Krakatoa Resources Ltd (ASX:KTA) has set the drills turning at the Dalgaranga Critical Metals Project, 70 kilometres from Mt Magnet, WA.
The Dalgaranga open pit is around 200 metres long, 40 metres wide and up to 15 metres deep and the presence of critical metal minerals such as tapiolite, tantalite, columbite, zinnwaldite and lepidolite (lithium-bearing micas) was recognised during preliminary field mapping.
Anomalous critical metals
Krakatoa’s rock chip sampling programs confirmed anomalous critical metals in late 2016 to mid-2017.
This sampling revealed the presence of anomalous rubidium (peak values of more than 5,000ppm) tantalum (1,854ppm) and niobium (725ppm) within the mine and southern pegmatite area.
The company has defined an exploration target based on historical drill holes of between 1.47-3.185 million tonnes with promising estimated grades of rubidium (500-2,000 parts per million or ppm), lithium (50-300ppm), niobium (100-500ppm), tantalum (25-100ppm), tin (50-700ppm) and tungsten (10-100ppm) as reported in November.
Buoyant prices fuelled by demand
Commenting on the drilling program, Krakatoa CEO Mark Major said: “With buoyant prices of the project’s critical and tech metals fuelled by demand, we look forward to announcing the nature and extent of this potential maiden resource.”
KTA has since significantly added to its 2017 tenure via a series of non-dilutive acquisitions. With currently high rubidium carbonate prices (rubidium carbonate over US$ 6,000/kilogram), the presence of significant rubidium mineralisation may provide a significant boost to the project’s economics.
Objective to deliver mineral resource
The objective of the drill program is to estimate a mineral resource, though the company is uncertain if the current drilling will produce an estimation because there has been insufficient historical exploration to do so.
The modelled pegmatite, on which the exploration target is based, has 156 historical holes (5,071 metres) and 11 holes (1,066 metres) drilled by Krakatoa in 2017.
Only four elements were assayed at that time. The company will expand the analysis with a focus on the rubidium, lithium, niobium, tantalum, tin and tungsten across the modelled target area.
The reverse circulation (RC) drill program is envisaged to consist of around 3,500 metres or roughly 30-35 drill holes.
Historical mining at Dalgaranga
Dalgaranga was discovered in around 1961 and underwent small-scale mining, including alluvial mining, over many years, producing tantalum, beryl, tin and tungsten. Lithium and niobium were not considered as metals of importance until the 2000s, when mechanised mining began.
In 1999 Australasian Gold Mines, later to become Tantalum Australia Pty Ltd, carried out close-spaced shallow resource drilling and discovered that the tantalum-bearing pegmatites are stacked vertically to a depth of at least 100 metres.
The company mined the Dalgaranga open pit from 2001 to 2002, processing via a pilot plant that finished in 2003. The mine was placed on care and maintenance in 2005 and infrastructure has been partially removed.