PURPOSE: To obtain a manganese dry battery with excellent storage stability, without using mercury (HgCl2) at all, by oxidizing heavy metal within manganese dioxide to use the manganese dioxide which has been converted into a stable oxide as an active material for a positive electrode.
CONSTITUTION: As a material of useful manganese dioxide, various manganese ores, for example, pyrolusite, ramsdellite, cryptomelane, silomelane and the like, or manganese salts, for example, manganese sulfate, manganese nitrate, manganese carbonate, manganese chloride, manganese phosphate and the like can be exemplified. Further, as to these materials, the materials which have the content of impurities as less as possible are preferable, and the materials can be used independently or by the combination of two kinds or more of the materials. As to the calcination of these materials, exemplifying the calcination of the materials within the range of 550∼1,000°C in the oxidizing atmosphere, for example, in the O2 gas, in the O2 added air or in the air is preferable, and the calcination time is not particularly limited and if it is about 10min∼4hr in response to the calcination temperature the purpose can be sufficiently achieved.
ISHIKAWA RYOHEI
TSUKUDA YUTAKA
OCHIAI HIROSHI
AIMI MASAMI
NIIYAMA MASANORI
MIYASHITA TAKAHIRO
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