To investigate effects of decomposition roasting temperature and necessary acid amount for decomposition, ore concentrate with TREO content about 39% was used as original ore concentrate (three samples named as Q3, Q5 and Q6), the rates of ore and acid (by chemical equivalence) were 1/, 1/ and 1/, decomposition roasting temperatures were changed in a range of 400 – 420 oC, roasting time was 2h. |