Depends on the quality of quicklime and classifier output fineness, there is usually more than 5% to 10% grits or residues discharged from the classifier, this is mostly over-burnt  & under-burnt limestones that are not reactive. These rejects from classifier are usually dumped, milled and mixed in the hydrated lime powder or milled and stored separately.

In case of grit milling, there are several different types of mill that can be used:

– Raymond mill: Raymond mill is most commonly used in China. it is suitable when the grits doesn’t contain much powder, namely output fineness of classifier not very high. Raymond mill has a built-in classifier, so milling sizes can be controlled easily, the mill output can be stored separately or mixed in the hydrated lime.

– Ball mill: Ball mill is very flexible with various feed quality, it can be used to mill grits or powder. It’s very convenient to install a ball mill when the milled rejects are ultimately mixed into the hydrated lime. In this case, the mill output and hydrated lime could share the one classifier, no need for a second classifier. If the milled grits are to be stored separately, then a second classifier would be required after the ball mill, which makes the process more complicated and not very desirable in comparison.

– Roller mill or impact mill: These mills have built-in classifier like the Raymond mill, which makes the process more compact, but unlike a Raymond mill, they can mill powder or grits. The only drawback is that they are much more costly than Raymond mill or ball mill. considering the low value of milled lime grits, it’s often not economical to use these mills, so they are rarely used.

Please give us a call or leave a message if you need a grit mill or lime hydration system, we’ll get back to you shortly.