Rodinia Lithium (CVE:RM)(OTCQX:RDNAF) announced Tuesday that it has received positive preliminary brine processing test results from its Salar de Diablillos lithium-brine project in Salta Province, Argentina, reporting an average lithium recovery rate of 65 percent.
The report, which describes a detailed process to recover lithium carbonate from the subterranean brines of Diablillos, proposes a combination of solar evaporation steps, in-field brine treatment, co-product potash and boric acid recovery, and chemical processing to produce lithium carbonate.
The process results in a high lithium recovery of 65 percent once the brine is saturated, producing 131,200 tonnes of potash (at a rate of 13:1) and 10,250 tonnes (at a rate of 1:1) of boric acid for every 10,000 tonnes of lithium carbonate.
President & CEO of Rodinia, William Randall, commented: "This processing report demonstrates the high quality brines of the Diablillos aquifers, resulting in a clean and efficient process with excellent recoveries of lithium.
"The low impurity levels, in particular magnesium and sulphate, allow for the harvesting of potash as a high impact co-product. The brine quality also ensures that the processing requires conventional reagents at moderate levels, meaning that we will not need to source expensive and hard to find chemicals."
The Salar de Diablillos property, which rests about 145 kilometres southwest of the city of Salta, has a recoverable inferred brine resource of 2.8 million tonnes lithium carbonate equivalent from an in-situ inferred brine resource of 4.9 million tonnes lithium carbonate equivalent.
Typically, when lithium is recovered from brine (considered the more economical and environmentally friendly process as opposed to hard rock), brine is pumped from subsurface aquifers, through a circuit of evaporation ponds to increase concentration.
High grades and recovery rates, favourable lithologies, low magnesium ratios and high specific yield rates are required to ensure enough contained brine will drain out of a formation by pumping.
The process in the preliminary report contemplates a series of ponds from largest to smallest, where the largest is used to bring brine to saturation and is designed to be unlined, reducing the capital cost of pond construction. Brine extracted from the final pond will have a concentration of approximately 12% lithium chloride, and will then be transported to the treatment facility, where boric acid and lithium carbonate are produced, the company said.
Last week, Rodinia reported that initial pump and tracer tests to assess the deep and shallow acquifers at the property confirmed high transmissivity and effective porosity values. The company also earlier confirmed the positive properties of the acquifers, as it said drilling at the site has consistently intersected sand and gravel dominant lithologies, with recoveries of between 10% and 100%, an important insight into what Rodinia's eventual production scenario should look like as brine typically flows much better when in loose sand and gravel, producing acquifers with high specific yield values.
The findings released today from the preliminary brine processing report will be included into Rodinia's upcoming preliminary economic assessment, which is expected sometime in the fourth quarter. The lithium recovery process was designed from initial brine, with an average composition of 580 mg/L lithium, 7200 mg/L potassium, and 520 mg/L boron.
The preliminary report is authored by Robert Cinq-Mars, who has 20 years of experience in the lithium industry, and has previously worked for Lithium Corporation of America, where he was manager of new resources and process development.
Rodinia Lithium is a junior mineral explorer with a primary focus on lithium in North and South America. In addition to its Argentina project, the company holds 100% mineral rights to approximately 70,000 acres in Nevada's lithium-rich Clayton Valley in Esmeralda County, and is currently in the process of assessing the size, quality and processing alternatives of the deposit.