High density sludge process

Figure 3 - High Density Sludge (HDS) Process Pilot Plant...

Lime precipitation, where the most well known applieation is the high density sludge (HDS) process... 

Solution polymerizafion. Highly exothermic reactions can be handled by this process. The reaction is carried out in an excess of solvent that absorbs and disperses the heat of reaction. The excess solvent also prevents the formation of slush or sludge, which sometimes happens in the bulk process when the polymer volume overtakes the monomer. The solution process is particularly useful when the polymer is to be used in the solvent, say like a coating. Some of the snags with this process its difficult to remove residual traces of solvent, if that s necessary the same is true of catalyst if any is used. This process is used in one version of a low-pressure process for high-density polyethylene and for polypropylene. 

---