GB/T 20937-2018Potassium magnesium of sulphate fertilizer (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 20937-2007 "potassium sulfate magnesium fertilizer", compared with GB/T 20937-2007, the main technical changes are as follows.

--- Modified free water, chloride ion, particle size, water insolubles index (see 4.2, 2007 edition 4.2);

--- Increased sodium ion, arsenic, cadmium, lead, chromium, mercury limit requirements (see 4.2);

--- Automatic analyzer method to increase the content of potassium oxide (see 5.3.2);

--- Increased sodium ion determination method (see 5.7);

--- Modified the determination method of water insoluble matter (see 5.9);

--- Increased methods for determination of arsenic, cadmium, lead, chromium and mercury (see 5.12);

--- Added some QR code or barcode to mark some product information (see 7.4).

1 Scope

This standard specifies the terms and definitions, requirements, test methods, inspection rules, marking, packaging, transportation and storage of potassium and magnesium sulfate.

This standard is applicable to magnesium, sulfur, etc. made from salt lake brine or solid potassium magnesium salt ore only by physical extraction or direct removal of impurities. A medium amount of potassium sulfate and magnesium fertilizer products.

This standard does not apply to products blended with potassium sulfate and magnesium compounds.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 6549 potassium chloride

GB/T 6679 Solid Chemical Products Sampling General

GB/T 6682 Analytical laboratory water specifications and test methods

GB/T 8170 Numerical Rounding Rules and Representation and Determination of Limit Values

GB/T 8569 solid chemical fertilizer packaging

GB/T 8576 Compound fertilizers - Determination of free water content - Vacuum oven method

Determination of free water content in GB/T 8577 compound fertilizers Karl Fischer method

GB 18382 Fertilizer identification content and requirements

Determination of Calcium, Magnesium and Sulfur in GB/T 19203 Compound Fertilizer

GB/T 22923 Determination of nitrogen, phosphorus and potassium in fertilizers by automatic analyzer

GB/T 23349 Fertilizers arsenic, cadmium, lead, chromium, mercury ecological indicators

Determination of Chloride Ion Content in GB/T 24890 Compound Fertilizer

Determination of particle size of GB/T 24891 compound fertilizer

HG/T 2843 chemical fertilizer products commonly used in standard titration solutions, standard solutions, reagent solutions and indicator solutions

HG/T 4365 water soluble fertilizer

3 Terms and definitions

The following terms and definitions apply to this document.

4 Requirements

4.1 Appearance. powdery crystal or granular product, no visible mechanical impurities.