GB/T 12496.17-1999Test methods of wooden activated carbon--Determination of sulphate (English PDF)

Foreword

The standards of the series Test methods of wooden activated carbon are the basis for testing the performance indicators of activated carbon: quality standards for activated carbon require corresponding test method standards. This series revises GB/T 12496.1 to 12496.22-1990, Test methods of wooden activated carbon.

Compared with the previous standards, some methods have been substantially changed in their order and procedure, others only editorially. Among the terms, "residue on ignition", "loss on drying" and "packing density" have been renamed "ash", "moisture" and "apparent density". GB/T 12496.3-1990 (acetic acid adsorption value) and GB/T 12496.4-1990 (zinc acetate adsorption value) have been deleted and transferred to GB/T 13803.5-1999, Activated carbon as catalyst carrier for vinyl acetate synthesis. GB/T 12496.5-1999 (determination of carbon tetrachloride adsorption) and GB/T 12496.17-1999 (determination of sulphate) have been added, and omissions in the previous standards have been made good.

From its date of implementation, this standard replaces GB/T 12496.1 to 12496.22-1990.

This standard was proposed by and is under the jurisdiction of the State Forestry Administration.

Drafting organization: Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry. Main drafter: Shi Yinrui.

This standard was first issued in 1990.

1 Scope

This standard specifies the method for determining sulphate in wooden activated carbon.

This standard applies to wooden activated carbon.

2 Normative references

The provisions of the following standard constitute provisions of this standard through reference in this standard. The edition indicated was valid at the time of publication. All standards are subject to revision, and parties using this standard should investigate the possibility of applying the most recent edition of the standard indicated below.

GB/T 6682-1992, Water for analytical laboratory use - Specification and test methods

3 Principle

The sample is extracted with hot water, and barium chloride solution is added to the extract to make it turbid. A standard quantity of sulphuric acid treated in the same way serves as the reference for the sulphate content of the activated carbon.

4 Reagents and solutions

The water used in this standard shall comply with grade 3 water of GB/T 6682. Unless otherwise specified, the reagents listed are of analytical grade.

4.1 Hydrochloric acid (GB/T 622): hydrochloric acid solution (1+9).

4.2 Barium chloride (GB/T 652): 120 g/L solution.

4.3 Sulphate standard solution [0.1 mg (SO4 2-)/mL]: weigh 0.1810 g of potassium sulphate dried to constant mass into a 1000 mL volumetric flask, dissolve in water, dilute to the mark and mix. This solution contains 0.1 mg (SO4 2-) per mL.

5 Procedure

Weigh 1.000 g of the dried sample (to the nearest 1 mg) into a 100 mL conical flask, add 25 mL of water, heat and boil for 5 min, and filter into a 100 mL volumetric flask. Wash the residue several times with hot water, combining the filtrate and washings in the volumetric flask, dilute to the mark and mix. Transfer 10 mL of this solution to a 50 mL colorimetric tube, add 25 mL of water and 1 mL of hydrochloric acid solution, and keep in a water bath at 30 °C to 35 °C for 10 min. Add 1 mL of barium chloride solution (4.2), mix, leave for 10 min and dilute to the mark. Treat 1 mL of sulphate standard solution (4.3) in the same way for comparison.

6 Expression of results

If after the above procedure the turbidity of the sample is lighter than that of the standard, the sulphate content of the sample is < 0.1%; if it is darker, the sulphate content is > 0.1%.