Charles George Warnford Lock.

Economic mining: a practical handbook for the miner, the metallurgist and ... online

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set. The characteristics of these pumps are independent plnng«
with exterior packing, valve-boxes subdivided into small chanibec
and leather-lined metallic valves with low lift and large siir£M»
The engines vary in size from 200 to 800 h.p. The pumps are i
constructed that before one plunger has completed its stroke anotU
has taken up the work. The column of oil is thus kept continnond
in motion, and the violent concussions which occur when the o
column is allowed to come to rest between the strokes are avoided.

Tankage at convenient centres of distribution is neoeesad
American tanks usuallv hold about 30,000 barrels. They are \
boiler plate, roofed with wood, covered with sheet iron^ the ro^
being usually slightly conicaL

Oil is frequently pumped, in hot weather, when it is most fluid,
distance of 80 miles. At high pressure leaks occasionally oocor, an
workmen sometimes have their hands cut to the bone by the fio
stream of oil issuing from some minute orifice when engaged i
stopping the leaks.

A very interesting feature of the pipe line system of transporta^
is the arrangement adopted for cleaning the pipes, and removiq
obstructions caused by sediment. The apparatus used (termed a "g«
devil ") consists in many cases of a brush of steel wire of conical fom
fitted, at the base or rear end of the cone, with a leather valve in
sections, strengthened with brass plates, and also furnished with lonl
steel wire guides. This instrument is impelled by the stream of oi{
and travels at the rate of about 3 miles an hour. Its pro grooo can \
traced by the scraping sound which it makes, and it is fouowed frcn
one pumping station to another by relays of men on foot. It mtu
never be allowed to get out of hearing, otherwise, in the event of \\
progress being arrested by an obstruction, it may be necessary to tak
up a considerable length of piping to ascertain its position.

It is by no means uncommon for storage tanks of crude petroleum i
be set on fire by lightning, notwithstanding the general omploymeu
of lightning conductors, the vapour whion the oil evolves readil;
taking fire, and communicating flame to the oiL When a tank ha
taken fire, the oil usually boils over, and to prevent this, holes throngi
which the oil may escape are made by firing round shot at the tanl
from small cannon. Such fires are occasionally of great magnitude



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NON-METALLIFEROUS MINERALS.



289



and, as may be imagined, involve no small danger to sorronnding
property.

EoglisH store tanks of the older form are arranged partly nnder-
gronnd, risiog to a height of about 4 ft. above ground ; this portion is
protected by a wall and about 3 ft. of conorete, and the roof is formed
of a layer of chalk about 1 ft. thick. In the more modem form of
storage tank the oovering is arranged so that a current of air can
pass over the surface of the stored petroleum. According to practical
experience it would seem that a tank open to the air is more suitable
for storage than one which is closed ; in the latter case, the manholes
Aze protected by a layer of earth. Li the one case, the more volatile
portions are sealed up ready to take fire, either by the approach of a
Light, or from a sudden or undue rise of temperature ; wnile in the
case of the open tanks the current of air carries off the volatile
rapours as fast as they are venerated. Aa nothing is stored but the
otfual class of petroleum with a fairly high flashing point, the loss by
evaporation is not sufficiently sensible to weigh against the greater
lafety brought about by this system. In Liverpool, the storage tanks
kre excavations made in the solid red sandstone rock, one side being
>mlt with concrete and brick.

The production of crude petroleum in the United States is about
i,0OO,OOO gaL yearly. In 1892 it reached 2,282,469 gal., of which
04,397 gal. were exported as crude petroleum, 16,393 gal. as naphtha,
^B9,418 gaL as illuminating oil, 34,027 gal. as lubricating oil, 403 gal.
« residue, and 69,876 lb. paraffin. The total output of the United
states to end of 1888 is computed at 373,000,000 gal., not counting a
raete of about 20,000,000 gal. The Caucasus affords about 3,000,000
PUR annually, Galicia about 1,000,000 barrels, Japan about 5000 tons,
taly about 200 tons, Canada about 1,000,000 barrels. Great Britain
bout 35 tons.

OxoheriU — Ozokerit, ozocerite, earth-wax, mineral wax, or cerisine,
\ a solid hydrocarbon, usually regarded as a petroleum very rich in
araffinu Its composition has been found to be :





MoldAYlao.


Urpetb.
Johnson.


Utah.




Malagatl.


SchroUer.


Newberry.


3brbon

];diogen


85-75
15-15


86-20
13-77


86 80
1406


86-15
13-75




100-90


99-97


100-80


99-90



It is supposed to be composed of several members of the paraffin
ries which are represented by the general formula C.Hj,, and,
»rhap0, contains certain of the defines. Its density ranges from
150 to -950, and its melting point from 136'' F. to 212'' F. Pure
ecimens resemble resinoas wax in consistency and translucency,
iBetiines with a foliated structure. Its colour is brown or brownish-
lUow by transmitted light, and leek-green by reflected light. The
orer qualities, which are black, and are either too soft from abun-

T7



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290 ECONOMIC MINING.

danoe of petroleum, or too hard (asphalt-like in character), are m
for the production of paraffin. Tne American mineral is dark bron
on the surface, but grows lighter in colour as the depoBit is workc
Energetic chemical reagents, such as sulphuric and nitric acids ai
alkahes, have no action on it. It is odourless and tasteless.

Galician mineral wax is found in Miooene clay shalee and di
marls, with intercalated sandstone, and it frequently aocompan]
rock salt and gypsum. At Boryslaw it is found after a deptii of \
to 70 ft., and some shafts have been sunk 700 ft, where the acoa
panying rock is strongly impregnated with oil. At Tmskawiec the
are surface veins of l^be wax, and the shafts have not been siink

Small quantities of ozokerit have been discovered in £ngland,
Binney quarry, Linlithgowshire, at the Urpeth colliery, ^jewcastl
on-T>ne, and in Wales. It is also found in Moldavia, and in t
neighbourhood of A gram, in Croatia, but the most important depos
are in Oalicia, at the northern foot of the Carpathian Mountains. T
exact localities are Boryslaw, Tmskawiec, Dwiniacz, and Stanmi
the first named being the most valuable. In America its occnrrcD
is reported about 50 miles north-east of Los Angeles, California ;
Texas, and in Utah. The only working deposits are situated ne
Pleasant Valley Junction and Soldiers' Summit, 114 miles east
Salt Lake City, on the Denver and Bio Grande Bailway.

In nearly every case the Gralician mineral is raised through v^
tical shafts or pits, over which a wooden roof is erected. The secti^
of the shafts in the first instance is 32 to 43 sq. ft. ; but when t
ozokerit formation is reached, an inner shaft 39 in. square is form
of timber, and the space between this and the timbering of the larg
shaft is filled with stiff clay. This construction is adopted to excla
the surface watt-r, which is kept down by hand-pumps during sinkii
From ^e bottom of the shafts, levels are driven into the ozokei
ground, the richer portions being raised and the refuse used to fill \
the old workings. The softer parts of the marl are dislodged 1
means of pick or wedge ; but where the rock is hard, and the perm
sion of the mining authorities can be obtained, dynamite is need. T
mineral is raised by hand, in skips or tubs holding 88 to 110 I
Hand ventilators are used for the purpose of ventilation, but ex|^
sions of gas are not uncommon. Safety-lamps are nsed in all 1
mines. The timbering of the shafts requires constant renewal a|
repairs ; in some cases it is almost impossible to keep the shafts p|
pendicular.

The water is usually raised in tubs, and much difficulty is exp«
enced in getting rid of it after it reaches the surface, on accouni
the numerous shafts and the broken nature of the ground. 1
mineral, when it leaves the tubs, is sorted by hand. The waste n
is picked out and tipped to spoil, lumps of ozdkeiit are specially
lected, and the remainder of the rock, containing fragments of wa
tipped into tanks full of water. On being well stirred, most of the
rises to the surface, and is skimmed off. The residue still oom
to 3 per cent, of wax. The* quantity of waste mineral being ool ,
able, and the distance between the shafts small, a special railway



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NON METALLIFEROUS MINERALS. 291

en built to remove the residues from the immediate neighbourhood
theminea

Ozokerit is largely used in Europe, especiallj in Bussia, as a sub-
itnte for beeswax. Refined ozokerit, or oeresin, is distilled, and the
laltine wax is employed for the manufacture of candles, which are
pecia% adapted for use in high temperatures, as they are less likely
gutter and bend than ordinary paraffin candles. Another product
bde from ozokerit by distillation resembles Yaseline, and is used in
itments and pomades. By the action of Nordhausen sulphuric acid
b rendered ^Aiite, and is consumed in that form by French perfumers
a sabstitute for lard in the process of enfleurage, the almost entire
lokbility of the hydrocarbon in alcohol giving it great advantage
nr animal fat. The residue in the retorts after distillation consists
a hard, black, waxy substance which is used for the manufacture
okonite, a valuable electrical insulating materiaL The black ozo-
tit residue is combined with rubber, welded by passing through
krs at moderate temperature, and vulcanised. Okonite is not only
;Dod insulator, but is remarkably flexible and tough.
The annual production of ozokerit in Gcdicia reached its maximum
1836, when the figure was 139,254 centners of 100 kilos, or say
000 tons. In 1890 the output had fallen to about 6000 tons. The
loe of best quality is about 302. a ton. The American production
■ 43,500 lb. in 1888, 50,000 lb. in 1889, 350,000 lb. in 1890, 50,000
in 1891, and 130,000 lb. in 1892. Its value is about 18/. to ^22.



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292 ECONOMIC MINING.



PHOSPHATES.

Deposits of phospbatic mineralfi haying di£fereiit characteristicB,
physical appearance and in chemical composition, as well as in t
results obtained from them, have been found in nearly every part
the globe. The commercial value of these is chiefly regulated by t
percentage of tribasic phosphate of lime they contain, llie rid:
they are in this element, the more valuable they are {esBteris par^
for the manufacture of superphosphates. But, the amount of p}»
phate of lime in a mineral cannot be taken as the only criterion of i
value, for it sometimes happens that a phosphate containing a low
percentage of this ingredient will make a stronger and better snp(
phosphate than a richer one containing more deleterious impuriti
The value is very much affected by the amount of lime carbonai
iron, alumina, and calcium fluoride present ; also, by its porosity
density, and the facility with which it can be reduced to a £ne po
der. If not in excessive quantity, lime carbonate is rather an adv^
tage than otherwise in the manufacture of a good conditioned snp^
phosphate, inasmuch as the carbonic acid disengaged from it wh
acid is applied, makes a mass more bulky and open, and causes it
appear porous or honeycombed when finished.

The presence of a large quantity of iron and alumina in mina^
phosphates is objectionable, for they not only absorb acid, but 8n[J
phosphates made from them have a tendency to ** go back," or beocn
insoluble again ; therefore, the unit percentage of lime phosphate
worth less in minerals containing a good deal of these, than in otbi
containing only a little. Calcium fluoride, which generally accoj
panics phosphatic minerals, also reduces their value. It wastes a<a
and in oecoming lime sulphate, its weight is increased to the detrisHJ
of the superphosphate. Silicious matter is a useless ingredient, bol
harmless one, except in so far as it causes an unnecessary weight
be moved about, and when in excessive quantity reduces the prop
tion of soluble phosphate in the superphosphate to such an extent
to make it unmarketable. Ordinary mineral superphosphate contai
biphosphate of lime equal to 25 to 28 per cent, of tribasic phosphf
of lime rendered soluble ; and, aa it is well known that good Cambrid
coprolites are capable of yielding this of a good chemical oompodtii
and in a dry powdery condition, the analysis of this mineral may
taken as a fair standard upon which to assess the yalue of othen.

Cambridge coprolites come from the Upper Greensand in 0^
bridgeshire, and occur as small nodular hard masses of a grey ook
(supposed to be fossil excrement of animals) or occasionally concretii
around bones, amongst which are found fish teeth and some verteb
Either from the exhaustion of the better sorts or from im]
washing, the quality has deteriorated, and there is now some di



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NON-METALLIFEROUS MINERALS. 293

t making stiperphospliate from them to contain more than 25 per
«it of solable phosphate. Their average composition is : —

Per cent.

Tribasio pboephate of lime 55 to 60

Liine oaroonate .. 12 », 18

Almniiia and iron oxide 3 „ 5

Caloinm fluoride 2 „ 4

iDsoInble siliciouB matter 6 „ 8

Sometimes the iron and alumina reach 10 to 14 per cent.

These coprolites are extracted by washing from a stratum not
iore than 1 ft. thick. An average yield is 300 tons per acre, and
imetimes as much as 3002. an acre nas been paid for the right to
igthem.

An inferior ooprolite is mined at Wicken, in Cambridgeshire,
iving the following composition : —

Per cent.

Moisture 1*66

L088 by ignition 2*97

Sand, silioa, and pyrites 24*46

Galcinm fluoride 2*02

Lune sulphate 1*53

Lime carbonate 10*16

Lime silicate and organate 6*40

Lime tri-phosphate 35*66

Ironoziae 7*56

Alumina 4*07

Phosphoric acid 2*67

In Su£folk, coprolites are found subjacent to the London clay, and
mcdst chiefly of rolled pebbles, with a small proportion of more or
IB perfect specimens of bones of various animals, as also some fish
id crnstacea. They were formerly regarded as fossilised excrements
t animals, for which reason they were called coprolites ; but they
re now supposed to be calcareous pebbles, which have undergone a
Beoliar change, and become impregnated with phosphoric acid by
ng continued contact with decaying animal and vegetable matter.
Ihe name peeudo-coprolite has been given from their resemblance to
b Cambridge coprolites, but they are distinguished from the latter
y a brownish ferruginous colour and a smoother surface. They are
ery hard, and generally contain too much iron oxide and alumina to
Dow them to be used safely in the manufacture of superphosphates,
liidr percentage composition is : —

Per cent.

Tribasio phosphate of lime 52 to 61

Lime carbonate 10 „ 17

Alumina and iron oxide 5 „ 10

Galcium fluoride 1 9» 4

Insoluble silicions matter 9 „ 12

Bedfordshire coprolites have an affinity to the Suffolk nodules,
lid are oompoeed generally of : —

Tribasio phosphate of lime 50

Lime carbonate 8

Alumina and iron oxide 8

Oiloiinn fluoride 4

Insoluble siliciouB matter 20



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294 ECONOMIC MINING.

Wales possesses very extensive phosphatio deposits in Mont^romery
shire, the mineral averaging abont 50 per cent, phosphate of Ume, 2j
silicions matter, 9 lime carbonate, 7 insoluble iron sulphate, and 1 ead
of alumina and iron oxide. The rock as mined carries much worth
less matter, and to dress it up to 46 per cent, standard costs Z%. \
ton. Its colour seems to be prejudicial to its sale, as the indostiy i
languishing*

England produces 10,000 to 30,000 tons of phosphate yearly.

In Eussia, coprolites are found in some abundance, but their poa
quality is indicated by the following figures : —

Per oont.

Tribado phosphate of lime S3 to 48

Limeoaroonate .... 5 „ 6

AlmniDa and iron oxide .. .. 5 „ 6

Galcimn fluoride 8^4

Inaoluble silicionB matter 42 „ 44

Enormous coprolite beds occur in France, notably in the neigli
bourhood of Boulogne and near the Belgian and Swiss frontiers. Th
Boulogne coprolites are met with as dark grey nodules, much assoc
ated with organic remains. They have been shipped in quantities t
England, and used in admixture with richer phosphatic material
Samples from Pas de Calais showed on analysis : —

IVreeot.

Moiftnre 0-610

Sand, p3rTitee, fto., insoluble in HGl 33-840

Silicic add 1*490

Calcium fluoride 2*100

Lime sulphate 2*487

Lime carixinate 11-360

Lime silicate, fto 7*860

Triphosphate of lime 29-150

M ofmagneeia 2-552

Iron oxide 2*11

Alumina 2*780

Phosphoric aoid 5*700

The production reaches about 300,000 tons annually.

Various complete analyses of Boulogne coprolites indicate t|
average contents to be : —

Moisture .. -79 to 1*74

Water of combination 1'04 „ 8*24

Phosphoric acid 17*69 „ 21*27

lime 30*41 „ 85*88

Carbonic acid 3*55 ^ 5*25

Sulphuric acid -85 „ *90

Fluorine 2*08 „ 4*69

Magnesia .. ' -25 „ -83

Iron oxide ;. 2*89 „ 6*24

Alumina 3*09 „ 5*89

Insoluble silidous matter 23*56 „ 28*45

Tribasic phosphate of lime 88*61 „ 46-97

Lime carbonate 8*07 „ 11*93

In the Ardennes, the beds lie beneath about 200 ft of olay.
France is particularly rich in phosphate. The south, centre, ncti
and east in particular are well supplied with it, as it has been



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NON'METALLIFEROUS MINERALS. 295

mated that the total amount existing in theee distriots exoeeds
32,000,000 tons. The production of natural phosphates rose in 1886
to 184,166 tons, representing a value of nearly 7,080,000 francs or
oyer 283,0001.

The number of quarries amounted to 796, and of workmen to
3160. The most important department was that of the Meuse, from
which nearly 52,000 tons of phosphate were obtained, the price of
which averaged about 25«. a ton. These phosphates, consumed partly
in the neighbouring departments, £nd their way also to Brittany and
La Vendee. In the Pas de Calais the production of phosphates, washed
and ground, amounted to 30,000 tons, with an average price of about
32«. per ton. After these two departments comes that of Lot, in
which the production amounted to 26,000 tons, sold in the Midi at
about 25«. per ton, after grinding. The department of the Gard sup-
pbed 13,000 tons of triturated phosphate. In the east of France,
phosphate of lime is obtained from the greensand ; principally from
chalk in the north ; and from calcareous soil in the departments of
the Gktrd, Lot, Aveyron, and Tam-et-Garonne.

The mineral known as Lot or Bordeaux phosphate comes from the
departments of Lot and Lot-et-Garonne, in France. It occurs in
pockets in fissures in the limestone, and also in thin layers, near the
sur&oe. Theee are covered with an alluvial soil and clay, containing
phosphates but much contaminated with iron and other impurities.
The pockets, of all shapes and sizes, and sometimes reaching 100 ft.
deep, are generally traced and indicated by narrow vertical veins of
deposit, which rise from them to the surface, and are mostly found on
the highest ground. It varies greatly in appearance, texture, and
composition. Occasionally, it is found in snow-white compact masses,
brealdng with an earthy fracture, and of a moderate degree of hard-
ness. The more ordinary kinds are of a dark yellow or brown, dense
and hard ; but it is frequently found of a dark agate colour, some-
what resembling the inside of broken flints, of a waxy lustre, stratified
and intersected with thin layers of iron oxide. It has the appearance
of being an aqueous deposit, and the probable cementing together of
himps of phosphates, bones, &c., with more or less alluvial clay and
tarth, by the percolation of dissolved phosphatic matter, may account
for the appearance, texture, and composition of some portions. The
white specimens are generally the richest, some being as high as 85
|ier cent, with a minimum (J per cent.) of iron, &c., but the bulk only
L-ontain 70 to 72 per cent., and with 4 or 5 per cent, of iron, &c.
Fossil bones and teeth are found in quantity. The surface phosphatic
LArth finds a ready sale on the spot. Analyses of two sample parcels

shoived: —

Percent.

Tribaaic phosphate of lime 55>45to67'ld

Lime carbonate 8*3 „ 15*81

Iron, alumina, fluorides, &0. 12*86 „ 4*2

Siliokms matter 19-13 „ 5*2

The best varieties of these phosphates are well adapted for the
Domnafacture of superphosphate.

German or Nassau phosphate, deposited like the Bordeaux variety



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296 ECONOMIC MINING.

in pockets, is fotind chiefly in the neighbourhood of the riveiB Lak
and Dill, in Nassaa. Some of it is of a yellow colour, breaking wit!
an earthy fracture ; other portions have the appearance of pieces c
phosphate, cemented together with ferruginous clay ; and in w
cases it appears in a crystalline form. The richest Tarieties are of
light yellow colour, and tolerably free from iron, &c. ; but the pn
dominating lower qualities are contaminated with much iron of
day, limestone, &c. The composition varies thus : —

Peroeot.

TribMio phoepbate of lime 58 to 65

Lime carbonate 5 „ 8

Iron and alumlDa 10 „ 15

Inaoluble matter 10 „ 12

From these phosphates there is no difficulty in making supe:
phosphate quite dry, but they invariably set extremely hard, an
they therefore require much breaking up. They cost about 26^0
a ton readv for market, and are much u^ed locally.

Spanish and Portuguese phosphorite generally goes under the nan
of Estremadura phosphate, from the province in Spain where it
chiefly found. It is hard, of light yellow colour, crystalline structur
and generally more or less mixed with quartz, and becomes phosplu
resoent when heated. It is tolerably free from iron and alumina, bi
contains variable and often considerable quantities of calcium fluorid
Following are some analyses of Estremadura phosphate : —

Percent.

Tribasic pbospbate of lime 72 to 80

Lime carbonate „ 9

Almnina and iron oxide 2',, 4

Calcium fluoride 2^4

Inaoluble silicious matter 4 „ 18

The production in 1890 was less than 1000 tons. In conversicj
into superphosphate about 30-33 per cent, of the phosphate is render^
soluble, but the lack of lime carbonate induces a dense and dan^
product requiring some time for getting into good condition.

Describing the deposits found in a series of caverns in Eooei
limestones on the north-eastern flank of the Pyrenees, in the Au^
Valley, Armand Gautier* mentions quantities of concretionary pho^
phorite and other phosphates, both of lime and alumina, varyiq
from 15 to 50 ft. in depth, being estimated to contain from 120,000 i
300,000 tons of phosphatic minerals, which difler in many reaped
from the ordinary phosphorites of stratified formations. Amoi^
these, one of the most interesting is brushite, a hydraulic dibasi
calcium phosphate (2CaOP205,6H20) which had only been knov^
previously as a secondary product incrusting the rook euano of Avj
Island and Sombrero in the West Indies. It contains phosphoric acj
43, lime 34. and water 23 per cent., and, as a rule, occurs in cmsi
upon and fQling fissures in the limestone rocks. The bulk of t^
deposit is, however, made up of mixtures of tribasic calcic phosphaj
and neutral phosphate of alumina, which vary within rather witi
limits, but frequently are in nearly equal proportions, about 24-3

• • Annaks dea Mines.'



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NON-METALLIFEROUS MINERALS, 297

per cent, of each, oontaining about 21\ per oent of phosphorio acid,
whidi 18 moBtly all soluble in weak acids. A third, and previously
imdeacribed subetanoe, to which the name of minervite has been given,
is a hydrated aluminic phosphate (Al303P205,7H20) which was found
is a white plastic mass, filling a vein 2-2\ ft. thick.

The gedo^cal formation of the South Carolina phosphate belt is
Hide up of Quaternary sands and clays overlying beds of Eocene
marls with the phosphate distributed over their surface or mixed up
indiacriminately with them. The total area covered by it is said to
be 70 miles long by 30 miles broad ; the richest and most accessible
portion being in the immediate neighbourhood of Charleston. Whether
the deposit is continuous or not over the whole of this zone, it
oertainiy varies considerably in depth and thickness. In many places



Online LibraryCharles George Warnford LockEconomic mining: a practical handbook for the miner, the metallurgist and ... → online text (page 33 of 76)