Limestone preparation and refining

Stone preparation comprises primary and secondary crushing. Screening ensures grading of the product into its respective grain sizes. If required, stone washing uses recycled water that is usually obtained from settling ponds.




Following the crushing process, intermediate stone stockpiling guarantees a steady supply of stone to the downstream processes. Quarries operate by day during the week, while transformation installations generally work around the clock.

In our lime and dolime-producing plants, stone fractions bigger than 20 mm are usually sent to calcining kilns. Limestone not destined for industrial calcination is generally further refined for use in other applications.

Some of our plants are also dedicated to manufacturing only chemical grade high-calcium limestone and/or dolomitic limestone for industrial applications. In these refining processes, the stone is either ground or dried and milled after the crushing unit to attain the purity and particle size specifications required for each market Lhoist supplies.