The disposal of kiln bypass dust produced during the manufacture of cement presents environmental and cost issues for cement plants worldwide. Many cement works have routinely landfilled this dust, but increasingly stringent environmental legislation and higher disposal costs have prompted the cement industry to find alternative ways to dispose/utilise bypass dust. Saudi-based Qassim Cement Co (QCC) considered its options and came up with a novel solution. By Jamal Khaled Irshoud, Qassim Cement Co, Saudi Arabia.

Clinker manufacture produces large volumes of bypass dust, especially alkali bypass dust. The handling, transport and disposal of such dust has been of great concern to QCC as it impacts its continuous environmental initiatives as well as the cement plant’s overall production costs. Landfill disposal costs are high in some areas. Bypass dust weakens environmental controls and contributes 15-30 per cent to the production cost/t of clinker. Therefore, a satisfactory disposal alternative needs to meet each of the following criteria:
• enhance environmental protection
• reduce dust volumes for landfill
• ensure high cement quality
• maintain production volumes.