Pinnacle Minerals Ltd (ASX: PIM) has received the final detailed product qualification report for the kaolin bulk sample from the Company’s Bobalong Kaolin Project, in the Great Southern region of Western Australia.
The results confirm that the Bobalong kaolin sample is suitable for a number of industrial uses by end-users and processors.
The report was undertaken by the Wuhan University of Technology (WHUT), one of China’s pre-eminent kaolin specialist centres, for two major kaolin processors in the ceramics market, in southern China, with the results representing a highly significant step in the development pathway of the Bobalong Kaolin Project.
The report concluded that the washed and graded kaolin from the Bobalong Project is a highly saleable product and meets the specific specifications of the two kaolin processors.
Given the positive outcomes of the qualification report, as a next step towards delivering commercial-scale quantities of high-quality kaolin to its two targeted kaolin processors, Pinnacle will now advance to confirm a maiden JORC Mineral Resource at the Bobalong Project when results from its resource definition drilling programme completed in the previous quarter are finalised.
The Bobalong kaolin is now independently proven to contain commercial grade kaolin, suitable for a number of different industrial uses,” Executive Director, Robert Hodby, said.
“This is an excellent result, with the test-work indicating the Bobalong kaolin’s suitability to be beneficiated to produce a kaolin product of high whiteness, and its flaky nature is indicative of the potential for a fine kaolinite product. We are now working to confirm final drill results and a maiden JORC Mineral Resource as a key next step at the Bobalong Project.”
Results Commentary
The independent test-work undertaken on the Bobalong kaolin bulk sample by WHUT has successfully and formally qualified the Bobalong kaolin for the two kaolin processors, and delivered positive outcomes in the key determining factors for kaolin quality; whiteness and flake size.
High Whiteness – In excess of 85%
It is acknowledged that the whiter the kaolin product, the greater the commercial use and the higher the value. Generally, it is accepted a whiteness above 80% is acceptable for most of the kaolin standards.
The average whiteness of the Bobalong ore sample was 81.47%. In addition, whitening testwork, designed to increase whiteness, and demonstrate the potential of the Bobalong ore to end-users, demonstrated that the whiteness can be significantly enhanced, to in excess of 85%, by adding a brightener (and calcination at 900℃).
Fine Particle Size
The initial grading test of the raw Bobalong kaolin ore showed that the kaolin has a fine particle size and the gangue (background) mineral has a coarser particle size. This is a positive outcome, as the gangue mineral may be removed by a simple graded purification process, leaving the desirable fine particle size.
The -0.045mm grain grade yield of Bobalong kaolinite is 66.5%, with the premium -0.002 mm particle size being 10.25%. Electron microscope work carried out by WHUT found that the Bobalong kaolin is layered and flaky. however also exhibits a wormlike formation.
Importantly, WHUT has concluded that the layers are easy to peel to reduce particle size. This is an important positive feature, as the finer the kaolinite, the higher its value.
There are eight kaolin standards covering the various kaolin industries; paper, enamel, rubber and plastic, ceramic and the coating industry. Within each standard there are several grades with different uses, all with differing requirements.
Of significant importance, it is envisaged that the potential end-users of a Bobalong kaolin concentrate will be able to process the Bobalong kaolin to match the demands of the different industry requirements.
Next Steps
Pinnacle is focused on the potential to direct ship a kaolin product to overseas markets and is currently receiving the final round of results from the resource definition auger drilling programme conducted in the previous quarter, with the results to be released to the market once finalised.
Pinnacle has engaged a Resource Geologist with kaolin experience to compile the results, and confirm a maiden JORC resource for the Bobalong Project, which is expected in the current quarter. Once the Resource is announced, Pinnacle will be in a position to advance off-take and supply discussions with its qualified kaolin processors in southern China.
As previously advised, Bobalong kaolin may also be amenable to calcination, and the Company has commenced a study on the calcination of kaolin. In addition to the whitening of the kaolin (as noted in the qualification report), the calcination process (heating kaolin to high temperatures in a largely oxygen-free environment) removes impurities to convert kaolin into metakaolin.
Metakaolin is a higher-value product which has the potential to replace up to approximately 20% of the cement used in concrete. This replacement may deliver stronger and lighter concrete, thereby significantly reducing the current carbon intensity of concrete production.
Pinnacle has commissioned an aeromagnetic and radiometric survey over the Bobalong and Holly projects, which it expects to be flown in September.
The data from this survey will be important in identifying all types or granite, and the location of dolerite dykes, faults and pegmatites. In addition to kaolin, the data will be useful in delineating bedrock and regolith that could potentially contain rare earths and other minerals.