GB/T 29401-2020Sulfur coated urea (SCU) (English PDF)

Foreword

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

This standard replaces GB/T 29401-2012 "Sulfur Coated Urea". Compared with GB/T 29401-2012, except for editorial changes, the main The technical changes are as follows.

--- Modify the term "initial nutrient release rate" to "a day nitrogen dissolution rate" (see 3.3, see 3.4 in the 2012 edition), change the term "static nitrogen "Dissolution rate" was revised to "Seven-day nitrogen dissolution rate" (see 3.4, 3.5 in the 2012 edition);

---Modified some technical requirements of Type I and Type II products (see Table 1, Table 1 of the 2012 edition);

--- Increase the limit requirements for toxic and hazardous substances in products (see 4.4);

---The test method of biuret content has been added (see 6.6);

---The test method of calcium and magnesium content has been added (see 6.10.1);

---Added the test method of trace element content (see 6.11);

---The packaging specifications of 10.0kg and 5.0kg have been deleted (see 8.1 in the 2012 edition).

1 Scope

This standard specifies sulfur-coated urea, sulfur-coated slow-release nitrogen fertilizer, sulfur-coated slow-release compound fertilizer, and slow-release sulfur-coated urea The terms and definitions, technical requirements, sampling, test methods, inspection rules, labels and quality certificates, packaging, transportation and storage of blended fertilizers.

This standard applies to the use of sulfur as the main wrapping material to wrap granular urea to achieve slow release of nitrogen.

The so-called sulfur-coated urea slow-release fertilizer includes but is not limited to sulfur-coated urea, sulfur-coated urea, sulfur-coated urea, sulfur-coated urea, sulfur-coated urea, and the like. and also It is suitable for sulfur-coated slow-release nitrogen fertilizer, sulfur-coated slow-release compound fertilizer and slow-release mixed fertilizer containing part of sulfur-coated urea.

2 Normative references

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

GB/T 2441.1 Determination of Urea Part 1: Total Nitrogen Content

GB/T 6679 General Rules for Sampling of Solid Chemical Products

GB/T 8170 Numerical rounding rules and the expression and determination of limit values

GB/T 8569 Solid chemical fertilizer packaging

GB/T 8572 Determination of total nitrogen content in compound fertilizers by titration method after distillation

GB/T 8577 Determination of free water content in compound fertilizers Karl Fischer method Determination of copper, iron, manganese, zinc, boron, and molybdenum content in GB/T 14540 compound fertilizer

GB 18382 Fertilizer labeling content and requirements Determination of calcium, magnesium and sulfur content in GB/T 19203-2003 compound fertilizer

GB/T 21633 Blended fertilizer (BB fertilizer)

GB/T 22924 Determination of Biuret Content in Compound Fertilizer (Compound Fertilizer)

GB/T 24891 Determination of particle size of compound fertilizer

GB/T 34764 Determination of copper, iron, manganese, zinc, boron and molybdenum content in fertilizers by plasma emission spectrometry

GB 38400 Limit requirements for toxic and hazardous substances in fertilizers

HG/T 2843 Commonly used standard titration solution, standard solution, reagent solution and indicator solution for chemical analysis of fertilizer products

NY/T 1117 Determination of calcium, magnesium, sulfur and chlorine content in water-soluble fertilizer

ISO 17322 Test method for sulfur-coated urea for fertilizers and soil conditioners

ISO 18643 Fertilizers and soil conditioners-Determination of biuret content in urea-based fertilizers by HPLC method

3 Terms and definitions

The following terms and definitions apply to this document.