These shistose pyrites being composed principally of coal, flint, alumina, and sulphuret of iron--the latter in excess--it was necessary to separate the sulphuret of iron, and transform it into sulphate as rapidly as possible.

They then left the transformation to complete itself, and it would not take less than ten or twelve days for the sulphuret of iron to be changed to sulphate of iron and the alumina into sulphate of alumina, two equally soluble substances, the others, flint, burnt coal, and cinders, not being so.

When the heap of pyrites had been entirely reduced by fire, the result of the operation, consisting of sulphate of iron, sulphate of alumina, flint, remains of coal, and cinders was placed in a basinful of water.

They stirred this mixture, let it settle, then decanted it, and obtained a clear liquid containing in solution sulphate of iron and sulphate of alumina, the other matters remaining solid, since they are insoluble.

Lastly, this liquid being partly evaporated, crystals of sulphate of iron were deposited, and the not evaporated liquid, which contained the sulphate of alumina, was thrown away.

Alumina in sentence

Related words