Mitsui Minings & Melting Co., Ltd.

Matsushita Electric Corp., Ltd.

Matsushita Electric Industrial Co., Ltd.

Hiroshi Sumida

Kiyoteru Enomoto

Hajime Murakami

Yoshihiro Sakurai

Michiko Inui

Yoshio Nakatani

Takuya Inoue

Takuya Deguchi

Masao Hidaka

Masaki Sato

Yoshiyuki Komatsu

Manganese dioxide for lithium primary batteries which is obtained by soda neutralization and heat treatment of electrolytic manganese dioxide and has a sodium content of 0.05 to 0.2% by weight and a process for producing the same.

Process of producing manganese dioxide for a lithium primary battery

A method for reducing Carbon contained in hydrogen storage alloys recovered from negative electrodes of nickel/hydrogen storage alloy secondary batteries of misch metal and alloys thereof as raw materials of hydrogen storage alloys for negative electrodes of nickel/hydrogen secondary batteries by adding titanium or zirconium or oxides of these elements, and melting in an inert gas atmosphere or in vacuum.

Method for reducing impurities in misch metal and alloys

An electrolytic manganese dioxide having a composition of MnOx, wherein X is 1.90 to 1.96, an adhesive moisture content of not less than 1.5% by weight as measured according to the procedure specified in JIS, and a content of bound water, eliminative in the temperature range of 120.degree. to 400.degree. C., of not less than 3.0% by weight as measured by gravimetry, a process for preparing the same, and a manganese dry cell comprising a cathode mix comprised of a mixing of the electrolytic manganese dioxide with a conductive acetylene black, preferably a conductive acetylene black having a BET specific surface area of 70 to 2.50 m.sup.2 /g, and an electrolyte composed mainly of zinc chloride and/or ammonium chloride. In the process of preparing the electrolytic manganese dioxide, after electrolysis and during or after neutralization, the manganese dioxide is heated in an aqueous solution at 50.degree. to 100.degree. C. for 12 to 48 hours in the presence of an alkaline ammonium compound.

Electrolytic manganese dioxide, process for preparing the same, and

In a method of producing manganese dioxide for a lithium primary battery, heat treatment for dehydrating water-containing manganese dioxide is carried out by continuously calcining the water-containing manganese dioxide at 440.degree. C. to 480.degree. C., preferably by controlling the flow rate of air introduced into the furnace to the value of from 20 to 2000 Nl per 1 kg water-containing manganese dioxide which is supplied into the furnace. According to this method, the residual bound water in the calcined manganese dioxide is reduced as compared those treated with a conventional method, and thus preservation property of a battery can be improved.

Manganese dioxide for lithium primary battery and method of producing

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Takehara, Japan

Hiroshi Sumida