The basic earnings of iron-ore mining company Kumba for the six months to June 30 are expected to between 24% and 29% lower than for the first six months of last year. The decreased R6 847-million to R7 347-million half-year earnings are largely attributable to a lower average realised free-on-board export iron-ore price and a decrease in sales volumes relative to the comparative period, the Anglo American group company stated in a release to Mining Weekly on Thursday.