The Salt Lake tribune. [volume] (Salt Lake City, Utah) 1890-current, 1911-10-25
COST Of PCRPHYRY
MINE EQUIPMENT
Engineering and Mining Jour-
nal Analyses Reports of the
New Companies.
UTAH COPPER IS LOW
Company Engineers Esti-
mates of Capacity Are
Greatly Outdone.
UTAH COPPER is LOW

certain deposits OF low grade copper orc
Incorrectly referred to a. "noFphSry
mlnes"-a miGnoner In several cases
that may, however, bc retained FOR con-
vcniopce-ha. been conducted on p scale
of magnitude compa rablc only 20 that oi
the Calumet q Hecla. in Michigan ana
has involved the expenditure o. huge
sums OF money, says the Engineering
and Mining Journal. !; is of interest ana
value TO summarize the expenditure ni
those concerns that have been brought
10 thc productive stage and may DC re-
sarded as having passed out Of the con
strucuvc stage Tho following data arc
taken from the official reports of thc re-
SpcCtiVc companies and from private IN
formation:
Develop. Construc- Other
Boston STmp'tS cSn.si. .o72.tSe sisoo.iSs t5t.sis
Miami . . 100000 100000 100000
Ttsh Cop, l.1so,ej9 lio2,,6 s@o'o'i
Capacity, Total
comoan,. Tons Of orc. Cost.
Boston Con. .....' 99 1000 900 sla,'SS lao o6S
Nevada con ......S. 100000 10000 .ooo
Utah copper co. 100000 6.il:,i9'
Cpon the face OF things tho Utah De,
Vcleopincnt appears 10 have cost aD"u'
81 50 rer ton OF annual capacity; the Bos-
ION Consolidated about s5.eo. tho Ne
v.da Consoiidatcd about $3.50. and the
Miami about $3.50. Before attempting 10
draw any conclusions from these hsures s,i'
IL Il important 10 consider what they
represent.
Explains Nevada Cost.
The Boston Consolidated. Utah Copper
company aud Nevada Consolidated arc
steam shovel mines. each with miIl'
while the Nevada Consolidated has
smeltery In addition thereto. This smeit-
ery has TO treat about $4,000 tons OF
concentrates per annum and probably us
capacity II IN excess OF 300.00O tons. Al
LOWING 81 ZOO poo Tor this. the cost OF the
remainder OF the plant is about s2sS per
ton.
In the light Of tho data available IL
IL not easy TO understand the low figure
~ tho Utah Copper company. To what
This company puts down as us plant
coSt We have added what II reports Tor
dumping facilities. railway construction.
etc The great difference from the hS-
ures Of the Boston Consolidated is 10
some extent eNplainable by The larger
scale Of operations but this Is Tar from
accounting for all Of IT, The probability
Is that the property account OF this
company contains great deal OF the
cost Of mine development In addition 10
what Is specifically reported as such. and
color Is lent TO this belief when II Is
noticed that the Utah Copper company
reports only about tie same amount on
this account Us do Boston and Miami
for Tar less tonua2es aud capacities We
10 not feel that the Sl.s0 figure OF tab
G0rnCt EuOuiI DC ldhtll 100 tcElOuslN-
Utah Copper Low.
Looking at the concentrating mills only
that of the Boston Consolidat ted cost
about $3.50 per ton; Utah Copper COM
pany, Sl.jI. and Miami, sl.J0. The Bos-
Ton mill hss no power plant and the
Miami figure l. exclusive of the power
plant. which serves both mine and bill
Estimating that II VIII use about 5000
horsepower. Of which the FIRST cost Is
about 1900, 900. the total milling cost Is
= ylDfu ki which doe- ia
Norably with that OF the Utah Copper
company. considering the smaller size
and the more elaborate construetiGn
The relatively large capital outlay at
Miami. aside from its mine Development
and mill construction, both OF which were
extraordinarily we'll done. is cSplaiuablc
chiefly by the facts that this is an UNDER
ground mine. requiring costly hois;nS
plant and accessories, and that its mill
u situated right AT the mine. Involving a
largo outlay for wsterworks. In the cases
OF The other porphyry mines the mills
arc situated nearer 10 water supply and
The orc IL transported 20 them by rail-
NAY, whereby the mining companies es-
cape tre cost OF plant At the expense
~ additional cost Of operation later on.
Capacity Estimates.
In the cases OF all Of the porphyrl
mines. except The Boston Consolidated
The estimates OF their engineers as 10
plant capacity have been greatly outdone
and IN Sou1o cases tho installation ol
plant has been such further increase "a
capacity has been gained II relative
ly slight expcnse. In taking tho figures
81 capacity as the diyisors. ne have used
the latest authenticated estimates. Per.
haps the quo,icuts available arc too rev
" permit = thoroughly reliable dcduc
Uon. In - far as they 60. however
thcy sccm 10 indicate that thc develop
ucnt and equipment Of a poTphyry mine
70 he operated hy steam shUycis nithou
smelling facilities, Is likely 10 cost from
- 20 $50 pcr ton of annual capacity
while Bu underground enterprise Of tn
nature or The Miami Is likely 10 cot
from $50 Ia $3.50
In plants of these huge capaciiici
variation. IN size do not result in =,
IaF=c differences IN the cost pcr ton q
they do IT, tho case OF smaller plants
or course there Is always likely To b.
variation among tho costs Of plants %
tho samc capacity. In this connection
ts 10 be EcTuc In mind that there is /
very direct rcaltion between first COS
of plant. percentage ~ mineral cXtiAc
ton and operating cost.