Method for determination of hexavalent chromium in basic chromium sulfate

Abstract

The invention relates to a method for determination of hexavalent chromium in basic chromium sulfate and belongs to the technical field of chemical analysis. The method comprises dissolving a sample to be measured, immediately adding MgCl2 and FeCl3 into the solution, adjusting pH to about 10 so that chromium hydroxide precipitates completely, filtering and washing the precipitates to completely separate hexavalent chromium from trivalent chromium, and detecting the hexavalent chromium in the filtrate by a diphenylcarbazide spectrophotometry to obtain the content of hexavalent chromium. The method realizes elimination of interfering elements and complete separation of trivalent chromium and hexavalent chromium, prevents too high hexavalent chromium content caused by oxidation of trivalent chromium into hexavalent chromium in separation and has high accuracy and a good precision.

Description

technical field

[0001] The invention relates to a method for determining hexavalent chromium in basic chromium sulfate, belonging to the technical field of chemical analysis. Background technique

[0002] Basic chromium sulfate is an important inorganic chemical product, widely used in printing and dyeing, ceramics, green ink and tanning process. Vanadium-making enterprises use vanadium-chromium waste residue recovered from vanadium-containing wastewater as raw materials to prepare basic chromium sulfate, which not only improves enterprise efficiency, but also is an effective way to solve chromium-containing waste. The valence state of chromium in basic chromium sulfate is mainly trivalent chromium and trace amount of hexavalent chromium. The industry standard HG / T2678-2015 "Industrial Basic Chromium Sulfate" has strict regulations on the content of hexavalent chromium in basic chromium sulfate. The determination methods of hexavalent chromium mainly include spectrophotomet...

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