Thos Begbie is a company with rare expertise. The historic South African foundry, which turns 115 years old this year, is one of only two in the world – the other being in the US – that has the ability to produce high-tonnage copper castings, while still retaining optimum levels of conductivity in the copper.

Although others in the world, notably the Japanese, manage to retain high conductivity in small mass-produced castings, they are invariably forced to resort to vacuum technology to achieve their aim.

Not so Thos Begbie, which is able, not only to retain high conductivity in huge castings – even up to 14 t if need be – but, also, to do so using atmospheric pressure alone, without having to resort to vacuum-based methods.

The world, having learnt of the rare ability of this Mpumalanga foundry, is now beating a path to its door, resulting in 60% of the production of its pyrometallurgical component manufacturing (PCM) division being exported.

The large high-conductivity copper castings made by Thos Begbie – generally in the 5 t to 8 t range – are regularly of the kind used as sidewall panels through which water is piped in order to cool large pyrometallurgical furnaces.

Thos Begbie uses large quantities of primary materials as opposed to scrap metals, consuming more than 2 000 t of virgin copper a year to ensure that its conductivity levels are optimised – and are highly impressed with the quality and on-time delivery of Zambian copper in particular.

The high conductivity of the copper is vital, as it facilitates the transfer of heat out of the furnaces.

In addition, slag that freezes on the sidewalls of the copper castings plays a crucial refractory role.

As a result, the furnaces can be kept in service for far longer periods. Significant cost savings result and, as a consequence, demand for the high-conductivity pyrometallurgical cast components is rising and the market for Thos Begbie's special expertise is continually expanding.

Adding to the company's international recognition is the fact that it is now a preferred global supplier to Canadian-based Hatch, which is the custodian of key intellectual property relating to the use of high-conductivity copper coolers in pyrometallurgy.

In casting high-conductivity copper, Thos Begbie has perfected the crucial skill of being able to remove oxygen from the copper without the use of contaminants.

Conventional degassing agents remove the oxygen from the copper, but reduce conductivity.

The best conductivity obtainable using some of the agents is 60 %, which is insufficient to draw the required heat out of the furnace.

By contrast, Thos Begbie achieves conductivities in the top ninety percents and its ability to degas copper in large volumes has become one of its crucial competitive advantages.

Another important skill in the field of copper cooling panel casting is making sure that piping is well bonded to the copper casting.

Bonding is key as it is linked directly to heat-transfer facilitation.

Thos Begbie has in-depth pipe-to-casting bonding experience and is able to guarantee a 98% bond throughout such castings.

Notwithstanding this, however, several of its large corporate clients insist on fully destructive tests being undertaken to ensure that piping is properly bonded to the copper casting, as there is fear of a very fine line existing between a good bond and no bond at all.

But in each non-destructive test, the company has emerged with flying colours, not the least being the destructive tests on panels carried out for the large nickel refinery at Cerra Matosa in Colombia and on panels for Anglo Platinum's Waterval slag smelter in the North West Province.

The company is also experiencing increasing demand for water-cooled copper launders, which transfer molten metal from furnaces to tapping systems.

It manufactures launders as a stock item, winning regular orders from Australia in particular in the past four years.

This is mainly the result of Thos Begbie being able to extend the life of the 1,8 t launders it casts, from the three weeks the Australians were used to when using an alternative design, to the twelve weeks now being enjoyed with the South African design.

It was Scottish engineer and entrepreneur Thomas Begbie who originally founded Thos Begbie in Johannesburg in 1887.

Following a war-related explosion in 1900, the company eventually relocated to a large site in Middelburg in 1907 – and has been there ever since.

Over the past 100 years, it has gone through a series of corporate ownership phases, passing from Anglo American to Barlows and then to a Samancor–Highveld Steel–Industrial Development Corporation joint venture.

But since July 1998, entrepreneurship has returned, with ownership in the hands of a seven-person management team and the workforce of 140.

This has had an enormous impact on the company's fortunes, with turnover more than trebling from the current R50-million a year at the time of the management buyout four years ago to R176-million today.

Turnover in high-conductivity castings alone is now more than R70-million a year.

The new owners succeeded in paying off the business in less than three years.

They have invested an additional R20-million into it cleverly, by acquiring important machinery at extremely low cost.

Moreover, some R800 000 in dividends has been distributed to the workforce – which has a collective 10% shareholding – and further distribution is imminent.

In addition to the ever-growing export opportunities now looming large on the horizon, domestic demand for the company's products has never been greater.

Being manufactured at the plant during the visit of Engineering News were castings for three large local contracts won by the company in the pyrometallurgical field.

The largest is a R29-million order for 84 high-conductivity copper sidewall water coolers and various other cast components, including 42 pressure rings, 84 contact shoes, electrode components, tapping assemblies, tapping blocks, slag inserts (monkeys) and launders.

All for Anglo Platinum's Polokwane Smelter in the Limpopo province, the castings are being manufactured from drawings supplied by Hatch, for delivery in June.

The second-largest contract now being fulfilled is one for R10-million, involving the supply of high-conductivity sidewall coolers, tap locks and contact shoes, this time from drawings provided by South African company Pyromet, of Johannesburg.

Delivery of these components, for a slag-melting furnace at Anglo Platinum's Waterval Smelter begins this month.

The third-largest contract now being fulfilled is one for R8-million-worth of copper-coolers and ancillary components, again from Hatch drawings, and these castings must be supplied to Anglovaal Mining's Chambishi copper-cobalt project in Zambia by July.

In all cases, drawings are downloaded on to Thos Begbie's computer-aided design system, from which patterns are made in wood or glassfibre.

Sand moulds are produced from the patterns, and, in the case of the copper coolers, tubular coils are positioned in the moulds so that they can bond with molten metal when it is poured into the mould.

Once the metal solidifies, the casting is extracted, fettled, cleaned and tested.

Thos Begbie MD Eugene Rossouw tells Engineering News that he expects the strong current demand for pyrometallurical components to persist for the next four years, as a result of growing acceptance of the effective furnace cooling technology migrating beyond platinum smelting to ferrochrome and ferromanganese smelting.

Moreover, Thos Begbie sales and marketing director Daan Delport reports that two more large export orders for pyrometallurgical components are expected this month, one for a copper smelter in India and the other for finger coolers for a nickel operation in Indonesia.

Negotiations are also at an advanced stage with a Swiss company seeking ongoing supply of pyrometallurgical components into Europe, at an anticipated rate of R50-million to R100-million a year.

The company is also poised to become a significant supplier of consumables for the steel industry, where several furnace rebuilds are expected globally and old cast-iron hearths in blast furnaces are giving way to water-cooled copper hearths.

The nature of the work that Thos Begbie does, though highly specialised, is still jobbing work.

While jobbing is infrastructure intensive, it is not commensurately offtake intensive.

In order to create a greater balance between infrastructure required and the volume of offtake, Thos Begbie last year commissioned a semi- continuous vertical copper-casting machine that produces copper slab in 5 m lengths.

In this way the company comes as close as a jobbing foundry can to attaining production foundry efficiency by having a constant flow of molten metal for both jobbing and slab production.

It is now producing quality copper slabs for a South African rolling mill which is, in turn, using its excess capacity in order to operate more efficiently by producing copper sheet and foil as both an import substitution and export initiative, again involving high-conductivity material for the electrical industry. Both Thos Begbie and the company owning the rolling mill have achieved volume throughput through the new arrangement and driven down costs through the dilution of fixed-cost elements.

As a result the company is able to melt copper cheaply, firmly believing that it melts copper at lower cost than any other foundry.

It has evidence that it does so at a third of some of its rivals, enabling it to win premium business on both the jobbing and production fronts.

Another great company attribute is its propensity to procure capital equipment frugally. An example is the vertical copper caster just commissioned, which members of the management team conceptualised on the back of a cigarette box.

This was eventually built locally at a fraction of the cost of international quotations.

The total project – including a 21-m-long by 20-m-wide factory and the 7,4-m shaft caster which is entirely South African right down to the Middelburg-procured programmable logic controllers – cost less than R3-million The lowest foreign quote, provided well before the current rand depreciation, from China, was treble the local price and the highest quote, from Germany, was ten times the local price.

In developing the machine, the South African team also managed important innovations, one being elimination of the need for a tundish.

As a result, molten metal passes from furnace to ladle to caster, as opposed to the normal flow from furnace, to ladle, to tundish and then to caster, eliminating an entire step of cost.

The company refurbishes copper furnace components. On the floor being refurbished when Engineering News called was an electrical trombone reactor for a large stainless steel producer, furnace wall panels for a mineral sands miner and bottom ring segments for a ferrochrome producer.

Thos Begbie has three divisions, the largest being the PCM division, where a multiplicity of components are cast, in addition to the high- conductivity side-wall copper coolers.

In its engineering division, the tubular cooling coils are welded and fabricated and large castings are deep-hole drilled and machined.

Some 20 000 X-ray welds have to be done in the production of the tubular coils in monel, stainless steel and copper and bent on computer numerically controlled (CNC) pipe-bending machines.

The X-ray function has been contracted out to inspection authority Raysonics, whose reports are sent directly to clients.

Shop-assembly of large furnaces is becoming a norm of the engineering department. All parts are match marked so that the furnace can be reassembled easily on site.

Because the factory floor has proved insufficient even for shop assembly, a new perfectly-even floor is to be installed, involving the space between rails, placed at 300 mm intervals, being filled in with an epoxy-based self-levelling cement.

This will provide a new 100 mm-thick surface on which future shop assembly will take place.

Being commissioned in the engineering division when Engineering News called was a large R2-million CNC machining centre on which large castings can be completely machined in one setting in half the time – 20 hours instead of the usual 40. Once again, the machine has been built at low cost by a South African company which made use of an old Gravenstaden casting in to which state-of-the-art drive elements for vertical and horizontal machining have been fitted. A deep-hole drilling machine, bought in rundown condition in the US, has been refurbished to drill 38 mm to 150 mm diameter holes to depths of three metres.

Copper panels 1 920 mm deep are drilled in less than two hours and holes 6 m deep can be end drilled.

The drill is ideal for drilling copper components for pebble-bed-type reactors, should these reactors be built in South Africa for export, as is expected.

The company's third division is its granular stainless steel division which has the capacity to produce 30 000 t of stainless-steel granules a year in what is the world's first fully- computerised granulation plant, served by 15,5 t overhead cranage. A high-volume melt facility uses stainless-steel scrap as a feedstock for the production of the granules. The granulation process involves molten stainless steel being tapped through a tundish into cold water where the metal solidifies into small granular particles that are moved to a dewatering screen.

The metal granules are transferred on to a feeder into a kiln dryer where moisture is removed in 2,5 minutes before the granules report to the granule stockpile.

Granules in all grades of stainless steel are produced and Engineering News witnessed the production of the 304 grade.

Visible was the scattering of the molten metal from the tundish, the smaller pieces going furthest and the larger ones entering the cold water earlier.

Water and fines are removed through a classifier system and pumped from the hot well through cooling towers back to the cold well, which provides the cold water for the granulation process on a continuously recycled basis.

As the particles of molten metal fly through the air, they get smaller and rounder.

As fully rounded particles do not transport well on the conveyor systems, every effort is made to produce flattish granules at a preferred density of 4,5 t/m3.

Scrap metal, by contrast, packs at a density of only 1,8 t/m3.

Tapping was taking place at a rate of 1,5 t a minute, the plant operating with six people on a four-shifts-a-day basis, four days on and four days off.

Columbus Stainless Steel, which adjoins Thos Begbie in Middelburg, purchases granular stainless steel from Thos Begbie for use as coolant,.

The granular stainless steel is also sold to the South African foundry industry as on-grade raw material for use as a superior alternative to scrap.