King River Resources makes progress with PFS into production of quality, high-value HPA at proposed Kwinana plant

King River Resources Ltd (ASX:KRR) is making progress with test-work for a pre-feasibility study (PFS) into the production of high purity alumina (HPA) using its specially developed refining process at a proposed processing operation at Kwinana in Western Australia. During the March quarter, HPA was produced at >4N (99.99%) purity by calcining high purity precursor materials purified by the company’s refining process. The materials were refined from industrial chemical feedstock material available from domestic and international suppliers. These >4N purity results are from five HPA production runs completed by Source Certain International (SCI), previously TSW Analytical Pty Ltd, and were calculated by the addition of all the assayed element impurities then subtracted from 100%. HPA samples were sent to an independent laboratory in Perth to verify the HPA purity using fusionXRF and fusion-laser ablation assay techniques with these assays set to help ensure quality control and quality assurance - an important step in completing the HPA pre-feasibility study (PFS). A phase analysis is planned to confirm the crystal structure of its HPA is 100% alpha alumina. New assay method SCI has developed a new assay method that has eliminated some of the conventional reagents and process steps that introduced contamination and the method has also significantly reduced the detection limits of most elements. A modified calcination and washing process has helped reduce silicon, chromium and iron contamination as well as volatile elements noted in previous test runs. Kwinana industrial site KRR has continued investigations for an industrial site in the Kwinana area, between 30-40 kilometres south of Perth in Western Australia. This area is close to a skilled and productive workforce and is host to specialist centres for chemical and resource-based processing, marine engineering, and shipbuilding. Kwinana also has industrial land areas specifically set aside for companies wishing to invest in downstream processing and other heavy or strategic industrial activities, including the Lithium Valley concept plan. Engineering studies Como Engineers’ capex and opex estimates are pending with some final vendor costings. On completion, the PFS documentation will be finalised for release to the market. Mini pilot-plant   KRR has started the development of a mini pilot plant to demonstrate that the KRR process works at a larger scale for a definitive feasibility study and to produce market samples. The process flowsheet and mass balances have been used to scale the mini pilot plant and enquiries with vessel vendors are underway. KRR has already purchased a rotary tube furnace for the calcination stage of the process with delivery in about eight weeks. The mini-pilot work will not hold up the release of the PFS. Other metallurgical developments Metallurgical HPA test-work is continuing to further refine the KRR process with the current focus on improving the precursor product to simplify the final calcination stage. Test-work is also ongoing into extracting high purity vanadium and titanium products from the company's Speewah vanadium deposit suitable as intermediate products for battery and master alloy applications. Mount Remarkable On the exploration front, King River enhanced the potential of its Mount Remarkable Project after revealing drilling results from a 33-hole, 2,310 metres reverse circulation (RC) drilling program completed in 2020 during the quarter, with assays including the discovery of a new high-grade gold zone. The best result was 6 metres at 5.25 g/t gold, including 1-metre at 30.1 g/t from the western side of the main Trudi 5 metre drilling. In addition, a new high-grade gold intersection was reported with the best result being 2 metres at 8.44 g/t gold, including 1-metre at 14.8 g/t. This is the first +10 g/t gold result outside of the Trudi Main prospect and the company considers this very encouraging for exploration of other veins at the main Mt Remarkable project area and on its other exploration tenements in the region. Reconnaissance exploration is planned to start as early as possible this dry season across KRR’s extensive tenement holdings in the region. This will allow follow up exploration and drilling of any new discoveries/targets as the year progresses. Kurundi Project At the company’s Kurundi Project in the Tennant Creek/Davenport region of the Northern Territory, reconnaissance exploration has returned high-grade gold, silver and copper rock chip samples. Results were very encouraging with high-grade gold results from multiple locations including: 16.05 g/t gold, 141 parts per million silver and 6.4% copper from veining at the main Kurundi workings; 13.55 g/t gold, 124 ppm silver and 0.37% copper from veining over 100 metres SE of the main Kurundi workings; 17.25 g/t gold and 115 ppm silver from veining 700 metres NW of the Kurundi workings; and 16.25 g/t gold, 138 ppm silver and 0.18% copper from veining 700 metres NW of the Kurundi workings. The company holds 7,900 square kilometres in 16 tenements in the Tennant Creek region around the Tennant Creek, Rover and Kurundi goldfields, covering four main project areas: Tennant Creek East, Tennant East/Barkley, Rover East and Kurundi. Kurundi next steps The company plans to continue exploration in the region during the first half of 2021 including reconnaissance at the Kurundi Project and surrounding tenements, soil sampling in the areas around Edmirringee and Whistle Duck, ground magnetics and gravity on EL31619 and further airborne magnetics in the Barkley region. Work in the first half of the year will be in preparation for the drilling of the best targets later in the year.