The Mining Magazine, Vol. 75, No. 5

1 ne Mining Magazine

VOL. L X X V . No. 5. LO NDO N, NOVEM BER, 1946. O N E SH ILLIN G ^{PR IC E}

One of a number of Heavy Duty Sledgers being manufactured by Fraser and Chalmers.

F. and C. Heavy Duty Sledgers are designed to crush run-of-mine ore, capacities 200/800 tons per hour. These are massive machines—equipped with automatic lubrication and water cooled bearings—

specially designed to meet the demand for large outputs required by mines and quarries.

FRASER & ^CHALMERS ENGINEERING ^WORKS

. ERITH, KENT.

TH E MINING MAGAZINE

A . C . W in d e r M otor w ith D ynam ic B raking at a Y o rk s h ir e c o llie r y ; the C o n tro l. D e sk is show n in th e foreground

« T O w m s M i Y m w p 's m m m

DC. DYNAMIC BRAKING

„ for A C W O N D E R S

/• # _

{ ^ ¡ j f U . . « * * / ^ h i s f ° r m ° f B r a k i n g c a n b e

f i t t e d t o e x i s t i n g e a u i o m e n t .

C E N T R A L IS E D C O N T R O L W IT H D R IV E R ’S D E S K incorporating :—

• Control Levers.

* Instruments.

• Miniature Precision Depth Indicator.

* Shaft Signals.

Servo operation of Liquid Co n tro ller.

f i t t e d t o e x i s t i n g e q u i p m e n t .

Our engineers are always available to discuss your Winder problems.

T H E ENGLISH E L E C T R IC C O M P A N Y LIM ITED

L o n d o n O f f ic e : Q U E E N ' S H O U S E , K I N G S W A Y , L O N D O N , W . C . 2

W O R K S : S T A F F O R D • P R E S T O N • R U G B Y • B R A D F O R D • L IV E R P O O L

TH E MINING MAGAZINE

SALIENT POLE-SYNCHRONOUS INDUCTION

MOTORS ^for COLLIERIES

ł A

L arg e n u m b e rs o f th is ty p e o f m o to r are in o p e ra tio n d riv in g C o m p r e s s o r s , Fans, e tc.

Advt. o f The General Electric Co., Ltd., Magnet House, Klngsway, London, W .C.2

5— 1 3

TH E M INING MAGAZINE

VALVES

k

! \

R E S I L I E N T P A C K I N G '

L U B R I C A N T

^ G R O O V E S

VITAL FOR POSITIVE SEALIN G

L U B R I C A N T / B A S E C H A M B E R

The LUBRICANT SEALS against Leakage

m the ‘A udco ’ Valve the plug is p o sitive ly but re silie n tly seated and the lub­

rica n t, besides sealing it against leakage, reduces the fric tio n o f tu rn in g . If stu ck th rough disuse, th e valve — again because of th e lu b ric a n t— can be eased and tu rn e d by th e application of p ressu re . A ll ‘ A u d co ’ Valves are tested h ydrau lic- a lly to e nsu re p erfectio n of m anufacture, c o rre c t assem bly, absence of p o ro sity and uniform ease of o p e ratio n . Y o u r own In sp ecto rs are welcom ed to be present during testin g, and testin g c e rtifi­

cates w ill alw ays be fu rnish ed on request.

S E R V I N G A L L F I E L D S F O R A L L P R E S S U R E S

M-W.JO

A U D L E Y E N G I N E E R I N G C O . L T D .

N E W P O R T , S H R O P S H IR E , E N G L A N D Telep h o n e : N E W P O R T , S h ro p sh ire 3246 A typical ‘A u d co ’

In stallatio n at a C hem ical w o rk s .

on Salt Liq u o rs.

A N D T E M P E R A T U R E S

4

THE MINING MAGAZINE

"Harco

WOVEN WIRE SCREENS

M an u fa ctu re d fro m s p e c ia lly to u g h e n e d ste e l to re s ist ab rasio n and f r a c tu r e , “ H a r c o ” S c re e n s last lo n g e r. L e t us q u o te you fo r S c re e n s th a t w ill re d u c e y o u r m a in te n a n ce co sts and g ive you in c re a se d o u t p u t w it h tr o u b le -fr e e s e r v ic e .

Catalogue M 269 sent on request.

C.A.H ARVE Y & Co. WOOLWICH ROAD. LONDON S.E.7. ⁽ l o n d c n ) Ltd.

5

TH E MINING MAGAZINE

ROSS ENGINEERS

LTD.

i t Send for Catalogue B2/B3

6

1 1 , W A L P O L E R O A D , S U R B I T O N , S U R R E Y .

Tele phone :

E lm bridge 2345.

Tons400

perH our

RECENT ROSS CRUSHING PLANTS 900 Tons per Hour for—

APPLEBY-FRODINGHAM STEEL Co., Ltd.

UNITED STEEL COMPANIES, LTD.

200 Tons per Hour for—

THE LANCASHIRE STEEL CORPN., LTD.

400 Tons per Hour for—

THE OXFORDSHIRE IRONSTONE Co. Ltd.

Ion'

. i n perH our

Ross Belt Conveyor Installation

TH E MINING MAGAZINE

Tw o of three Steam Tu rb in e- driven Gas Boosters installed in the Fulham Gas W o rk s of The Gas Light & Coke C o ., Ltd .

M O TO R -D R IV E N C O M P R E S S O R S , B LO W E R S , AND E X H A U S T E R S .

B T H

^{R U G B Y} A 3677

A U ST R A L IA . Sydney:

Australian General Electric Proprietary Ltd., G .P.O . Box 2517.

Melbourne : Australian Gen­

eral Electric Proprietary Ltd..

G .P.O . Box 538-F.

N EW Z E A L A N D . Welling­

ton : National Electrical &

Engineering Co., Ltd., P.O.

Box 1055.

C H IN A . Shanghai : Inniss & Riddle (China) Ltd., 43, Yuen Ming Yuen Road.

Hong Kong : Inniss & Riddle (China) Ltd.. 1st Floor David House, 67-69, Des Voeux Road Central.

IN D IA . Calcutta : Associated Electrical Indus­

tries (India) Ltd., P.O . Box 271. Bombay : Associated Elec­

trical Industries (India) Ltd., P.O .B ox 484.

R H O D E SIA . Bulawayo : Johnson & Fletcher Ltd., P.O. Box 224.

SO U T H A FR IC A . Johannesburg : Wilson & Herd Ltd.. P .O . Box 7733.

Capetown : Wilson & Herd, Engineering (Pty.), Ltd. P.O . Box 1459.

W E ST A FR IC A .

Sekondi, Gold Coast Colony • The West African Electrical Co., P.O . Box

.

K EN Y A . U G A N D A . T A N ­ G A NYIKA.

Nairobi: R. G. Vernon & Co., P.O. Box 124.

Nairobi: British East Africa Corporation (1939) Ltd., P.O . Box 182.

Dar-es-Salaam : Lehmann’s (Africa) Ltd. (for lamps only), P.O. Box 163.

an d others throughout the w orld.

7

‘ i f

I P L £ ^ ] f i ï

T H E M INING MAGAZINE

A TYPICAL CROSSLEY - PREM IER HORIZONTAL ENCLOSED

M ULTI-CYLINDER DIESEL ENG INE Sizes up to 4,000 B .H .P .

CROSSLEY-PREMIER ENGINES LTD.

S A N D I A C R E , N r. N O T T I N G H A M

8

Every inch a Screen

P E G S O N -T E L S M IT H

SCREENS

make the Grade

T h e b est a d v e rt is e m e n t o f a P e g so n -T e lsm ith H e a v y D u ty S c re e n lies in its p ro d u c tio n . T h e m a ch in e is d esign ed and b u ilt to do fa ste r g ra d ­ ing o f th e h ig h e st s ta n d a rd . P o sitiv e c o n tro lle d v ib ra tio n p ro d u c e s a c ir c u la r m o v e m e n t in a v e rt ic a l plane causing th e ag g reg ate to d an ce u p on th e m esh. T h e s c re e n and th e v ib r a t­

ing u n it are p e rfe ctly b alanced and no e x t r a

load is im p o se d on th e su p p o rtin g s t r u c t u r e . T h e s te e l shaft w ith its self-alig n in g c y lin d ric a l r o lle r b e arin g s is m o u n ted on th e h o riz o n ta l fra m e o f th e e q u ip m e n t. Y o u can d ep e n d upon th e P e g so n -T e lsm ith H e a v y D u ty S c re e n fo r both n o n -sto p e fficie n t o p e ra tio n and a p e r ­ f e c tly g ra d e d p ro d u c t. W r i t e fo r th e fu lle st d e ta ils, w h ic h w ill be w illin g ly su p p lie d .

F o r the grading of sm aller sizes the Pegson- T e lsm ith L ive W ir e Screen and the Pegson O pen D e ck Screen possess all the qualities of the h eavier equipm ent. T h e y rapidly s tra tify and accu rate ly grade m aterial at a high rate of speed upon economical p o w er consum ption.

PEGSON Ltd.,

Iddesleigh House, Caxton St., W estm inster, London, S .W . I. Phone : A b b ey 2373.

W o r k s : C O A L V I L L E , L eice ste rsh ire .

9

TH E M INING MAGAZINE

SEND FOR THIS BOOKLET

This new and attractively illustrated booklet •— issued by the Ministry of Fuel and Power — sets forth in simple non-technical language the theory and practice of the Structural Insulation of Industrial Buildings.

It shows how to save money on the capital cost of new buildings and how this initial economy is followed by a reduction in operating costs.

It illustrates how structural insulation can be applied to existing buildings to ensure substantial annual fuel savings,

and quotes the case of an actual factory where a simple measure of insulation, carried out without interfering with pro­

duction, saved 42% of the heating fuel and led to increased production.

It tells of the materials to use, how to use them and how much of them to use.

Specially written for management, every Executive concerned with the design, erection or operation of industrial build­

ings, should study this booklet.

It includes sections on

• The Th eory of Structural Insulation ' • W h at Structural Insulation Saves.

• How it can be applied to existing buildings.

• A ltern ative methods of insulation for various structures, etc., etc.

Write now for a copy to the Ministry of Fuel and Power, Fuel Efficiency Branch, Queen Anne’s Chambers, Dean Farrar Street, S W .l.

STRUCTURAL

I N S U L A T I O N

iH E MINING MAGAZINE

w Me t r o vickX

f thrustors 1 operating main' land auxiliaryi t brakes (Mesh ^{& i}

^ h a n d

wheel cut aw ayM

to show

i

^ ^ ^ th ru sto r) I

r K its h p \

M etrovick ' m otor driving t a m an-riding i haulage jA

Increased safety w ith consequent increased output is assured in this Beckett & Anderson man-riding haulage, through automatic control by main and auxiliary brakes. Each brake is operated by a FLA M EP R O O F electro-hydraulic th ru sto r which applies the necessary pressure sm oothly, rapidly and w ith full reliability.

Th e main driving m otor is a M etrovick 125 h.p., 2,200 v. type F W machine. It is a Slipring Induction m otor w ith totally- enclosed fan-cooled enclosure certified as fully FLA M EP R O O F.

>PO!

k e

r T r r T n i r n i ^ ^ — co.. l t d.

TRAFFORD PARK MANCHESTER 17.

1 1 J/M 602

TH E M INING MAGAZINE

O j g

o n

jliiimli d d M <kt

D ia m o n d C o 1 '1 ’

5 m T h e V a lu e o f C o r e S a m p les.

D r ill c o re s g iv e yo u an a ctu a l se c tio n o f r o c k o r o re fo rm a tio n as it e x ists at d e p th . Laid o u t in th e o r d e r re m o v e d fro m th e c o r e b a r r e l, c o re s fu rn ish an a c c u ra te r e c o rd o f m a te ria l p e n e tra te d by y o u r b o re h o le. P h y sica l c h a ra c ­ t e r is t ic s o f r o c k a re re v e a le d . C o r e s

fro m o re fo r m a tio n s sh o u ld be h alved h o r iz o n ta lly w it h a c o r e s p lit t e r . O n e h a lf can be an alyse d w it h slu d g e o r c u ttin g s fo r m in e ra l c o n t e n t , and th e o t h e r half re ta in e d fo r p e rm a n e n t r e c o r d . In a g iv e n e x p lo r a t io n , sam p le s t h u s r e c o v e r e d y ie ld d ata on th e lo c a tio n , s iz e , and q u a lity o f y o u r o re b o d y.

The L O N G Y E A R Pioneer Straitiine—

A Small D rill for Prospecting

M any lik e ly m in e ra l p ro s p e c ts a re in rou g h c o u n t r y and in r e m o t e re g io n s. In o r d e r to c o re d r ill th e m to p ro v e v a lu e s yo u need a lig h t, co m p a ct m a ch in e easy t o m o ve and h an d le in su ch a re a s. T h e p e tr o l- d r iv e n P io n e e r S t r a itiin e is b u ilt fo r ju s t su ch p u rp o se s . D r illin g ca p a city is 600 ft. o f f - in . c o re .

T h e P io n e e r is lo w in co st. A ls o it is e co n o m ica l in o p e r a tio n d u e t o high d rillin g e fficie n cy and th e use o f b o r t z b its.

If d e s ire d th e d r ill is a v a ilab le w ith an a ir o r e le c t r ic m o to r fo r u n d e rg ro u n d d rillin g . W r i t e fo r p a rtic u la rs.

CANADIAN LONGYEAR, LIMITED, North Bay, Ontario, Canada

L O N D O N R E P R E S E N T A T IV E

A U S T IN H O Y A N D C O M P A N Y , L I M I T E D , 39, St. James Place, S.W . I O t h e r re p re se n ta tiv e s in O s lo , N o r w a y ; H e ls in k i, F in la n d ; Jo h a n n e sb u rg , S . A . ; P e rt h ,

W e s t e r n A u s t r a l i a ; W e llin g to n , N e w Z e a la n d .

12

TH E MINING MAGAZINE

UNIFORMITY

The constant uniform ity of Bear Brand Xanth ates is one of the outstanding characteristics of these widely accepted flotation reagents.

U sers know that any single drum or carload of drum s can be depended upon to show the same quality as previous or subsequent shipments.

Z3— Potassium Ethyl X anthate Z4— Sodium Ethyl X anthate Z5 *—Potassium Amyl X anthate Z6 *— Potassium Pentasol Amyl X anthate Z8—Potassium Secondary Butyl X anthate Z9— Potassium Isopropyl X anthate Z10— Potassium Hexyl X anthate

*From Sh arp ies A m y l A lco h o l

G R E A T W E S T E R N D I V I S I O N

THE D O W C H E M I C A L C O M P A N Y

S A N F R A N C IS C O C A L I F O R N I A , U . S . A .

pioneer producers of Xanthates for metallurgical use

C H E M I C A L S I N D I S P E N S A B L E T O I N D U S T R Y

13

TH E M INING MAGAZINE

H e r e is o n e o f 16 A v e lin g - B a rfo rd 4 J y a rd D ie s e l S h u t tle D u m p e rs , su p p lie d to M r. H a r r is o n & C o ., o f L e e d s, in 1945. R e p e a t o r d e r s fo r t w o in M ay th is y e a r and a f u r t h e r fo u r in Ju n e s h o w th a t M r. H a r r is o n v alu es th e e c o n o m y o f th e d ie se l m a ch in e w it h its s h u ttle w o r k in g .

A v e ra g e c o n s u m p tio n fo r 8 -h o u r d ay 2 / 3 g allo n s of d ie se l o il.

F ir s t in tro d u c e d in 1939, o v e r 150 a lre a d y at w o r k .

AVELING-BARFORD, LTD

G R A N T H A M , E N G L A N D

Leaders in Road Construction & Building P la n t- - - -

14

THE MINING MAGAZINE

Producer of the W o rld ’s W idest Line of Major Industrial Equipment . . . over 1,600 Different Products that Further Good Living !

A L L I S - C H A L M E R S M A N U F A C T U R I N G C O M P A N Y o ffer p ro d u c ts o f q u a lity and in t e g r ity as th e b u ild e rs o f th e w o r l d ’s w id e s t ran ge o f m a jo r in d u stria l e q u ip m e n t.

F o r A llis - C h a lm e r s b u ild s complete p o w e r g e n e r a tio n , d is t rib u tio n and c o n t r o l e q u ip ­ m e n t— p u m p s— m o to rs — V - b e lt d riv e s — c ru sh in g , c e m e n t and m in in g e q u ip m e n t—

flo u r— m illin g , food and ch e m ica l p ro ce ssin g e q u ip m e n t— in all, o v e r 1,6 0 0 d iffe re n t p ro d u c ts th a t aid in d u s t r y and f u r t h e r good liv in g ! Y o u r e n q u irie s fo r in fo rm a tio n o r lite r a tu r e w ill r e c e iv e p ro m p t a t te n tio n fro m —

ALLIS-CHALMERS

MANUFACTURING COMPANY,

T O T T O N , S O U T H A M P T O N

T e le p h o n e : T O T T O N 3161/2.

15

New design improvements are making jigging a preferred method for concentrating certain types of ores which cannot be economically treated otherwise. Here is one of the newer Allis-Chalmers ⁶

foot by

ft.

inch

This jig has a capacity of ⁷⁵

T P H of feed

mesh. Each

to

% greater capacity than

TH E MINING MAGAZINE

R U S T O N - B U C Y R U S L T D . , L I N C O L N

E X C A V A T O R S P E C I A L I S T S

16

For 70 years the leading name in

XCAVATION

A 5-W Diesel W alk­

ing Dragline with

150 foot boom and

y a r d b u c k e t

stripping cover in

an ironstone mine.

TH E MINING MAGAZINE

B A L L & T U B E M IL L S

A 4-FT. x 8-FT. B A LL M ILL ASSEM BLED IN O U R W O R K S

We also manufacture

M I N E H E A D F R A M E S A N D A C C E S S O R I E S , N ISSEN STA M P M I L L S , A K I N S C L A S S I F I E R S , R U G G L E S - C O L E S & L O W D E N D R Y ER S, V IB R A T IN G S C R E E N S , R O T A R Y D R U M F I L T E R S

and other Ore Dressing equipment

HEAD, WRIGHTSONeCL™

S T O C K T O N F O R G E , S T O C K T O N - O N - T E E S

TH E M INING MAGAZINE

R ecent developm ents in radio science present the surveyor w ith a new instrum ent of extrem e utility and precision, this is the D ecca N avigator.

Surveyors engaged in com pleting the accurate m apping o f large areas of both land and sea will find th a t by using the D ecca N avigator the w ork can be accom plished in bu t a fraction of the tim e required by older m ethods.

W orking from an easily erected transportable radio transm itting station the D ecca N avigator gives a continuous fix o f position on direct reading dials for boat, ’plane or m obile party, to a degree óf accuracy so high and at a tim e cost so low as to revolutionise the whole practice of surveying.

The Decca Survey Department will gladly quote you for a Navigator equipment to suit your specific needs if you will tell them the nature of your business and the areas you pro­

pose to survey. I f required, a Decca Engineer will be sent to discuss the matter with you. No obligation will be incurred.

The D ecca Navigator Company9 L im ited

(S u rv e y D e p a r tm e n t) 1-3 B rix to n R o a d , L o n d o n , S .W .9 t e l e p h o n e : R e l i a n c e 3 3 1 1 t e l e g r a m s a n d c a b l e s : D e c n a v , L o n d o n

18

TH E MINING MAGAZINE

Where space is limited, or where any arduous work has to be done, Dunlop hose will give you the most trouble-free results, because it combines exceptional flexibility with rugged strength and resistance to wear.

OBTAINABLE F RO M YOUR USUAL FACTOR OR WHOLESALER

D U N L O P w

D U N L O P R U B B E R C O . L T D . (G E N E R A L R U B B E R G O O D S D IV IS IO N ) , C A M B R ID G E S T R E E T . M A N C H E S T E R

5—2 19

TH E MINING MAGAZINE

ROPE

PROBLEMS

gRITISH Ropes Limited offer their services to manufacturers faced with rope problems. These prob­

lems are highly technical: they involve practical knowledge of rope usage only to be gained by the most extensive experience.

For many years British Ropes Limited have made ropes and fittin gs for e v e r y in d u stry throughout the world. Their practical experience is unique.

There is no rope problem to which they are unable to find the answer—and supply the rope.

BRITISH ROPES LIMITED

M A N U F A C T U R E R S O F W I R E R O P E , W I R E , H E M P C O R D A G E & C A N V A S

H e a d O ffice: D O N C A S T E R , E N G L A N D

___________________________ B R

.20

Swift action—

Sure closure Sure closure is a feature of all Saunders Valves. The resilient Diaphragm, of a grade to suit the fluid under control, ensures this even with gritty contents.

Here is a model with quick- acting "O N -O FF” control, one of many patterns available for special applications.

T h e H a n d b o o k g i v e s d e t a i l s and technical data.

"'tlaciasin wns-ii j

r'^_

S A U N D E R s 'H S S B K fc V A L V E C O . L T D C W M B R A N • N E W P O R T • M O N M O U T H S H I R E

TH E MINING MAGAZINE

I

T H O S . F I R T H fr J O H N B R O W N L T D . , _SHEFFIELD

TD

21

T H E M INING MAGAZINE

R O T A R Y

K I I A S «ft COOLERS

For Lime, ^ulphate, Vanadium, Wolfram, Lithopone, Fluorspar, Diatomaceous Earth, etc.

Complete Plants can he supplied.

Kilns from 2 ft. to 10 ft. 6 in. diameter and up to 350 ft.

long are made hy Edgar Allen c& Co., Ltd.

A trained mechanical and chemical staff deals with problems. Submit yours to—

E D G A R ALLEN & CO, LIM ITED.

IM P E R IA L S T E E L W O R K $ :- S H E F F I E L D .9 '■

22

THE MINING MAGAZINE

" 8 0 0 S e r i e s ' s

, , s w r

E A R ' «

« N i t « ’ * O C K

(MMtRft*-5

COM-

ftlOSfW [lUORW**

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A

p , 0doC ,0 0 .0 69.8

_ lc, 6-58 ° ' 42 30.1 0 .0 -' 3

F«e<* an,[o'8 . , 6-5®

C°n n m'lne

^'r0 93.42

1at P si 2 ± '

F E L D S P A R O RE Rem oval of bio tite, tourm aline gar- o x i d e s .

Using Reagent 801 for flo tatio n of iron

% % F e z O a

W e ig h t A n a l y s i s D is t r ib u t io n

100.0 0.236 100.00

ate

n inerals)... 9.55 2.16 87.38

Feldspar) 90.45 0.033 12.62

n if i i O S ^ ^ r % 6 o o r 9

* * " a ''/" >0/0 %° M * 05>

* ■ **2°* ]0° °

, ,* W0,9 , Q

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98.98

,

8798 2 9 9

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Develop*-«1

Pr l" C

a n i v' a9h' treatm ent

Series" ^

m i d 9 n e , „ „ 8 6 8 h a v e p r a C U

and new 1'«“ .

' r ° "

a p P l l c a t l 0 n 9 r t i e s a 9 9 0 c i a f e d V r l ,

bearing inrPu n d Feb b p a r and Glass Sands an ^ Kyan> e

other mrneral^e^elineSyentte-

Sillim am tea iUustrate the

T y p i r a l

resu 1»

effecuvenesso ^ are m erely

midReagen t^ B iaU ppU cauon8

indicaU'eof P flo(atlon where GARH11

g i a» * * N O i

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1 RYAHItt R 0 H ORt WAGNH '18

MtPHU'Ht tYEHltl

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1 0 " ' a 9 t 0 ° - ° ° Q v ° .

°'’9

, a -l9»/o

CYANAMID PRODUCTS Ltd Berkhamsted. Herts.

5 — 3

23

ROBERT HUDSON L td . ■ “ “ “ LEEDS

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TH E MINING MAGAZINE

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TH E MINING MAGAZINE

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TH E M INING MAGAZINE

STANDARD DUMPY LEVEL

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TH E MINING MAGAZINE

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TH E MINING MAGAZINE

For H a u l a g e in

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TH E MINING MAGAZINE

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Photograph b/ kind permisiion of

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32

TH E M INING MAGAZINE

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TH E MINING MAGAZINE

A P R O D U C T O F T H E

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TH E M INING MAGAZINE

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36

T H E MINING MAGAZINE

They stayed in action— at Waterloo ! In face of repeated attacks the British squares stayed in action, and wrote a glorious chapter in the annals of history.

‘They stayed in action’

For pumping abrasive pulps we claim that Vacseal pumps stay in action longer than any other. For the jobs that really punish a pump you need the Vacseal. The Vacseal design eliminates gland wear. No sealing water is required. An open type 3 -bladed impellor ensures that the pump cannot choke. The working parts are built in ‘ Ferloy ’ work- hardening metal, or rubber-covered for neutral or acid circuits.

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MINING D R I L L

S T E E L

‘ H E C L A I 8 ^’

/

6

1

W m

HOLLOW O R SOLID

CATALOGUE No. 4 5 7 SENT ON REQUEST.

H A D F I E L D S L T D . , E A S T H E C L A W O R K S , S H E F F I E L D , E N G L A N D .

The Mining Magazine

Pu b l i s h e d o n t h e 1 5 t h o f e a c h m o n t h a t Sa l i s b u r y Ho u s e, Lo n d o n,

E.C.

f o r Mi n i n g Pu b l i c a t i o n s, Lt d.

Editor :

A.R.S.M., M .Sc., Assoc.Inst.M.M.

Manager : St. J. R. C.

A.R.S.M., D.I.C., F.G.S. Chairman : H. E.

O.B.E., J.P.

Telephone : MONarch

- Telegraphic Address : Oligoclase. Codes : McNeill, both Editions, & Bentley.

B

O

, N ew York : A m er. Inst. M . & M .E . S

! I. U .S.A ., $3 per annum , including postage. üer a“ 1*1111, including postage.

Vol. LXXV. No. 5. LONDON, NOVEMBER, 1946. O N E S H IL L IN G ^{PR IP F}

C O N T E N T S

D

D

M

P

E

Notes ... 274

National Coal Board ; Institution of Mining Engineers Examinations ; Tunnellers Old Comrades’ Associa­

tion ; Rand Mining Costs ; Rhodesian Subsidy for Low-Grade Gold Mines ; British Overseas Mining Association ; Opening of Selkirk Hall.

The Tin Industry... 275

Attention is called to the proposal to establish an International Tin Study Group.

The Mineral Industry of Uganda . . . . 276

A summary of a recen£ Imperial Institute lecture.

M

R

... 2 7 7 N

C

R

... 2 8 0

280 280

A

Colombian Survey . . . . TV. W. Wilson 281

Notes that include a review of the country’s mineral resources.

Cooling for the Ultra-Deep Mine

Maxwell McGuinness 292

A proposed “ high-column ” refrigeration scheme to control air temperatures at working faces.

The Czechoslovakian Non-Ferrous Metals Industry . . J. Malkovsky 295

A review of the present position.

O

- D

N

... 3 0 0 The Mill Atmosphere ; The Baum Jig ; Quebec Pilot

Plant ; Separation of Potassium and Sodium Sulphates.

L

E

“ Canadian Magnesium Production ”

Dr. W. F. Chubb 304

“ Mining Efficiency ” A . Fairfax Scott 304 E

L

... 3 0 4

N e w s L e t t e r s

Vancouver ... 3 0 6 Labour ; Atlin ; Portland Canal ; Alberni ; Victoria ; Nanaimo ; Lillooet ; Cariboo ; Osoyoos ; Nelson ; Slocan ; Yukon Territory ; Alaska ; British Guiana.

Toronto ... 3 0 9 Gold Production ; Porcupine ; Kirkland Lake ; Sudbury ; North-Western Ontario ; Manitoba ; Quebec.

Melbourne ... 311 Gold Production ; Mount Morgan ; Victorian Coal Resources ; Briseis Consolidated ; South Kalgurli Ore Treatment ; Northern Territory.

P e r s o n a l ... 3 1 4 T r a d e P a r a g r a p h s ... 3 1 4 , Fraser and Chalmers Sink and Float P lant 315 Simmonds Hi-Shear Stop Pin ... 316 Craelius XO-2 Diamond Core Drill . . . . 317 M etropolitan-Vickers Contactor U n it.... 318 M e t a l M a r k e t s ... 3 1 9 S t a t i s t i c s o f P r o d u c t i o n ... 321 P r ic e s o f C h e m ic a ls ... 3 2 3 S h a r e Q u o ta tio n s ... 3 2 4 M in in g D ig e s t

Tests w ith Shaped Charges

R. S. Lewis and G. B. Clark 325 Closed-Circuit Screening W. M . Stephen 328 Placer Gold in British C olum bia... 330 Mining French Slate ... S. Gradel 333 Geology at Eldorado, Great Bear Lake

R. M urphy 335 R e c e n t P a t e n t s P u b l i s h e d ... 3 3 8 N e w B o o k s, P a m p h le ts , e t c ... 3 3 8 S

I

t o

C

L

3 3 9

5 — 4 2 7 3

EDITORIAL

I T is interesting to note that Dr. Jacob Bakker, mining engineer of the N ether­

lands State Coal Mines, has joined the National Coal Board as Adviser to the Chief Mining Engineer.

T HE Institution of Mining Engineers recently announced that the scheme of examinations for Associate Membership is to be inaugurated in 1947. For the first five years these examinations are to be on a voluntary basis, but after April 30, 1952, admission to Associate grade is to be re­

stricted to applicants who have qualified by examination.

O LD Tunnellers will be interested to learn that it is proposed to hold a Reunion Dinner in London about March next.

Members of the Tunnellers Old Comrades’

Association who are interested are asked to communicate with the Honorary Secretary of the Association, c/o the Institution of Mining and Metallurgy.

A T a special meeting of the Transvaal Chamber of Mines held last month Mr. G. Carleton Jones, the president, re­

viewed the demands being made at present on the gold-mining industry by the Union Government, suggesting that if costs con­

tinued to rise at the present rate it was likely that the consequent closure of mines would precipitate a decline in employment. In this connexion note should' be taken of the renewed claims of native workers for in­

creased rates of pay If these are granted they could be met by deliberately raising the grade of ore milled, although such a step could be taken only at the risk of advancing the demise of some of the lower-grade pro­

ducers. The alternative would seem to be a revision of taxation policy by the Union Government and this has already been suggested by representatives of the Rand Mineworkers’ Union.

E A R LIER this m onth a motion was approved in the Rhodesian Legislative Assembly tem porarily accepting the principle of subsidizing the operations of low-grade gold mines. The Southern Rhodesian Minister of Mines and Public W orks said the intention was to support the activities of mines with a chance of becoming economic producers. The maximum subsidy allowable would be 40s. an oz. and, while a 5% margin between revenue and working costs would be perm itted, no profit on any such operation was envisaged. Earlier the Minister had suggested that any such subsidy should be available : (a) W hen a mine is unable to continue under present conditions, but has a reasonable chance of becoming an economic producer, and (b) when the closure of a mine would result in a serious economic loss to the community or a perm anent loss of ore which would be recoverable if subsidized.

I N the course of his address at the first general meeting of the British Overseas Mining Association, held on November 11 in London, the Hon. R. M. Preston, who presided in the absence of the president, Lord Geddes, drew attention once again to the Association’s direct succession to the Mining Taxation Committee, set up and financed by 12 of the principal London mining houses. The work of the Taxation Committee has been taken over by the Taxation and Tariffs Sub-Committee of the Association, which has, in addition, set up three other Sub-Committees. The first of these is concerned with the Association’s finances, while the second—the Public Relations and Liaison Sub-Committee—

preserves contacts with Government depart­

ments and other organizations connected with mining and metallurgy. Lastly there is an Information and Statistics Sub-Com­

mittee to circulate current information to

members. In this connexion it is interesting

to note that in conjunction with the British

Non-Ferrous Metals Federation and the

British Non-Ferrous Smelters’ Association

it is hoped to establish a British Bureau of

Non-Ferrous Metals Statistics early in 1947

274

NOVEMBER, 1946 275

T H E ceremony of opening Selkirk Hall, 50 Holland Park, London, W. 11, took place on October 24. This is the first of the halls of residence for students of the Imperial College and is the gift of Mr. William Selkirk.

In some introductory remarks the Rector (Mr. R. V. Southwell) paid tribute to the founder’s generosity and referred also to the scholarships in mining which the same benefactor has endowed. Mr. Selkirk, after formally unlocking the door, made a short speech in reply, in the course of which he referred to his early training as a mining engineer as being of a more practical kind as there were few colleges in existence in those days. Of the benefits of such accommodation he rightly said : “ I do not see that it can be other than a great advantage. It gives them excellent oppor­

tunities for further studying if they wish, opportunities for discussions with students who are studying other branches of engineering, and the advantage of learning how to live in harm ony with their fellow students. . . . Students will, I trust, derive great benefit from the scholarships and from the use of this hall.” He also expressed the hope that successful past students and others interested in mining might be persuaded by his example to come forward and assist in the establishment of similar residences—a hope which wre can only echo. It is not without interest to add that of the available places in this first Im perial College Hall of Residence half are at present taken by students of the Royal School of Mines, although it m ust be emphasized that places are open to students of all three colleges.

The Tin Industry

It was suggested in our last issue that the International Tin Conference then being held in London might be able, in broad terms, to define the future of control in the industry.

Actually decisions on these lines were taken.

Briefly it can be said that the main tasks of the Conference were to survey the present position of the tin-producing industry and to review possible future supplies of the metal in the light of probable trends in consumption and production, taking into account the tremendous task of rehabilitation that faces those at work in the Far East. It was proposed accordingly that recommendations should be made to the interested Govern­

ments that during the expected period of tin

shortage thought likely to cover the next two years the allocation of the metal should remain in the hands of the Combined Tin Committee in W ashington and also that consideration should be given to the establish­

m ent of an International Tin Study Group.

Following the Conference the head of the United Kingdom delegation, Mr. G. Archer, of the Ministry of Supply, stated that the Study Group, if set up, would be on similar lines to th at already established for rubber, which had now been at work for two years.

The two groups would be planned to fit into the general pattern of the international trade organization already envisaged and now' being considered. The duties of such groups are to find ways and means of dealing with possible situations that m ay arise and to make recom­

m endations to the interested Governments.

It is hoped, as our Metal Markets corre­

spondent points out elsew'here in this issue, that the new Study Group wall be able to start work at the end of the current year, when the current International Agreement is due to conclude.

From the evidence presented to the Con­

ference it emerges that tin production for 1946 has been estim ated at 94,000 tons and that consumption, largely by drawing on existing stockpiles, would reach 137,000 to n s;

production for 1947 is expected to reach 142,000 tons. It is thought that by 1948 this figure will have reached some 190,000 tons, but that the 200,000 mark wall not be attained until the following year. The general con­

clusion is reached, therefore, that, after making full allowance for uncertainties, there is unlikely to be an excess production of tin for the next two years and that any question of production control does not call for urgent attention.

Meanwhile in the Far East it w'ould seem

that the path to rehabilitation is not proving

as smooth as was at one time expected, lack

of' supplies and political difficulties standing

much in the way. At the end of September

stocks of tin ore in the United Kingdom

amounted to 8,052 long tons, a reduction of

nearly 1,000 tons as compared with stocks

at the beginning of the month, when they

stood at 9,049 long tons. Official figures

show that stocks of tin metal held by the

Ministry of Supply on September 30 were

8,738 tons, compared with 9,267 tons at the

beginning of the month, w'hile stocks held by

consumers at the end of September were

calculated at 4,237 tons and reported to be

3,908 tons. There were no arrivals of tin