Process for binding waste liquor or sludge

In the process for binding sludge comprising forming a mixture of hydraulic mortar and sludge in the presence of inhibiting zinc or phosphorus compounds and allowing said mixture to set, the improvement consisting of utilizing a weight ratio of hydraulic mortar to sludge solids of from 30:1 to 0.5:1, the sludge having a solids content of up to 60% by weight with the remainder water, and subjecting said mixture of hydraulic mortar and sludge to a milling operation to increase the specific surface area of the solids, especially of the hydraulic mortar, by 50% and more and that more solid particles especially of the hydraulic mortar pass through a particular sieve size after said milling, than before said milling, before said mixture is allowed to set.

In the process for binding sludge comprising forming a mixture of hydraulic mortar and sludge in the presence of zinc oxide and allowing said mixture to set, the improvement consisting of utilizing a weight ratio of hydraulic mortar to sludge solids of from 30:1 to 0.5:1, the sludge having a solids content of up to 60% by weight with the remainder water, and subjecting said mixture of hydraulic mortar and sludge to a milling operation to increase the specific surface area of the solids, especially of the hydraulic mortar, by 50% and more and that more solid particles especially of the hydraulic mortar pass through a particular sieve size after said milling than before said milling, before said mixture is allowed to set.

In the process for binding waste liquor or sludge comprising forming a mixture of hydraulic mortar and waste liquor or sludge in the presence of zinc oxide and allowing said mixture to set, the improvement consisting of subjecting said mixture of hydraulic mortar and waste liquor or sludge to a milling operation before said mixture is allowed to set.