SN/T 1828.16-2019Test method of classification for import and export dangerous goods - Part 16: Nitrate substance (English PDF)

5.1 Test items

Oxidative solids test.

5.2 Number of samples

500g of representative substance was randomly selected from the goods to be inspected for the test of hazardous characteristics.

SN/T 182.8.16-2019

5.3 Test preparation

5.3.1 Potassium bromate reference substance

It is sieved but should not be ground. The particle size is from 0.15mm to 0.30mm. It is industrially pure. Dry to constant weight (at least 12h) at 65 ° C, and then place Return to the desiccator (with desiccant), cool and set aside.

5.3.2 Fiber

Cellulose filaments, with a length of 50 µm to 250 µm and an average diameter of 25 µm. The dried cellulose filament is made into a thin layer with a thickness of not more than 25 mm, dried to a constant weight (at least 4 h) at 105 ° C, and then placed in a desiccator (with a desiccant), and cooled for later use. Moisture content (based on dry weight) should Less than 0.5%, if necessary, can extend the drying time.

5.3.3 Ignition source

That is, an inert metal wire (such as nickel/chromium) connected to the power supply should meet the following characteristics.

a) Length. 30cm ± 1cm;

b) Diameter. 0.60mm ± 0.05mm;

c) Resistance. 6.0ohm/m ± 0.5ohm/m;

d) Power consumption of metal wire. 150W ± 7W;

e) See Figure A in Appendix A for metal wires. The shape shown in Figure 1.

5.4 Test equipment

5.4.1 Glass funnel

A 60 ° glass funnel with a closed end and an inner diameter of 70 mm.

5.4.2 Test plate

The test slab should be impervious and meet the following requirements.

a) Length. 150mm;

b) width. 150mm;

c) thickness. 6mm;

d) Thermal conductivity (at 0 ° C). 0.23W (m · K).

5.4.3 Balance

Can be accurate to 0.01g.

5.5 Test procedure

5.5.1 30.0g ± 0.1g of the reference material and fiber mixture are arranged according to the mass ratio of potassium bromate to cellulose 3. 7, 2. 3 and 3. 2.

30.0g ± 0.1g of the substance to be tested (the particle size is the particle size to be used for transportation) and the cellulose mixture according to the mass ratio of the sample to the cellulose for 4. 1 and 1. 1 configurations, each part of the mixture should be mechanically mixed as thoroughly as possible without excessive force.

5.5.2 Use a glass funnel to make the mixture into a truncated cone with a bottom diameter of 70mm. Place this cone sample on a flat surface with low thermal conductivity Flat ring metal ignition wire.

5.5.3 Connect the ignition wire to the power source and keep it energized during the test. If the mixture does not catch fire and burn, keep it on for 3 min. Remember the recorded burn time is from power on to the end of the main reaction (eg flame, hot or flameless combustion). Intermittent reaction after the main reaction Responses such as sparks or crackles should not be considered. If the heated wire breaks during the test, the test should be repeated. For each sample SN/T 182.8.16-2019 Five parallel experiments were performed.

6.1 Determination of danger level

Perform tests in accordance with 5.5 to determine whether dangerous goods should be classified as 5.1 oxidizing substances and classified as dangerous according to Table 1.

6.2 Judgment of packing level

According to its danger level, select the applicable packaging category according to Table 1.

Table 1 Whether the dangerous goods should be classified into 5.1 oxidizing substances and the applicable packaging category

The mass ratio of the sample to cellulose was 4. 1 and 1. 1.

Average burning time during test Whether it should be included in 5.1 Oxidizing substance hazard class applicable packaging category Mixture of potassium bromate and cellulose with a mass ratio of <= 3. 2 the average burning time is highly dangerous for Class I packaging the mass ratio of the sample to cellulose was 4. 1 and 1. 1.

Average burning time during test Whether it should be included in 5.1 Oxidizing substance hazard class applicable packaging category Mixture of potassium bromate and cellulose with a mass ratio of <= 2. 3 Moderately flammable and does not meet Class I packaging standards are moderately hazardous Class II packaging Mixture of potassium bromate and cellulose with a mass ratio of <= 3. 7 Mildly dangerous Class III packaging with an average burning time that does not meet the Class I and Class II packaging standards no fire or burning, or mass ratio of potassium bromate and cellulose Average burning time for mixtures > 3. 7 should not be included in 5.1 Oxidizing substances--See Appendix B for examples of nitrate hazard assessment.

SN/T 182.8.16-2019

Appendix A

(Normative appendix) Test plate and ignition wire

Figure A. 1 Test plate and ignition wire

A- bottom of cone sample (70mm diameter); B- heating wire; C- low thermal conductivity plate SN/T 182.8.16-2019 Appendix B (Informative appendix)

Example of nitrate risk assessment

Table B. 1 Example of risk assessment of nitrates

Material average burning time (seconds) Result 4.1 1. 1 Ammonium nitrate (crystalline) Calcium nitrate (anhydrous) Calcium nitrate (tetrahydrate) Ammonium nitrate Cobalt nitrate (hexahydrate) Nickel nitrate Sodium nitrate Strontium nitrate (anhydrous) III packaging II packaging Non-5.1 items II packaging Non-5.1 items Non-5.1 items II packaging Non-5.1 items Burning time of reference substance and cellulose mixture 3.7 potassium bromate/cellulose for 100 seconds 2.3 potassium bromate/cellulose for 54 seconds 3.2 potassium bromate/cellulose for 4 seconds Note. The test results listed are for illustration only, because the results obtained by using an oxidant will depend on its particle size and so on.

SN/T 182.8.16-2019