The Mining Magazine
M anaging Director and Editor : W . F . W h i t e . A ssistants : S t . J. R. C. S h e p h e r d , A .R .S .M ., D .I.C ., F .G .S .; F. H i g h a m , A .R.S.M ., M .Sc., F.G .S.
P u b l i s h e d o n t h e 1 5t h o f e a c h m o n t h b y M i n i n g P u b l i c a t i o n s , L i m i t e d , a t S a l i s b u r y H o u s e , L o n d o n ,
E.C.
2.
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Vol. X LV 1I. No. 3. L O N D O N . S E P T E M B E R , 1932.
o n e ps h?l u n gC O N T E N T S
P A G E PA G E
E d i t o r i a l
Toronto
1 6 4Notes ... 130
P o r c u p in e ; K irkland L ak e ; O ther O n tario G old F ie ld s ; T he O ttaw a C o n fe r e n c e ; C helsea P o ly te c h n ic Old S u d b u r y ; N o rth-W estern Q uebec ; G reat B ear L ake.S tu d e n ts’ A sso c ia tio n ; M in ing Research a t B ir m in g
h am U n iv e r s it y ; A eria l S u r v e y in g ; T h e B r itish
V ancouver
... 1 6 6Ar t i c l e s
Gold Mining in th e Sudan
Association ; Moonlight and Timber. Mineral Production ; Portland Canal ; Porcher Island ; S o u t h A f r i c a n M i n i n g 1 3 0 Taku River jA tlin; B r i e River ; Lillooet; Coast;
, , ,, .. . „ ° , ... . „ . Cariboo; Sheep Creek; Osoyoos ; East Kootenay.
The report of the Union Government Mining Engineer
for 1931 is briefly reviewed. I p o h ... 168
S e c o n d a r y M e t a l s i n t h e U n i t e d S t a t e s 1 3 1 Reorganization of the Industry; Gold. Preliminary statistics received from the United States a on Bureau of Mines are examined. PERSONAL ... 169
M in in g i n B r i t i s h C o l u m b i a 1 3 2 Tr a d e Pa r a g r a p h s ... 169
Two reports issued by the Department of Mines at Victoria _ , . are discussed. P a rk e r M u lti-B u ck et E x c a v a to r ... 169
Re v i e w OF Mi n i n g 1 3 4 S m ith L oad In d ic a to r ... 170
Me t a l Ma r k e t s ... 171
St a t i s t i c s o f Pr o d u c t i o n ... 173
K . S . T w i t c h e l l 1 3 7 P r i c e s o f C h e m i c a l s ... 175
A description of past activities on the Red Sea coast C O 1 n r and an account of present-day operations and oHARE QUOTATIONS ... 17b potentialities S t o p e - F i ll i n g W . E . S i n c l a i r 1 4 5 M i n i n g D i g e s t Observations on some methods of stope-filling employed R esid u al Gold a fte r C y anidation on mines in South and West Africa. J Thurlow 177 D e r b y s h i r e M i n i n g ..L e s lie B . W i l l i a m s 151 M illing a t B rita n n ia ... w . G. Hatch 179 (Continued from the August issue, p. 94.) D rill S teel ... R . H . D avis 182 „ S m eltin g A n tim o n y in N ew S outh W ales T h e I .M .M . B e n e v o l e n t b u n d 1 5 8 w . Brazenall 184 S ev en th L is t of S ubscriptions. S h rin k a g e Stoping ... R. K . W arner 185 D iam o n d s in th e B elgian Congo B o o k R e v i e w s a . e. Brugger 187 F o x ’s “ B a u x ite a n d A lum inous L a te rite ” M agnetic C o n cen tratio n . . T. F . M yners 188 J . B . Scrivenor 158 M illing a t M i a m i ...H . D. H u n t 188 S ociety of P e tro le u m G eo p h y sicists’ H ecla C o n cen trato r, Gem, Id ah o “ G eophysics, 1931,” A m erican I n s titu te W . L . Zeigler 189 of M ining a n d M etallurgical E n g in e ers’ S h a ft S inking a t G rand Saline, T exas “ G eophysical P ro sp ec tin g , 1932,” a n d M . T aylor 189 A le x a n ia n ’s “ T ra ité P ra tiq u e de S inking P ra c tic e an d Costs . . R . H . Poston 189 P ro sp ec tio n G éophysique ” Dr. H . Shaw 159 P u rc h a sin g a n d S upply M ethods xt r F . L . B ishop and A . E . Keller 190 NEW S Le t t e r s E q u ip p in g a Mine in th e T ri-S ta te D istric t B r i s b a n e ... 1 6 1 j . r. Reigast 190 Mount Isa Activities ; Underground Work and Output ; T heo retical M e ta llu r g y ... E. T. K elly 190 Mount Wandoo Goldfleld ; Another Goldfield ; Mount Coolon ; Expedition to Central Australia ; Coal SHORT N O T IC E S ... 19 0 Mining ; Port Pirie Smelting W orks ; Mount Lyell Company. RECEN T PATENTS PUBLISHED ... 191
Johannesburg ... 163
H eid e lb e rg ; M eyer and Charlton C losed D o w n ; Solar Ne w Bo o k s, Pa m p h l e t s, e t c... 1 9 2
? u " v 1 ^ T h L m 7 f n nzJlubnd ; ^ h o V t i a n ^ S D IV ID E N D S D E C L A R E D ... 1 9 2 asg^ p e ActoUr i alGOldDlSCOVery; Unempl°yed Men N E W COM PANY R E G IS T E R E D ... 1 9 2
3 — 2 1 2 9
E D I T O R I A L
I T is difficult to estim ate th e results of the O ttaw a Conference, since the inter-E m pire agreem ents are n o t valid u n til th e y have been ratified by th e respective G overnm ents.
The only m a tte r in which m ining men m ight be considered to be directly in terested was the proposal to place a d u ty equivalent to 2d. per pound on copper im ported from any country outside the B ritish Common
w ealth.
A CH ELSEA Polytechnic Old S tu d e n ts’
Association is to be in au g u rated a t a m eeting to be held on N ovem ber 4, on the occasion of th e opening of th e polytechnic extension by th e P arliam en tary Secretary to th e B oard of E ducation. I t is hoped th a t there will be a good attendance of old students, those desiring fu rth er particulars being asked to com m unicate w ith the h onorary secretary of the new association at th e polytechnic.
th e m echanization of in d u stry as a m ixed blessing, as it results in the disappearance of craftsm anship and reduces th e necessity for toil. Professor R ankine, in his address as president of th e section of m ath em atical and physical sciences, dealt w ith the progress of geophysical m ethods of m ineral finding.
A L E T T E R in a recent issue of Nature recalls a discussion in 1928 on the effect of m oonlight on tim ber begun in the In stitu tio n and com m ented on in the
M a g a z i n e .Dr. Sem m ens propounded the th eo ry in our Ju ly issue th a t th e light of the moon during its early phases h ad a hydrolysing effect. The sam e investigator now advances proof of th is co ntention as the outcom e of her experim ents w ith leaves, which go to show th a t th e starch is hydrolysed by th e m oonlight, th u s causing sugary essences to en ter th e sap, th e presence of which renders th e tim b er m ore a ttra c tiv e to insects.
D U R IN G 1931 th e w ork done in the m ining research lab o rato ry a t B irm ing
ham U niversity was, as usual, m ainly con
cerned w ith th e coal m ining industry, the rep o rt ju st issued containing full details of th e investigations com pleted or in hand.
Mining com panies and m iners in th is co u n try are now fully aware of th e dangers of silicosis and research on rock d u sts as well as konim eter tests of mine air are deservedly tre a te d as of im portance.
T H E use of aircraft as an aid to m ining and prospecting is becoming increasingly common. Following reference last m onth to their successful em ploym ent in New Guinea for th e tra n sp o rt of dredge p a rts and th e announcem ent of th e in ten tio n to conduct an aerial survey of th e R an d comes th e news from A ustralia of a survey flight over a wide area in th e n o rth which it is hoped will be helpful in m apping rugged oil-bearing country.
'"T^H E annual m eeting of the B ritish I Association was held for the fifth tim e a t Y ork— th e place of its inception— from A ugust 31 to Septem ber 7. Sir A lfred Ewing, in his presidential address, surveyed the field of scientific progress from the point of view of th e engineer and was disposed to regard
S ou th A frican M ining
W ith th e o u tp u t from th e gold-mining in d u stry during 1931 co n stitu tin g a record and w ith every prospect of y e t another record being established in 1932, th e ta sk of th e U nion G overnm ent M ining Engineer in preparing his annual r e p o r t1 m u st hav e been pleasanter th a n he probably anticipated, having regard to th e poor conditions pre
vailing in other branches of th e mining industry. The only oth er m etalliferous product shipped in larger q u a n tity last year was m anganese ore, th e o u tp u t increasing from 58,572 to n s to 115,889 tons, although th e value only rose from £91,858 to £127,884, b u t as shipm ents from Post- m asburg were suspended in O ctober last the figures for th e current y e ar m ay be expected to show a severe set-back. All oth er m ining products registered decreased o u tp u ts and conditions as regards em ploym ent generally deteriorated. The stim ulus given to opera
tions on th e R a n d m ines by th e world-wide dem and for gold was, however, sufficient to ensure th a t salaries and wages for th e year and m oney spent on stores would be m ain tain e d and it is satisfactory to note th a t the
1 U nion of S o u th A frica— D e p a rtm e n t of M ines an d In d u strie s , A n n u al R e p o rt of th e G o v e rn m en t M ining E n g in eer, 1931. P ric e 10s. 6d.130
la tte r item showed a slight increase over the figures for 1930. Mining in th e Union is, therefore, in an enviable position and nothing perhaps indicates this b e tte r th a n th e im proved labour returns, the m onthly statem en ts having shown a continuous in
crease, in spite of th e fact th a t em ploym ent on th e diam ond mines has all b u t ceased, while a continued decline is recorded in the num bers em ployed by th e coal mines. From this it will be seen th a t th e gold-mining in d u stry is fo rtu n ately in a position to absorb m uch of th e labour no longer required in other branches of industry.
It is gratifying to note from th e report th e continued decrease in th e accident ra te on the W itw atersrand gold mines during th e year, the figure having fallen from 2'56 to 2'35 per 1,000, th is im provem ent being m ainly due to the fact th a t there were no abnorm al accidents. I t is clear, however, th a t the problem created by increasing pressures due to th e depth of w orking m ust involve continued changes in th e m ethods and am ount of support if th e accident ra te is to be kept down, for experience in th e shallower workings cannot be expected to be altogether applicable to conditions a t depth. D eaths due to explosives accidents show a continued decrease, as m ight be expected, b u t those in connexion w ith trucks and tram w ays again show an increase, m ainly due to m ishaps w ith runaw ay tru ck s in mines on th e F a r E ast R and, and th e G overnm ent engineer has considered it wise to w arn th e m anagem ents on those mines th a t unless th ey can succeed in reducing th e accident ra te from these causes fu rth er legislation m ay be necessary.
A ltogether it m ay be deduced from th e report th a t th e good effects of th e Safety F irst Campaign, which was energetically carried on during th e year, are being continued.
Turning to th e m echanization of the industry, it is recorded th a t on th e gold mines th e rock m ined during th e year by m eans of rock- drills am ounted to 95'48% of the to ta l tonnage hoisted, as com pared w ith 96-34%
in 1930 and 59'59% in 1921, while 75% of the drills em ployed are now hand-held jack- ham m ers, against 30% for 1921. Again, it is noted how th e m ethod of sludging has changed during the past 10 years, all drills em ployed on th e R and to-day being classed as passing w ater only through th e steel. The to ta l num ber of drills on th e R and now num ber 9,390 against 8,768 a year ago, and the fact th a t B ritish m anufacturers continue to more th a n hold their own in this field
is indeed gratifying. As regards phthisis conditions, it is recorded th a t, on th e whole, these were found to be m easurably satis
factory and th a t the regulations have been generally complied w ith, w hilst it is im p o rtan t to note th a t th e liability to contract the disease h ad undergone a m arked decline during th e past decade. It is evident th a t w orking conditions on th e R and continue to im prove, in spite of the increased depth of operations, and this is m ainly due to the general high level of efficiency which is m aintained by the m anagem ents.
Reviewing conditions in South Africa generally, it m ust be ad m itted th a t the im portance of th e R and is so great th a t it is difficult to form a correct estim ate of th e relative values to the Union of the gold-mining and other industries. I t is certain, however, th a t the R and can continue to carry th e Union when all other prim ary commodities are in the doldrum s and it is difficult not to feel th a t th e Union Govern
m ent is, to some extent, jealous of the industry, although realization of how easy it would be to allow th e political views of the in d u stry to prevail doubtless explains to some ex ten t th e a ttitu d e of conscious rectitude preserved by th e Union A dm inistra
tion. R eturning to th e report, it is regret
table, perhaps, th a t it is somewhat out of date, as th e inquiries in progress during the year were not concluded in tim e to be recorded, so th a t the work of the Low Grade Ore Commission, for example, which has already been reviewed in these columns, m ay be regarded as providing a less biased view of th e problem s confronting the R and.
As to th a t p a rt of the in d u stry concerned w ith m etals other th an gold, conditions can only im prove as world conditions improve, a sta te of affairs which all hope m ay be near at hand.
S econ d ary M etals in the U n ited S tates
The continued decline in th e prices of
p rim ary m etals which prevailed during the
greater p a rt of 1931 natu rally affected the
collection of scrap for th e production of
secondary m etals. Prices for scrap metals,
alloys, and residues declined so rapidly th a t
th e operations of dealers were at times
seriously ham pered and, in consequence,
m any furnaces active during 1930 became idle
or worked on a m uch reduced scale. It is
not surprising, therefore, th a t the latest
retu rn s from the U nited States, dealing with
132
th e recovery of m etals from secondary sources during 1931, should show a fu rth er falling off in value and q u a n tity . The value of th e non-ferrous m etals included in th e retu rn s recovered from these sources is estim ated to have been $110,674,600, which is $82,580,500, or 43% , less th a n in 1930, while th e to ta l q u a n tity was down by 21% . The decrease in value was largely due to the m uch lower average prices prevailing for all th e prim ary m etals, b u t th e m ain decrease in q u a n tity of secondary m etals tre a te d was in copper and brass, th e o u tp u t of these being reduced by 27% , th e value declining by nearly 50% . The table given below sum m arizes th e production in short tons of secondary m etals in th e U n ited S tates for 1931 and th e figures for 1930 are added for com parison :—
1930 1931
C opper, in clu d in g t h a t in
alloys o th e r th a n b ra ss . 332,800 261,000 B rass sc rap re m e lte d . . 192,000 122,800 L ea d as m e ta l . . . 129,000 128,800 L e a d in alloys . . . 126,800 105,900
Zinc as m e ta l . . . 49,300 34,800
Z inc in alloys o th e r th a n b rass 7,700 7,400
T in as m e ta l . . . 5,600 5,500
T in in alloys a n d ch em ical
co m p o u n d s . . . 20,600 14,300
A n tim o n y as m e ta l a n d in
alloys . . . . 8,082 7,900
A lum inium as m e ta l . . 19,700 15,200 A lu m in iu m in alloys . . 18,900 15,100
N ick el as m e ta l . . . 500 270
N ickel in n o n -ferro u s alloys
an d sa lts . . . 2,400 1,800
W ith th e reduction of prim ary supplies coming on th e m ark et and th e increase of stocks, it is evident th a t th e qu an tities of m etal produced from secondary sources still am ount to a significant to tal.
E xam ining in some detail th e figures given in th e report, it m ay be noted th a t, while th e shipm ents of scrap copper to E urope were double those of 1930, th e shipm ents of scrap brass declined. The q u a n tity of secondary copper produced by sm elters and refineries in th e U nited S tates tre a tin g m ainly prim ary m etal decreased from 140,270 to n s in 1930 to 78,064 tons in 1931, th e to ta l production of secondary copper m etal last year am o u n t
ing to 188,300 tons, against 244,800 tons in 1930, while th e copper content of secondary brass and other alloys was 158,700 tons, as com pared w ith 222,400 tons in 1930. T hus th e to ta l am ount of secondary copper recovered in 1931 was 347,000 tons, as com
pared w ith 467,200 tons in 1930. In th e case of lead th e secondary m etal recovered by sm elters whose m ain business is th e tr e a t
m ent of ore was 43,774 tons, th a t coming from sm elters tre a tin g only scrap an d drosses being 85,026 tons, th e to ta l of 128,800 tons com paring w ith 129,000 to n s in 1930. These quantities, however, m ake no allowance for secondary lead recovered in rem elted alloys, which in 1931 to talled 105;900 tons, against 126,800 tons in th e previous year. The to ta l production of secondary lead in th e U nited S tates for 1931 was, therefore, 234,700 tons, as com pared w ith a production of th e prim ary m etal am ounting to 442,764 tons, figures which em phasize th e im portance of the secondary m etal in d u stry . T u rn in g to zinc, it m ay be noted th a t th e production of unalloyed secondary m etal fell from 49,300 to n s in 1930 to 34,800 tons in 1931, while the zinc recovered in alloys, including brass, was 37,400 tons, against 50,000 tons. In th e case of zinc d u st produced from dross a slight gain was recorded, th e o u tp u t for 1931 from th is source am ounting to 7,478 tons, as com
p ared w ith 6,394 tons in th e previous year, while 8,700 tons of zinc dross was used for zinc d ust, as against 7,450 to n s in 1930. The zinc co n ten t of zinc salts m ade from skim m ings showed little change when com
pared w ith 1930, th e figures being 35,969 tons against 37,013 tons, b u t th e secondary zinc content of lithopone increased to 15,111 tons from th e 14,679 to n s recorded for 1930.
The figures for tin show th a t secondary pig tin am ounted to 5,500 to n s in 1930, against 5,600 tons in th e previous y ear, th e tin recovered in alloys an d chem ical com pounds declining from 20,600 tons to 14,300 tons.
The o th er im p o rta n t m etals covered by the re tu rn s are, as will be seen from th e table, alum inium , antim ony, an d nickel, and in each of these th e 1931 o u tp u t of secondary m etal showed a decline, alth o u g h each rem ains an im p o rta n t item .
M ining in B r itish C o lu m b ia
The recent arriv al in th is co u n try of the annual rep o rt of th e M inister of Mines of B ritish Columbia for 1931 was followed alm ost im m ediately b y th e statistical sum m ary and review of th e m ineral industry of the same Province covering th e first six m onths of th e c u rren t year, so th a t, in review ing th e two publications sim ul
taneously, it is possible to obtain a b etter
conception of business tren d s in W estern
Canada. T he key m etal a t tim es like the
present is, n a tu ra lly enough, gold and, while
th e 1931 o u tp u t of th is m etal from b o th placer
and lode sources showed a decline as com
pared w ith th e previous year, it is already evident th a t th e o u tp u t for the current year will be m uch larger. Indeed, as th e P ro vincial M ineralogist rem arks, the search for gold has become th e param o u n t feature of B ritish Columbian: m ining activities in 1932 and, while actual production has increased in a satisfacto ry m anner, th e finding of new gold properties and the developm ent of others already known m ay be taken as an augury of an even greater expansion in the future. As regards lode mining, pride of place seems ab o u t to be yielded by the Prem ier com pany to the Pioneer, while the o u tp u t of th e Reno and Lorne properties is also expanding. As regards placer mining, a com parison is a little more difficult. Placer gold is m ainly produced during th e second half of th e year, th e m ajor clean-ups a t m ost properties being m ade in th e au tum n, so th a t, while it is estim ated th a t $70,000 in placer gold was produced up to the end of June in th e cu rren t year, it is felt th a t this figure is no guide as to w hat the y ear’s to tal production will be, the figure for 1931 being
$291,992. One of the m ost im portant features during the present year has been the large num ber of inexperienced people who have gone out into th e backwoods in an atte m p t to m ake a living by m ining work.
Many of these newcomers to the profession have not persisted long in their efforts, it is tr u e ; nevertheless, a num ber of these new men m ay become useful prospectors and their discoveries m ay prove of benefit to the industry.
In B ritish Columbia gold m ining has never been of th e same im portance as has th a t for other m etals and yet at the present tim e it is only in gold th a t any expansion of activities is being w itnessed. I t is encouraging to note, however, th a t th e m ajor m ining properties in the Province have m anaged to rem ain open during th e period of h a rd tim es, efficiency of operation having prevented a complete shut down. I t is evident, therefore, th a t conditions are likely to im prove rapidly as soon as general business trends upw ards.
D uring th e first half of th e present year the silver o u tp u t shows a considerable decline when com pared w ith the corresponding period of 1931, th e decrease being m ainly due to th e curtailm ent of operations a t the Sullivan mine, which is also responsible for heavy declines in th e Provincial o u tp u t of lead and zinc, these m etals being almost entirely produced by the Consolidated
com pany from th a t mine. The copper o u tp u t of th e Province also shows a sharp decrease during th e first half of the current year and here again th e drop is m ainly due to the curtailm ent of operations by one com pany. N early the whole of th e copper o u tp u t of B ritish Columbia is produced jo in tly b y th e G ranby com pany’s mine at Anyox and by the B ritan n ia and the decreased o u tp u t a t th e la tte r enterprise is responsible for m ost of the decline in the 1932 figures for th e Province. I t should be noted here th a t the incidence of the U nited S tates la test tariff on copper has h it these pro
ducers very badly, for m ost of th e copper used to cross the border. O ther m arkets are being sought for th e B ritish Columbian o u t
p u t, b u t the future is at the m om ent regarded as som ew hat obscure. As regards coal, the value of th e o u tp u t has also declined in the p resent year, b u t coal, perhaps, will be the first m ineral to respond to any im provem ent in general conditions, so th a t there is some consolation in th e fact th a t, although the value of the o u tp u t to June 30 last was
$3,636,900 against $3,968,000 for the first half of 1931, th e o u tp u t had actually risen from 793,600 long tons to 806,200 long tons.
S tru ctu ral m aterials and miscellaneous m inerals are also being produced on a dim inished scale during th e present year, b u t here again the o u tp u t is likely to show a read y response to any im provem ent in trade.
The activ ity w ith which th e search for gold is now being carried on in th e Province brings w ith it its a tte n d a n t danger. The Provincial Mineralogist, in his introduction to th e sum m ary for the first half of the current year, has, therefore, thought it wise to issue a w arning to investors against undue optim ism or a too easy belief in the exaggerated sta te m ents of unscrupulous prom oters. In this respect the reports of the resident engineers, which accom pany the sum m ary, should prove valuable, for inform ation is given which should enable those interested to appraise all such prom otions. The work of th e Mineral Survey of B ritish Columbia has always been beyond reproach and it is unfo rtu n ate th a t the present financial state of the Province should have m eant a c u rtail
m ent of its activities. A retu rn to norm al
conditions in the m ining industry, however,
should enable this im p o rtan t departm ent to
resum e its valuable pioneer work on the same
scale as hitherto, w ith equal benefit to the
profession and th e com m unity.
R E V I E W O F M I N I N G
In trod u ction . — The
m ost im p o rtan t feature of the past m onth has been the stead y rise in th e prices of com m odities, th e im provem ent in the non-ferrous m etals having been of a su b stan tial n atu re. In A ustralia, in the course of th e introduction of the new budget, it was announced th a t the gold b o u n ty was to be suspended as from Septem ber 13, probably not to be restored u ntil gold falls to £5 per oz. a t Melbourne.
T ran svaal.—The o u tp u t of gold on the
R and for A ugust was 943,174 oz. and in outside districts 48,148 oz., m aking a to ta l of 991,322 oz., as com pared w ith 981,160 oz.
in July, the A ugust to ta l being another new m o nthly record. The num ber of natives em ployed on the gold mines a t the end of the m onth totalled 217,658, as com pared w ith 217,525 a t th e end of July.
I t was announced last m onth th a t in th e sinking of No. 17a sub-vertical shaft on the Crown Mines th e South Reef was encountered a t 5,240 ft., th e average value being 7-7 dwt.
over a w idth of 25 in. A t 5,360 ft. th e Main Reef L eader was intersected, the value a t this point being 20-3 dw t. over 15 in. of reef.
The dip of th e reefs being 4° less th a n a t the nearest operating section 4,000 ft. away, th ey have been cut m uch earlier th a n had been anticipated.
In terestin g disclosures a t d ep th are also announced b y the L u ip aard ’s Vlei, th e W est R and Consolidated, and th e W est Springs companies. On th e L u ip aard ’s Vlei driving tow ards the new Midas sh aft is being accelerated w ith a view to th e early in ter
section of the Midas shoot area, while on the W est R and p ro p e rty the m ain reef has been struck in the w est sub-incline shaft a t th e 31st level, the value of the first 50 ft.
sam pled being 14-6 dw t. over a reef w idth of 68 in. A t W est Springs th e bore-hole in No. 2 south-east haulage intersected th e reef 200 ft. below, th e core assaying 18'7 dwt.
over a tru e w idth of 34 in.
Shareholders of th e Meyer and Charlton com pany were inform ed last m onth th a t e x trao rd in ary m eetings are to be held in Johannesburg in O ctober a t which the requisite proposals for th e liquidation of the com pany will be considered. A com plete clean-up of th e plan t is now in progress and arrangem ents are in hand for the realization of the rem ainder of the com pany’s assets.
In a circular to shareholders of the New K leinfontein com pany it is sta te d th a t the
finance necessary to enable operations to be conducted on a larger scale has been arranged.
In re tu rn for an option up to D ecem ber 31, 1933, to ta k e over 100,000 ex-enem y shares a t 8s. 6d. per share, certain of the larger shareholders have g u aran teed th e provision of £40,000 in S outh A frican currency as and w hen it is required.
A t th e e x tra o rd in ary m eeting of W itpoort Gold Areas, held th is m o n th , th e resolution for w inding up th e com pany was approved.
T he accounts of Oceana C onsolidated for th e year to Ju n e 30 la st show an adverse balance of £74,731, m ain ly arising from losses on in v estm en ts, deferred lan d pay
m ents, and farm s.
Favourable developm ents on the property of th e M essina (Transvaal) D evelopm ent Com pany are recorded in a cable issued by the com pany la st m onth. I t is sta te d th a t on the K lode w ork on th e 11th level has exposed a to ta l of 179 ft. of ore assaying 3-74% copper, while on th e w est end of the sam e lode at the 13th level a new ore shoot has been exposed, which over 342 ft. sam pled gives very prom ising results. O ther bodies discovered betw een the 11th and 13th levels are now proved to be continuous an d th e develop
m ent results being obtained are said to be very satisfactory.
S ou th ern R h o d esia .—T he
o u tp u t of gold from S outhern R hodesia d u rin g Ju ly was 47,331 oz., as com pared w ith 48,441 oz.
for th e previous m o n th and 44,765 oz. for Ju ly , 1931. O ther o u tp u ts for Ju ly last were : Silver, 12,350 oz. ; coal, 39,030 tons ; chrom e ore, 515 tons ; asbestos, 822 tons ; tin, 1 ton.
The rep o rt of th e L onely R eef com pany for the three m onths to Ju n e 30 last states th a t in May a com m encem ent was m ade on th e tra n sp o rt of a sm all tonnage of ore from th e P eter P an claim s to th e Lonely mill, 976 tons from th a t source being m illed during the q uarter. The ore com ing u p to expecta
tions, th e claim s have now been purchased outright a t w h at is sta te d to be a reasonable figure. Some alteratio n s are to be m ade to th e Lonely p lan t in order to enable it to deal w ith an increased tonnage from the P eter Pan section and a light railw ay is being p u t down to connect th e properties.
In th e rep o rt of the Cam and M otor com
p an y for th e q u a rte r ended Ju n e 30 last it is
sta te d th a t a Crowe-Merrill precipitation
p la n t has now been installed in place of the
zinc ex tra c to r boxes and th a t it is operating satisfactorily. A crushing p lan t has been erected a t the Petrol shaft to prepare oxidized ore for tre a tm e n t in th e residue retreatm en t p lan t.
The results of exploration on th e Caliph claims are given in th e report of Rezende mines covering the three m onths to Ju n e 30 last. It is sta te d th a t No. 1 bore-hole passed through reef form ation a t a d ep th of 317 ft., the core assaying 6-7 dw t. over 29 in. No. 2 bore-hole was p u t down to 498 ft., b u t no ore has been encountered, owing to faulting.
N orthern R h od esia.—As a precautionary
m easure, th e R oan A ntelope com pany has made arrangem ents enabling it to place 7%
convertible debenture stock during the course of the n ex t year in order to obtain approxi
m ately £200,000 as additional working capital. I t is sta te d th a t the com pany does not anticipate having to issue any of this debenture stock, unless there is a severe set-back in the price of copper.
I t was announced last m onth th a t the Rhodesia Broken Hill D evelopm ent Company had decided to offer to th e holders of options expiring a t A ugust 31 the right to extend their options a t 5s. per share up to A ugust 31, 1934, on p aym ent of a fu rth er 3d. per share.
This would leave 4s. 3d. per share to be paid.
Shareholders of th e N orth C harterland E xploration Com pany were inform ed last m onth th a t th e directors were on th e whole satisfied w ith th e rep o rt of Mr. Justice Maugham, the commissioner a t the recent inquiry into th e com pany’s concession in N orthern Rhodesia, believing th a t their claim for com pensation has been in a large measure upheld.
N igeria.—A t m eetings of shareholders of
the London Tin Corporation, held last m onth, it was unanim ously approved th a t the unissued preference shares of the corpora
tion should be cancelled and th a t ordinary shares should be created in their place.
D uring th e year ended March 31 last th e Y arde K erri Group Tin Mines, L td., m ade a w orking profit of £408. A fter allowing for debenture interest and th e debit balance of
£794 brought in from th e previous account, however, there was a deficit of £1,161 to be carried forward. In consequence of restric
tion arrangem ents th e com pany’s o u tp u t for th e year am ounted to only 65 tons, as com pared w ith 149 tons in th e previous year, th e price per ton realized being £78 12s. 4d., against £84 3s. 7d. The proved ore reserves a t th e end of th e period under review were
estim ated to be 1,361 tons. I t is stated th a t a considerable decrease has been effected in running expenses, a factor which should have greater effect on th e accounts for th e current
»year.
The rep o rt of Tin Properties, L td., for the year to Septem ber 30, 1931, shows a loss of
£8,981. Operations on the com pany’s pro p erty were discontinued a t th e end of December, 1930, its quota being disposed'of in March last.
The accounts of the London Nigerian Power Com pany covering th e year ended F eb ru ary 29, 1932, show a profit of £6,603.
A fter allowing for debenture interest, how ever, there was a debit balance of £1,293, which, afte r deducting th e sum of £214 b rought in, left a deficit of £1,079 to be carried forward.
G old C oast.— Shareholders of the A shanti
Goldfields Corporation were inform ed last m onth th a t th e reef h ad been cu t in the main cross-cut on the No. 27 level a t 528 ft. from th e m ain shaft and later advices show th e ore a t th e point of intersection to have a w idth of 4 ft. and an average assay value of 36'8 dw t. The corporation has declared a second interim dividend of 25% in respect of th e year ending Septem ber 30, payable on or after th a t date. I t will be rem em bered th a t this y ea r’s dividend is on a larger capital, a scrip bonus of 33J % being issued a t th e end of th e last financial year.
A u stralia.—Advices from A ustralia re
ceived this m onth are to the effect th a t the New South W ales basic wage rate has been reduced from £4 2s. 6d. to £3 10s. A two m o n th s’ notice has been given by th e Union to end their present agreem ent and to enter in to negotiations for a fixed wage ra te a t Broken Hill.
L ast m onth a dividend of Is. per share was declared b y th e N orth Broken H ill com pany.
I t is sta te d th a t this, like th e dividend in Ju n e last, will be paid prim arily out of accum ulated funds.
In th e re tu rn for th e m onth of A ugust shareholders of Boulder Perseverance, L td ., have been inform ed of the results achieved by th e new plant. D uring th e period from August 15 to 31 2,621 tons of ore was treated a t a cost of 16s. 9d. per ton, th e gold recovered being valued a t £4,057, while in addition it is estim ated th a t bullion to th e value of £750 has been absorbed in th e plant. The ex trac
tion is estim ated a t 95% and it is tho u g h t
th a t operating expenses will soon be reduced
to 12s. per ton. U ntil certain modifications
m aking for sm oother running and increased capacity have been effected it is considered advisable to continue th e running of th e old plant.
New G uinea.— Shareholders
of New G uinea Goldfields were inform ed last m onth th a t the Golden Ridges mill sta rte d treatin g ore on A ugust 16. A t th e same tim e th e announcem ent was m ade of a new discovery of ore some 2,500 ft. from and 600 ft. above th e Golden Ridges ore-body.
India.—The report of the In d ian Copper
Corporation for th e half-year to Ju n e 30 last states th a t the mill treated 90,737 short tons of ore, averaging 3-04% copper, w ith a recovery of 97-58%, as against 79,089, averaging 3-258% copper, for the same period of 1931. The o u tp u t of the sm elter was also higher, a t 2,160 long tons of refined copper, while th e o u tp u t of th e rolling mill rose to 2,408 long tons of yellow m etal sheet.
N undydroog Mines, L td., has announced an interim distribution of 20% , equal to 2s. per share, this representing th e largest interim p aym ent since th e com pany was recon
structed in 1920.
B alaghat Gold Mines, L td., which, in pursuance of th e a u th o rity conferred by th e special resolution approved on Ju ly l i , intends to pay th e preference dividend for th e six m onths ended Ju n e 30 last, equal to 6d. per share, will also p ay a dividend of 2s. 3d. per share to holders of both ordinary a n d preference shares.
A circular to shareholders of the B alaghat com pany sta te s th a t as all form alities w ith respect to handing over the m ine to th e N undydroog com pany have been concluded, an extrao rd in ary m eeting is to be held on O ctober 3 at which it will be proposed th a t th e com pany should go in to v o lu n tary liquidation.
B u rm a .—E u rth e r w ork on the Mwedaw
ore-body, now being opened up b y th e K afue Copper D evelopm ent Com pany, has shown the average w idth to be 24 ft., averaging 16 dw t. in value.
M alaya.—The
rep o rt of the R aub A ustralian Gold Mining Com pany for the year ended F e b ru a ry 29 last shows a profit of £71,647, against £41,008 in the previous year. The tonnage milled was 36,130, an increase of 4,510 tons on the previous y e a r’s to tal, while th e to ta l yield of gold from all sources am ounted to 24,452 fine oz., against 22,304 fine oz. The ore reserves a t the end of the year were estim ated to be 46,800 tons, as com pared w ith 33,400 tons at the end of
the previous year, 28,200 tons of th e present reserve averaging m ore th a n 10 dw t. W ork a t the Silensing m ine is still in 'hand, b u t so far it is im possible to give an opinion of its value.
C anada.— Shareholders of th e Mining
C orporation of C anada were inform ed last m onth th a t th e A shley mill h ad s ta rte d on A ugust 25 and th a t it was running sm oothly a t h alf capacity, tre a tin g 75 tons daily.
M exico.—The rep o rt of th e Mexican
Corporation, L td ., for th e th ree m onths to Ju n e 30 last states th a t 14,807 ft. of develop
m ent was com pleted during th e period, m ostly in th e oxide area n ear th e surface, w ith, it is stated , very satisfactory results.
In addition 1,370 ft. of diam ond drilling was com pleted, principally in th e sulphide section, as a guide to developm ent a n d to te s t the walls of th e veins. Milling results for th e period were norm al an d th e p re -treatm en t p la n t for rebellious m anganese-silver ores has now been p u t in to service.
D uring th e th re e m onths ended Ju n e 30 th e S an ta G ertrudis Com pany, L td ., tre a te d 74,048 short to n s of ore, th e revenue being estim ated a t $159,653. The ore tre a te d all came from th e properties of th e Com pania Dos Carlos and m illing results were norm al a n d satisfactory.
P a n a m a .— D ebenture and share holders
of P a n am a C orporation h av e been inform ed by th e liq u id ato r th a t he w ill sh o rtly be in a position to arrange for th e exchange of certificates in th e old com pany for those of th e new.
S p ain .—An offer of £3,984 of debenture
stock has been m ade b y San F in x T in in order to m ake up th e £10,000 offered in October, 1931. The com pany is a t presen t in the hands of a receiver, b u t a successful result of th e present appeal would enable the com pany to go to th e C ourt to obtain sanction for new proposals.
M etals.—The statistics for tin available
a t th e end of A ugust indicated a decrease of 2,051 tons in th e visible supplies, in addition to which there was a decline of 1,020 to n s in th e S tra its unshipped surplus, m aking a to ta l decrease of 3,071 tons, an am o u n t considerably in excess of ex p ectatio n s.
Figures for lead an d zinc production, issued
last m onth, showed an estim ated production
of lead during Ju ly of 87,109 tons, 28,487
tons less th a n th e average m o n th ly o u tp u t
of 1931, while th e zinc o u tp u t was estim ated
a t 61,403 tons, 22,780 to n s less th a n th e 1931
m o n th ly average.
G O L D M I N IN G IN T H E S U D A N
By K. S. T W I T C H E L L . B.Sc.
T h e a u t h o r d e s c r ib e s p a s t a c tiv itie s o n th e R e d S e a c o a st o i th e S u d a n a n d d e a ls w ith p r e s e n t- d a y o p e ra tio n s a n d p o te n tia litie s .
W hen a tniniijig engineer visits the E g y p tian Museum a t Cairo and looks at the am azing exhibits from th e tom b of King T utankam en, he n atu ra lly thinks of the m ines th a t produced th e gold for th e wonderful ornam ents an d coffin. The au th o r personally h a d a feeling of great p ity and wondered how m an y lives h a d been tak en in obtaining th e gold for th e coffin alone, for th e w inning of gold in those far-off days was carried out under conditions sometimes awful beyond description. In Cyprus, th e early m ining was done by heating each face with fires, w ater th en being dashed on the hot rock to cause cracks to develop, excava
tions being th en m ade w ith moils and picks.
The charcoal, ashes, dum ps of broken pottery w ater jars, and m arks of th e moils and picks are th e basis for the above sta te m ent.
In th e Sudan th e following m ethod of operations is described by D iodorus about 100
B .C .,an d th e a u th o r takes th e liberty of quoting from a bulletin prepared by Stanley C. D unn 1
The kings of E g y p t co ndem ned v a s t m u ltitu d e s to th e m ines w ho w ere notorious crim inals, prisoners of w ar, a n d perso n s c o n v icted by false a c c u sa tio n — the v ictim s of re sen tm en t. A nd n o t o nly th e individuals them selves, b u t even w hole fam ilies are doom ed to th is lab o u r, w ith th e view of p u n ish in g the g u ilty a n d pro fitin g b y th e ir toil. T he v a s t num bers em ployed are bou n d in fe tte rs a n d co m pelled to w o rk b y d a y an d n ig h t w ith o u t in te r mission, a n d w ith o u t h o p e of escape ; for th e y lay over th e m b a rb a ria n soldiers w ho sp e ak a foreign language, so t h a t th e re is no p o ssib ility of conciliating th e m b y p ersuasion or th ro u g h fam iliar intercourse. No a tte n tio n is p a id to th e ir persons, th ey hav e n o t even a piece of ra g to cover th e m selves ; a n d so w retch ed is th e ir co n d itio n t h a t all w ho w itness it deplore th e excessive m isery th e y endure. No rest, no in term issio n from to il is given eith er to th e sick or m aim ed ; n e ith e r th e w eakness of age n o r w o m a n ’s infirm ities are re g ard ed ; all are driven to th e ir w ork w ith th e lash, till a t la s t, overcom e w ith th e in to lerab le w eig h t of th e ir afflictions, th e y die in th e m id st of th e ir toil. So these u n h a p p y c re a tu re s alw ay s ex p ect worse to come th a n th e y e n d u re a t th e p resen t, a n d long for d eath as preferab le to life.
The follow ing is a free tra n s la tio n from M u ller’s te x t of A g a th arc h id e s’ d escrip tio n w ritte n a b o u t th e sam e tim e :— T he m eta l-b e arin g rocks which arc called g o ld -b earin g a re in te n se ly black, b u t am ong
1 S ta n le y C. D u n n . “ N otes on th e M ineral D eposits of th e A n g lo -E g y p tia n S u d a n .” B u lle tin No. 2. S u d an G o v ern m en t.
th em is pro d u ced a stone th a n w hich n o th in g is w h iter. Of th ese m o u n tain s, those w hich are rugged a n d hav e a n a lto g e th e r h a rd n a tu re th e y b u rn w ith wood ; a n d w hen th e y a re softened b y fire th e y ex p erim en t on th em , a n d c u t th e loosened stones in to sm all pieces w ith a n iron chisel.
B u t th e p rin cip al w ork is t h a t of th e artificer w ho is skilled in stones. T his m an show s to th e diggers th e tr a c k of th e m etal, a n d a p p o rtio n s th e whole w ork to th e needs of th e w retch ed m en in th e follow
ing m an n er :— Those w hole in stre n g th a n d age b re ak th e places w here shines th e w hite stone w ith iro n -c u ttin g ham m ers. T h e y use n o t skill b u t b ru te force, an d th u s th e y d rive in th e rock m an y galleries, n o t s tra ig h t b u t b ran ch in g in all d irections like th e roots of a tree, w herever th e stone p re g n a n t w ith gold m a y diverge.
These m en th u s, w ith candles bou n d on th e ir foreheads, c u t th e rock, th e w hite stone show ing th e directio n for th e ir labours. P lacing th e ir bodies in ev ery conceivable position, th e y th ro w th e frag m en ts to th e g ro u n d — n o t each one according to his stre n g th , b u t u n d e r th e eye of th e overseer, who nev er ceases from blows. T h en boys, creeping in to th e galleries du g b y th e m en, collect w ith g reat lab o u r th e stones w hich h av e been broken off, a n d c a rry th e m o u t to th e m o u th of th e m ine.
N ex t, from th ese a crow d of old a n d sickly m en ta k e th e stone an d lay it before th e pounders.
These are stro n g m en of som e th ir ty y e ars of age a n d th e y stren u o u sly pou n d th e rock w ith a n iron p estle in m o rta rs c u t o u t in stone, a n d reduce it u n til th e larg est piece is no bigger th a n a pea. T hen th e y m easu re o u t to o th ers th e p o u n d ed stone in th e sam e q u a n tity as th e y h a v e received it.
T he n e x t ta s k is perform ed b y w om en, w ho, alone or w ith th e ir h u sb an d s or relations, are placed in enclosures. Several m ills a re placed to g e th e r in a line, a n d sta n d in g th re e to g eth e r a t o n e handle, filth y an d a lm o st n ak ed , th e w om en lay to a t th e m ills u n til th e m easure h an d ed to th e m is com pletely reduced. A nd to ev ery one of th o se w ho b e a r th is lot d e a th is p referable to life.
O thers, called Selangeus (workers a t th e ta b le or Serahgex), ta k e from th e w om en th e pow der th u s produced. These are th e artificers, in w hom lies th e pow er of c arry in g to th e en d th is w ork of royal u tility . T h ey p o u r th e stone a lre a d y m illed on a ta b le ra th e r b road an d polished w ith a sm ooth surface, w hich, how ever, does n o t lie flat b u t has a slight in clin atio n . On th is tab le th e y ru b w ith th e ir h a n d s th e d u st m ixed w ith w ater, first lightly a n d th e n w ith g re ater pressure. B y th is m eans th e e a rth y p articles are dissolved a n d flow dow n the slope of th e tab le, b u t t h a t w hich is h e a v y an d w o rth a n y th in g rem ain s on th e wood. A nd w hen th e Selangeus h as freq u e n tly rinsed th e m a tte r o u t w ith w a ter, he h an d les th e d u st lightly, w ith soft th ic k sponges, an d p ressing lig h tly from tim e to tim e he abs'orbs from th e tab le a n d th ro w s aw ay t h a t w hich is soft an d light, e n ta n g led in th e web of th e sponge.
T here rem ain s to th e Selangeus sep arated on th e tab le t h a t w hich is h e av y an d shines, a n d w hich on acco u n t of its w eight is n o t easily m ovable. T his he tra n s m its to th e cooks, who, im m ed iately th e y
137
138
Fi g. 1 .— Sk e t c h Ma p o f t h e Co u n t r y No r t h o f Po r t Su d a n.
receive it b y w eight, p u t it in to a c la y p o t, a n d in p ro p o rtio n to its q u a n tity th e y a d d a lu m p of lead, som e g rain s of salt, a little alloy of silv er a n d lead, a n d b a rle y b ra n . T he p o t’s m o u th b ein g carefu lly co v ered a n d looted ro u n d , th e y cook it five d ay s a n d five n ig h ts consecutively. O n th e follow ing d ay , w hen th e b u rn t m ate ria ls are cooled, th e y p o u r th e m in to a n o th e r vase. T h ey find none of th e th in g s w hich w ere p u t in to g eth e r, b u t o nly a m ass of m o lten gold, little less b y w eig h t t h a n th e o riginal m a tte r.
Judging by th e num ber of the ancient mines so far known in th a t portion of the
Sudan lying n o rth of P o rt Sudan to the E g y p tian frontier an d w estw ards towards th e Nile, it seems logical th a t m uch of E g y p t’s gold came from th is d istric t. As th e ancients used prisoners of w ar an d other slave labour for m ost of th e ir mining, th e cost was only for food. T herefore the grade of ore did not have to be high and m ining was done on practically all outcrops containing appreciable am o u n ts of free gold.
The first record of gold being m ined was
139 in th e era of Menes, ab o u t 3,800
B .C .,and
th e first record w ritten was in 2,500
B.C.I t is recorded th a t in 1,500
B.C .Thutm osis III received an annual trib u te of 2,400 pounds of gold (about £132,000 value a t par), b u t in 1,440
B .C .th e am ount of gold h ad decreased to betw een 600 and 800 pounds. The descriptions previously quoted and those by S trabo bring th e history of gold m ining up to th e first of th e C hristian E ra. A t this tim e all m ining seems to have been stopped during a period of nearly 900 years.
There was an o th er period of a c tiv ity during th e te n th cen tu ry
a.d.as recorded by Cufic inscriptions on rocks ; th e au th o r has seen some of these in N ejd and H edjaz, A rabia, and he was inform ed th a t th ey were m ade in th e tim e of H aroun R achid, about
a.d.960.
th e y are willing to act as guides to find others. Form erly only mines 'near well- travelled caravan routes were known. The very ju st and hum ane tre a tm e n t by the present operators has allayed fear and distru st in th e n ative in h ab itan ts and g reatly facilitated th e recruiting of labour as well as th e prospecting for other ancient workings. In view of w hat has been found during th e p a st year, it seems reasonable to expect several additional discoveries during th e next year or two.
The au th o r was th e guest of three partners, who are operating th e G arabien mine. They also own th e W adi Oyo mine and have tak en out a prospecting licence on th e Y eit ancient workings. These men, who m ight be said to be defeating th e present world
Fi g. 2 . — Mi l l a n d He a d f r a m e a t t h e Ga r a b i e n Mi n e.
There is no doubt th a t great quantities of gold were ex tra cte d in ancient tim es, b u t th a t it was not all tak en out is proved by th e fact th a t th e Om N abardi mine is sta te d to have produced £250,000 sterling, and in th e area visited, th e G abait mine produced 60,000 tons of ore averaging 28 pennyw eights or £5 7s. per ton, m aking a to ta l of £320,051 during th e period of 1914-31. From 1902 to 1905 there was a considerable am ount of prospecting in the above area, which lies betw een th e latitu d es 20° and 22° N orth and m eridians 36° and 37° 15' E ast.
W ithin th e p ast year several ancient mines have been discovered b y th e use of intelligent gifts to natives working in the mines now in operation. Now th a t these men realize th a t th e y and their families gain m oney a n d food by m ines being worked,
depression, as well as developing a p a rt of th e E m pire, are T. M. Foley, M. J. Bishop, and T. A. Clarke.
The G arabien mine is 70 miles’’’from the R ed Sea harbour of M uhammed IQ ol and 173 miles northerly from P o rt Sudan by road and eight miles from th e G abait mine.
The country rocks are highly m etam orphosed, th e workings lying entirely in a schist. The ancients stoped to th e surface for about 500 ft. As the partners have had years of m ining experience in th e Sudan, they im m ediately commenced sinking to determ ine th e value of th e ore under th e old workings.
The sites of th e ir operations are shown by th e accom panying m ap (Fig. 1).
These workers commenced operations on
J a n u a ry 20, 1931. A t the beginning of
A ugust, work was stopped by flooding due
to heavy rains. D uring th a t period they
140
showing excavating being done for the No. 3 shaft hoist, as well as th e surface p lant.
In Fig. 4 a m ost efficient sheet-iron wheel
barrow is shown, suitable for narrow drives.
I t m akes use of a conveyor belt roller, which is superior to th e usual wheel, as it is much m ore stable.
W ork a t G arabien has been delayed for six m onths on account of th e inflow of w ater. A lthough th is is b u t 25 gallons per m inute, th e m akeshift pum ps have repeatedly broken down, allowing th e mine to fill up to th e No. 1 level. I t was only by th e end of Ju n e, 1932, th a t th e new electrical in stallatio n finally began to function, so th a t driving, sinking, and stoping from No. 2 level could be resumed.
The m anner in which lack of adequate cap ital causes increased costs, is well shown in this case, for it h as resulted in such delay owing to th e absence of suitable equipm ent on h an d to deal w ith em ergencies such as w ater. If am ply financed each one of the th ree p a rtn e rs could be operating a similar
F i g . 3.— G a r a b i e n M i n e . V i e w s h o w s e x c a v a t i o n F O R No. 3 S H A F T H O I S T , W IT H No. 1
S H A F T H E A D F R A M E I N T H E B A C K G R O U N D .
had sunk and driven a to ta l of 447 ft. a t a cost of 65J P.T ., or 13s. 8d. per foot, exclusive of ad m inistration charges. D uring th is tim e stoping was carried on and, w ith th e developm ent work, produced a to ta l of 833 tons, which was milled, yielding 258 oz.
of fine gold, or 6'1 dw t. per ton. The operators estim ate th e tailings to be 3 dw t., which gives an average value per to n of 9‘1 dwt.
The milling is done by a one 750-lb. sta m p mill an d a 30-in. S traub ball-m ill, crushing to 30 mesh, and am algam ating on a 1-ft.
by 2-ft. plate. The average daily o u tp u t am ounts to eight tons. The tonnage of ore m ined exceeds th e above am ount as it is all hand-sorted before milling. The tailings are im pounded for subsequent re treatm en t.
Fig. 2 shows th e mill and th e tailings th a t were left w ith th e m ain shaft headfram e at
th e right. Fig. 3 is a m ore d ista n t view
F i g . 4 . — W h e e l b a r r o w a t G a r a b i e n .S E P T E M B E R /- 1932
LONGITUDINAL SFfTlON
O 'P 20 30 40 50 CO 70 60 90 100 HO 120
F E ET
LE G E N D
N? I SHAFT ANCIENT STOPES...-
NEW STO PES ...
DEVELOPMENT ORE 155 TONS.
STOPED ORE 700 TONS.
EXTRACTION 6-1 DWTS FINE GOLD PER'TGN.
Fi g. 5 .
. SUDAN.
mine instead of all three rem aining a t the one place until enough gold is obtained to equip th e other properties. Although the inflow of w ater has caused such delay it is a n a tu ra l asset, as 35 tons per day would be ample for a large increase in milling capacity, if the w ater were reasonably conserved and reused.
The size of th e vein a t G arabien varies from 18 in. to 4 ft. From w hat th e w riter saw it would average under 2 ft., b u t this would yield a considerable tonnage if th e ore shoots extend th e full length of the ancient workings. A longitudinal section through th e m ine is shown in Fig. 5.
The present to ta l costs a t Garabien, exclusive of adm inistration, are 8 dw t. of
ore per mill. T h a t treated to-day averages 9 dwt. (tailings assayed 3 dw t.). The sample ta k en by th e au th o r in th e lowest workings an d a t th e w ater level gave 1 oz. 8 dw t.
value an d th e vein was 22 in. wide. From 35 tons of ore m illed in J u ly since th e w ater has been under control, an extraction averaging 15'4 dw t. has been attained.
The partners stated th ey expect to mill an average of 15 dwt. heads. W ith efficient equipm ent all costs should decrease, also th e tailings, b u t there will be an adm ini
strativ e cost to be added.
A fter a few days a t G arabien th e w riter visited some ancient workings discovered last March. These are called th e Yeit m ine, and are situ ated 49 miles (by car) northerly
Fi g. 6 . — On t h e Ro a d t o t h e Wa d i Oy o Mi n e
142
from G arabien an d ab o u t 20 m iles w est from Mersa (harbour) D alw in on th e R ed Sea coast, where dhows an d light d raft vessels can land supplies from P o rt Sudan.
The p a rty travelled by car, although there were no roads, to th is p roperty. A little work w ith a road grader a n d drags would m ake th is place easily accessible by car an d light lorry.
A t Y eit, th e w orkings are stopes in th e surface on seven veins c u ttin g a t 90° across a ridge of diabase, w hich is schistose in places. The apex of th is ridge lies a t an elevation of 2,180 ft. (by aneroid). The slopes average 29° down b o th sides from
Oyo m ine, 80 miles north-w esterly. I t is 55 miles south-w est of H aleib, a harbour on th e R ed Sea an d lies a t an elevation of 1,350 ft. Fig. 6 shows Mr. T. N. Foley
en route w ith th e au th o r.A t W adi Oyo considerable ore h as been e x tra c te d from th e one vein w orked. Fig. 7 shows in th e background th e tailings from th e mill, an d ju st behind these are th e ancient an d m odern w o rk in g s ; in th e left-hand foreground, near th e to p of th e hill, dumps from ancient operations on a parallel vein are seen. No m odern w ork has been done here, so th a t th ere is scope for a possible additional tonnage. The appearance of the
Fi g. 7 . — Wa d i Oy o Mi n e. An c i e n t w o r k i n g s a r e s h o w n o n t h e l e f t a n d O N T H E R I G H T T H E M O D E R N W O R K B E I N G D O N E B E L O W T H E M .
