161 
ANALYSIS OF WATER CONTAINING ALUMINUM SALTS 
AND FREE SULPHURIC ACID FROM AN 
INDIANA CoaL MINE. 
S. D. Conner. 
Within the past year the writer was called upon to test some drainage 
water from a coal mine for the Vandalia Coal Company of Terre Haute with 
a view of determining whether such water could be used for irrigation pur- 
poses. 
A qualitative examination indicated only a trace of chlorides and nitrates, 
but an abundanee of sulphates. 
The following substances were quantitatively estimated: 
AE ( SO) center Cae wie ec es cee tances .016 per cent. 
WAS Onis Mien aes tae eee ee Als Der cenit. 
INTE Ole ae ge erica ee epee oe eR, .O74 per cent. 
Hire eallas Olen a7 ein weer on) suet: .005 per cent. 
‘oye Solitels. bac bosodacccas sa Bjoern 
Contrary to expectations, no soluble iron was found, although a slight 
floeeulent precipitate of iron (probably basic ferric sulphate) was noted 
in the bottom of the bottle, indicating that originally some iron had been 
in solution. 
In the mining of coal more or less iron pyrites (FeS:) is exposed to the 
air. This pyrites in the presence of oxygen and moisture is oxidized, forming 
ferrous sulphate and sulphuric acid. The sulphuric acid coming in contact 
with clay, shale, ete., would dissolve calcium, magnesium, aluminum and other 
basic elements which might be present. Upon continued exposure to air 
the ferrous sulphate (Fe SOx,) in solution would be oxidized to basic ferric 
sulphate (Fe(OH)SO,) and precipitated. 
Water such as the writer analyzed is acid in reaction, due to the presence 
of free sulphuric acid and also to the hydrolysis of the aluminum sulphate. 
Such water would be injurious to vegetation and consequently unfit for 
irrigation purposes. 
5084—11 
