| 摘要 |
<p>Cement is admixed during mfre. with a prod. capable of converting Cr6+ salts present, known to cause dermatitis, to harmless Cr salts. Pref. prod. may be a salt, pptg. the salts to insoluble chromates, e.g. BaCl2, Pb(NO3)2, Pb(CH2COO)2, or a salt reducing the salts to Cr3+ salts, e.g. KI, and is used in 2-5 times the stoichiometric amt. required, to cause pptn. or reduction. Pref. percentage quantities and product added are: 0.03 Pb(NO3)2, 0.025 Pb(CH3COO)2, 4 BaCl2, 0.02 Ki, 0.05 Na2S, 0.05 (NH4)2S, 0.1 FeSO4, 0.02 Na2SO3, 0.02 Na2S2O3, 0.02 NaHSO3.</p> |
