The company shipped four cargoes totalling 24,000 tonnes from Port Hedland to Chinese-based converters since October to the end of 2018 and has reported increases in performance during the last quarter as it worked through teething issues with its plant.
Altura managing director James Brown said the company was not overly concerned by the initial challenges, as it was "not uncommon for a new plant to experience operational delays", but he said the junior expected to see several months of steady growth in the production profile, while maintaining the quality of its concentrate and meeting shipping targets.
"During November 2018 the process plant was able to deliver output of up to 70% of nameplate over several continuous 24-hour periods, demonstrating the capability of the plant at that stage of commissioning," he said.
"The key challenge is to stabilise the plant and deliver consistent output tonnage in line with product specifications."
It is working with its consultants and contractors to address the commissioning and ramp-up phase at the Western Australian operation.
The crushing and screening portion of the plant has been modified and since December has been operating at about 72% of crusher capacity in line with ramp-up expectations, while the dense medium separation plant is at 81% of nameplate, with an overall recovery of 54% equating to 68% of design.
Total production completed during December was 7500t or 83% of DMS plant capacity output of 9000t per month.
The flotation plant has provided the commissioning team with the main operational challenge, and considerable downtime in the plant was attributed to performance of the ball mill and tailings thickener.
Significant upgrades have been completed and Altura expects to reach a consistent throughput before the end of March.
The company has also noted that the ore from its section of the Pilgangoora deposit has exceeded customer expectations with grades as high as 6.2% lithium oxide and averaging 6.1% Li2O, above the 6% target.
The company has an agreement with Chinese-based Ganfeng Lithium for 100% of stage one production until 2020 and an option for half of production for stage two.
Phase two is planned to boost production to 440,000tpa from 2020 pending a final investment decision that is set to follow a review of the stage one operations and the ramp-up to nameplate production.
Altura shares were last traded on Friday at 16.5c, valuing the company at around $300 million. Its share price has staged a recovery since mid-December, but is still significantly off the almost 50c it reached in March 2018.