Andrada Mining has produced lithium concentrate in the form of a high purity petalite lithium concentrate. The concentrate was produced as part of the company’s off-site pilot test programme to investigate the metallurgical potential of the pegmatites from its mineral license areas around the town of Uis in Namibia.
Anthony Viljoen (CEO) commented:
“We are extremely pleased to announce the production of our first saleable bulk lithium concentrate. This milestone follows the previously reported successful laboratory scale test work and we believe it moves us one step closer to full-scale lithium production.
“With the completion of the on-site pilot plant imminent, we intend to expedite bulk pilot test work on all our mineral licenses. Simultaneously, we plan to increase pilot-scale production of lithium concentrate for testing with potential offtakes to achieve initial lithium sales.
“We believe that this represents a huge step towards realising the value of our mineral assets in Namibia and we look forward to updating the market in due course.”
First bulk lithium concentrate from the bond equipment testing facility
Andrada commenced its pilot test programme for lithium during the first quarter of the 2023 calendar year, consisting of bulk sampling and pilot processing. DMS processing of bulk samples from the company’s Nai Nais licence is currently being conducted by Bond Equipment, a specialist in mineral processing solutions and a test work provider in South Africa.
The first concentrate of 0.5 tonnes of high purity petalite (lithium), as in the images below, is from these bulk samples. Offsite pilot DMS processing at Bond is ongoing, and the company expects to produce more than 10 t of concentrate from these samples.
The iron (Fe2O3) in the concentrate is believed to be a product of the ferrosilicon used in the DMS process and there is potential to reduce this contaminant further through magnetic separation. The company believes that the concentrate may be suitable for both the industrial market, as well as feedstock for lithium refineries producing lithium carbonate or lithium hydroxide. The bulk sample for this pilot test had a head grade of 1.50% Li2O.
Nai Nais bulk samples were prioritised because the currently accessible Uis resource is weathered thereby impacting grades. Higher grades are expected in the slightly deeper Uis resource which will be accessible after the present push-back. Nonetheless, the Uis and ML129 pegmatites display similar styles of mineralisation.
Therefore, based on exploration and sampling results, Andrada regards this Nai Nais sample as representative of the higher grade petalite portions of the Uis ore body.
Preparation of the sample material entailed initially crushing it to a top size of 8 mm at the Uis Mine circuit.
Thereafter, it was transported to the Bond test facility where it was deslimed at 0.5 mm and then screened into coarse and fine size fractions at 2 mm. The above results were produced from the coarse size fraction and processing of finer size fractions will be subsequently piloted. The petalite concentrate will be used to conduct test work with potential offtakers, including petalite conversion to lithium carbonate or lithium hydroxide.
On-site lithium pilot plant construction update
Construction of the on-site lithium bulk-sampling pilot plant is on schedule and on budget to be completed in June 2023. The pilot plant consists of a crushing, screening, DMS and a gravity separation circuit.
Following completion of construction, the on-site pilot bulk processing for lithium is expected to expedite Andrada’s bulk pilot test work and increase lithium concentrate production. The pilot plant processing capacity will be 20 tph with minimum annual production targeted at 2,400 tonnes and an upper annual production target of 10,000 tonnes.
This facility could generate annual revenues of between US$5million to US$20 million at the upper levels of production assuming an average grade of 4.0% Li2O and an average petalite price of US$2,000. It is intended that a pilot lithium flotation and sensor-based ore sorting circuit will be added in the near-future to provide additional optionality in the treatment of lithium ores.
Source: Mining Review Africa
