Premature filter blinding of slurry solids separation filter

[RCMRon]

We seperate iron ore concentrate from a 72% density slurry and before we had a flotation process the filter bags would wear out and blind in about 13 to 15 weeks. Since floatation, actually reverse flotation becasue we float the silica which is rejected and the iron ore is kept, our filter bage on our disk filters are only lastiong4 to 6 weeks due to blinding. They blind fast and do not even get to wear out. We use dectrin and amine. Does anyone have any ideas?

 

[HEC]

From your description, it would appear that the particle size distribution (PSD) has altered significantly. The filter bags will allow the smaller material to penetrate into the weave and cause the blinding. To validate this I recomend that you look at the PSD and solids density upstream of the float process (the slurry you were feeding) and compare that to the PSD and solids density down streram (the slurry you are now feeding). This will provide valuable information in determining actual cause.

Most likely cause is the silica was creating a filter surface that either prevented material penetrating into the weave or assisted with release of the filtercake from the cloth.

Mark Hutton