Barium Sulphide: Heavy Spar Roasted with Coal

Barium sulphide is the barium half of lithopone, the white pigment. Thorpe (1912): roast 100 parts of heavy spar with 20 parts of coal slack or charcoal. Caking bituminous coal soaks through the mass and reduces it completely; with charcoal, mix very thoroughly. The roasted mass still holds carbon and some unchanged spar: hot water takes out the barium sulphide. Left in air it turns to carbonate and smells of rotten eggs, so keep it closed. The picture: our own drawing.

中级

1 day

说明

Grind and mix

Grind 100 g of heavy spar and 20 g of bituminous coal slack and mix them very thoroughly.

此步骤所需材料：

Barite (Heavy Spar)100 克

所需工具：

烟煤

研钵与研杵

等臂天平

Roast

Roast the mixture in a crucible in the furnace. The coal cakes and runs through the mass, reducing the spar.

所需工具：

深腹黏土坩埚

木炭坩埚炉

皮手套

Cool and close it up

Let it cool and put it straight into an airtight jar. It holds spare carbon and some unchanged spar; hot water dissolves out the barium sulphide when you use it.

所需工具：