Test Method for Packing Density of Coal‑based Granular Activated Carbon

It is a black porous granular carbon material manufactured from anthracite and bituminous coal through crushing, carbonization, high‑temperature steam activation and sieving. It is divided into two types: crushed irregular granular carbon and extruded columnar granular carbon. It contains abundant micropores to capture impurities in liquids and gases via physical adsorption. It features high mechanical strength, good wear resistance, low pulverization tendency and can be regenerated for repeated use. With well‑developed pores, it delivers excellent gas‑phase adsorption performance and high cost‑effectiveness, while its ash content is relatively higher compared with coconut‑shell‑based or wood‑based activated carbon.

Test Purpose

1. To characterize the packing compactness of granular activated carbon.
2. To provide basic parameters for loading‑capacity design and feeding calculation of equipment such as activated‑carbon adsorption towers and filters.
3. To indirectly reflect the particle‑size distribution and inter‑particle void condition, serving as an indicator for product quality evaluation.
4. To ensure consistent filling volume for activated carbon of different batches and stable operating conditions of adsorption equipment.

Test Samples and Apparatus

Test Sample: Coal‑based granular activated carbon
Test Apparatus: ST‑61 Activated Carbon Packing Density Tester, compliant with GB/T 7702.4.

Test Procedures

1. Sample drying: Take an appropriate amount of coal‑based granular activated carbon sample and dry it in an oven at 150℃±5℃ for 2 h. Samples with known moisture content may skip the drying process.
2. Sample sieving: Take approximately 300 mL of dried sample, sieve for 60 s on a sieve shaker with the matching bottom sieve for particle‑size testing to remove dust and fine broken particles.
3. Sample loading: Pour more than 100 mL of sieved sample into the storage funnel.
4. Feeding and packing: Adjust the height of the storage funnel and the inclination angle of the vibrator, then switch on the vibrator. Control the sample falling rate at 0.75‑1.0 mL/s. The sample flows through the feeding funnel into a 100 mL graduated cylinder until it exactly reaches the 100 mL mark.
5. Weighing: Take out the graduated cylinder and weigh the mass of activated‑carbon sample inside, accurate to 0.1 g.
6. Parallel test: Repeat steps 1‑5 to complete measurement of the second parallel sample.
7. Calculation: Calculate according to the formula for packing density. If the sample contains moisture, convert to dry‑basis packing density by deducting moisture content.
8. Result judgement: If the difference between two parallel results ≤ 25 g/L, take the arithmetic mean and round the result to an integer.

Test Result

The packing density of the tested sample is 480 g/L.