Analysis Method of Titanium Dioxide Production--Analysis of Intermediate Control Projects (3)

    12. Inspection of pH value of dry powder of calcined products
First prepare the pH test solution as follows. 025克。 The phenol thymol blue 0. 025g, bromo thymol blue 0. 4g, methyl red 0. 065g, phenolphthalein 0. 25g. These four reagents are dissolved in 400mL of absolute ethanol, heated to complete dissolution, Dilute to 1000 mL with distilled water, then adjust to yellow-green with 0.1 mol/L sodium hydroxide solution. If excess, use 1:1 sulfuric acid to neutralize to yellow-green.
Generally, the calcined material is burnt to the yellow and green, which meets the requirements.
XIII. Determination of potassium carbonate concentration
Wash the beaker with distilled water first, then take 10 mL of potassium carbonate solution, add 4 drops of methyl orange, rinse the wall with about 50 mL of distilled water, and use 3 mol/L sulfuric acid solution.

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    XVI partial titanate measured iron content of
1. Principle The ferric amine is reduced to divalent iron with hydroxylamine hydrochloride under the conditions of pH 2-3. Its reaction formula is as follows:
4FeC1 ₃ +2NH ₂ OH·HCl===4FeC1 ₂ +H ₂ 0+6HCl+N ₂ 0
Then, with phenanthroline as a color developer, a stable orange-red coordination compound is formed with ferrous iron at a pH of 5, and the colorimetric is carried out, and the maximum absorption rate at a wavelength of 508 nm is obtained.
2. Drawing of the standard curve of iron The standard solution of iron salt [1mL containing 0. lmg (Fe)] should be accurately weighed 0. 8634g of pure grade iron ammonium vanadium , first dissolved in 100mL distilled water, add 5mL concentrated sulfuric acid, Transfer to a 1L volumetric flask, dilute to the mark with water, and shake well.
Dilute 10 times when drawing a standard curve.
Drawing of the iron standard curve (with a blank solution as a reference): Add 50 mL of distilled water to each of the n 100 mL volumetric flasks, and add a standard solution of iron to the microtiter tube [1 mL containing 10 μg (Fe)], OmL, 1. OmL, 2.OmL, 4.OmL...10. OmL, then add 10% hydroxylamine hydrochloride 2mL, 30% sodium potassium tartrate 8mL, shake well, and put a small piece of precision pH test paper (pH 0.5-5.0) After adjusting the pH to 2-3 with ammonia water (diluted ammonia water first, then dilute ammonia water), after cooling, add 2mL of 25% sodium acetate solution to make the pH value 5, then add 1.5 mL of phenanthrene, diluted with water. To the mark, shake it, place it for 20 minutes, and measure its extinction value at 510 nm.
The standard iron solution is used as the abscissa and the extinction value is plotted on the ordinate.
3. Determination of the sample Take about 8g of slurry, put it into a 300mL beaker, add 25mL of concentrated sulfuric acid, put it on the electric furnace to heat it to dissolve, after it becomes a clear transparent liquid, cool it, then pour it into a 100mL volumetric flask, use Dilute the distilled water to the mark and shake well. 2mL suction release 500mL Erlenmeyer flask, and adding 1. 5g mixed acid aluminum sheet 50mL Determination of total titanium.
Put 30% sodium potassium tartrate 2.5 mL, put in a 50mL colorimetric tube, add 10% hydroxylamine hydrochloride 2. 5mL, add 1:3 sulfuric acid 2mL, adjust the pH to 5 with concentrated ammonia, add sodium acetate monoacetate Buffer 2. 5 mL, plus 0.4% of phenanthroline 1. 5 mL, diluted to the mark with distilled water, allowed to stand for 10 min, measured blank.
2mL, the above titanium solution 2mL, added to a 50mL colorimetric tube, adding 30% sodium potassium tartrate 2. 5mL, plus 10% hydroxylamine hydrochloride 2. 5mL, adjusted pH with concentrated ammonia 5, plus sodium acetate-sodium acetate buffer 2 mL, and then add 0.4% phenanthroline 1. 5 mL, dilute to the mark with distilled water, let stand for 10 min, and measure the blank with a 721-type spectrophotometer of 510 nm wavelength (distilled water is placed in front, blank is placed in the back, and then taken out The distilled water is poured off, and the blank sample is placed at the original distilled water position, and the sample is placed in the original blank). [next]