Technical visit to Green Cement Plant
By Ir LAM Chi Sing
A technical visit to Green Cement plant was conducted on 20 November
2021. It was co-organized with the Institute of Materials, Minerals and Mining
(IOM3)- Hong Kong Branch. The green island cement plant was originally established
in Macau in May 1886. It was relocated to Hong Kong for operation in January
1887, and then resided to Tap Shek Kok Tuen Mun in 1982 for operation till now.
The speaker introduced the flow of cement manufacturing workflow operation that
the raw materials were unloaded in dock yard, using conveying belt system and
transferred for grind milling, then transferred to pre-heat tower through
rotary kiln for treatment, then clinker cooler and stored in clinker silos for
final finish mills before delivery to
the customers. Throughout the manufacturing process, the quality of product
should be tested through laboratory examination and auto sampler with X –ray
analysis. The cement was also tested to its compressive strength test. The bulk
cement discharging was packed by automatic bag placer and automatic palletizer
for loading to the customers.
To save carbon footprint reduction, alternative fuel will be used to
reduce carbon dioxide emission, the raw meal of limestone, silica sand,
flyash/clay and iron slag to become using of gypsum, CEM 1 Additive and fly-ash
as for clinker for burning from 380 degree Celsius temperature to reach 1450 degree
Celsius, then to cement cooler and silo for storage.
Co-processing using cement kiln was also adopted, unwanted undersize
limestone from quarry, fly-ash from coal fire waste, bed ash from sludge
incinerator and copper slag from copper smelter were used as for fuel of
burning in manufacturing cement process, so that the wastes from rubber tire
derived fuel (RDF); plastic derived fuel (PDH), wood derived fuel (WDF), yard
waste, and polyurethane residue (PUR) were used for carbon emission reduction.
An alternative cementitious materials such as pulverizing ash (PFA) and
Granulated Blast Furnace Slag (GGBS) were also used for carbon footprint
reduction.
After the talk, we were led to visit the cement manufacturing yard and
their laboratory room and control room to see the workflow operation.
The visit ended with on spot question-and-answer session.
Group photo with the representatives of Green Island Cement Plant