Ann: Results of Meeting, page-21

there are two main REE minerals at kvanefeld steenstrupine and eudialyte and unfortunately lots of other minor ones. also the ore is too fine grained to be able to seperate by the cheaper magnetic , electric or gravity, so you are forced to use the much more expensive floatation .and worse a double floatation is required ,first to take out the sulphides (so you don't get hydro fluoric acid forming )and secondly a phosphate float for the steenstrupine. a third floatation for the silicate eudialyte would not be possible. thus recovery of the heavy rare earth is poor .
For comparisons the eudialyte only deposits are coarse grained (biggest crystal i have seen is 3m long). the ore is also much simpler and often only has three groups of minerals thus cheap dry magnetics can be used.