H j , - iiie.-ço,
Mining Magazine
Managing Director : W . F . W h i t e . Assistant : St. J . R . C. S h e p h e r d ,
A .R .S.M ., D .I.C ., F.G .S.
E d ito r : E d w a r d W a l k e r , M .Sc., F.G .S.
A ssis ta n t: F . H i g h a m ,
A .R .S.M ., M .Sc., F .G .S.
i;1"
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 b y Mi n i n g Pu b l i c a t i o n s, Li m i t e d, a t Sa l i s b u r y Ho u s e, Lo n d o n, E . C . 2 .
Oligoclase. Codes : M c N e ill, b o th E ditions, & B e n tle y . Telephone : L o n d o n W a ll 8938. Telegraphic A ddress :
„ „ / N e w Y o rk : A mer. In s t. M. & M.E.
B r a n c h O f f i c e ^ C h ic ag o : 360, N . M ichigan Blvd.
]1 2 s. p er annum , including postage.
Subscription j u .S A., $3 p er annum , including postage.
Vol. XL1. No. 3. L O N D O N , S E P T E M B E R , 1929.
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Notes ... 130
The Mi n i n g Ma g a z i n e Staff ; Sir Jo h n Cass In stitu te ; Imperial Sm elting C orporation ; In te rn atio n a l Con
gress of Mines, M etallurgy an d Applied G eo lo g y ; The Tin Producers’ Association ; Birm ingham Mining Research L a b o ra to ry ; E m pire M arketing B oard ; The Sinoia C u t ; D r. Pirow on S outh Africa’s future and Sir Thom as H olland on th e U nion’s Iron and Steel In d u stry .
The T h ird E m p ire M ining C ongress . . 131
Arrangements for th e S outh African m eetin g are briefly described.
Secondary M etals in th e U n ite d S ta te s 132
Interesting figures are given for th e o u tp u t of ‘ ‘ recovered ’ ’ metals.
The L im popo B r id g e ... 133
The opening of the B eit B ridge and future develop
ments in Rhodesia are discussed.
Re v i e w o f Mi n i n g... 1 3 4 Ar t ic l e s
The G eology of S able A n telo p e a n d N eighbouring M ines, N o rth -W e s te rn R hodesia
R. M u rra y-H u g h es a nd A . A . F itc h The V o lum etric E s tim a tio n of L ea d
by th e M o lybdate M ethod
/ . E . Clennell The S o u th T e rra s R a d iu m D ep o sit,
Cornwall
T . Robertson and H . G. D in es Book Re v i e w s
Eve and K e y s’ '' A p p lied G eophysics in th e Search for M inerals ” ... H . Shaw
"G eophysical P ro sp ectin g ” H . Shaw N iggli’s “ Ore D eposits of M agm atic O rigin ”
T ran slated b y H . C. B oydell
A . B ram m all Brown an d D e b e n h a m ’s “ S tru c tu re a n d S u rfa c e ” ... A . B ram m all H entze’s “ S in te rn , Scbm elzen u nd
Y erblasen Sulfidischer E rze u n d H iitte n - p ro d u k te ” ... H en ry L ouis G m elin’s “ H a n d b u ch d er A norganischen
Chemie : E isen ” ... M . S. Fisher Ne w s Le t t e r s
Jo h a n n esb u rg ... 157
N itrate D eposits in S.W. Africa ; D iam ond Fields of T anganyika ; The New Coalfield ; A New E xtraction Process ; Im p o rtan t discovery of Asbestos ; Railway to th e Chrome an d A sbestos F ie ld s ; Aeroplanes for M ining Engineers.
137
142
147
153 154
155 155
156 157
PA G E
B r i s b a n e ... 1 5 9 M ount Morgan ; Chillagoe Ore T r e a tm e n t; N orth
Queensland Mining ; M ount I s a ; The Coal I n d u s tr y ; New Guinea Leases.
V a n c o u v e r ... 1 6 1 T he K ootenays ; B ritannia Beach ; P ortla n d C a n a l;
V ancouver Island ; Peace R iver Region ; R eport of Progress.
T o r o n t o ... 1 6 3 S u dbury D istrict ; P o rcu p in e; K irkland Lake ;
R ouyn ; P atricia D is tr ic t; M anitoba ; Chibougamou.
C a m b o r n e ... 1 6 6 In tro d u c tio n ; W heal K i t t y ; P o lh ig e y ; J a n t a r ;
U nem ploym ent in the Mining D istricts.
Pe r s o n a l... 1 6 7 Tr a d e Pa r a g r a p h s ... 1 6 8 T he B ridge-M eg R esistan c e T e s te r ... 169 N ew E q u ip m e n t a t th e B arn sto n e C em ent
W o r k s ... 169 Me t a l Ma r k e t s ... 1 7 1 St a t i s t i c s o f Pr o d u c t i o n... 1 7 3 Pr i c e s o f Ch e m i c a l s... 1 7 5 Sh a r e Qu o t a t i o n s ... 1 7 6 Mi n i n g Di g e s t
C o n c en tratio n b y Jigs on T in D redges
O. B . W illiam s 177 P la tin u m C o n cen tratio n in S o u th A frica
T . K . Prentice 180 T h e P ro b le m of S eco n d ary T in in B o liv ia
(concluded from A u g u st issue, p. 115) Joseph T . Singewald, J r . 183 T h e C ayzer T in -S m eltin g F u r n a c e ... 185 O p en -cu t M ining
F . E . Cash and M . W . von Bernew itz 187 S m elting a t R io T in to ... H . R . Potts 188 W a te rv a l P l a t i n u m ... 188 A nodes for E le ctro ly tic Zinc
U. C. T a in to n 189 S tro n tiu m Supplies --- R . M . Santm yevs 189 Sh o r t No t i c e s... 1 9 0 Re c e n t Pa t e n t s Pu b l i s h e d ... 1 9 1 Ne w Bo o k s, Pa m p h l e t s, e t c... 1 9 1 Co m p a n y Re p o r t s ... 1 9 2 F abulosa Mines Consolidated ; R hodesia B roken H ill D evelop
m en t ; Rhodesian and General Asbestos C orporation ; T etiuhe Mining C orporation ; W aihi G rand Ju n ctio n .
Di v i d e n d s De c l a r e d... 1 9 2 Ne w Co m p a n i e s Re g i s t e r e d... 1 9 2
3—3 129
E D IT O R IA L
T
H E c u rre n t issue m a rk s th e co m m e n ce m en t of th e 2 1 st y e a r of p u b lic a tio n of th e M a g a z i n e . Mr. E d w a rd W a lk e r h a s b ee n co n n e c te d w ith it since its in c ep tio n a n d h a s b ee n e d ito r since 1916, w hen Mr. W . F . W h ite b ec am e m a n a g in g d ire c to r. A s re c o rd e d on th e c o n te n ts p ag e since J u ly , Mr. F . H ig h a m , A .R .S .M ., M.Sc., F .G .S ., is now a s s is ta n t to th e e d ito r a n d Mr. S t. J . R . C. S h ep h erd , A .R .S .M ., D .I.C ., F .G .S ., w ho h a s b e e n w ith th e Ma g a z i n e fo r th e p a s t fo u r y e a rs, a s s is ta n t to th e m a n a g in g d irec to r.T
H E 1929-30 Session of th e S ir J o h n Cass T echnical I n s titu te , of Je w ry S tre e t, A ld g ate, com m ences th is m o n th . T h e classes, w h ich are h e ld in th e evenings, in c lu d e a course on m e ta llu rg y w h ich m e e ts th e re q u ire m e n ts for th e L o n d o n degree of B .Sc. in E n g in eerin g .A
T th e s ta tu to r y m e e tin g of th e Im p e ria l S m eltin g C o rp o ra tio n it w as a n n o u n c e d th a t 750,000 o rd in a ry sh a re s w o u ld be offered for su b sc rip tio n a t a n e a rly d a te in o rd e r to p ro v id e fu n d s for th e e x ten sio n of w orks.T h e c h a irm a n also s ta te d t h a t befo re long co p p e r sm e ltin g w o u ld b e co m m en c ed a n d t h a t a rra n g e m e n ts h a d b e e n m a d e for th e m a n u fa c tu re of zinc w h ite a n d lith o p o n e.
A
N I n te r n a tio n a l C ongress of M ines, M etallu rg y , a n d A p p lie d G eology is to b e h e ld a t Liège n e x t y e a r in co n n e ctio n w ith th e I n te r n a tio n a l E x h ib itio n . T h e a rra n g e m e n ts are in th e h a n d s of L ’A ssociatio n des In g é n ie u rs S o rtis d e l ’E co le de Liège a n d L a Société G éologique d e B elge à Liège, a n d in fo rm a tio n c a n b e o b ta in e d from M. L epersonne, 16, Q u ai des E t a t s U nis, Liège. T h e C ongress w ill la s t fo r a w eek a t th e e n d of J u n e a n d w ill in c lu d e th e u su a l m eetin g s, rec ep tio n s, v is its to w orks, a n d o th e r fu n c tio n s.
T
H E T in P ro d u c e rs ’ A sso ciatio n , th e o b je c ts of w hich w ere d iscu ssed la st m o n th , h as been re g iste re d as a c o m p a n y lim ite d b y g u a ra n te e a n d S ir P h ilip C unliffe-L ister, M .P. (ex -P re sid e n t of th e B o a rd of T ra d e ), h a s co n sen te d to beco m e c h a irm a n of th e A ssociation a n d of th e C ouncil. A n E x e c u tiv e C o m m ittee of C ouncil h a s also b ee n a p p o in te d , w ith S ir W illia m B. P e a t, th e e m in e n t c h a rte re d a c c o u n ta n t, asd e p e n d e n t c h a irm a n . I t is n o ta b le that Mr. C. V. T h o m a s, h e a d of th e Tronoh g ro u p , a n d Mr. F . E . M air, representing th e O sb o rn e-C h ap p el g ro u p , are members of th is co m m ittee .
T
H E E m p ire M a rk e tin g B o a rd is a G o v e rn m e n t D e p a rtm e n t w hich does n o t com e v e ry p ro m in e n tly before th e notice of m in in g engineers. P e rh a p s its only direct c o n n e ctio n w ith m in in g h a s been its associatio n w ith th e I m p e ria l G eophysical Experi
m e n ta l S u rv e y , som e p a rtic u la rs of which w ere g iv e n in th e la s t issue. Indirectly, h o w ev e r, th e fo ste rin g of ex h ib itio n s by the B o a rd h a s b een of a d v a n ta g e to th e mining w o rld in m a n y w ays. In looking through the r e p o r t for th e p e rio d fro m its foundation to th e e n d of M arch la s t w e also find reference to o th e r w o rk fin an ced b y th e B oard that w ill a p p e a l to th e m in in g m a n . F o r instance, th e re se a rc h in to c o n d itio n s of cold storage of food— a m a tte r of im p o rta n c e in hot c o u n trie s — ch e a p m e c h a n ic a l tra n s p o rt in o u t- of - th e - w a y p laces, a n d m eans for su p p ressin g p e s ts su c h as th e tsetse fly.
T a k in g it a lto g e th e r, th e re fo re , th e B oard is a n o rg a n iz a tio n c o n c e rn in g th e existence of w hich th e m in in g m a n sh o u ld n o t be entirely u n co g n iza n t.
S
O M E tim e ago a d e s c rip tio n w as given in th e se p ag e s of th e M ining Research L a b o r a to ry w h ich is a n a d ju n c t of Birmingh a m U n iv e rsity . T h e re p o r t of th e work d o n e d u rin g 1928, w h ich h a s ju st been p u b lish e d , gives a n o u tlin e of th e many p ro b le m s t h a t a re rec eiv in g th e atten tio n of th e d ire c to rs of th e la b o ra to ry . Like many o th e r sim ila r in s titu tio n s its energies are c ra m p e d b y sh o rtn e s s of fu n d s and con
te m p la te d ex te n sio n s of th e buildings have h a d to b e p o stp o n e d . A m ong th e many s u b je c ts rec eiv in g a tte n tio n m ay be m e n tio n e d th e d eh u m id ify in g of m ine air by m e a n s of silica gel, th e liq u efactio n of cod b y h y d ro g e n a tio n th ro u g h th e action of v a rio u s c a ta ly s ts , of w h ich ammonium m o ly b d a te a p p e a rs to h a v e been th e most successful, a n d th e sp o n ta n e o u s combustion of coal.
m -
I
N J u n e la st, w h en d iscu ssin g Rhodesian d ev e lo p m e n ts, w e s ta te d t h a t, though th e S in o ia-K afu e s h o rt c u t b etw e e n Beira a n d N o rth e rn R h o d e sia w as h e ld u p b y the ra ilw a y a u th o ritie s , th e p e r s is te n t demands 130;\ ^ »otjj; for if w ould r e s u lt in p re se n t o b je ctio n s p i oi t(#: being overcom e. U n fo rtu n a te ly for , ^ir, it-, Rhodesians, a f u rth e r official refu sal to are consider th e p ro je c t h a s b een issued. T h e authorities are d efin itely of opinion t h a t th e construction of su c h a line w o u ld e n ta il a Jdescriptiu serious loss to th e a d m in is tra tio n , for it of the 111» '" would m ean th e m a in te n a n c e of tw o railw a y is an 3 . : lines w ith v e ry little increase in traffic.
He ret® ; To make u p for th is e x tr a co st of o p e ra tin g ' v T ; the railways it w ould be n ec essary to raise H ojtif! d the rates to such a n e x te n t t h a t th e cost
' ■ of hauling b y th e new a n d sh o rte r ro u te e hborat f!lli would in effect b e h ig h e r th a n th e p re se n t
; : charges b y th e longer ro u te . T h e railw ays, ties I''° - to consequence, w ill n o t co n sid er th e p ro p o sal
- «ice until the tim e arriv e s w h en m ore local traffic is in p ro sp ect.
" attend | ---
■ftijofii T N R . H A N S P I R O W , G o v ern m e n t M ining ' .y A —: U E ngineer to th e U n io n of S o u th
W'-'tigh tie c Africa, h as sim u lta n eo u sly issued h is re p o rt
■'I Td £ for 19 2 8 a n d d eliv ered a p re sid e n tia l ad d re ss s to have beasft f0 fbe Chem ical, M etallurgical, a n d M ining tspontaiHK® Society. As re g a rd s gold, he e s tim a te d t h a t
another th o u sa n d m illion p o u n d s ’ w o rth remains to be e x tra c te d on th e R a n d a n d r : - : its extensions a n d he p o in te d o u t t h a t
■ diamonds will give in c re asin g rev e n u e for nientlv before some years, b u t h e r e ite r a te d th e g en e ral o. Perhapsitri belief th a t S o u th A frica will d ep e n d in th e mmghasbeenitn future on coal a n d b ase m e ta ls r a th e r th a n erialGeophysoll on gold a n d diam o n d s. One of th e v isito rs a t me partiafc: the m eeting w as Sir T h o m a s H . H ollan d , ie last is* i who followed u p his ad d re ss b efore th e B ritish rmgofeihibitaE: Association on th e w o rld ’s resources of
afaitajetote minerals a n d m e ta ls w ith d e ta ile d a rg u m e n ts s. Inlookmgtlra on the sub ject. In p o in t of fac t, he re -s ta te d od from its foffiie the views w hich he h a d ex p ressed in p rev io u s ast we also idt years before th e I n s titu tio n of M ining an d anted bv the Ik Metallurgy a n d th e E m p ire C ongress in jujngna F«® Canada. H e is a far-seeing m a n , w ho can
•onditionsofcdis state his opinions w ith clearness a n d force, . 0[ jjuportai and w h atev er m a y be th e a c tu a l re su lt of lechanical taf his cam paigns h is services in d raw in g (aces and m* attention to th e e x h a u s tib ility of o u r m in e ral jcii'astiet® resources an d to th e folly of o u r p re se n t therefore, tl*^ Micawberlike a t titu d e c a n n o t b e gain said . ,mini itee®& ^ ne ^he m o st in te re stin g of h is re m a rk s
-hould not k® at the S o u th A frican m e etin g w as to th e effect that a n y c o u n try , to g et full benefit of its base m e ta l o u tp u t, m u st h a v e a hom e focussing M*1 industry b ased on iron a n d ste el m a n u fa c tu re , stated ttafl ^ is or|iy in th is w ay th a t a c o u n try can
cut bet"'®1' esta b lish m a n u fa c tu re s on a larg e scale.
® ¿eld f I O therwise th e m e ta ls are e x p o rte d to th o se 1 rsjstent dec lands w here th e re is a co n su m p tiv e dem an d
a n d th e tr a n s a c tio n s e n d as fa r as th e p ro d u cin g c o u n try is con cern ed . U n d o u b te d ly S ir T h o m a s ’s su g g e stio n s w ill c a rry w eight a n d w ill en c o u rag e th o se w hose a m b itio n is to e x p a n d S o u th A fric a ’s iro n a n d ste el in d u s try a n d p lace it on a p e rm a n e n t a n d p ro fita b le basis.
T h e T h ir d E m p ir e M in in g C o n g r e s s W ith th e to u rs of th e B ritis h A sso ciatio n a n d th e In te r n a tio n a l G eological Congress over, u n d iv id e d a tte n tio n c a n now b e given to m a k in g a success of th e T h ird (Triennial) E m p ire M ining a n d M etallu rg ical Congress, to b e h e ld in S o u th A frica e a rly n e x t y ea r.
T h e first C ongress w as h eld in 1924 a t th e W em b ley E x h ib itio n a n d th e second to o k th e form of a to u r th ro u g h C a n a d a d u rin g 1927, w h ich is still fresh in th e m em o ry of o u r rea d ers. T h e p ro g ra m m e for th e th ir d C ongress, as m a p p e d b y th e co m m itte e fo rm e d b y th e S o u th A frican I n s titu tio n of E n g in e ers a n d th e Chem ical, M etallurgical, a n d M ining S ociety of S o u th A frica, w hich is u n d e r th e p resid e n cy of Sir E rn e s t O pp en h eim er a n d h a s th e a c tiv e su p p o rt of th e G o v ern m e n ts of th e U nion a n d th e R ho d esias, prom ises to b e as com prehensive a n d of as g re a t in te re s t as t h a t of th e C a n ad ian v isit. T h e C ongress will open a t Cape T ow n on M arch 24, w ith a session a t w hich a n in a u g u ra l a d d re ss w ill b e given.
T h e tw o follow ing d a y s will b e d e v o te d to a fu rth e r session a n d to v isits in cluding C ape P o in t, th e B o ta n ic a l G ardens, a n d G roote S chuur. T h e p a r ty w ill th e n leave b y tr a in for K im b erley , w h ere tw o d a y s will be sp e n t a t th e d ia m o n d m ines. P roceeding th e n c e to Jo h a n n e sb u rg , th re e d a y s will b e occupied in v isitin g th e gold a n d coal m ines a n d in ho ld in g th re e sessions. T h e n e x t p lace of h a lt w ill b e M afeking, w here th e v isit w ill be only b rief— ju s t long enough for th e p a r ty to jo in in th e re g re t of t h e in h a b ita n ts th a t Sir R o b e rt B ad en -P o w ell d id n o t choose “ L o rd M afeking ” as h is title — a n d n e x t d a y th e v isito rs will rea ch B u law ay o . H ere a fu rth e r session w ill b e held a n d su b se q u e n tly th e p a r ty w ill sp lit in to tw o, ta k in g different ro u te s fro m A p ril 10 to 18 a n d jo in in g ag ain a t B ulaw ayo.
N o. 1 to u r w ill cover W a n k ie C olliery a n d B ro k en H ill, B w an a M’K u b w a, N ’K a n a , an d R o a n A n telope m ines, a n d on th e r e tu r n jo u rn e y tw o d a y s w ill b e sp e n t a t V ic to ria F alls. T hose ta k in g to u r No. 2 will v isit W ankie, th e V icto ria F alls, th e Z im babw e
132 T H E M IN IN G M A G A Z IN E
ru in s, S alisb u ry , th e S h a m v a gold m ine, a n d th e S h a b a n i asb esto s m ines. B o th to u r s will d e v o te h a lf a d a y to th e M ato p o H ills, th e
“ V iew of th e W o rld , ” 18 m iles from B u law ay o , w h ere Cecil R h o d e s lies b u rie d in co m p a n y w ith D r. Ja m e so n a n d Sir C harles C oghlan, th e first P rim e M in ister of R h o d esia. T h e tw o p a rtie s w ill th e n jo in a n d v isit P re to ria , th e P re m ie r d ia m o n d m ine, th e A m ia n th u s asb esto s m ine, th e K ru g e r N a tio n a l P a rk , a n d th e B a rb e rto n gold m ines, a n d th e n p ass in to N a ta l, w h ere th e coal m ines a n d ste el w o rk s w ill b e in sp e cte d a n d v isits p a id to L a d y s m ith , Colenso, a n d D u rb a n . F in a lly th e itin e r a ry includes B loem fontein, P o r t E liz a b e th , O u d tsh o o m — n e a r w hich a re th e Cango s ta la c tite cav es— a n d th e K n y s n a fo rests, a n d th e to u r will conclude a t C ape T ow n on M ay 8. I n th e a c c o u n t giv en h e re n o m e n tio n h a s been m a d e of th e p la tin u m w o rk in g s a n d of o th e r m in in g o p e ra tio n s of som e im p o rta n c e , b u t it is p ro b a b le t h a t if th e re is sufficient desire ex p re ssed to v isit th e se ce n tres a rra n g e m e n ts m a y b e m a d e to squeeze th e m in som ew here. N e ith e r is S o u th -W est A frica in c lu d e d in th e to u r, a n d h ere a g a in som e m o d ific atio n of o r a d d itio n to th e p ro g ra m m e m a y b e m a d e.
T o th e v isito rs th e m in in g d is tric ts w ill be th e p rim a ry o b je c ts of in te r e s t fro m a p rofessional p o in t of view , b u t th e ir h o sts will h a v e m u c h else to show th e m . T h e scenery a n d th e o th e r in d u strie s w ill receiv e a tte n tio n a n d e v e ry th in g w hich is of special a ttr a c tio n w ill be seen. S om e of th e se sig h ts h a v e a lre a d y b ee n m e n tio n e d in th e foregoing a c c o u n t of th e to u r, b u t th e re are m a n y o th e rs in c lu d ed in th e p ro g ra m m e . T h e asc e n t b y ra ilw a y of th e H e x R iv e r M oun tain s to th e p la te a u of th e K a rro o p ro v id es a n o ta b le view . T h e g am e p rese rv e a t th e K ru g e r P a r k w ill b e of e x c e p tio n a l in te re st to b o th zoologist a n d h u n te r, for it is believ ed t h a t specim ens in p le n ty of ev e ry A frican a n im a l a re to b e fo u n d th e re , a n d as th e p a r k occupies 9,000 sq u a re m iles th e y live u n d e r n a tu r a l co n d itio n s. O strich lan d , th e T o v e rw a te rp o o rt defile, a n d th e p a n o ra m a of th e D ra k e n sb e rg a re also u n fo rg e tta b le fe a tu re s of th e c o n tin e n t.
As reg a rd s th e cost of th e v isit, th e official figure for th e p e rio d fro m M arch 24 to M ay 8 is given a t £140 to £150, w hich includes h o te l a c co m m o d atio n a n d tra n s p o r t b y ra il a n d m o to r, in fa c t e v e ry th in g ex c ep t d rin k s a n d tobacco. T o th is m u s t b e a d d e d th e fare b y ste a m e r from E n g la n d o r o th e r
s ta rtin g p o in t. T hese fares v a r y widely ac co rd in g to ac co m m o d a tio n a n d th e speed of th e vessels. O n th e U nion-C astle line th e y m a y b e a n y th in g fro m £75 to £160 for th e r e tu r n jo u rn e y fro m E ngland to C ape T ow n, less 20% re b a te for members of th e p a r ty . In conclusion i t should be a d d e d t h a t th o se d esirous to participate in th e tr ip sh o u ld co m m u n ic a te without d e la y w ith C ongress H e a d q u a rte rs, 100, F o x S tre e t, Jo h a n n e s b u rg , o r w ith Mr. C.
M cD erm id, 225, C ity R o a d , L ondon, E.C.
S e c o n d a r y M e t a ls in t h e U n i t e d S t a t e s
T h e U n ite d S ta te s B u re a u of Mines p u b lish es fa irly d e ta ile d e s tim a te s of the o u tp u t of se c o n d a ry m e ta ls ev ery year—
t h a t is, th e a m o u n t of m e ta l produced fro m sc ra p a n d w aste. T h ese statistics, as w as m e n tio n e d b y Mr. J . B. Richardson in h is p a p e r before th e I n s titu tio n of Mining a n d M e tallu rg y la s t D ecem ber, are of im p o rta n c e in a rriv in g a t a c c u ra te figures for th e to ta l a m o u n t of m e ta l com ing on th e m a rk e t, a n d th e in c re asin g proportions of se c o n d a ry m e ta ls rec o v ered indicate the a tte n tio n p a id to th e conserving of the w o rld ’s m e ta l resources. T h e following ta b le gives th e figures for th e production of se c o n d a ry m e ta ls w ith in th e United S ta te s d u rin g th e y e a r 1928 :—
S h o rt Tons C opper, in clu d in g t h a t in alloys
o th e r th a n b ra ss . B rass sc rap re m e lte d L ea d as m e ta l L ea d in alloys Zinc as m e ta l
Zinc reco v ered in b rass Zinc in alloys o th e r th a n b rass T in as m e ta l .
T in in alloys a n d ch em ical com po u n d s
A n tim o n y as m e ta l A n tim o n y in alloys A lu m in iu m as m e ta l A lu m in iu m in alloys N ic k el as m eta l
N ick el in n o n -ferro u s alloys an d
sa lts . . . . .
T h e a m o u n t of se c o n d a ry c o p p e r produced as m e ta l w as 230,000 s h o rt to n s, while 211,400 to n s of c o p p e r w as co n tain e d in se co n d a ry b ra ss a n d 95,000 to n s in alloys o th e r th a n b rass, m a k in g a t o t a l recovery of no less th a n 536,400 to n s of copper. As reg a rd s zinc, in a d d itio n to th e recovery as sp e lte r a n d alloys, it is e s tim a te d that
325.000 302.000 138.000 170,600
70,700 66 ,000 12,500 8 ,2 00 27,600 745 11,155 24,500 23,300 635
Mtcros l i oil
teas I
3,865
6,208 to n s of zinc d u s t w as m a d e fro m zinc
1 't y
dross and t h a t 12,186 to n s of zinc w as contained in 61,665 to n s of lith o p o n e m a d e from zinc sk im m in g s a n d ashes, w hile 9,692 tons of zinc w as c o n ta in e d in 44,057 tons of zinc ch lo rid e m a d e from sim ilar material. Som e d e ta ils a re also a v a ila b le relating to th e rec o v ery of tin . T h e d etin n in g plants tr e a te d 215,431 to n s of clean tin plate scrap a n d 550 to n s of old tin -c o a te d containers a n d rec o v ered 877 to n s of m e ta llic tin and 2,216 to n s of tin in th e form of 4,592 tons of oxide a n d chlorides. I t ap p e ars, therefore, t h a t th e in d u s try of co llecting tin from old tin can s h a s m a d e no progress in the U nited S tate s.
To give some id e a of th e re la tiv e a m o u n ts of prim ary a n d seco n d a ry m e ta ls p ro d u ce d in the U n ited S ta te s, it m a y be sa id th a t th e outputs of se co n d a ry copper, le ad , a n d zinc were 536,400 to n s, 308,600 to n s, a n d 149,200 to n s resp e ctiv ely , c o m p ared w ith 1,103,000 tons, 780,000 to n s, a n d 594,500 tons of th e p rim a ry m e tals. A s re g a rd s tin, the to ta l of p rim a ry tin , 87,327 to n s, w as imported. I t m u s t be rem e m b ere d in m a k in g these com parisons th a t som e of th e seco n d ary metal m ay h a v e been re-w o rk ed m ore th a n once. N ev e rth ele ss th e p ro p o rtio n of secondary to p rim a ry m e ta l seem s large.
Perhaps th is is due to th e fa c t t h a t A m ericans scrap th e ir m a c h in e ry so lib erally .
of th e R h o d e sia n railw a y s w ith D elagoa B a y a n d th e pro v isio n of an a lte r n a tiv e ro u te from B u law ay o to P re to ria a n d J o h a n n e sb u rg . In th e m e a n tim e , befo re th is co n n e ctin g ra ilw a y is b u ilt, th e b rid g e w ill afford v a lu a b le fac ilities to ro a d traffic, b o th h e a v y a n d lig h t.
T h e m a in m o to r ro ad s so u th w a rd s in R h o d e sia , fro m S a lisb u ry via V ic to ria a n d from B u law ay o via G w anda, converge on th e b rid g e a n d th e th r o u g h traffic w ill be im m en se ly f a c ilita te d b y its existence.
W e h a v e sa id t h a t th e b u ild in g of th e b rid g e d raw s a tte n tio n to th e v a lu e of th e
T h e L im p o p o B r id g e
The opening on A u g u st 31 of th e b rid g e over th e L im p o p o R iv er, co n n e ctin g th e Transvaal w ith S o u th e rn R h o d esia, m a rk s another ste p in th e e s ta b lish m e n t of a d e q u a te com m unications in S o u th A frica a n d in c i
dentally calls a tte n tio n once m ore to th e beneficent effect of th e A lfred B e it T ru s t.
The bridge crosses th e riv e r a t a p o in t nin e miles n o rth of th e M essina co p p er m ine. I t is 1,560 ft. long, 32 ft. w ide, a n d co n sists of fourteen steel spans, a n d it is d esigned in such a w ay as to a c c o m m o d a te b o th ra ilw a y and ro ad traffic. T h e b u ild in g h a s b e e n in the h an d s of th e S o u th A frican R a ilw a y A dm inistration, w h ich is also b u ild in g a m ile of railw ay in to R hodesia, w here a to w n sh ip called “ B e itb rid g e ” is bein g founded. T h is new to w n sh ip is s itu a te d a b o u t 90 m iles from W e st N icholson, w hich is th e p re se n t term inus of a s p u r line ru n n in g s o u th from B ulaw ayo. A glance a t th e m a p w ill show th a t th e logical conclusion of th e en te rp rise will be th e c o n tin u a tio n of th e lin e from W est N icholson to th e b rid g e a n d th u s th e lin k in g
A lfred B e it T ru s t to S o u th A frican dev elo p m e n t. T h e la te A lfred B e it h a d alw ay s to ld Cecil R h o d e s t h a t co m m u n ic atio n s w ere th e k e y to S o u th A frican p ro s p e rity a n d w hen he d ied he le ft a la rg e su m of m o n e y to b e u se d in p ro m o tin g schem es for th e e s ta b lish m e n t of such com m u n icatio n s, th is m o n e y bein g v e s te d in a b o d y called th e B e it R a ilw a y T ru s t. I t h a s a lre a d y b een re c o rd e d in th e se p ages t h a t th e e x ten sio n of B e ira p o r t w as a id ed b y g r a n ts fro m th is T ru s t a n d a sim ilar g ra n t for th e b rid g e o v er th e L im popo now im p ro v e s th e p o sitio n w ith re g a rd to D ela g o a B a y .
R E V IE W O F M IN IN G
I n t r o d u c t io n .— Mr. S n o w d e n ’s s tr a ig h t t a lk a b o u t B r ita in ’s b u r d e n h a s h a d a s a tis fa c to ry effect a n d o u r sh a re in th e r e p a ra tio n s h a s b e e n in c re ase d . T h is in c id e n t h a s s tre n g th e n e d o u r p o sitio n m o ra lly a n d fin an c ially . T h e coal a n d iro n tr a d e s of th is c o u n try show som e im p ro v e m e n t a n d th e ra ilw a y re c e ip ts from goods traffic h a v e in c re ase d . T h e m erg in g of B olckow V a u g h a n a n d D o rm a n L o n g is lik e ly to a m e lio ra te c o n d itio n s, n o t o n ly on th e N o rth -E a s t co a st, b u t in th e K e n t coal a n d iro n field. T h e m e ta l m a rk e t h a s b e e n fe a tu re le ss d u rin g th e p a s t m o n th a n d th e re is no e x c ite m e n t in tin .
T r a n s v a a l.— T h e o u tp u t of gold on th e R a n d d u rin g A u g u st w as 850,952 oz.
a n d in th e o u tsid e d is tric ts 38,649 oz., m a k in g a to ta l of 889,601 oz. T h e n a tiv e s em p lo y ed on th e gold m in es a t th e e n d of A u g u st w ere 190,062, as c o m p a re d w ith 190,031 a t th e en d of J u ly .
C a p e P r o v in c e .— D r. P irow , a c tin g M in ister of M ines, h a s s ta te d in P a r lia m e n t t h a t th e A lex a n d e r d ia m o n d field in N a m a q u a la n d h a s a lre a d y y ie ld ed sto n e s v a lu e d a t £7,000,000 a n d t h a t a n o u tp u t of
£1,000,000 a y e a r fo r f o rty y e a rs m a y be expected.
T h e B ritis h Swiss I n te r n a tio n a l C o rp o ra
tio n an n o u n c es th a t it h a s p a id £302,000 to th e G o v ern m e n t of th e U n io n of S o u th A frica, th is b ein g th e e s tim a te d co st of th e ra ilw a y n ow in course of c o n s tru c tio n from K o o p m a n sfo n te in to P o stm a sb u rg . T h e M anganese C o rp o ratio n , w hich, as a lre a d y rec o rd e d in th e se colum ns, w as fo rm ed b y th e first n a m e d c o rp o ra tio n to dev elo p th e P o stm a sb u rg m a n g a n e se d ep o sits, h a s d ep o sited se cu ritie s w o rth £100,000 w ith th e U nion G o v ern m en t.
S o u t h e r n R h o d e s ia .— T h e o u tp u t of gold d u rin g J u ly is r e p o rte d a t 46,369 oz., as co m p ared w ith 48,406 oz. in J u n e a n d 48,960 oz. in J u ly la s t y e a r. O th e r o u tp u ts for J u ly w ere : S ilver, 8,774 oz. ; coal, 100,295 t o n s ; ch ro m e ore, 33,310 t o n s ; asbestos, 3,585 t o n s ; arsen ic, 14 t o n s ; co ru n d u m , 1 t o n ; m ica, 16 to n s ; tin , 5 to n s ; d ia m o n d s, 63 c a ra ts .
The C am a n d M o to r G old M ining Co.
r e p o r ts a decrease in th e ore re se rv e s b o th as re g a rd s to n n a g e a n d a s sa y v alu e . T h e figures a t th e en d of J u n e w ere 1,026,500 to n s a v e ra g in g 51s. 2d. p e r to n , as c o m p a re d w ith
1,060,000 to n s a v e ra g in g 53s. l i d . when the e s tim a te w as m a d e la s t y e a r. T h e company also s ta te s t h a t th e g ra d e of ore m ined is e x p e c te d to b e lo w er th a n n o rm a l during th e n e x t few m o n th s u n til c e rta in high-grade ore c a n b e m in e d .
N o r t h e r n R h o d e s i a .— T h e Rhodesian S election T ru s t re p o rts th e re su lts of No.
15 b o re a t M ufulira, w h ich p assed through th e second a n d th ir d ore-bodies. The true w id th of th e ore w as in d ic a te d a t 109 ft.
a v e ra g in g 3 -4 4 % copper, th e tw o ore-bodies b ein g s e p a r a te d b y o n ly 4 -3 ft. which av e ra g e d 1 • 12% copper.
T h e K a n sa n sh i co p p er-g o ld m ine, which is b ein g re o p e n e d b y th e R hodesia-K atanga Co., is to b e c o n n e c te d w ith th e Benguela R a ilw a y b y m e a n s of a b r a n c h line, partly in N o rth e r n R h o d e sia a n d p a r tl y in Portuguese A ngola. T h is line w ill b rin g th e m ine within 1,200 m iles of I.o b ito B a y . T h e la s t progress re p o r t issu ed b y th e c o m p a n y gives the ore rese rv e s so fa r d ev e lo p e d a t 1,371,510 tons av e ra g in g 6 '4 % c o p p e r a n d 5 dw t. gold per to n . T h is e s tim a te does n o t include the g r a p h itic co p p e r b e d s o r th e n o rth e rn section of th e m ine, w h ich a re lik e ly to increase these figures su b s ta n tia lly .
T h e re h a s b ee n u n e x p e c te d delay in o b ta in in g a fu ll o u tp u t of elec tro ly tic zinc at R h o d e sia B ro k e n H ill ow ing to technical difficulties, th e p la n t b ein g th e first to treat silica te of zinc w ith w hich is associated u n u s u a l m in e rals. T h ese difficulties have b een ov erco m e a n d th e o u tp u t sh o u ld become n o rm a l b y O cto b e r. T h e c a p a c ity of the p la n t w ill b e s till f u r th e r in creased when a d d itio n a l fac ilities a re p ro v id e d a t the h y d ro -e le c tric p la n t, a n d th e m o n th ly output sh o u ld th e n beco m e 1,500 to n s. Much d e v e lo p m e n t a n d p ro sp e c tin g h av e recently b ee n d one w ith th e o b je c t of discovering f u rth e r b o d ies of le a d ore, a n d b y the d ia m o n d -d rill so m e th in g lik e 200,000 tons h a v e been in d ic a te d . T h e la te s t new s is that hole L 30 s tru c k ore a t 387 ft., p a s se d through 25 ft. of silic a te of zinc, th e n 101 ft. of su lp h id e ore a s sa y in g 2 6% of le a d a n d 26% of zinc, a n d a fte rw a rd s p assed in to silicate of zinc ag a in . W h e n th e le a d position h a s b een rec tifie d it is in te n d e d to proceed w ith th e e re ctio n of a v a n a d iu m p l a n t ; in th e m e a n tim e sm a ll p a rc e ls of th e p ic k ed ore are b ein g sold. T h e c o m p a n y still requires w o rk in g c a p ita l a n d h a s d ec id e d to issue a 134
still ref
short loan of £250,000 on th e se c u rity of th e hydro-electric p la n t. I t is e x p e cted , w hen the ab o v e-m en tio n ed m e ta llu rg ic a l p ro gramme h as been co m p leted , t h a t it w ill be possible to re tire th e lo a n b y th e ta k in g u p of shares on w hich th e re are o p tio n s a t present.
T a n g a n y ik a .— R a ilw a y s in T a n g a n y ik a Territory are g ra d u a lly increasing. A fte r the com pletion of th e line from T a b o ra to Mwanza on L ak e V ic to ria , a tte n tio n w as paid to th e c o n tin u a tio n w e stw a rd of th e line from th e e a st co a st a t T a n g a . I t is n ow announced th a t th e ra ilw a y h a s b een co m pleted for a d ista n c e of 50 m ites fro m th e terminus a t M oshi, th u s rea ch in g A ru sh a.
This will help in d eveloping th e h ig h la n d s of Mt. Meru, w here th e re is a lre a d y a w h ite settlement.
D i a m o n d s .- -T h e C o n so lid ated D iam o n d Mines of S o u th -W est A frica, w h ich is u n d e r th e control of th e A nglo A m eric an C o rp o ratio n of South A frica, p u b lish es som e d e ta ils of the diam ond d ep o sits on th e shore n o r th of the O range R iv er. T h is m a rin e te rra c e has been p ro v ed for 1 0 m iles a n d th e g ro u n d is estim ated to c o n ta in a t le a st a m illion carats. B efore p ro ce ed in g to p ro d u c tio n , the com pany in te n d s to seek a la rg e r a llo t
ment for S o u th -W e st A fric a u n d e r th e agreement am o n g th e le ad in g p ro d u cers.
N ig e r ia .— T h e N o rth e rn N ig eria (Bauchi) Tin Mines re p o rts t h a t th e o u tp u t of tin concentrates d u rin g th e q u a rte r A pril to June w as 500 to n s, a n increase of 50 to n s over th e preced in g q u a r te r a n d 80 to n s greater th a n d u rin g th e co rresp o n d in g period last year. T h e o u tp u t d u rin g th e c o m p a n y ’s year ended J u n e 30 w as th u s 1,850 to n s, as compared w ith 1,710 to n s d u rin g th e p rev io u s twelve m o n th s. I t is ex p e c te d t h a t th e output will be a t a low er r a te d u rin g th e next few m o n th s, as it is d esirab le to d ev o te as m uch pow er as possible for strip p in g the o v erb u rd en d u rin g th e ra in y season.
A u s tr a lia .— As re p o rte d la s t M arch, the G olden H orse-Shoe m ine a t K algoorlie was sold to th e L ak e View a n d S ta r in order t h a t th e lodes p assin g from Lake View in to G olden H orse-S hoe g ro u n d could be w orked b y th e L ak e View, th e purchase p rice bein g 900,000 4s. shares in th e la tte r co m p an y . T h e G olden H orse- Shoe d irec to rs h a v e since d ecided to d is trib u te these sh ares am ong th e ir sh a re h o ld ers in the p ro p o rtio n of one sh a re in resp e c t of each of th e 800,000 p referre d o rd in a ry shares of 5s. each a n d one sh are for ev ery
th re e o rd in a ry sh ares, th e d istrib u tio n b ein g effected on th e liq u id a tio n of th e old co m p an y . A t th e sam e tim e a new co m p an y h a s b een form ed, called th e G olden H orse Shoe (New), L td ., w ith a c a p ita l of
£220,000 in 1,100,000 sh a re s of 4s. each, to ta k e o v er th e rem a in in g assets, w hich co n sist of 2,553,000 to n s of a c c u m u la te d ta ilin g s assay in g 7s. lOd. p er to n . A p la n t is in course o f e re c tio n for th e tr e a tm e n t of th e se ta ilin g s a t th e r a te of 40,000 to n s p e r m o n th a n d it is ex p e c te d to b e r e a d y for o p e ra tio n in J a n u a r y n e x t.
B o u ld er P ersev e ra n ce re p o rts t h a t a b ore-hole d riv en in th e 1,600 ft. level off th e L ak e View lode in a n o rth e rly d irec tio n p assed th ro u g h a n ore-b o d y w hich w as su p p o se d to be a d o w n w ard c o n tin u a tio n of th e E a s t B o u n d a ry lode fo u n d on th e 1,300 ft. level. T h e core a v e rag ed 5 oz. 4 d w t.
ov er a w id th of 1 1 ft. 4 in. A cro ss-c u t follow ing th e b ore-hole h a s su b se q u e n tly confirm ed th e v alu e in d ic a te d b y th e bore, b u t ow ing to th e k n o w n p a tc h y n a tu re of th is lode on th e 1,300 ft. level m ore w o rk is to be done on it on th e 1,600 ft. level b efore th e tr u e v alu e of th e ore can be ju d g e d .
A cable m essage re p o rts t h a t th e n e t p ro fit of th e B ro k en H ill P ro p r ie ta ry Co. for th e y e a r e n d e d M ay 31 w as £332,671, as a g a in st
£222,616 th e y e a r before. T h e o u tp u t of p ig iro n w as 330,803 to n s, as c o m p ared w ith 333,368 to n s, a n d of steel in g o ts 374,059 to n s, as co m p ared w ith 359,389 to n s. T h e lead- zinc m in e w as n o t w o rk ed d u rin g th e y ear, b u t a s ta r t w as m a d e on th e r e tre a tm e n t of old residues, 65,676 to n s y ielding 9,009 to n s of le ad co n c e n tra te s. A n a rra n g e m e n t h a s been m a d e w ith M essrs. S te w a rts a n d L lo y d s for th e m a n u fa c tu re of steel tu b e s in A u s tra lia a n d a co m p a n y called th e B u ttw e ld Co. h a s b een fo rm e d for th e purp o se. A t th e s u b se q u e n t m e etin g of sh a re h o ld e rs th e c h a irm a n s ta te d th a t a rra n g e m e n ts w ere in h a n d for reo p e n in g th e lead-zinc m in e a t B ro k en H ill.
T h e W h itw o rth F in a n c e a n d M ining C o rp o ra tio n an n o u n c es t h a t M r. J . W . N ew b ery is v isitin g its Q u een slan d tin p ro p e rtie s a n d th a t one of th e d irec to rs, Mr. S. C. M agennis, will a rriv e a t th e p ro p e rtie s sh o rtly . O ur B risb a n e co rre
sp o n d e n t also w rites re la tin g to th e p ro p e rtie s in w h ich th e co rp o ra tio n is in te re ste d . A n im p o rta n t g ro u p in th e C ity h a s ta k e n an o p tio n on a blo ck of sh ares, w hich, if th e re su lts of e x a m in a tio n s are sa tisfa c to ry , w ill p ro v id e th e a d d itio n a l finance req u ired .
T H E M IN IN G M A G A Z IN E
S ev eral references h a v e b een m a d e r e c e n tly b y o u r B risb a n e c o rre sp o n d e n t to th e o rd ers for coal se n t fro m A u s tra lia to E n g la n d . F u r th e r new s cam e to h a n d la s t m o n th to th e effect t h a t a n o rd er for 40,000 to n s of coal from S co tla n d , W ales, a n d N o rth u m b e rla n d h a s b ee n p la c e d b y th e 'V icto ria n R a ilw a y s D e p a rtm e n t. T h is coal is to b e u se d on th e lo c o m o tiv e s as a n a d m ix tu re w ith W o n th a g g i low -grade coal a n d displaces b e s t M a itla n d coal, w hich h a s h ith e r to b ee n u se d for th is p u rp o se.
T h e E le c tro ly tic Z inc Co. of A u s tra la s ia a n n o u n c es t h a t th e c a p a c ity of its h y d r o e le c tric s ta tio n a t R isd o n , T a sm a n ia , is to b e e n la rg e d from 50,000 to n s p e r y e a r to 65,000 to n s , in o rd e r to t r e a t th e m a te ria l from th e R o seb ery m ines.
N e w G u in e a - — D r. R ich a rd so n , geologist to th e A n g lo -P ersian Oil Co., w ho h a s b een m a k in g in v e stig a tio n s in N ew G u in ea for th e G o v e rn m e n t of A u stra lia , re p o rts f a v o u ra b ly on th e s tr u c tu re of th e A ita p e region. H e is of o p in io n t h a t th e fold ed ro ck s of th e M iocene age, w ith p ro v e d oil in d ic a tio n s, p re se n t th e m o st h o p e fu l p ro p o sitio n his p a r ty h a s y e t e n c o u n te re d a n d t h a t full scope sh o u ld b e afforded for its co m p lete in v e stig a tio n .
M e x ic o .— T h e S an F ra n c isc o M ines of M exico r e p o r ts a b re a k d o w n of th e p la n t of th e c o m p a n y w h ich su p p lies electric p o w er to th e m ine, w ith th e re s u lt t h a t for som e w eeks th e m ill h a s b ee n ab le to w o rk a t o n ly h alf c a p a c ity . I t is h o p e d to resu m e th e u su a l o u tp u t b y O cto b e r 1.
C o lo m b ia .— T h e N u s R iv e r G old M ines, L td ., c o n tro l of w h ich w as re c e n tly a c q u ire d b y th e A n g lo -O rien tal g ro u p , re p o r ts t h a t th e d redge ere c te d b y th e p rev io u s co n tro llers h a s n o t p ro v e d s a tis fa c to ry a n d t h a t th e Y u b a A sso ciated E n g in e ers, u n d e r th e ad v ice of Mr. V iv ia n C lark, h a v e re c o m m e n d e d th e e x p e n d itu re of $60,000 in rem o d e llin g th e d redge a n d $75,000 in p ro v id in g electric pow er. A loan w as n e g o tia te d w ith th e A n g lo -O rie n tal a n d G en e ra l I n v e s tm e n t T ru s t, b u t c a p ita l w ill also b e re q u ire d for th e p u rp o se of c a rry in g o u t Mr. C la rk ’s re c o m m en d a tio n s.
J a p a n .— T h e T o y o T in Co., a m e m b e r of th e A n g lo -O rien tal g ro u p , w h ich w o rk s th e M ita te tin m ine, r e p o rts t h a t th e new m ill is a lm o st r e a d y to s t a r t a n d t h a t d e v e lo p m e n ts on th e 550 ft. cro ss-c u t a re en couraging. In o rd e r to p ro v id e f u rth e r w orking c a p ita l a n d r e p a y lo a n s, th e c o m p a n y h a s c r e a te d 2 0 0 , 0 0 0 n ew s h a re s of 1 0s.
136
e ach , of w h ich 150,000 a re b e in g p a r to sh a re h o ld e rs.
S p a in .— T h e T ig o n M ining a n d Finance LodA' C o rp o ra tio n , of w h ich Mr. R . E . Palmer is c h a irm a n , re p o r ts t h a t th e development of th e e le m e n ta l su lp h u r d e p o sits is pro- iitA^
ceeding sa tisfa c to rily . U n til th e new plant r«^
for s u lp h u r e x tra c tio n is co m p leted th e old sit*cei C larete fu rn a ce s a re b ein g em ployed. The a n tim o n ia l-silv e r-le a d p r o p e r ty is being te s te d b y d rilling, b u t th e tin pro p erty is ¿mite b ein g le ft for th e tim e , as th e results of * 0 in v e s tig a tio n are n o t su fficie n tly promising Iron w ith tin a t th e p re s e n t price.
C a m p B i r d .— A rra n g e m e n ts h av e been 4 Si m a d e for a closer affiliation between ft'iitf C am p B ird a n d C o n so lid ated G old Fields. 4 4 T h e offices of C am p B ird , S a n ta Gertrudis, L ($
M exican C o rp o ra tio n , a n d o th e r companies 4? 1 of th e C am p B ird g ro u p w ill b e m oved to th o s e of th e G old F ie ld s a t 49, Moorgate. Y G old F ie ld s w ill a p p o in t d ire c to rs to the s e v e ra l b o a rd s a n d w ill su b sc rib e £250,000 C am p B ird d e b e n tu re s . C am p B ird also a n n o u n c e s t h a t it h a s tra n s f e rr e d its interests in th e L a k e G eorge m in e in N ew S o u th Wales to a c o m p a n y called th e L a k e George Metal C o rp o ra tio n , w h ich w ill e re c t a treatm ent p la n t w ith a n in itia l c a p a c ity of 500 tons u • p e r d a y .
S e l e c t i o n T r u s t.— T h e S election Trust, of w h ich Mr. C h e ste r B e a t ty is th e moving s p irit, re p o rts a p ro fit of £213,248 for the y e a r e n d e d M arch 31 la st, as com pared with
£53,594 th e y e a r before. T h e 2 0 0 ,0 0 0 l\°/0 1
£ 1 p re fe re n c e receiv e th e ir d iv id e n d and the 600,000 £ 1 o rd in a ry sh a re s receive a dividend of 1 0% . S ince th e close of th e y e a r £300,000 6-|-% d e b e n tu re s h a v e been issued, for the p u rp o se of p ro v id in g th e co m p an y with fu n d s to en a b le it to p a r tic ip a te in new c a p ita l issues of th e R h o d e sia n an d other - c o m p an ie s in w h ich it is a larg e shareholder. ■*
T h e re p o r t giv es p a rtic u la rs of th e various c o m p an ie s w h ich it c o n tro ls— nam ely, the C o n so lid ated A fric an S election T ru st, which h a s d ia m o n d in te re s ts th r o u g h subsidiaries !1' in th e G old C oast a n d N a m a q u a la n d , the N R h o d e sia n S election T ru s t a n d th e Roan A n telo p e C opper M ines, w hich are developing j®K co p p e r p ro p e rtie s in N o rth e rn R hodesia, the 1 ^ T e tiu h e M ining C o rp o ra tio n , w hich works a lead-zinc-silver m in e in e a s te rn Siberia, h th e T re p c a M ines, w h ich h a s developed lead-zinc ores in J u g o sla v ia , a n d th e Novo B rd o M ines, w h ich is d ev e lo p in g similar I 4 p ro p e rtie s a d jo in in g th o se of th e Trepca 1 T
Mines. *
■ '-ft
NEIGHBOURING MINES, NOR TH-W ESTER N RHODESIA
By R. M U R R A Y -H U G H E S , F.G.S., A.Inst.M.M., a n d A. A. FITC H , A.R.C.S., B.Sc.
Lo c a t io n.— I n F ig. 1 a tria n g u la r a re a is shown a t A 120 m iles w est of B ro k en H ill, a station on th e B ulaw ayo-C ongo R ailw ay . It marks a concession w hich w as g ra n te d to the N orthern C opper C om p an y , a n d w ith in it are th ree sm a lle r a re a s (Fig. 2), each of ten square m iles, w h ich w ere h a n d e d to a subsidiary, th e K a fu e C opper D ev e lo p m e n t Company. F ro m w est to e a st th e se a re a s are nam ed from th e p rin c ip a l m in es s itu a te d within each, S ilver K ing, C ry sta l J a c k e t, and Sable A ntelope, 8T m iles se p a ra tin g the first a n d la st.
Ge n e r a l Ge o l o g y L—T h e s e d im e n ta ry rocks in th e a re a belo n g to th e L u sa k a and K afue S y stem s, e q u iv a le n t to th e Transvaal a n d P re to ria S y stem s of S o u th Africa. T hese se d im e n ta rie s h a v e been folded a n d th e n m e ta m o rp h o se d b y th e intrusion of a larg e g ra n ite m ass know n as the Hook G ra n ite (Fig. 2). T h e se d im e n ta rie s form hilly co u n try .
Lo cal Ge o l o g y.— T h e L u sa k a B ed s in the area consist of a series of lim esto n e, shale, dolom ite, grey w ack e a n d q u a r tz ite ; they show a p re d o m in a n t strik e fro m e a st to west d ip p in g to th e so u th . T h e y h a v e been g rea tly folded, th e local folds a p p e a rin g to be m in o r p lic atio n s on th e flanks of a pitching an ticlin e, w hose ax is ru n s a b o u t three miles n o rth -w e st of th e m ines, p itc h in g to the n o rth -e a s t.
Small fa u lts are n u m e ro u s, th e m o v e m en ts being accom panied b y a coarse b rec cia tio n . In all of th e fau lt-b rec cia s, th e c e m e n tin g material is do lo m ite w ith v a ry in g a m o u n ts of iron a n d m a n g an ese rep la cin g th e calcium and m agnesium . T h e w e a th e rin g of th e se brecciated bodies is stro n g ly c o n tra s te d w ith that of th e lim estone. I n th e b re c c ia te d bodies th e ce m e n t oxidizes to a deep red d ish - brown colour, th e lim esto n e fra g m e n ts rem aining pin k . T h e ro ck show s a weathering ty p ic a l of in so latio n , form ing m iniature in se lb e rg s, 2 w hile th e soil d eriv ed from it is full of n odules of iro n a n d m a n g an ese oxides, c o n so lid a ted to fo rm a la te rite . The lim esto n e gives rise to p in n a cle d a n d serrated o u tc ro p s, 6 to 50 ft. high, a n d produces a s tic k y re d soil.
1 V ide R . M u rray -H u g h e s a n d A. A. F itc h , Q.J.G.S., vol. 85, pp . 109-66, 1929.
2 V ide E d ito ria l N o te , Geol. M ag., 1923, pp. 383-4.
A w ell-defined cleav ag e is n o tic ea b le in ro ck s to th e n o r th of th e m ines, b u t it dies o u t w ith in 3 o r 4 m iles of th e m . T h e c o n ta c t m e ta m o rp h is m due to th e H o o k G ra n ite show s itself as m a rm o riz a tio n , a n d in places as silicification of th e lim esto n e. I n th e
Fi g. 1 — Sh o w i n g Lo c a t i o n o f t h e Co n c e s s i o n i n t h e No r t h o f Ka f u e Di s t r i c t, No r t h e r n Rh o d e s i a.
S ilver K in g m ine a g ro u p of m in e tte in tru sio n s is m u c h in evidence. T h e n e a re st o u tc ro p of th e H o o k G ra n ite is 8 m iles aw ay, a n d p a r t of th is d ista n c e is across a n allu v ia l p la in of th e R iv e r K afue. F u r th e r m ore, th e c o n ta c t p lunges v e ry g en tly , a n d th e g ra n ite is p ro b a b ly less th a n 1 ,0 0 0 ft.
fro m th e su rface a t th e m ines.
Th e Or e De p o s i t s.— T h e d ep o sits a re p ra c tic a lly all of one ty p e , n am ely , b re c c ia te d p ip es in th e L u sa k a L im esto n e (Figs. 3 a n d 6). W ith in th e se p ip es th e m e ta lliz a tio n is re s tr ic te d to th e p erip h e ry . 137
138 T H E M IN IN G M A G A Z IN E
F u rth e r, w here th e pip es a re inclin ed , th e o re is c o n c e n tra te d alo n g th e foot-w all.
T h e pip es v a r y in d ia m e te r fro m 800 y a r d s in th e case of th e S able A n telo p e to 70 y a r d s in th e case of th e M aurice G ifford. T h e S ilver K in g is ex c e p tio n a l in t h a t th e m e ta lliz a tio n occurs in s h a tte r- b e lts follow ing th e m in e tte dykes.
O xidized a n d se co n d a rily e n ric h e d ores a re n o t a b u n d a n t, e x c ep t a t th e S ilver K in g m ine, w h ere th e re a d y w e a th e rin g of th e
Fi g. 2 . — Sh o w i n g Lo c a t i o n o f t h e Mi n e s w i t h
R E S P E C T TO T H E G R A N IT E C O N T A C T . T H E RO UG H LY T R IA N G U LA R A R EA O F T H E LA R G E Co n c e s s i o n, b o u n d e d o n t h e No r t h b y t h e Ka f u e Ri v e r, i s i n d i c a t e d.
m in e tte h a s allow ed a m o re fre e a n d d e e p e r circ u la tio n of su rface w ate rs.
Sable A ntelope M in e .— T h is e n o rm o u s
" plug ” of brec cia (Fig. 3) show s a ste e p p itc h to th e e a st, so t h a t th e m e ta lliz e d p o rtio n o u tc ro p s a t th e w e ste rn m a rg in , w h ere it follows th e p e rip h e ry a n d h a s b ee n d ev e lo p e d u p to th e p re s e n t for 300 ft. A p ec u lia r fe a tu re is th e d iffe re n tia tio n of th e d e p o sit in to arse n ica l a n d n o n -a rse n ic a l p a rts . I n its n o rth e rly p a r t it is com posed of chalco- p y rite a n d b o rn ite , w hile in its so u th e rly p a r t it is esse n tia lly te n n a n tite w ith su b o rd in a te a m o u n ts of th e firs t-n a m e d m in erals.
T h e m a ssiv e te n n a n tite b re a k s into jetiM re c ta n g u la r blocks, a n d w a te r following the ifc®
lines of w eak n ess d e p o s its film s of oxidized ft ^ p ro d u c ts. I n th e te n n a n ti te are found o cc asio n al m asses of b o rn ite , 4 to 6 in. in jjfi^
d ia m e te r, su rro u n d e d b y a red-stained Lit ^ a u re o le 1 to 18 in. w ide. I n th e northern LfiJ##
p o rtio n of th e m ine, m asses of alm o st solid UJi®1 b o rn ite w ere fo u n d , one of w h ich yielded L \0, 500 to n s of p ra c tic a lly p u re m ineral.
A s tu d y of th in a n d p o lish ed sections of the ores show s th e follow ing to h a v e been the seq u en ce of e v e n ts in th e m ineralization.
(1) A first sta g e re s u ltin g in th e produc
tio n of a w h ite c ry sta llin e dolom ite with s tr ia te d cu b es of p y r ite . Occasionally t h e o rd e r of c ry s ta lliz a tio n is reversed, a n d rh o m b s of d o lo m ite a re included in irre g u la r m a sses of p y rite .
(2) In te r-m in e ra liz a tio n brecciation.
(3) C e m e n ta tio n of th e b rec cia b y grey d o lo m ite c a rry in g b o rn ite , chalcopyrite, a n d ch alco cite. T h e c h a lc o p y rite m a y form a m e sh s tr u c tu r e in th e b o rn ite , a primary s tr u c tu re d u e to u n m ix in g of a sulphide m a tte in te r m e d ia te in co m p o sitio n between b o rn ite a n d c h a lc o p y rite . T h e chalcocite te n d s to o cc u r s e p a r a te fro m th e other su lp h id es, b u t, w h ere th e y a re in association, th e c h a lc o cite is sh o w n to b e la ter. This g re y c e m e n tin g d o lo m ite re p la c e d a p a rt of th e b re c c ia te d m a te ria l, as is show n by the su b -a n g u la r n a t u r e of th e b rec cia fragments, a n d b y th e o cc u rre n ce of a few residual k e rn e ls of p y r ite in th e co p p e r sulphides, w h ich h a v e b e e n m a rg in a lly en rich ed in the h ig h ly cu p rife ro u s e n v iro n m e n t of th e grey d o lo m ite.
(4) T h e fin al sta g e s of e n ric h m e n t are due to se c o n d a ry processes. T h e p y rite of the w h ite d o lo m ite, w h ich is u n a lte r e d during th e course of th e p r im a ry m ineralization, is e n ric h e d to c h a lc o p y rite a n d th e n to ch a lc o cite. T h e b o rn ite d evelops covellite alo n g cra ck s a n d m a rg in a lly , th e chalco
p y rite m e sh re sis tin g e n ric h m e n t an d pro
je c tin g th ro u g h th e covellite.
(5) O x id a tio n re s u lts in th e appearance of a n a b u n d a n t la te r ite w ith loose nodules com posed of th e h y d r a te d o x id es of iron and m a n g an e se. S ev era l c o n c e n tra te d bodies of th e se iro n d e p o s its w ere fo u n d , a n d in one w illem ite w as d isc o v ered in th re e small, irre g u la r m asses, b u t n o t a s so c ia te d with a n y m e ta lliz a tio n b y co p p e r, a n d a mile f u rth e r fro m th e H o o k G ra n ite c o n ta c t.
S ilv er K in g M in e .— T h is is m a rk e d by a n o u tc ro p , 300 ft. lo n g a n d 70 ft. wide, of a n a lm o st b la c k ro c k lo c ally stained
‘"'te ir. ;
yellow w ith iron. I t re p re se n ts th e zone of contact m e ta m o rp h is m on e ith e r side of th e minette dykes, a n d m a rk s th e ir course, w hich is N. 65° E . A t th e m o st w esterly p o in t it rises into a sm a ll h ill o r k o p je 1 0 0 ft. high which shows a b u n d a n t coarse q u a rtz , a n d limonite in ra d ia l co n cretio n s. S everal veins were exposed on th e low er p a r t of th e outcrop, a n d a n u m b e r of sh a fts w ere su n k following th e m , b u t w ere a b a n d o n e d a t water-level (90 ft.), w ith o u t h a v in g u n co v e red
from th e a ssay rec o rd s in th e a c co m p an y in g ta b le .
0/I I I
0/ I l l
0/
Cu /o
49-77 /o
6-93 18-03
S — — 4-80
Insol. 11-78 15-29 14-18
FeO . A 3-37 9 -29 17-14
M nO . -1 3 -76 1 -50
CaO . 4-77 30-23 2 5-78
MgO 0-96 6-53 4 -7 9
S ilv er (oz. p e r 20 — 52-07
long ton)
Fx g. 3 . — Pl a n o f t h e Sa b l e An t e l o p e Pi p e.
»
a pocket. T h e ro c k tra v e rs e d w as com posed mostly of coarse sid e rite w ith m u c h calcite stained b y m a n g an ese oxide.
The o u tc ro p is a b r u p tly te r m in a te d a t its eastern en d b y a f a u lt w h ich crosses it obliquely ru n n in g N. 10° E . T h e fa u lt show s num erous v ein s of p y ro lu site a n d occasional specks of ch a lc o p y rite, w hich h a v e given rise to green co p p er c a rb o n a te sta in s a t th e surface. T h e fa u lt is p o st-m in e tte in age, for fra g m e n ts of th is d y k e-ro ck occu r in the fa u lt-b re c c ia as allogenic c o n s titu e n ts.
I t w as a t th e ju n c tio n of th is fa u lt w ith th e crush-zone t h a t th e la rg e st ric h p o ck e t w as discovered.
T h e co m p o sitio n of th e ore c a n b e g a th e re d
I. T y p ical assay of ore from th e rich po ck et, o ccu rrin g to th e e ast of th e fa u lt. (From th e old assa y records.)
I I . P ic k ed m a te ria l from d u m p s of sh a fts to th e w e st of th e fa u lt (a n aly st R . M .-H .).
I I I . O re from 200 ft. level, w est of fa u lt (a n aly st R . M .-H .).
A ty p ic a l a ssay of th e b la c k copper p ro d u c e d from sm eltin g th e se ores is :—-
Cu
/o 96-00
S 2-50
F e 0-50
Mn 0 -40
As 0-20
B i 0-10
Slag Ag Au
0-30 45
0-0075
oz. p e r long to n
