Australian Coal Spontaneous Combustion Prevention Project at a Port

At the port’s coal yard, there are 441,600 tons of Australian coal stored. Affected by national policies, customs clear- ance and stacking of Australian coal have been suspended since September 2020. As the storage time has lengthened, the temperature of the coal piles has gradually increased, and some piles have repeatedly shown spontaneous combus- tion hot spots. Since November 2020, the port company has adopted various measures, including covering the piles with geotextile impermeable membranes and imported black-and-white membranes. However, it was found that the geotex- tile impermeable membranes and imported black-and-white membranes had poor sealing performance and could not be effectively secured in strong winds and heavy rain, resulting in high damage rates. Once the coal pile temperature exceeds 70°C, the covering cloth can also be ignited.
At the site, a whole pile of Australian coal (about 50,000 tons) was selected, and the highest temperature of the pile reached 88°C. The pile was divided into the sea side and the land side; the sea side was sprayed with a new type of sealing material, while no other measures were taken on the land side. After spraying the sealing material, distributed tempera- ture measurement points were arranged, and daily temperature measurements were taken on both the sea and land sides. The measured data were compiled, and temperature-time trend charts were drawn for comparison to verify the effectiveness of the sealing material.
The experiment showed:① The temperature on the sea side sprayed with the new sealing material was 9–12°C lower than that on the unsprayed land side.② After spraying the new sealing material, the coal pile temperature decreased daily and later stabilized at an average of 35°C.③ For the same coal type, the temperature of coal pile No. 7 in the yard, which was sprayed with the new sealing material, was 12–15°C lower than that on the sea side of coal pile No. 8 at the same meter position.④ After spraying the new sealing material, the temperature at each point gradually decreased. After market research and combined with the experimental results, Zhejiang Energy Port Company decided to purchase the new sealing material through targeted negotiations, and the purchase was approved by the group company.