Iron Ore Concentration No. 2. [Volume: 8, Issue: 2, 1888, pp. 97-111]

No. 2.]

CHARCOAL IRON WORKERS.

97

TABLE F.
THE PERCENTAGE OF ASH AND PHOSPHORUS IN DIFFERENT
KINDS OF WOOD INFLUENCED BY THE AGE OF THE TREES.
4 4,.. 1 0. 0
KIND OF TREE.. o, Wo, 0 0
IFr 00 1 90 0$
14 Fir,......... Young, Bark,. 2.93 1.464 0.216
15 Birch, I Young,. Bark,. 1.59 1.958 0.153
1 Pine,. Oildi. You,.. Wood,.. 0.17 1.105 0.009
2 Fir,.Old,... Wood,.. 0.20 0.570 0.006
3 Birch,........ Old,... Wood,. 0.20 2.407 0.024
4 Pine, fir and birch, Old,... Wood,.. 0. 19 1.361 0.013
5 Pine,........ Young,. Wood,. 0. 16 1.511 0.011
6 Fir,.Young,. Wood,.. 0.19 0.838 0.008
15 Birch,.Young,. Bark,.. 1.59 1.953 0.153
16 Pine, fir and birch,. Young,. Bark,. 1.93 1.793 0.167
These trees were all grown in Ljusne, and felled in both winter and spring'

Iron Ore Concentration, No. 2.

Our first contribution having been devoted to wet concentration,
we may properly introduce at this time the dry method, but will
also illustrate a plant designed for wet concentration, now used
experimentally for the dry process, and refer briefly to some of the
enterprises which have been established.
An examination of the patent office records shows that the inventions for separating magnetic from non-magnetic materials are
numerous, covering all varieties of machines and arrangements.
The first patents were for separating iron from brass filings, re