Method for reducing chromate dermatitis
OwnerPoul L. Rasmusseninventor
Life of this patent
Estimating the term…
Abstract
A dry cement composition containing an amount of ferrous sulphate (FS) for eliminating or substantially reducing the content of water-soluble chromate, is produced by grinding a starting material (C, G) in a cement mill, and the ground cement material is passed from the mill to a storage container (33). The ferrous sulphate in an amount of 0.01-10 and preferably 0.4 percent by weight is added to and mixed with the starting material in a dry or non-dissolved condition at a location or at locations upstreams of the storage container (33). The ferrous sulphate is preferably added to the starting material upstream of the cement mill.
Claims8
A method for reducing chromate dermatitis, comprising:
- feeding a continuous flow of a starting material mixture comprising cement binder clinker into a cement mill, the mixture containing water soluble chromate;
- grinding the starting material in the cement mill;
- continuously transferring ground cement material from the cement mill to a storage container;
- adding non-dissolved ferrous sulfate in an amount of 0.3-1 percent by weight to said flow of material at least at one location upstream of the storage container;
- and
- mixing the ferrous sulfate with the ground cement material so as to produce a cement composition in which the water-soluble chromate is chemically reduced when water is added to and mixed with the composition.
Dependencies are inferred from the claim text.