An investigation into the possibility of utilizing local (N.Z.) deposits of manganese (Pyrolusite) in dry cell manufacture

Abstract

One of the minerals used in the manufacture of a dry cell battery which, because of the vital part played in obtaining satisfactory service capacity, must be of essentially high grade, is manganese di oxide. At the present time the manganese ore used in the manufacture of this product is chiefly obtained from the Caucasian Mountains in Russia, from India, South Africa and the U.S.A. Prior to receipt is passed over magnetic separators and subjected to crushing and milling to give a fineness such that 85% will pass through 200 mesh I.M.M. This is carried out to ensure that an active physical surface is obtained. The manganese ore obtained from South Africa is first grade, having a manganese di oxide content of from 80-85%, as is also that obtained from Pittsburg with a manganese di oxide content of 73% but with different physical properties and impurities. Papuan and Queensland manganese ores have been utilised to a very limited extent in Australia while New Zealand ore has been used to the extent of 90 tons only, constituting a sample shipped to Australia in 1938. Generally speaking, it is considered that ore mined in New Zealand as well as giving poor shelf life properties has a high acidity and this has accounted for the fact that New Zealand manganese has not been incorporated in dry cell manufacture to any extent.