1 Scope
This part of SN/T 2087 specifies combustion bomb-auto potentiometric titration method when determining chlorine content in coal.
This part is applicable to determination of chlorine content in coal and determination range is between 0.03% and 0.30%.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 212 Proximate Analysis of Coal
GB/T 213 Determination of Calorific Value of Coal
GB 474 Method for Preparation of Coal Sample
3 Method Summary
When a certain amount of coal sample is combusted in oxygen-bomb with excessive oxygen, the released chlorine will be absorbed by dilute base solution. Elute the oxygen-bomb with water to transfer all absorbing solution into a beaker, then acidize with nitric acid and determine chlorine content by using silver electrode as a measuring electrode and by automatic potentiometric titration of standard solution of silver nitrate.
4 Reagents and Materials
Unless otherwise specified, only guaranteed reagent and ultrapure water with resistivity larger than or equal to 18.2 MΩ•cm are used in this part.
4.1 Nitric acid (ρ=1.42 g/mL).
4.2 Ammonium carbonate.
4.3 Silver nitrate.
4.4 Sodium chloride, standard reagent.
4.5 Ammonium carbonate solution (100 g/L): weigh 100g of guaranteed ammonium carbonate reagent, dissolve it into a 1,000mL water, mix them uniformly and transfer to a reagent bottle. Prepared immediately before use.
Foreword i
1 Scope
2 Normative References
3 Method Summary
4 Reagents and Materials
5 Apparatus
6 Samples
7 Procedure
8 Calculation of Result
9 Precision
Annex A (Informative)Working Condition of Apparatus
