GB/T 8035-2009Benzol products of coal carbonization-determination of acid wash test (English PDF)

5.1 Potassium dichromate

AR.

5.2 Concentrated sulfuric acid

AR concentration of about 98%, or nearly 18mol/L.

5.3 sulfuric acid solution

95% ± 0.5%.

5.4 potassium permanganate

AR.

5.5 potassium permanganate solution

1L solution containing 3.2g of potassium permanganate.

5.6

double distilled water or equivalent purity.

6.1 colorimetric tube mill mouth

with a ground stopper, high 100mm, inner diameter of 13mm ± 0.5mm colorless transparent tube, there are two standard colorimetric tube ring

Engraved lines engraved on the bottom line from 70mm ± 1mm, the next engraved line bisecting its volume, two parts does not exceed the difference between the volume of 0.1mL.

6.2 volumetric flask

volume 1000mL.

6.3

pipette or burette.

6.4 water bath

to maintain the 20 °C ± 1 °C.

6.5 colorimetric box

lined with white porcelain plates and a fluorescent lamp.

6.6 Oscillator

Ping Zhen Zhen distance 100mm, frequency of 150 times/min ± 10 times/min.

7.1 preparation of standard colorimetric solution

7.1.1 Alternate preparation of sulfuric acid

one double distilled water and a concentration of about 98% concentrated sulfuric acid (1/1) mixed preparation.

7.1.2

previously dried to constant weight of potassium dichromate by 105 °C ~ 110 °C 10g ± 0.0002g spare sulfuric acid dissolved in 1000mL

As a liquid formulation, and as shown in Table 1, the preparation of different concentrations of colorimetric solution.