PERTH (miningweekly.com) – Mineral sands miner Base Resources reported a strong operational performance at its Kwale project, in Kenya, with the mine producing a record three-million tonnes of ore on the back of the successful commissioning of a 400 t/h hydraulic mining unit.

Combined with the existing dozer trap mining unit, which mines higher-grade ore while the hydraulic mining unit mines the thinner, lower-grade perimeter blocks, mining operations surpassed the previous best total ore mined by 26%.

However, the average mined ore grade was lower in the quarter, owing to the hydraulic mining unit remaining in the low-grade perimeter blocks while the mining method is being refined. Base reported on Tuesday that the average grade would improve by the end of the financial year in June, as the equipment moved to higher grade blocks.

The company reported that the lower feed grade and lower recoveries at its wet concentrator plant had resulted in overall production of heavy mineral concentrate (HMC) decreasing. The miner said HMC production would increase once mining moved into higher grade areas by the financial year-end.

As a result of the proportionally lower ilmenite content of low grade ore, ilmenite production decreased to 116 982 t in the December quarter, from 121 821 t in the previous quarter. Rutile production stayed consistent at a quarterly record of 22 870 t, compared with 22 458 t in the previous quarter. Zircon production declined slightly from 9 050 t in the September quarter to 8 591 t in the December quarter, reflecting the lower zircon content of the feed.

In line with lower production, ilmenite sales decreased to 97 047 t, from 13 441 t in the September quarter and 103 035 t in the corresponding period, and rutile sales fell to 19 773 t, from 23 023 t in the previous quarter and 23 896 t a year earlier. However, zircon sales increased to 9 432 t, from 8 525 t in the September quarter and 7 723 t in the corresponding period.

Although only accounting for 15% of volume, rutile sales account for about 50% of revenue each year. In the December quarter, Base reported two bulk rutile sales, which combined with a 40% strengthening of ilmenite prices, has resulted in the average revenue rising to a record $250/t, from $200/t in the corresponding period.

Meanwhile, Base has downgraded its rutile and zircon production forecasts for the 2017 financial year, to reflect the lower-than-forecast first-half production, while factoring in the ongoing mineral separation plant optimisation and debottlenecking at the higher feed rates.

Rutile production is now expected to be between 88 000 t and 93 000 t, instead of the previous guidance of between 88 000 t and 95 000 t, while zircon production is forecast to be between 33 000 t and 37 000 t, instead of the expected 35 000 t to 40 000 t.

Ilmenite production expectations remain unchanged at between 450 000 t and 480 000 t.