Basic Oxygen Furnace Slag
Products and Services > Basic Oxygen Furnace Slag > Physical and chemical properties of BOFS

Raw materials and production processes

BOFS graded aggregates are by-products of BOF steelmaking in a wholly integrated steel mill. Their main chemical compositions are CaO, SiO2, Al2O3, Fe2O3, etc. The molten slag is cooled and solidified into basic oxygen furnace slag, which then undergoes crushing, magnetic separation, and screening to make BOFS graded aggregates. Their physicochemical properties are listed as follows:

Composition(%) SiO2 Al2O3 CaO Fe2O3 P2O5 MnO pH
BOFS 7 ~ 11 1.2 ~ 2.4 38 ~ 45 15 ~ 30 1.8 ~ 2.6 2.5 ~ 4.5 12.1 ~ 12.4
  True proportions Water absorption rates Rates of the Los Angeles (L.A.) abrasion test Rates of the soundness test
Natural gravel 2.64 1.7 27.2 2.9
Basic oxygen furnace slag 3.4 2.6 11.4 1.3

Features

There are low abrasion, low sodium sulfate bonds, high hardness, and high uniaxial compressive strength in BOFS graded aggregates. They are full of calcium, silicon, iron oxides, etc., all of which are similar to natural gravel. When they are used in makeshift pavements for construction or as filling materials, they resist pressure and abrasion well and are also cementitious. Furthermore, their bearing capacity is better than that of natural graded materials, and they are excellent engineering materials.

Applications

(1) Land leveling and preparation projects: Parking lots, makeshift pavements for construction, etc.

Engineering Project

Taiwan High Speed Rail, Ret-Ser Engineering Agency’s Technology Industrial Park, Tainan, Luzhu Science Park, Xinshi Science Park, and the recreational pier of Xingda Port are a few examples.

(2) Seawall backfill

Engineering Project

the South Star Yacht Industry Park Project in Dalinpu

Environmentally Friendly Products

Product footprints

The use of Basic Oxygen Furnace Slag in asphalt concrete pavement extends the service life (6 to 10 years) by approximately four times compared to the use of natural gravel asphalt concrete pavement (1.5~2 years). Using Basic Oxygen Furnace Slag as an aggregate for asphalt concrete pavement not only reduces natural resource extraction and achieves sustainability but also extends the service life of asphalt concrete pavement and reduces the frequency of road patching. This significantly reduces inconvenience to road users during patching, and improves road safety by enhancing pavement quality. In summary, the use of Basic Oxygen Furnace Slag in asphalt concrete pavement can create a triple win of environmental, economic, and social benefits.

Recycled green building material labels

ISO/TS 14067 Product Carbon Footprints by BSI

Modified slag graded materials