دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: a compound in which chromium has a valence of 6, e.g., sodium bichromate. Chromate may be added to drilling fluids eimer directly or as a constituent of chrome lignites or chrome lignosulfonates. In certain areas, chromate is widely used as a corrosion inhibitor, often in conjunction with lime.

n: mined lignite, usually leonardite, to which chromate has been added or has reacted. The lignite can also be causticised with either sodium or potassium hydroxide.

n: See chrome lignosulfonate.

n: Mined lignite, usually leonardite, to which chromate has been added and/or reacted. The lignite can also be causticized with either sodium or potassium hydroxide. The chrome lignite is used for rheology stabilization and filtration control of the drilling

n: Produced by the reaction between sodium chromate and brown coal. Used as durothermic mud thinner.

n: the substant is made by fermenting to get rif of sweet and alkalize with tall and thendepositing and geing rid of calcium sulphate with subphurous acid ferrum and at last being oxidated by sodium bichromate

n: I. a dial gauge used on the rig to measure the hookload. 2. substances in acid-base titrations that, in solution, change colour or become colourless as the hydrogen ion concentration reaches a definite value, these values varying with the indicator. In other titrations. such as chloride, hardness, and other determinations, these substances change colour at the end of the reaction. Common indicators are phenolphthalein and potassium chromate.

n: Na2Cr2O7. Also called sodium dichromate. See chroma/e.

n: Na2CrO4. See chromate.

n: A type of salt in which chromium atoms are in the plus-6 valence state, such as potassium chromate, K2CrO4. Chromium compounds of various types have been used in lignite and lignosulfonate and other mud additives to enhance thermal stability. Since the la

n: A type of salt in which chromium atoms are in the plus-7 valence state, such as potassium dichromate, K2Cr2O7.

ZnCrO4,yellow powder,poisonous and can cause cancer,which is mainly as a depressor of corruption.