Mining Mirror June 2019 | Page 14

Global news and projects The scheduled kiln refractory replacement has been completed and regular production has resumed. Montero is looking to re-mine the tailings dumps at the historical Uis tin mine in Namibia. Engineering services company Civmec was chosen by Albemarle to construct the lithium hydroxide plant at Kemerton, while BGC Contracting was hired to provide earthworks and construction access at the site. The USD1-billion Kemerton facility is expected to become WA’s largest lithium plant once completed. (Source: Australian Mining). Namibia Montero files resource estimate Montero Mining and Exploration has filed its maiden lithium and tin resource estimate for the Uis tailings project in Namibia. The project consists of large coarse sands and fine slimes tailings waste deposits on surface. The tailings material represents the waste processed material derived from the Uis pegmatite tin mine, the largest tin mine in Africa, prior to its closure in 1990. The independent estimate was prepared by Deloitte Technical Mining Advisory. The mineral resource estimate is based on the preliminary drilling programme of 63 air core drill holes on the waste material. The quantity and grade of coarse and fine material for six tailings deposits (Zones A to E) were estimated by ordinary kriging. Two commodities were considered in the estimation of the mineral resources, namely lithium (LiO 2 ) and tin (SnO 2 ). Zone A represents the largest tailings deposit and contains coarse tailings material, while Zones B to E and Zone A fines represents the fine tailings material. A total inferred mineral resource of 14.4 million tonnes at 0.37% LiO 2 and 17.1 million tonnes at 0.05% SnO 2 is estimated. Insufficient test work on lithium extraction has been completed on the 2.71 million tonnes of fine tailings material (Zones A4, [12] MINING MIRROR JUNE 2019 B, C, D, and E) to include this lithium in the resource estimate at this time. According to Dr Tony Harwood, president and CEO of Montero, further in- fill drilling and metallurgical test work will be required to upgrade the inferred resource to an indicated resource. “Montero is evaluating early production scenarios with potential partners in order to meet expected demand with the growth of electric vehicles and battery metals requirements,” says Harwood. Brazil Production resumes at Maracás Menchen Toronto based Largo Resources announced in their first quarter 2019 results that the company’s Maracás Menchen mine in Brazil has produced 2 099 tonnes of vanadium pentoxide (V 2 O 5 ) at an average global recovery rate of 80%. According to Largo, the scheduled kiln refractory replacement has been completed and regular production has resumed. According to the company, production in January 2019 and February 2019 was affected by maintenance in the fusion section of the plant, and unanticipated power outages, which mostly occurred in February. Production in March of 548 tonnes of V 2 O 5 was, as anticipated, significantly impacted by the scheduled kiln refractory replacement which resulted in 11 days of production downtime, being two days less than the expected. A complete replacement of the kiln refractory occurs every two years as a consequence of the high temperatures utilised inside the kiln, which weakens the kiln's durability over time and causes stability issues with recoveries. Largo expects that the replacement of the kiln refractory will help to minimise the need for minor repairs that were performed to the kiln throughout 2018. Global V 2 O 5 recovery rates averaged 80% during the quarter representing an increase of 5% compared to quarter one in 2018. This can be mostly attributed to improved recoveries in the leaching and precipitation sections of the plant during January and February. Largo Resources Largo Resources’ Maracás Menchen vanadium mine in Brazil. www.miningmirror.co.za