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In the refining of zinc, solutions of zinc sulfate are treated with hydrated lime to co-precipitate heavy metals such as barium. Calcium sulfate can also be recovered and re-used from scrap drywall at construction sites. These precipitation processes tend to concentrate radioactive elements in the calcium sulfate product.
Mixing the two compounds forms a barium sulfate precipitate, which causes turbidity in the solution. A 0.5 McFarland standard is prepared by mixing 0.05 mL of 1.175% barium chloride dihydrate (BaCl 2 •2H 2 O), with 9.95 mL of 1% sulfuric acid (H 2 SO 4 ).
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO 4 ·2H 2 O. [4] It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk.
Dilute solutions (0.05–0.15 M) of oxalic acid can be used to remove iron from clays such as kaolinite to produce light-colored ceramics. [53] Oxalic acid can be used to clean minerals like many other acids. Two such examples are quartz crystals and pyrite. [54] [55] [56]
If the concentration of a sulfuric acid solution is c(H 2 SO 4) = 1 mol/L, then its normality is 2 N. It can also be called a "2 normal" solution. It can also be called a "2 normal" solution. Similarly, for a solution with c (H 3 PO 4 ) = 1 mol/L, the normality is 3 N because phosphoric acid contains 3 acidic H atoms.
A brown, acidic solution of iron(III) chloride. Like the solid hydrates, aqueous solutions of ferric chloride also consist of the octahedral [FeCl 2 (H 2 O) 4] + of unspecified stereochemistry. [9] Detailed speciation of aqueous solutions of ferric chloride is challenging because the individual components do not have distinctive spectroscopic ...
In this process, the steps of raw material processing, fuel preparation, clinker burning and cement grinding constitute major emission sources for particulate components. While particulate emissions of up to 3,000 mg/m 3 were measured leaving the stack of cement rotary kiln plants as recently as in the 1960s, legal limits are typically 30 mg/m ...
Portland cement is usually made from cheap, quarried raw materials, and these usually contain substantial amounts of Cr, Mn and Fe. For example, limestones used in cement manufacture usually contain 0.3-1% Fe 2 O 3, whereas levels below 0.1% are sought in limestones for white manufacture. Typical clays used in gray cement rawmix may contain 5 ...