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50-250C (122-482F) | 80-250C (176-482F) | 120C (248F) | 150C (302F) | 180C (356F) | 185C (365F) | 200-450C (392-842F) | 200-1000C (392-1832F) | 200C (392F) | 210-280C (410-536F) | 250-370C (482-698F) | 260C (500F) | 290C (554F) | 300-330C (572-626F) | 300C (572F) | 370C (698F) | 370-950C (698-1742F) | 400-600C (752-1112F) | 400C (752F) | 425-650C (797-1202F) | 500-600C (932-1112F) | 512C (953F) | 535C (995F) | 540-600C (1004-1112F) | 650-900C (1202-1652F) | 750-1000C (1382-1832F) | 750-850C (1382-1562F) | 760C (1400F) | 760C (1400F) | 787C (1448F) | 800-1100C (1472-2012F) | 815C (1499F) | 815C (1499F) | 843C (1549F) | 850C (1562F) | 850C (1562F) | 850-950C (1562-1742F) | 870-900C (1598-1652F) | 871C (1599F) | 900C (1652F) | 900-1000C (1652-1832F) | 900C (1652F) | 926C (1698F) | | 954C (1749F) | 980C (1796F) | 982C (1799F) | 990C (1814F) | 1025C (1877F) | 1025-1325C (1877-2417F) | 1050C (1922F) | 1050C (1922F) | 1065-1120C (1949-2048F) | 1082C (1979F) | 1100C (2012F) | 1100C (2012F) | 1100C (2012F) | 1300C (2372F) | 1325C (2417F) | 1330C (2426F) | 1360C (2480F) | 1418-1428C (2584-2602F) | 1420C (2588F) | 1510C (2750F) | 1550C (2822F) | 1565C (2849F) | 1650C (3002F) | 1785C (3245F) | 1990C (3614F) | 2300C (4172F) | 2320C (4208F)

932C (1709F)

Manganese compounds may begin to fume

Manganese fumes are toxic. It is difficult to verify this temperature as that where fuming could begin (because welding is the context of almost all pages dealing with the topic and their temperatures are obviously much higher). That being said, the level of concern about manganese metal fume fever in that field can only be described as alarm! The melting point of manganese metal is 1245C (around cone 7). Impure manganese compounds are used in ceramics, it is reasonable to believe that these could melt and gas at lower temperatures. In our own testing, especially when mixed with frits, manganese melts vigorously far below cone 6.

Related Information

Decomposing manganese granular particles are causing this stoneware to bloat


This is a cone 6 stoneware with 0.3% 60/80 mesh manganese granular (Plainsman M340). Fired from cone 4 (bottom) to cone 8 (top). This body is normally stable to cone 8, but with the manganese it begins to bloat at cone 7! This is evidence that particles of manganese are generating gases as they decompose and melt at the same time as the body is vitrifying, these produce volumes and pressures sufficiently suddenly that closing channels within the maturing body are unable to vent them out.

How do metal oxides compare in their degrees of melting?


Metal oxides melting

These metal oxides have been mixed with 50% Ferro frit 3134 and fired to cone 6 oxidation. Chrome and rutile have not melted, copper and cobalt are extremely active melters, frothing and boiling. Cobalt and copper have crystallized during cooling. Manganese has formed an iridescent glass.

Links

Hazards Manganese in Clay Bodies
Manganese is used to stain clays (using black) and to impart fired speckling (as a decorative effect). It is dangerous?
Hazards Manganese Inorganic Compounds Toxicology
Hazards Manganese and Parkinsons by Jane Watkins
A story of one person and manganese poisoning.
Hazards Manganese: Creativity and Illness by Dierdre O'Reilly
A story of one persons struggle with manganese toxicity
Hazards Manganese Toxicity by Elke Blodgett
A story of the struggle of one person to identify and deal with manganese toxicity
Temperatures Manganese dioxide decomposes to MnO (535-)
Temperatures Manganese oxide melts (1785-)
By Tony Hansen
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