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Chromium, nickel and cobalt contents of some Australian cements
Author(s) -
Tandos Ram,
Aarts Ber
Publication year - 1993
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/j.1600-0536.1993.tb03401.x
Subject(s) - hexavalent chromium , chromium , cobalt , chromate conversion coating , chemistry , nickel , nuclear chemistry , cement , lime , wastewater , inorganic chemistry , metallurgy , environmental chemistry , materials science , environmental engineering , organic chemistry , engineering
The total chromium, nickel and cobalt concentrations of 8 Australian Portland cements ranged from 49 to 99 μg/g, 5 to 54 μg/g and ≤1 to 13 μg/g, respectively. The water‐soluble chromate concentrations of the cements ranged from 0.2 to 8.1 μg/g, and the sodium sulphate‐extractable chromates from 1.4 to 9.7; μ g/g. Results for water‐soluble nickel (≤0.2 μg/g) and cobalt (≤0.05 μg/g) indicate that the metals are present only as water‐insoluble compounds. The significance of the various data is considered from a dermatological point of view. Cement extracts for the analysis of water‐soluble hexavalent chromium (chromates) are stable for at least 12 days. The optimum extraction lime for hexavalent chromium in cement appears to be I h Almost 100% reduction of hexavalent chromium is possible after 1 h using 100x the stoichiometric value of iron (II) sulphate. The chromates can become gradually insolubilized when the solution from the water added is in direct contact with the cement, i.e., over a period of > 60 min to 7 days, even without the addition of iron (II) sulphate.