Manganese limits

Sunda, W. G. and Huntsman, S. A. (1996). Antagonisms between cadmium and zinc toxicity and manganese limitation in a coastal diatom, Limnol. Oceanogr., 41, 373-387. 

The correlation between CA formation and manganese limitation in A. niger was studied through transcriptome and proteome profiling. Beside the three already described responses, two novel responses were observed, including strong down regulation of phosphoenolpyruvate carboxykinase (PEPCK) and two cation transporters. ... 

Poulsen L, Dai Z, Panisko E, et al. Transcriptome and proteome analysis of the correlation between citric acid formation and manganese limitation in Aspergillus niger. Regulatory processes in Aspergillus niger 2012 43-61. 

Procedure. A drop of the neutral test solution is placed on a spot plate, followed by a drop of saturated potassium periodate solution, a drop of 2 iST acetic acid, and two drops of 1% solution of tetrabase in chloroform. According to the amount of manganese present, a more or less deep blue color is formed. Limit of Identification 0.001 y manganese Limit of Dilution 1 50,000,000... 

In 1957, Ethyl Corp. announced anew antiknock compound, methylcyclopentadienyknanganese tricarbonyl [12108-13-3] (MMT). MMT is almost as effective as lead on a per gram of metal basis, but because manganese was more expensive than lead, MMT was not widely used until limits were placed on the lead content of gasoline. MMT was used in unleaded fuel between 1975 and 1978. After a large fleet test suggested that MMT could increase exhaust emissions because it interfered with catalysts and oxygen sensors, EPA banned its use in unleaded fuel in 1978. MMT is used in Canada in unleaded fuel. 

Germanium tetrachloride refined for use in making optical fibers is usually specified to contain less than 0.5 to 5 ppb of each of eight impurities vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc. Limits are sometimes specified for a few other elements. Also of concern are hydrogen-bearing impurities therefore, maximum limits of 5 to 10 ppm are usually placed on HCl, OH, CH2, and CH contents. 

Aniline Oxidation. Even though this is quite an old process, it still has limited use to produce hydroquinone on a commercial scale. In the first step, aniline is oxidized by manganese dioxide in aqueous sulfuric acid. The resulting benzoquinone, isolated by vapor stripping, is reduced in a second step by either an aqueous acidic suspension of iron metal or by catalytic hydrogenation. 

Ore Size. The particle size of manganese ores is an important consideration for the smelting furnace. In general, the ore size for the furnace charge is —75 mm with a limit to the amount of fines (—6 mm) allowed. Neither electric furnaces nor blast furnaces operate satisfactorily when excessive amounts of fines are in the charge. 

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. 

In the other market areas, lead naphthenates are used on a limited basis in extreme pressure additives for lubricating oils and greases. Sodium and potassium naphthenates are used in emulsiftable oils, where they have the advantage over fatty acid soaps of having improved disinfectant properties. Catalyst uses include cobalt naphthenate as a cross-linking catalyst in adhesives (52) and manganese naphthenate as an oxidation catalyst (35). Metal naphthenates are also being used in the hydroconversion of heavy petroleum fractions (53,54) and bitumens (55). 

Limits aie also specified foi platinum, oiganics, copper, 2inc, antimony, selenium, nickel, manganese, ammonium, and chloride. Fed. Spec. O-S-801E. 

The last brown pigment to be considered is the Hon manganese brown. This is the deep brown associated with electrical porcelain insulators and with artware and bean pots. In many gla2es the presence of manganese wiH cause poor surface and unstable color. Hence, the use of this pigment is limited to dark colors on products where gla2e surface quaHty requHements are modest. 

Iron Oxides. In addition to the black iron oxide, there are several natural and synthetic yellow, brown, and red oxides. As a class, they provide inexpensive but dull, lightfast, chemically resistant, and nontoxic colors. The natural products ate known as ocher, sieima, umber, hematite, and limonite. These include varying amounts of several impurities in particular, the umbers contain manganese. Their use is limited because of low chroma, low tinting strength, and poor gloss retention. 

Tin is usually not regarded as an impurity except in high tensile strength manganese—bron2e where it is limited to 0.2% maximum. Tin lowers both the tensile strength and the ductihty of the alloy. 

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