rio tinto plc said ironore shipments from its australian mining operations were flat in 2022 reaching the low end of the companys forecast range as projected but estimated higherthananticipated production costs due to cost inflation the company which is the worlds top producer of iron ore alongside brazils vale sa said it shipped 873 million metric tons of iron ore from australias pilbara region in the fourth quarter of the year up 4 on the same period of 2021 that took fullyear exports to 3216 million tons the same as the year prior rio tinto earlier said shipments would likely only reach the low end of an estimated 320millionton to 335millionton range thirdquarter shipments were disrupted by two unplanned rail outages on tuesday the miner said 2022 pilbara ironore unit cash costs are likely to end up slightly above the top end of its forecast of 19502100 a ton after an increase in diesel prices labor costs and other rising expenses