GB/T 1997-2008Coke-sampling and preparation of samples (English PDF)

3.1 Lot and batch

Coke of same specification at same delivery shall be deemed as one lot, and the mass of one lot of coke is called batch.

3.2 Basic lot

It means the specified minimum batch.

3.3 Share sample

It means the coke sample obtained by sampling tool when it works one time at one part of one lot of coke (continuous times available for manual sampling).

4.1 Moisture sample

4.1.1 After moisture sampling, it shall be immediately put into a corrosion-resistant sample storage barrel with a sealed cover or other watertight sealed container. Tightly cap the barrel or container after each share sample is put in place.

4.1.4 For obvious damp samples, when the determination results are affected during the preparation of samples, the samples and the container shall be weighed together. Spread the samples in a thin layer on a steel plate in a warm and well-ventilated room for air drying; or put the samples into a large oven for incomplete drying before natural cooling. Weigh the container and the dried samples.

4.1.5 The precision of weighing apparatus shall be proper. The maximum capacity of the weighing apparatus shall not exceed 5 times of the sample mass; the minimum division value shall be less than 1/1000 of the maximum capacity.

4.1.6 The total precision of this Standard in sampling, preparation of samples and determination shall be ±1.0% (absolute value) when the degree of confidence is 95%. The total precision of coke of which the moisture is over 10% shall be ±10.0% (relative value).

4.2 Quantity and mass of share sample

The quantity and mass of share sample listed in this Standard shall be the minimum ones that are required to reach specified sampling precision. When the actual lot is less than the basic lot, the quantity and mass of share sample shall not be reduced progressively at the actual lot-basic lot proportion.

5.1 Sampling tools

5.1.1 Long-handle sampling shovel Specification of long-handle sampling shovel is shown in Table 1 and Figure 1.

5.1.2 Sample storage barrel

The barrel mouth shall be tightly connected to the cover. It is made of nonabsorbent and corrosion resistant material.

5.2 Sampling place

5.2.1 The transfer point from coking plant convey belt to iron-making plant convey belt.

5.2.2 The coke falling point of the coke bin or discharge spout.

5.2.3 The transfer point of loading and unloading truck, ship or over-casting convey belt.

5.2.4 Different layout points in the truck, ship or coke pile during loading and unloading.

5.2.5 On the convey belt for transporting coke.

5.3 Batch

5.3.1 Basic lot is 500 t. During the daily production, quantity of coke transported per shift shall be regarded as a batch; if quantity of coke transported per shift is less than 200 t, then the quantity of coke transported per day shall be regarded as a batch.

5.4 Determination of quantity and mass of share samples

5.4.1 The minimum quantity of share samples of one lot of coke shall be determined in accordance with Table 2; for coke batch that is greater than 500 t, the quantity of share samples shall be increased according to the method specified in 4.2. The quantity shall be increased by 1.3 times for ship and large-pile sampling.

5.5 Sampling in coke flow

5.5.1 During the coke transporting by belt conveyer, the interval of share sampling shall be determined according to the batch and the quantity of share samples of each batch.

5.5.2 Sampling at coke bin or discharge spout

The sampling at coke bin or discharge spout is the same as that in coke flow (5.5.1 a)).

5.5.3 Sampling of loading and unloading truck, ship or over-casting by adopting belt conveyer is the same as that mentioned in 5.5.1. However, if there is no conditions to install a mechanical sampling funnel, sampling shall be conducted as specified in 5.5.4.

5.5.4 Other sampling methods in loading and unloading truck, ship or cover-casting.

5.5.4.3 Sampling in ship

Sampling in ship shall be also conducted during the loading and unloading.

Divide the coke stored in the freight house into several sampling layers. The upper sampling layer is 0.1 m ~ 0.2 m away from the top;

6.1 House, equipment-tools

6.1.1 Preparation room

Preparation room shall include preparation of samples (crush, mix, divide, screen, etc.), storage of samples, drying, etc. The room shall be large and bright enough without being affected by rain or wind or foreign dust. It shall have dust-proof equipment.

6.1.2 Crusher

Crusher applicable to preparation of samples includes jaw crusher, roll-type crusher and other sealed grinders. Theses equipment can be used as long as their material and ratio of crushing meet corresponding requirements, without contamination and easy to clean.

6.1.3 Divider

The inside surface shall be smooth. It shall adopt sealed type to prevent loss of moisture and powder sample. Cone type, rotary type or dichotomous type shall be adopted. Before use, the divider shall be calibrated according to the provisions in GB/T 2007.5. The precision calibration result shall comply with corresponding requirements.

6.1.5 Sampling shovel, sample tray, brush, weighing apparatus, thermostatic drier, etc.

6.1.4 Screen

6.1.4.1 Perforated screen size. 60 mm×60 mm

6.2 Preparation of samples

6.2.1 Preparation of total moisture samples

Crush all coke sample to be less than 60 mm. The sample mass shall not be less than 40 kg after fully mixing and dividing. Crush the sample to be less than 13 mm. Divide the samples into two equal shares. One of them shall be used to divide special samples for determining moisture, and the other shall be used to divide samples for other analyses. Mixing method is described in 6.3.1, and division method is described in 6.3.2.

6.2.2 Preparation of analysis samples

Evenly mix the other sample that has been crushed and is less than 13 mm, and the splitting shall not be less than 4 kg. Crush its size to be less than 6 mm, and the evenly mixed splitting shall not be less than 2 kg. Crush its size to be less than 3 mm, and the evenly mixed splitting shall be 1 kg. Completely crush 1 kg of sample to 1 mm. […]