2012
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The problems of cement equipment for industrial use refractory cement rotary kiln from the perspective of environmental protection is also restricts the development of the cement kiln refractories, in accordance with the development trend of domestic and international cement kiln refractories, on the whole to low chromium and chromium-free direction, to produce such a trend for two main reasons: the direct cause of magnesium chromium brick refractory in the ecologically harmful Cr "formed in the refractory phase boundary, the chromium ore with alkali and CaO, BaO and Si02 oxide contact, the trivalent chromium into hexavalent chromium, is extremely harmful to people's health. 1979 found stacked in the field after use of magnesia-chrome bricks drowned outflow of hexavalent chromium, hexavalent chromium easily soluble in water per liter of water soluble 600 to 8009, when the aqueous solution containing hexavalent chromium content of more than 0.5mg , skin, respiratory, nervous, nasal septum, lung and other organs of the body causing serious harm, the information that it is carcinogen. Chromite as magnesium chrome brick, brick-making raw materials, more than the form of trivalent (Cr2O3) exist, neither toxic, will not be carcinogenic, but under an atmosphere of high-temperature oxidation of cement rotary kiln, and cementitious materials in the alkali metal oxide material response, harmful chromic acid alkali. Magnesite-chrome brick debris-MgO exists, the solution is slightly alkaline generally prone K2cr207. Imapct crushers are acceptable for abstracts whose compressive backbone is beneath 360Mpa, and atom admeasurement is beneath 500mm. This affectionate of apparatus appearance simple maintenance, top crushing arrangement and crushing ability etc. K2Cr04 is a weak oxidizing compounds, high chemical stability, integration into the environment very difficult to restore a non-toxic trivalent chromium, in many cases containing hexavalent chromium compounds are stable...
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