GB/T 3286.6-2014Methods for chemical analysis of limestone and dolomite—Part 6: The determination of phosphorus content—The phosphomolybdate blue spectrophotometric method (English PDF)

Foreword

GB/T 3286 "Methods for chemical analysis of limestone and dolomite" is divided into nine sections.

--- Part 1. calcium oxide and magnesium oxide content complexometric titration and flame atomic absorption spectrometry;

--- Part 2. Determination of silica content of silicon molybdenum blue spectrophotometric method and perchloric acid dehydration gravimetric method;

--- Part 3. Determination of alumina content of chromium azure S spectrophotometric and complexometric titration;

--- Part 4. Determination of iron oxide content of phenanthroline spectrophotometric method and the flame atomic absorption spectrometry;

--- Part 5. Determination of periodate oxidation of manganese oxide spectrophotometry;

--- Part 6. Determination of phosphorus content of phosphorus molybdenum blue spectrophotometric method;

--- Part 7. Determination of sulfur content tube furnace combustion - potassium iodate titration method, high-frequency combustion infrared absorption method and barium sulfate gravimetric method;

--- Part 8. Determination of the weight loss on ignition;

--- Part 9. Determination of carbon dioxide content of the caustic asbestos absorption gravimetric method. This section GB/T Section 63286 of. This section drafted in accordance with GB/T 1.1-2009 given rules.

This Part replaces GB/T 3286.6-1998 "limestone, dolomite Chemical analysis methods Determination of phosphorus content", and GB/T 3286.6- Compared to 1998, the main technical changes are as follows.

--- The standard name be changed to "limestone and dolomite chemical analysis - Part 6. Determination of phosphorus content of phosphorus molybdenum blue spectrophotometric law";

--- Normative references canceled the reference standard reign, and adds some reference standards;

--- Carried out jointly between laboratory precision test statistics obtained by the repeatability limit (r) and reproducibility limit R instead of "allowable difference";

The concentration of sodium citrate solution --- 4.8 by the 15g/L to 25g/L, sodium citrate was added in 7.5.1 by the amount of change 5mL To 3mL.

1 Scope

GB/T 3286 provisions of this part of the determination of phosphorus content by phosphorus molybdenum blue spectrophotometric method.

This section applies to the determination of limestone, dolomite and metallurgical lime phosphorus content. Measurement range (mass fraction). 0.001% phosphorus content ~ 0.20%.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

GB/T 2007.2 bulk minerals sampling and sample preparation General manual sample preparation method

GB/T 6379.2 measurement methods and results of Accuracy (trueness and precision) - Part 2: Determine the standard measurement method to repeat Of the basic methods of reproduction Laboratory use specifications and test methods

GB/T 6682 Analysis

GB/T 8170 repair value expressed about the rules and limit values and judgment

3 Principle

Sample temperature burning, decomposition with hydrochloric acid, perchloric acid smoke. About 0.5mol/L HCl medium in order to hydroxylamine hydrochloride and ascorbic acid As a reducing agent, and the resulting reduction of phosphomolybdic heteropoly acid is phosphorus molybdenum blue at 825nm wavelength spectrophotometer measured absorbance.

4 Reagents