Malaysia: memories of Penang and the Kinta Valley

In the 1980s I had four memorable visits to Malaysia and I hope that this blog posting might put me in touch with some of the many people that I met in that fascinating country, in the same way that my recent blog on Egypt brought me, and Antonio Peres, back in touch with our host in Cairo, Prof. Refaat Boulos.

In 1981 I spent 9 weeks in January-February and 4 weeks in July as a visiting lecturer at the Universiti Sains Malaysia on the beautiful island of Penang.

Penang

I wonder what became of the 4 students that I tought during my first visit:

Nine weeks was more than enough to present a short course on mineral processing, so I had plenty of time to explore the island, and to spend a couple of weeks back-packing in Bangkok, Singapore and Bali, but the highlight of both trips was the time that I spent on the mainland in Ipoh in the Kinta Valley. Here for the first time I saw the contrast between the mining and processing of tin in Cornwall, from hard rock ores, and the processing of alluvial deposits on a very large scale.

The tin mining industry was at the time of my visit the major pillar of the Malaysian economy.  The country was producing almost 63,000 tons of tin annually, accounting for 31% of world output. It was the world's leading producer and employed more than 41,000 people, the most important area being the Kinta Valley, the world's most productive tin field. Perak was the wealthiest state in Malaysia, its capital Ipoh being fondly known as “The City of Millionaires”. During my time in Ipoh I was hosted by Mike Joll of Osborne and Chappel, co-author of a book on Malaysian tin mining. The last time I saw Mike he was living in Helston, Cornwall, so I would love to know what became of him.

Dinner with local miners in Ipoh (Mike Joll is 4th from left)

Dinner at SEATRAD (South-East Asia Tin Research and Development)

By the end of the 19th Century, Malaya (now Malaysia) was the world’s largest tin producer and the Cornish industry, once the world's largest producer fell into rapid decline. The mines in Cornwall were very deep, and mining and processing were expensive, comminution of the hard rock being followed by gravity separation on shaking tables, calcining to burn off arsenic, and, in the 20th century, removal of sulphides by froth flotation. Due to large amounts of fines, and poor liberation, recoveries were low and concentrate grades typically lower than 40-60%. Although the alluvial ores were of much lower grade (as low as 0.02% tin) compared with the hard rock ores of Cornwall (around 1% tin), mining could be carried out at a relatively vast scale, no comminution was necessary, the minerals were coarse and fully liberated and very simple, cheap gravity methods effective in producing concentrate grades of 70-75% tin.

Chinese miners were the main producer of Malayan tin ores before the British came. The British brought in dredges, which increased tin production tremendously but the smaller gravel pump mining operations were most commonly used in the Kinta Valley. In these mines the ore-bearing ground is broken down by high pressure water jets known as monitors, the resultant slurry being pumped to a huge wooden sluice box, or palong, down which slurry flows over a series of baffles, behind which the cassiterite and other heavy minerals settle out. Periodically the flow is stopped, the baffles are lifted and the heavy mineral concentrate is sluiced out. Primary tin concentrate is further processed in a secondary concentrator or ‘‘tin shed’’ involving wet and dry gravity methods, magnetic and electrostatic separation, by-products including ilmenite, rutile, zircon, monazite, xenotime, and struverite.

Gravel pump mine

Palong concentrators

Palongs

It was also interesting to see women toiling in the +30C heat to further recover cassiterite by panning, using wooden pans called dulangs. By 1900 the dulang had become widely used by groups of independent women (dulang-washers) to undertake freelance mining operations. During the 19th and 20th centuries it is estimated that dulang-washers recovered almost 150,000 tonnes of tin in concentrates, or over 2% of the country's total production.

Dulang-washing

Dredges are very expensive and were operated by large multinational companies, but they are highly efficient machines which can operate practically non-stop and lower grade deposits can be profitable because of the high tonnage of material treated. The dredge is essentially a floating mine where mining and ore dressing are done on board. The ore bearing earth, in flooded paddocks, is dug by chain buckets and broken down by monitors, jigs being used to concentrate the ore. The main disadvantage of dredges is that they cannot recover heavy minerals lying between limestone pinnacles, which are often very rich in tin.

Dredge

In July 1985 I was back for four weeks at the University in Penang but this time accompanied by Barbara, Amanda and Jon.  

Amanda, Barbara and Jon exploring the Penang capital, Georgetown

With local children on our favourite beach at Batu Ferringhi

In the photo below I am with USM staff Radzali Othman, Tuan Basar, Abdul Latiff and Kok Keong Cheang. Where are they now I wonder?

During our 4 weeks in Penang I made only a very brief trip across the water to the Butterworth tin smelter but the tin operations on the mainland were blissfully unaware of the crisis that would befall on them 3 months later.

At the Butterworth tin smelter

Apart from a fairly recent stop-over in Kuala Lumpur for a couple of days my last visit to Malaysia was in 1988, to give a presentation at the International Symposium on Research and Development in the Extractive Metallurgy of Tin and Related Metals, a very low-key affair as the Malaysian tin industry had suffered very rapid decline since my last visit.

Malaysia had been the world's largest tin producer until October 1985 when prices dropped by 50% and more than 300 tin mines stopped their operations. By 1994, the country's production had fallen to 6,500 tons, with only 3,000 people employed in the industry. The only tin dredge remaining was not producing tin, but was open as a tourist attraction.

Visiting the remaining tin dredge with ISRADEMT delegates

By 2016 Malaysian tin output was only 3,500 tonnes, and by then the country was ranked 9th in the world for production. It seems unlikely that the Kinta Valley will ever be a major producer again, as no new deposits have been found, whereas Cornwall, whose tin mining days were eclipsed by the Malaysia finds, is set for a possible revival.

Whatever happens, we have very fond memories of our time in Malaysia and of its very friendly people.

@barrywills