Government has allocated R100-million over a three-year period to the development of a titanium industry in South Africa.
This money, flowing from the Department of Science and Technology (DST), will be made available to the CSIR’s Titanium Centre of Competence (TiCoC), says CSIR materials science and manufacturing light metals manager Dr Willie du Preez.
South Africa has the world’s second-largest titanium-bearing resources in the world, after Australia, but it does not produce any metal. TiCoC was founded by the DST to remedy this situation.
Of the R100-million in allocated funding, R29-million will be spent on the construction of a pilot plant to produce titanium powder at a rate of 2 kg/h by the second quarter of next year.
“We recently received the go-ahead and the funding for the plant,” notes CSIR materials science and manufacturing light metals research group leader Dr David van Vuuren. “We are in the detailed design phase of the plant now.
“Our primary activities all centre around efforts to make powder from the titanium-bearing mineral.”
Producing titanium powder is a vital building block in establishing a titanium industry.
The current process used worldwide to create titanium metal uses a number of expensive steps to produce the metal. For example, midway through the process it makes a titanium sponge that is porous, and still in need of vacuum arc refining before it can become a useable material.
However, the CSIR’s method delivers a titanium metal powder that can be sintered together to directly produce mill products, such as tubes, sheets or bars. From here, strong, lightweight parts are made, such as for the automotive, medical or aerospace industries.
“We follow a new, shorter route to a solid, usable metal,” says Du Preez.
“We also want to make it cheaper for the end-user,” adds Van Vuuren. “We can save an estimated 25% in costs by using powder to go directly to mill products.”
The CSIR is in a race with a number of countries, including the US and Australia, to create a simpler, smarter, cheaper way to produce titanium metal than the currently more-than-50-year-old process.
Construction of the CSIR’s pilot plant is to be followed by a semi-commercial test facility producing 500 t of titanium powder a year.
Such a facility would represent the first step in the industrialisation of the new process, says TiCoC commercialisation director, Dr Oliver Damm, and will include the involvement of commercial partners.
This is to be followed by a full-scale commercial plant with a production capacity of 20 000 t/y.
Starting the feasibility studies on this project is planned for 2018.
Damm is also hopeful that the currently small local titanium manufacturing industry will grow as the CSIR proves the cost advantage of its powder process.
A vital part of the centre’s work is to create local capacity and demand within the local manufacturing industry for the CSIR’s technology by 2020, notes Du Preez.
“We need companies to be ready to use the powder produced by these plants as the process unfolds.”
FOUNDRY HELP REQUIRED FOR INVESTMENT CASTING
Other building blocks required in the DST’s research and development-led titanium industrialisation programme include the ability to create investment castings, as well as to machine titanium castings, and to form and forge titanium.
The centre has already made headway in terms of investment casting, and is currently exploring routes for commercialisation.
Also known as lost-wax casting, investment casting is an industrial process used to create metal parts with great detail that are difficult to achieve with other casting methods. Investment casting uses a pattern that is destroyed as part of the process, thus making an investment in the finished product.
The mould cost for investment casting is considered to be minimal, compared with other forms of permanent mould-casting or die-casting.
However, casting titanium is not as easy as it sounds, as titanium reacts with oxygen and most ceramic oxides, warns Du Preez.
“Only a few players can cast titanium on a commercial scale, and nobody shares their technology to do so.”
To cast titanium, one needs to create a mould that does not react with the metal, and the metal must be melted and cast in a vacuum. Also, despite doing all of this, there remains an oxygen-rich layer of oxygen that needs to be removed from the casting – all of which the CSIR have now achieved.
“We are working towards building a demonstration plant for this casting process,” notes Du Preez. “We are hoping a local foundry can work with us on executing this project.”