GB/T 4698.13-2017Methods for chemical analysis of titanium sponge,titanium and titanium alloys - Part 13: Determination of zirconium content - EDTA complexometric titration and inductively coupled plasma atomic emission spectrometry (English PDF)

2.1 Method summary

The sample is dissolved with hydrochloric acid, hydroxylamine hydrochloride is added to eliminate the interference of iron and other coexisting elements, and the mixture is heated under hydrochloric acid medium to dimethyl

Phenol orange as an indicator, with EDTA standard titration solution titration of zirconium.

Niobium coexist titration end of the phenomenon back to the phenomenon should be repeated heating titration end of the color constant.

2.2 Reagents

Unless otherwise specified, only reagents that are identified as analytically pure and laboratory-grade water are used in the analysis.

2.2.1

Hydrogen peroxide (p = 1.10 g/mL).

2.2.2

Hydrochloric acid (1 1).

2.2.3

hydroxylamine hydrochloride solution (100g/L).

2.2.4

zirconium standard solution (1mg/mL).

2.2.4.1

Preparation Weigh 3.533g zirconyl chloride (ZrOCl2 · 8H2O) in 500mL beaker, add 100mL hydrochloric acid (2.2.2) so that

Dissolved into 1000mL volumetric flask, diluted with water to the mark, mix well.

2.2.4.2 Calibration

Pipette three 25.00 mL portions of zirconium standard solution (2.2.4.1) into three 250 mL beakers, dilute with water to about

100mL, add 1g of ammonium chloride, heated to 70 ° C, ammonia solution was added dropwise under stirring (11) to ammonia smell, heated to boil, remove and place

30min. Filtered on medium speed quantitative filter paper and the precipitate was washed 4 times with ammonium nitrate solution (20 g/L) and twice with water. Will precipitate and filter paper

Into a constant weight platinum crucible, drying, ashing, burning in a high temperature furnace at 1000 °C to constant weight.

According to equation (1) calculate the concentration of zirconium standard solution (2.2.4.1).

c1 = (m2-m1) × 1000 × 0.7403

V1 (1)

In the formula.

c1 --- zirconium standard solution (2.2.4) of the actual concentration in milligrams per milliliter (mg/mL);

m2 --- zirconium dioxide and platinum crucible mass, in grams (g);

m1 --- platinum crucible mass in grams (g);

V1 --- Remove the volume of zirconium standard solution (2.2.4.1), in milliliters (mL);

0.7403 --- Zirconium dioxide conversion factor for zirconium.