METHOD FOR PREPARING NICKELIFEROUS LATERITE ORE MIXTURES FOR REDUCTION ROASTINGS

摘要

1355851 Nickeliferous laterite ore mixtures SHERRITT GORDON MINES Ltd 16 Sept 1971 [1 Oct 1970] 43320/71 Heading C1A A moist unground mixture of nickeliferous laterite, containing limonite and serpentine ores, is dried and divided into two fractions, one fraction consisting of fine particles below a certain size, e.g. in the range 65-325 mesh (having a high iron content) and the other fraction consisting of course particles above that size (having a low iron content), the two fractions then being continuously combined in proportions necessary to give a reduction roaster feed having a constant iron content. The moist ore may be first dried in the kiln 10 with hot gases having a high velocity in the range 7-20 ft./sec., the entrained fine fraction of size less than 200 mesh (having an iron content of more than 40%) is collected in 12 and transferred to the high iron store 14. The dried coarse fraction is then passed, via screen 16 to remove large rocks, to comminuting apparatus 18 and 22, the fines being transferred to the high iron store 14 and the coarse fraction to the low iron store 24. The material drawn from the two stores is blended in 26 to provide a reduction roaster feed of constant iron content with a variation of less than 1%.