ASX-listed Shaw River Manganese confirms that, in line with its objective to begin a low-cost start-up development, results from metallurgical tests at its 75.7% owned Otjozondu Manganese project, in Namibia, aligns well with the company’s intention.“The most significant outcome from this test work is the positive indication that the ore is amenable to simple, low cost, gravity separation using common beneficiation technology,” says Shaw River’s MD Peter Benjamin. The manganese exploration and development company revealed that all samples responded positively to gravity separation and reported manganese and manganese + iron upgrade from beneficiation test work. Further, Shaw River said that comminution test work indicates samples are very hard and abrasive, which is consistent with its expectations, adding that the proportion of fines in the product is small and because of the hardness of the ore, degradation during handling and transport is expected to be low. The company noted that the metallurgical assessment programme was planned and supervised by Independent Metallurgical Operations based in Perth Australia, and completed by SGS Minerals, to assist Shaw River in determining the metallurgical characteristics of the ore. Densimetric analysis of the Otjozondu deposit was conducted using the individual particle pycnometry (IPP) technique conducted by MPIPP Perth to determine the upgrade potential of the ore. The data collected from this test work will be used for developing a suitable process flow sheet and mass balance for the beneficiation circuit, the company explained.
The high grade of iron within the dense fractions as well as historical data indicates that additional manganese grade improvement could be achieved through low cost, magnetic separation.Meanwhile, Shaw River advised that manganese market investigations it undertook have revealed a potential market for a medium grade manganese, medium grade iron product with total combined grade of Mn+Fe greater than 50%, which is currently marketed to Chinese smelters. “Examination of the test work results indicate that this grade can be achieved using a lower density cut point therefore increasing overall yield. A Mn+Fe product containing greater than 36% Mn could command a premium price,” the company noted. In addition to project studies underway as part of the Otjo project development review, further metallurgical test work by Shaw River involving PQ sized (85mm) diamond core and/or bulk samples is planned to determine the optimal beneficiation process, and will test a number of additional deposits identified during the 2012 mineral resource drilling program. The company concluded that low cost exploration activities are continuing to identify new zones of manganese for drill testing.