F E AT U R E

JURUTERA, December 200712

INTRODUCTIONT h e re were two main factors that hadcontributed to the rapid development ofthe Malayan tin industry in the mid-19thC e n t u r y. One was the discovery of rich tinfields in Perak and Selangor. The other wasa high demand for tin because of thedevelopment of tin canning. By the end ofthe 19th Century, Malaya was already theworld’s largest tin pro d u c e r.

To d a y, Malaysia only produces lessthan 1.5% of total world pro d u c t i o n( refer to Table 1). Once the brightest starof the Malaysian economy, tin mining isnow considered a sunset industry. Whatwent wro n g ?

The main reason is because of the totalcollapse of the world tin industry inOctober 1985 when the price of tin fell bym o re than 50%. The other factor is therehas been no new discovery of tin fields.P re v i o u s l y, most of the tin mining land wasowned by the government. Furthermore ,

converting agriculture land for mining hasbecome too expensive.

The high price of tin has caused greatexcitement in the tin mining industry.People are now talking about investing inthe industry. The intention of this paperis to give a brief review of the industryfrom a former tin miner’s perspective.The future of the tin industry depends onthe price of tin, the value of the ringgitand, most importantly, the discovery ofnew tin fields. Is there tin at the end ofthe rainbow?

HISTORY OF TIN MININGTin ore has been mined in Malaya forcenturies. At that time, mining methodswere primitive and tin ores were minedalong the river banks. It was thediscovery of large deposits of tin ore inLarut, Perak, in 1848 by Long Ja’afar thatstarted the development of the tinmining industry in Malaya. Long Ja’afaremployed Chinese miners to mine hisland. Later, Chinese merchants from theStraits Settlements were encouraged toinvest in the mines which led to the largeinfluxes of Chinese immigrants. An evenricher deposit of tin ore was discoveredin the Kinta Valley in Perak, which laterbecame the richest tin deposits in theworld. Meanwhile, large deposits of tinwere also discovered in Selangor.

The tin production at Larut was verysuccessful until the Larut War which

b roke out due to conflicts between theMalay chiefs and their respective Chinesepartners. Similar wars also broke out inS e l a n g o r. The wars had disrupted thesupply of tin which led to the Britishintervention in 1874.

Chinese miners were the mainp roducer of Malayan tin ores before theBritish came. The British brought ind redges, which increased tin pro d u c t i o nt remendously and, subsequently, re p l a c e dthe Chinese miners as the largest pro d u c e rof tin in the country.

Tin Mining in Malaysia- Is There any Revival?...........................................................................................................................................................................................................................

By: Engr. Yap Keam Min, FIEM, P.Eng.

Figure 1: A gravel pump tin mine in Chendriang,Perak in 1989

Figures 2,3,4: Tin ores occur in various formsfrom very fine to coarse. The coarser the ore, themore the impurities

*Tin prices from 2001 are quoted in US$ per tonne.The figures are converted to RM (takingUS$1=RM3.80)(Sources: Malaysian Tin Bulletin and MSC Bhd)

Year Production Average(tonnes) Price

(RM$/kg)

1970 73,795 10.99

1975 64,364 15.94

1980 61,404 35.72

1985 36,884 29.67

1986 29,134 15.39

1989 32,034 23.09

1990 28,468 16.45

1991 20,710 15.05

1994 6,458 14.14

2000 6,307 20.45

2001 4,972 16.80*

2002 4,215 15.44*

2003 3,358 18.58*

2004 2,746 32.20*

Table 1: Tin production of Malaysia and tin price

JURUTERA, December 2007 13

F E AT U R E

TIN ORETin occurs in the form of cassiterite (SnO2)or tin ore which is associated with otherheavy minerals, most commonly iro n .Most of the tin ore is in sand-like formwith the occasional large pieces. Figures 2to 6 show various forms of tin ore. Lode tinis shown in Figures 5 and 6. The larg e rform needs to be crushed and grindedb e f o re being dressed. Most of theMalaysian tin deposits are alluvial and theb e d rocks are normally limestones,decomposed granite or schist. Tin bearinglayers or ‘pay dirt’ are locally known as‘karang’ (Figure 7). The ro u g hconcentrates obtained from the ‘palongs’and dredges are roughly 20%-30% tin.They have to be further rewashed to about

70%-75% tin before selling to the smelters.The residuals are known as ‘amang’ whichcontains tin ore and other heavy minerals.It is difficult for the layman to diff e re n t i a t ethe ‘amang’ from tin ore .

TIN SMELTING INDUSTRYI n i t i a l l y, tin was sold in its unre f i n e dstate. However, being the world larg e s tp roducer of tin, it was natural for thecountry to have its own smeltingfacilities. It was more economical toexport tin in the form of blockscommonly known as ingots. An exporttax on unsmelted tin ore wasi n t roduced as well. At the smeltingfactories, tin were made 99.9% pureand exported as ingots. Plants were setup in Singapore in 1887 and atButterworth in 1902. To d a y, Malaysiastill has some of the most eff i c i e n tsmelting plants in the world.

METHODS OF MININGThe Old WaysThe old Chinese method of mining wasmainly carried out by hand. The groundwas manually dug by ‘changkol’ (hoe)and the ‘karang’ was carried to hydraulicsluices. Tin ores were re c o v e red bypanning. Dewatering of the mine pit wasalso done by hand using buckets.Chinese miners used chain pumps whichrun on water wheels. Flooding of themines was common and, often, deepmines had to be abandoned. The Britishi n t roduced steam engines andcentrifugal pumps which started thegravel pump method.

Gravel PumpGravel pump (Figure 8) is the mostcommon method of tin mining. The orebearing ground is broken down by highp re s s u re water jets known as ‘monitors’( F i g u re 9) and the resultant slurry iswashed to a sump in the pit floor. Theg round is kept steep so that the slurry slidesdown to the sump by gravity. A g r a v e lpump pumps all the material up to anelevated ‘palong’. ‘Palong’ is a hugewooden sluice box (Figure 10) to trap andsave tin ore. Tailings are dumped intoretention ponds (Figure 11) or old mineholes. Water is recycled for use. The cost ofsetting up a gravel pump is much lowerc o m p a red to that of a dre d g e .

DredgingThe introduction of dredges marks asignificant change in the Malayan tinmining industry (Figure 12). Dre d g e sa re highly efficient mining machineswhich can operate practically non-stop

Figure 5: Lode tin ore

Figure 6: A large piece of lode tin ore

Figure 7: Karang or pay dirt is normallyassociated with gravel

Figure 8: The author with a huge gravel pumpwhich was powered by a 620hp of Cumminsengine. Note the size of the engine

Figure 9: High pressure water jet or monitorbreaking up the ore bearing earth

Figure 10: Palong, a giant sluice to collect tin ore

Figure 11: Tailings dump – tailings are stored inimpounded dams

F E AT U R E

JURUTERA, December 200714

(24 hours with labourers working onshifts). Land of lower grade depositscan be profitable because of the highy a rdage of materials treated. Thed redge is essentially a floating minew h e re mining and tin ore dressings aredone on board. The ore bearing earth isdug by chain buckets and broken downby monitors; and jigs are used to washthe tin ore .

The main disadvantage of dredges isthat it cannot recover tin ores lyingbetween limestone pinnacles. Limestonecavity is often very rich in tin ore deposits.The gravel pump method is usually usedto ‘clean up’ the cavities.

The first dredge was employed in 1912at Batu Gajah, Perak. Within two decades,d redges overtook the gravel pumpmethod as the main producer of tin.H o w e v e r, dredges are very expensive andw e re normally owned by large multi-national companies.

Dulang Washing‘Dulang’ washing or panning (Figure 1 3 )once played an important part in themining industry and used to contribute a

fair percentage of tin produced in thec o u n t r y. A ‘dulang’ is a wooden circ u l a rpan similar to the gold miner’s pan. The‘dulang’ is moved in a circular motionuntil the lighter materials are thrown offleaving tin ore. Most ‘dulang’ washersw e re Chinese women and they have topossess licences to mine and sell tin ore .The licence is known as a ‘dulang’ passwhich is issued by the MinesDepartment. Favourite mining are a swere abandoned mines and river banks.‘Dulang’ washing is used to clean up theore in areas where pumps and monitorscould not reach.

Open Cast Primary TinIn areas where tin ore occurs in rocks andboulders, the ore bearing materials aredug by excavators and transported bydump trucks to a collection pit. Monitorsare used to break up the materials. Theore bearing rocks are crushed and got h rough a separation process. A nexample of an open cast mine is theRahman Hydraulics in Perak.

Underground MiningAs the name implies, mining is carriedout underground in tunnels and shafts.The most famous mine was theexhausted Sungei Lembing in Pahang.

MINES DEPARTMENT ANDMINING ENACTMENTIn the early years of mining, there wereno laws or regulations. When the Britishtook over the administration of thecountry, they set up the Land and Minesdepartment to oversee the proper leasingof mining land. In around 1896, a miningenactment was implemented to controland regulate the tin mines.

All mines are re q u i red to obtainhydraulic licences before any miningactivities can proceed. Licences areissued by the Mines Department andhave to be renewed yearly. Applicationfor the licence should include a proposedplan of the mining scheme with thefollowing information:1. Method of mining2. Position and size of ‘palong’ 3. Intended or proposed location to be

mined4. Location, area and capacities of tailings

and dry dumps

5. Size of the tailing bunds and place ofdischarge

6. Monthly average volume of yardage 7. Size of pumps and engines 8. Indication of the depth of the mine

The application has to be endorsed bya Professional Engineer (PE). Mineinspectors and their technicians from theMines Department make re g u l a rinspection of the mines.

TIN PRICEH i s t o r i c a l l y, tin has always been afluctuating commodity. The price of tind ropped about 50% during the gre a tdepression years from 1929-1934. In 1931,the tin producing countries voluntarilyenforced the International Tin Controlscheme where each country was given anexport quota.

The International Tin Council (ITC)was formed in 1956 to control the priceof tin. Both the major producer andconsumer countries were involved inthe council. In 1983, the Association ofTin Producing Countries (APTC) wasalso formed for the same purpose.H o w e v e r, due to the poor state of thetin industry, the council was dissolvedin 1990. Table 1 shows tin orep roduction and price since 1970; note the instability of the price andsliding output.

MALAYSIA’S TIN RESERVEIt is a very difficult task to even guessthe reserve of tin in Malaysia. Most ofour tin had come from alluvial depositsand it is time to look for the motherlode. The Geological Survey ofMalaysia has done extensive studiesand results have shown that there maybe large primary deposits (lodemining) along the main range. Miningthe mother lode re q u i res a very larg einvestment and the cost of pro d u c t i o nis high.

Some of the large alluvial re s e r v e sa re under developed towns and citieswhich are difficult to mine forobviously reasons. It has been re p o r t e dthat the town of Gopeng in Perak sitson a very rich reserve and there hasbeen attempt to relocate the town formining. The other possibility is inf o rest reserves like Belum in Perak.

Figure 12: The classic dredge, an efficient miningmachine in flat alluvial ground

Figure 13: Dulang washers played an importantpart of the tin mining industry

F E AT U R E

JURUTERA, December 200716

It is interesting to note that theMineral Commodity SummariesJanuary 2006 by the United StatesB u reau of mines (Table 2) givesMalaysia an impressive figure of1,200,000 tonnes of tin reserve, thirdonly after China and Brazil. If thef i g u re is even half true, the tin industrymay have a chance.

TIN MINING AND THEENVIRONMENTNowadays, protection of thee n v i ronment is a hot topic. Tin mininghas created some enviro n m e n t a lp roblems such as the silting of rivers,waste lands and mining pools withslime. Figure 14 shows an ex-miningpool with slime.

It has been proven that mining andconservation of the environment couldco-exist as the rehabilitation of mineshas shown great results. Oil palmshave been successfully planted in ex-mining grounds. Constructions in ex-mining grounds have been carried outs u c c e s s f u l l y. In fact, many housingestates in Selangor, Kuala Lumpur andPerak are built on ex-mining land. Ex-mining pools are used forre c reation purposes such as theClearwater Sanctuary.

Tin mines have, for many years,p rovided sand to the constru c t i o nindustry. Malaysia is fortunate to havesome large mining pools which wereconverted into landfills. Ex-mining poolscan be also used for flood control (theSMART project).

SOME INTERESTING FACTS1 . Most productive tin mine in the worldThe Ayer Hitam No 2 Dredge atPuchong, Selangor, was declared themost productive tin dredging ever. In themonth of November, 1976, in just 30days, its output was recorded at 801.26tonnes. [5]

2. Collapse of tin The tin buffer stock system collapsed inOctober 1985. The controlled price of tinfell from RM29 to around RM15.

3. Malaysia is a net importer of tin oreF rom being the largest producer in the

Figure 14: An ex-mining pool - a challenge for geotechnical engineers Figure 15: Drilling for primary deposits

Mine production Reserve base (estimates)

2004 (estimates) 2005

United States - - 40,000

Australia 800 800 300,000

Bolivia 16,800 17,000 900,000

Brazil 12,200 12,300 2,500,000

China 110,000 115,000 3,500,000

Congo (Kinshasa) 2,000 2,000 NA

Indonesia 66,000 80,000 900,000

Malaysia 3,000 2,000 1,200,000

Peru 42,000 42,000 1,000,000

Portugal 500 500 80,000

Russia 2,500 3,000 350,000

Thailand 600 650 200,000

Vietnam 4,000 4,000 NA

Other countries 4,000 1,200 200,000

World total (rounded) 264,000 280,000 11,000,000

Note: NA =Not available

Table 2: World mine production and reserve base

(Source: Mineral Commodity Summaries, January 2006, U.S. Geological Survey-US Bureau of Mines)

F E AT U R E

JURUTERA, December 200718

world, Malaysia is now a net importerof tin ore. The ores are for the smeltingplants in the country and it is still one ofthe largest exporters of refined tin.

4. US stockpileThe US government has a stockpile (GSAsales) to control the price of tin.

5 . Tin ore mined at the Federal HighwayA rich deposit of tin ore was discoveredduring the construction of the highway.A ‘palong’ was constructed to mine thearea and, rightly so, as otherwise, the tinore would have been lost forever.

6. Monitors run by waterfallA Chinese tin miner in Perak converted awaterfall to power his monitors.

7. Old Chinese miners’ beliefsIt is said that tin ore can be separated bya sheet of paper. All the soil testing andinvestigation will come to naught if youdo not have luck.

FUTURE PROSPECTThe revival of the tin mining industrydepends on the discovery of new tinfields and the stability of the price oftin. New land has to be opened by thegovernment for prospecting by theminers. Pre s e n t l y, any land, agricultureor otherwise, that is converted formining has to be surre n d e red to thegovernment after mining activities hasceased. The future is probably in theexploration and discovery of primarytin deposits (Figure 15).

CONCLUSIONTin mining is indeed a sunset industry inMalaysia. It would take a miracle for it toreturn to its past glory. The main obstacleis that there is no land with rich tindeposits. For the last two decades, tinores had been mined from dredged outareas, old mines and reworking of thetailings. Most of the known tin ore areasare of low grades.

The government should study theconversion of agriculture land for mining.The law should be amended so that theland would be returned to the land ownerafter mining activities have ceased. The tinshould be extracted before anydevelopment comes in as, otherwise, thetin ores would be lost fore v e r.

The viability of a tin mine dependsnot only on its reserves and effectivemining methods but also on the demandfor tin and the value of the ringgit. Therecent increase in the price of diesel addsto the plight of the tin mining industry, asfuel constitutes a high percentage of theoperational cost.

The price of tin has always beenunstable and miners are sceptical on thesustainability of its prices. The presenthigh price is due to the demand fromChina and the ‘metal boom’. The price ofmost metal are on re c o rd high andfinancial analysts are talking about theexpected bubble burst, similar to thedot.com experience a few years ago.

The future of tin is probably in miningprimary deposits. However, evenexploration works for primary tin involveshigh capital investment and high risk. ■

REFERENCES

[1] Geological Survey of Malaysia, Potential for Development ofthe mineral industry in Malaysia – a guide for Mineralexploration strategy, 1985

[2] United States Bureau of Mines, US Geological Survey, mineralcommodity summaries, January 2006

[3] Kok K C, History of Malaya and Singapore, Oxford Universitypress Pte. Ltd, 1996

[4] Gullick JM, Kuala Lumpur 1880-1895.Pelanduk Publications,1988

[5] Guinness Book of records, 1980 edition.