Our Raw Materials
The combustion of pulverised coal at high temperatures and pressures in power stations produces different types of ash. The 'fine' ash fraction is carried upwards with the flue gases and captured before reaching the atmosphere by highly efficient electro-static precipitators. This material is known as Pulverised Fuel Ash (PFA) or 'fly ash'. It is composed mainly of extremely fine, glassy spheres and looks similar to cement.
The 'coarse' ash fraction falls into the grates below the boilers, where it is mixed with water and pumped to lagoons. This material, known as Furnace Bottom Ash (FBA) has a gritty, sand-like texture.
The use of PFA and FBA in construction has been established for decades. Applications range from providing the cementitious material in concrete, to use as a simple fill material or a lightweight aggregate in the manufacture of blocks.
