Manganese, electrolytic

Blue manganese lV) fluoride, Mnp4 (Mn plus Fj), is immediately hydrolysed by water complex hexafluoromanganales containing [MnF j] " ions are yellow (electrolytic oxidation of lower fluorides or use of BrFs). 

However the Mn (aq) ion can be stabilised by using acid solutions or by complex formation it can be prepared by electrolytic oxidation of manganese(II) solutions. The alum CaMn(S04)2.12H2O contains... 

ANHBIOHCS - BETA-LACTAMS - PENICILLINS AND OTTiERS] (Vol 3) EMD. See Electrolytic manganese dioxide. 

Electrolysis of Aqueous Solutions. The electrolytic process for manganese metal, pioneered by the U.S. Bureau of Mines, is used in the Repubhc of South Africa, the United States, Japan, and beginning in 1989, Bra2il, in decreasing order of production capacity. Electrolytic manganese metal is also produced in China and Georgia. 

Manganese metal made by this process is 99.9% pure. It is in the form of irregular flakes (broken cathode deposits) about 3-mm thick, and because of its brittleness, has Httle use alone. Most of the electrolytic manganese that is used in the aluminum industry is ground to a fine size and compacted with granulated aluminum to form briquettes that typically contain 75% Mn and 25% Al. 

The impurity levels in electrolytic manganese metal are as follows ... 

Electrolytic Manganese Dioxide. The anodic oxidation of an Mn(II) salt to manganese dioxide dates back to 1830, but the usefuhiess of electrolyticaHy prepared manganese dioxide for battery purposes was not recognized until 1918 (69). Initial use of electrolytic manganese dioxide (EAfD) for battery use was ia Japan (70) where usage continues. 

Electrolytic Oxidation. Electrolytic oxidation of ferromanganese or manganese metal is a one-stage process that circumvents the problem of ore impurities. Moreover, this procedure can be used with low caustic concentrations at room temperature. This process is based on the following... 

Total world capacity for electrolytic manganese dioxide (FMD) is estimated to be in the area of 194, 500 t/yr, and aimual capacity of chemical manganese dioxide (CMD) is estimated to be in the range of 40,000 t. Producers are fisted in Tables 18 and 19, respectively. Capacity and process information on potassium permanganate is given in Table 17. 

The most significant nonferrous use of manganese compounds is for primary batteries, where manganese dioxide is the principal constituent of the cathode mix. In the standard Leclanchn ceU, 2inc and ammonium chloride are mixed to form the electrolyte, a mixture of carbon and MnO forms the cathode, and 2inc acts as the anode (221). The principal ceU reaction is as foUows ... 

In the case of the alkaline manganese dioxide cell, only high quaUty synthetic manganese dioxide, typically an EMD (224), is used and graphite is the cathode. The anode is an amalgamated 2inc. Potassium hydroxide serves as the electrolyte and the reaction can be summari2ed as follows ... 

Several more traditional materials have found specific though limited commercial apphcation as metal anodes. Examples are lead [7439-92-1] and ziac [7440-66-6] ia the electrogalvaniziag practice. Lead dioxide [1309-60-0] and manganese dioxide [1313-13-9] anode technologies have also been pursued. Two iadustrial electrolytic iadustries, aluminum [7429-90-5] and electric arc steel, stiU use graphite anodes. Heavy investment has been devoted to research and development to bring the advantages of DSA to these operations, but commercialization has not been achieved. 

Oxidation. Nitroparaffins are resistant to oxidation. At ordinary temperatures, they are attacked only very slowly by strong oxidi2ing agents such as potassium permanganate, manganese dioxide, or lead peroxide. Nitronate salts, however, are oxidi2ed more easily. The salt of 2-nitropropane is converted to 2,3-dimethyl-2,3-dinitrobutane [3964-18-9], acetone, and nitrite ion by persulfates or electrolytic oxidation. With potassium permanganate, only acetone is recovered. 

Solvent for Electrolytic Reactions. Dimethyl sulfoxide has been widely used as a solvent for polarographic studies and a more negative cathode potential can be used in it than in water. In DMSO, cations can be successfully reduced to metals that react with water. Thus, the following metals have been electrodeposited from their salts in DMSO cerium, actinides, iron, nickel, cobalt, and manganese as amorphous deposits zinc, cadmium, tin, and bismuth as crystalline deposits and chromium, silver, lead, copper, and titanium (96—103). Generally, no metal less noble than zinc can be deposited from DMSO. 

Wax ring seal Asphalt seal Support washer Cathode mix manganese dioxide, carbon, electrolyte... 

Cell Chemistry. Work on the mechanism of the carbon—2inc cell has been summari2ed (4), but the dynamics of this system are not entirely understood. The electrochemical behavior of electrolytic (FMD), chemical (CMD), and natural (NMD) manganese dioxide is slightly different. Battery-grade NMD is most commonly in the form of the mineral nsutite [12032-72-3] xMn02, which is a stmctural intergrowth of the minerals... 

Cylindrical alkaline cells are 2inc—manganese dioxide cells having an alkaline electrolyte, which are constmcted in the standard cylindrical si2es, R20 "D", R14 "C", R6 "AA", R03 "AAA", as well as a few other less common si2es. They can be used in the same types of devices as ordinary Leclanchn and 2inc chloride cells. Moreover, the high level of performance makes them ideally suited for appHcations such as toys, audio devices, and cameras. 

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