Sulfur evolution (in the ceramic firing process)

50-250C (122-482F) | 80-250C (176-482F) | 120C (248F) | 150C (302F) | 180C (356F) | 185C (365F) | 200-1000C (392-1832F) | 200-450C (392-842F) | 200C (392F) | 210-280C (410-536F) | 260C (500F) | 290C (554F) | 300C (572F) | 300-330C (572-626F) | 300C (572F) | 370C (698F) | 370-700C (698-1292F) | 400-600C (752-1112F) | 400C (752F) | | 470-1200C (878-2192F) | 500-600C (932-1112F) | 512C (953F) | 540-600C (1004-1112F) | 650-900C (1202-1652F) | 750-850C (1382-1562F) | 750-1000C (1382-1832F) | 760C (1400F) | 760C (1400F) | 787C (1448F) | 800-1100C (1472-2012F) | 815C (1499F) | 815C (1499F) | 843C (1549F) | 850-950C (1562-1742F) | 850C (1562F) | 850C (1562F) | 870-900C (1598-1652F) | 871C (1599F) | 900C (1652F) | 900-1000C (1652-1832F) | 900C (1652F) | 926C (1698F) | 932C (1709F) | 954C (1749F) | 980C (1796F) | 982C (1799F) | 990C (1814F) | 1025-1325C (1877-2417F) | 1025C (1877F) | 1050C (1922F) | 1050C (1922F) | 1065-1120C (1949-2048F) | 1082C (1979F) | 1100C (2012F) | 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)

This happens on first fire for many bodies. Sulfur is an impurity in many ball clays and related stoneware and earthenware raw clays, it occurs as calcium sulfate (selenite, the same mineralogy as plaster). Different sources indicate wider and narrower ranges for this, it is difficult to establish exactly.

Hazards	Sulfur Dioxide Toxicity This gas can be produced when clays are fired in a kiln. What can you do?
URLs	http://en.wikipedia.org/wiki/Sulfur Sulfur at Wikipedia
Minerals	Selenite A transparent crystal form of the mineral gypsum. This can occur in clays and is the cause of efflor

425-650C (797-1202F)

Sulfur evolution

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