Valorization en France des laitiers siderurgiques: Fid-Bau Portal

Valorization en France des laitiers siderurgiques

Alexander, J.

Blast-furnace slag is considered a valuable secondary raw material for use as an hydraulic binder when in vitreous form and as aggregate when in crystalline form. The main areas of use are: 1. Road-building and civil engineering: vitreous slag is used as a binder in gravel/slag and sand/slag mixtures (500 Mio t of these products have so far been used in France). There is also the all-slag product known as grave-laitier tout laitier, in which vitreous slag is used as the binder and crushed crystalline slag as the aggregate. 2. Cement-making: vitreous slag is an essential constituent of a number of common cements. 3. Concrete: vitreous slag (as-is, pre-crushed or ground) can be used as an active constituent of concrete and in precasting. 4. Glass-making, mineral wool, sandblasting, etc. A total of 3.1 Mio t of blast-furnace slag were used in road-building in 1994. The main uses of steelmaking slag are in: 1. Agriculture, where LD slag is employed, sometimes after enrichment, as a fertilizer and soil conditioner. 2. Road-building and civil engineering: under certain conditions, steelmaking slag is used as aggregate in surface courses and bituminous concretes, as hardcore and in the making of noise barriers. 3. Cement-making: as a raw material in the making of clinker. Sales of slag in France in 1994 amounted to 5.2 million t of blast-furnace slag and 1 million t of steelmaking slag.