Beneficiation of low-grade, high-phosphorus manganese ores of Andhra Pradesh, India, by wet high-intensity magnetic separation plus jigging or hydrocyclone classification
Sb. Kanungo et al., Beneficiation of low-grade, high-phosphorus manganese ores of Andhra Pradesh, India, by wet high-intensity magnetic separation plus jigging or hydrocyclone classification, MIN MET PR, 17(4), 2000, pp. 269-275
Jigging of the -2.8 +0.7-mm size fraction of a friable, low-grade manganese
ore sample from Andhra Pradesh increased the Mn content of a concentrate b
y 7% to 8%, with nit average recovery of 57%. The jig concentrate was mixed
with the unjigged -0.7-mm size fraction and ground to -150 mum. The sample
was then subjected to wet high-intensity magnetic separation (WHIMS). The
magnetic fraction thus obtained showed an increase in Mn content of 6%, but
with an overall recovery of only 50%. The results of hydrocyclone classifi
cation of -150-mum ground ore indicated that the method is not capable of u
pgrading the manganese content, as both ferromanganese oxides and aluminosi
licate gangue minerals constitute the fine size fraction. However, when the
nonmagnetic fraction obtained from the WHIMS of-150-mum ore is subjected t
o hydrocyclone classification and the underflow obtained is subjected to WH
IMS again, an overall recovery of about 50% to 52% is obtained with at leas
t a 7% to 8% increase in the Mn content of the product. The phosphorus cont
ent in the product is not reduced by either of the two combinations of meth
ods. The complex association of phosphorus with all the major phases in the
ore has been clearly demonstrated from the linear correlation between the
distribution ratios of major constituent phases and phosphorus.