GB/T 6730.26-2017Iron ores - Determination of fluorine content - Thorium nitrate titrimetric method (English PDF)

1 Scope

GB/T 6730 provisions of this part of the thorium nitrate titration Determination of fluorine content.

This section applies to the determination of natural iron ore, iron ore, sinter and pellet fluoride content. Measurement range (mass fraction).

2.00% ~ 15.00%.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version applies to this article

Pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 601 chemical reagent standard titration solution preparation

GB/T 6682 analytical laboratory water specifications and test methods

Preparation of pre-dried samples for iron ore analysis GB/T 6730.1

GB/T 8170 rounded repair rules and limit values of the representation and judgment

GB/T 10322.1 Iron ore sampling and sample preparation methods

GB/T 12805 Laboratory glassware burette

GB/T 12806 laboratory glassware single standard line capacity bottle

GB/T 12808 laboratory glassware single standard pipette

3 principle

Sample with perchloric acid and phosphoric acid at 130 °C ~ 140 °C by steam distillation, the separation of fluorine and co-existing elements, adjusting the pH 3.0 ~ 3.2 to

Methyl thymol blue as an indicator, titration with thorium nitrate standard solution. To determine the amount of fluorine.

4 Reagents and materials

Unless otherwise indicated in the analysis, the use of only approved analytical reagent and in line with GB/T 6682 more than three distilled water or its

The purity of water.