502 GEOLOGY OF OHIO. 
burned without the addition of fuel, being ae made into piles of 
irregular shape and allowed to burn. 
The loss of weight in burning varies of course with the character 
of the ore. It is as high as 40 to 50 per cent. in the blackbands spoken 
of, and as low as 20 to 30 in the limestone ores. After the ore is roasted, 
and when taken to the furnace it is usually sereened to remove the final 
portions of the accompanying gangue clay and dirt. This partial 
cleaning of the ore constitutes all the further preparation it receives, 
going then directly to the furnace. The difference between roasted and 
unroasted ore will be shown by the following analyses: 
1 2. 3 
Protoxid CxO TOM, «i<.sccseont soon otiee v-cleas coos enacts delece os eeeeanal demeestoctecenes 31.16 38.8 
SESQWlORIMEROT TOM sac cercaese ss sccenss eoseonneceneneececcee sense 63.78 TAQ Ea Qaeeahccs 
Silicageeeees saints edieneeaae eel ran aaaledesnaiote ba taoneteemnoeaecnaeacetees 22.15 22.20 15.80 
AETV G 5 ees vc Suces aie Soa a debs Sula wo diettoec once cee me ere ce Solon Santee 1.12 3.18 2.97 
Mig On CS aiees oe ocaetn- teen en cae ancaensdateesooteeeeneeetmecenoeceunes 0.42 1.96 1.26 
PAN ULI T Aso escent cece nie sudenieteeseecces Seiceiecis she cdaterdeeeees 7.43 6.06 10.64 
Oxiderotimancanese ceite.ccascseneceoccseemececneneoeotaeseees undet. 0.93 \ 
Opn soveNe AGT! ENG! OHAALIG TNHFETP.c0500 008600006 9600000006000 |Jocooos co0c00n00 22.80 23.75 
IW Or eee tisewtac ccd suscdccs cieslscye des cects vi ce raeceaneremepbis waclostioesaee Oy I Bhi! 2.78 
PHOS PWOKUSW25.ccsesene esse sk sete cetera oro ucecewencccear 0.18 0.06 0.08 
Sul pl Uh ee occu cons sestecdeesesa-cessance eeace Teac seeseesmor eee 0.38 0.12 0.15 
Metallic inom scacescceccce .cccsutese ciacesneneee eee seeeee ceteeeee 44.65 . 29.40 30.20 
1. Average sample roasted limestone ore, Bessie Furnace, Straitsville, Ohio. 
2. Gray limestone ore, raw, from Crafton, Hocking Valley, same ore as above. 
3. Gray limestone ore, Bessie Furnace, same as No. 1. 
The increase in the sulphur in the roasted ore is probably due to 
the coal slack used in the pile. 
In other parts of the country the roasting of ores has received more 
special attention. Kilns of numerous devices have been built for 
the more perfect roasting of iron ores, and described in the various 
journals with the object not only of less expense, but more complete cal- 
cination. Of these kilns the Westmann kiln and Taylor kiln may be 
mentioned as examples. Théy have been tried in New Jersey, and at 
the Shelby Iron Works of Alabama. ‘Both are particularly adapted to 
the elimination of sulphur from the ore, this object being accomplished 
by the heating of the ore out of contact with the fuel, and in such a 
way as to secure an abundant supply of air. 
