Determination of the filter cake component, ferrous sulfate monohydrate?
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This post was last edited by xwtsq on 2011-7-20 23:07. There is currently a filter cake containing FeSO4·H2O, along with other inorganic salts and low-concentration sulfuric acid (about 25%), with a solid content of around 80%. I want to determine the amount of FeSO4·H2O in this filter cake; I’m not sure how to do it (Will FeSO4·H2O turn into FeSO4·7H2O if dissolved in water?)
Determination of the content of monohydrate ferrous sulfate in ferrous sulfate by X-ray diffraction K-value method, Electronic Journal of Chemical World, Issue 05, 1996; Articles from Chemical World magazine, Pan Shiwei...
1: For dissolving the water sample, directly adding potassium dichromate standard solution yields ferrous ions. It can be converted to ferrous sulfate. 2: If, after dissolution, stannous chloride is added for reduction and then potassium dichromate is used for titration, that will give the total iron content. It’s that simple; the method becomes clear once you think about it. You’re not a beginner, are you?
I find it unlikely that the slag contains 25% acid. Unless it is very dilute. Actually, there are a few points you need to pay attention to when doing this: 1: The acidity level must be sufficient to prevent hydrolysis and the formation of precipitates. 2: Nitric acid or hydrogen peroxide should not be added, nor should heating be used. Because this converts ferrous iron into ferric iron. It’s not allowed then. 3: It is best to weigh the sample in an iodine flask to prevent oxidation by air.
Reply to 4# *angjiyuan1: The 25% refers to the concentration of sulfuric acid in the filter cake, not its mass fraction. The actually measured concentration lies between 20% and 25%, while the iron content is around 16%; when converted to ferrous sulfate monohydrate, this corresponds to 48%, which is in good agreement with the values described in the literature.