Few chief executives get quite so excited about a single plant as Thomas Leysen, the head of Brussels-based Umicore, when discussing a 120-year-old factory in Belgium.

Likening the factory in Hoboken, near Antwerp, to a “treasure trove”, Mr Leysen says it can extract 17 different metals from a feedstock of old batteries and other discarded electrical goods.

“We can take from the plant each year more than 40,000 tonnes of lead, some 20,000 tonnes of copper, a few thousands tonnes of nickel, 1,000 tonnes of silver, a few tens of tonnes of gold and some 50 tonnes of platinum group metals,” enthuses Mr Leysen.

The Hoboken plant – which Umicore says is the biggest in the world for specialised metals recycling – has been improved since the late 1990s with investments of €500m ($689m).

The stream of high-value products from the factory is one reason why Umicore – a speciality materials company which until 2001 was called Union Miniere and was built 100 years ago on the copper resources of the former Belgian Congo – has in the past year attracted the attention of stock market investors.

Helped by increased interest in metals-related stocks, caused by the boom in metals prices worldwide linked to high demand in China, Umicore’s share price has soared in the past three years, far outstripping the main Belgian stock market index.

In recent years, Umicore has quit most of its former areas of mining, to concentrate on “downstream” fields closer to customers.

An example is its decision late last year to spin off its zinc smelting and alloying operations to a new London-based venture, partly-owned by Zinifex of Australia, that is due to seek a stock marketing listing in the next few months. Mr Leysen, a 46-year-old former lawyer, says the company has a new focus on “areas where we have a global business, and in which we are, or are capable of becoming, one of the leaders.” He says the strategy is starting to show through in Umicore’s financial results.

Last year, Umicore increased net profits by 37.6 per cent to €195.8m, compared with €142.2m in 2005, on sales ahead 11.2 per cent to €1.9bn, the latter excluding revenues from its precious metals operations which are subject to extreme price fluctuations.

One important field for Umicore is automotive catalysts, a business in which it has about a 25 per cent market share, just behind the other two leaders: Johnson Matthey of the UK and Germany’s BASF.

In this industry, which has worldwide annual sales of about €2bn, excluding the value of precious metals that go in the catalysts, Umicore last month bolstered its position through an agreement to buy for $55.6m the vehicle catalyst division of Delphi, the US car parts company that has filed for bankruptcy.

Mr Leysen says Umicore’s catalysts group is well-placed to take advantage of the trends influencing the development of this industry – expected to experience strong growth in the next 20 years as a result of increased interest in curbing the environmental impact of cars and trucks.

Makers of automotive catalysts have to find technical solutions that will tailor each catalyst to work efficiently with specific engine types. The number of engine types is likely to keep rising, especially as carmakers introduce different forms of engine to suit the emerging economies likely to experience the largest rise in automotive sales in the next decade.

“Each time a vehicle maker brings out a new engine, a new type of catalyst is required,” says Mr Leysen.

“The large degree of variation means in the course of a year we produce several hundred different types of these devices to suit the requirements of our customers.”

Umicore is also one of the biggest makers of lithium cobaltite, a speciality material used in rechargeable batteries, and has a joint venture with De Beers, the world’s biggest diamond producer, to make high-technology artificial diamonds for use in applications such as cutting tools.

It also makes specialist platinum linings that ensure certain kinds of chemical reaction – for instance to make high-strength glass – are free from contamination.

Another exotic material where Mr Leysen says Umicore has a strong position is germanium, a material related to silicon which is particularly useful for forming into extremely high-power solar cells incorporated into space satellites so their electricity supply will last for years without the need for batteries.

“World production of germanium comes to only about 100 tonnes a year and of this Umicore provides about half,” Mr Leysen says. – Financial Times