We employ the following recycled or industrial waste material as a substitute for our raw materials in the cement manufacturing process.

Gypsum

We utilize synthetic gypsum, a by-product of the Flue Gas Desulphurization ("FGD") process at Hong Kong Electric's Lamma Power Station, in the manufacturing of cement. In fact, we consume nearly all synthetic waste gypsum in Hong Kong.

For example, in 2003, 52,000 metric tonnes of gypsum from Flue Gas Desulphurization ("FGD") of coal fired power plants was recycled to make cement and no natural gypsum is required.

PFA

We pioneered the use of Pulverized-Fuel Ash ("PFA") in cement production in Hong Kong and southern China.

PFA is the ash residue after burning coal in power plants. PFA is usually disposed by dumping it into ash lagoons unless can be recycled. GIC provides a safe and environmentally friendly disposal for PFA produced by the utility companies in Hong Kong.

PFA is recycled as Aluminum ("Al") constituent in our clinker production process. It replaces the use of valuable natural resource of Bauxite and Clay. It is incorporated into the finish grinding process to produce Portland Pulverized-Fuel Ash Cement ("PPFAC"). The pozzolanic activity of PFA modifies the hydration mechanism of cement and provides improved durability.

Slag

Slag Material from blast furnaces and foundries is imported as a major iron (Fe) constituent to substitute the use of natural iron ore in the clinker production process.

Slag contributes 2% by weight in every tonne of our raw material used.

Unwashed Silica

Unwanted river sediment dredged for recovering river channels is recycled as our silica (Si) constituent in the manufacturing of clinker. It accounts for 9% of our raw materials used.

Crushed rock fine limestone (CRFL)

Limestone is a valuable mineral used extensively in various industries such as the steel refining industry, paper industry, as well as an aggregate in the construction industry. However, during the mining and processing of limestone for these applications, a fine residual portion is produced. GIC has upgraded its material handling facility to recycle this low value industry by-product in its clinker manufacturing process.