Initial estimates anticipate a cost of full repair to the operating infrastructure of the furnace of R1.5 million , to be jointly incurred by Mintek and Braemore. The majority of this cost will be for the repair and replacement of electrical cables. The furnace is anticipated to return to full production within 10 days.

The incident was caused when water from a water leak came into contact with molten material, which instantly vapourised the water, causing a series of minor explosions. This is the first incident of this nature in five years of operating the ConRoast technology at Mintek and occured during a period of trialling high sulphur content material in the furnace. The incident further supports the requirement of a complete ConRoast process, which under normal operating procedures removes all sulphur from the feed material through a roasting step.

Normal operating conditions take into account the hazards associated with such an event and the nature of the ConRoast technology allowed the incident to be quickly contained.

Metix slipping devices

South African smelting and technology equipment specialists Metix is a rare beast, spending time actively seeking solutions that will enhance productivity and reduce downtime – usually long before clients have commissioned the upgrades.

Offering the full scope of EPCM services on smelter projects, detailed engineering of furnace-related infrastructure, in-house procurement, cost control systems, site construction, as well as quality assurance and safety, Metix is all about innovation.

According to Metix technology equipment director Jacques Venter, much interest is currently being expressed by international clients and potential clients, even though the industry is in a slowdown. “Based on previous project success, we have had some international contact and are in constant communication with clients across Europe, China and India.”

A key area of interest is in work that Metix has completed for mining giant Lonmin – a primary producer of Platinum Group Metals (PGMs). “Metix was commissioned in 2007 as project manager on an operation that included the rebuilding of an entire furnace for Lonmin in Rustenburg,” says Venter. “While stripping the old furnace, we noticed that the slipping devices, as well as the contact shoes and bus shoes were almost destroyed by corrosion. We suggested to the client that we replace the slipping devices with new ones made from stainless steel, which would provide more resistance to the highly-corrosive environment of the furnace.”

Metix re-engineered the slipping devices that had been originally supplied decades ago. “The design was excellent. We made some minor improvements and alterations and installed the devices with no problems,” says Venter. “The set up procedure was simple and performance has been excellent, with no complaints from our client.” That, in this business, is key to success: The client is content and comfortable that the slipping devices will last around 20 years and greatly reduce safety issues.

Metix decided on stainless steel for the harsh environment as, says Venter, “where SO2 gas comes into contact with water it becomes H2SO3, a very corrosive compound”, creating a hazardous atmosphere that corrodes copper and steel.

While re-engineering the original pressure ring design, Venter also increased the contact pressure between the contact shoe and the casing to prevent arc damage between the two parts, reducing the amount of paste that builds up between the contact shoes and casing.

“Before implementation the contact shoe had to be opened and sandblasted clean, which is now a thing of the past. We redesigned and strengthened the spring that applies pressure and this has reduced paste leaks substantially. It is the first time Metix has done this in a platinum furnace.”

During the Lonmin project, Metix also applied a ceramic coating to all copper components in what is believed to be a first in South Africa. “The ceramic coating is able to withstand temperatures greater than the melting point of copper,” Venter explains. “The ceramic is applied in a similar manner to powder coating and is baked onto the etched-cleaned bare metal. This coating is resistant to sulphur corrosion and thus protects the copper.”

Again, the success of the final result is determined by ‘no complaints from the client’ and Venter says that all indications are that an improvement in production was achieved. “The 9 MVA six-in-line furnace was turning out record production rates on a regular basis after the rebuild.

Another area to which Metix applies its extensive knowledge and passion is that of slipping devices. “Slip-throughs in furnaces can kill people,” says Venter, “which is why many plants are replacing their devices.”

Metix offers a solution where cost is of concern, in a device that is more economical than most but is also failsafe against slip throughs. “The only drawback with this slipping device is that does not allow for back slipping. However, in the platinum industry, backslipping is not required” he says. If backslipping is required by the client then Metix offers its standard slipping device, fully capable of backslipping.

“What makes this design completely failsafe against slip throughs is that both slipping bands are permanently clamped, and either of the bands can hold the full weight of the electrodes. This means that the bands are able to support more than double the electrode mass.”

With over 30 draughtsmen and several design engineers in its employ, Metix has developed patented technology that has caught the eye of international companies. “We have three international patents on our pressure rings, which is now a flagship piece of equipment.” Metix has also applied for patents on furnace roofing and sealings.

Venter says that new technology is attributable to much of Metix’s problem solving capabilities. “We offer an innovative approach and continually look for areas in the industry that can be improved. Some years ago we realised that we needed our own electrode equipment, so we set about designing the best possible solution. The results have been more than pleasing.”

As mines continue to search for ways to maximise the lifespan of their equipment and decrease downtime, Metix continues to innovate. “Every minute of downtime that can be saved contributes to the lowering of production costs,” Venter says. “A client that has equipment that doesn’t give any trouble will be more productive than a competitor.”

Even while many local companies have switched their furnaces off for the time being, Metix is not in the business of waiting for things to improve: “There are new avenues to explore,” Venter notes. “We are looking at the international arena, in particular the Chinese market, which is still looking at furnace expansion. We have had some interest from Norway and other European, companies and we will continue to seek solutions to global mining issues.”

Article by: Ngage

In its largest lump-sum turnkey (LSTK) project to date, Metix has reached and celebrated its 250 000 hour lost time injury-free construction milestone.

Andrew van Niekerk - Metix

Metix Engineering Director Andrew van Niekerk says that the size of this 600 000 ton per annum sinter plant project for Metix provides additional challenges compared to previous projects. “It is also the first time we have worked with Sinosteel’s ASA Metals, which has turned out to be a fantastic opportunity and privilege for us.”

 ASA Metals requires a strict adherence to SHEQ (safety, health, environment and quality) standards and, thanks to the compliance to these and Metix procedures on site the above 250 000 hours were achieved. Van Niekerk notes that the combined system of standards and procedures promotes awareness of surroundings and the mechanisms that exist regarding personal safety and health. “It includes task breakdown, risk assessments and permits required for personnel to work safely.”

Having started the ASA Metals project at the end of October 2007, and with a Ready for Hot Commissioning (RHC) target towards the end of the 2009 second quarter, there are currently 350 construction personnel active on site. Metix will be increasing its construction management team of 15 to 30, in an aggressive move towards earlier construction and commissioning completion.

The local construction industry has provided challenges for Metix. “Our biggest challenge has been to stay within budget,” Van Niekerk says. “In light of monstrous price escalation experienced during 2008 – especially in steel – we fortunately acted pro-actively at the start of the contract and were able to place our orders early. In-house knowledge and experience associated with all project disciplines allowed us to generate accurate (>95%) bills of quantities and sign contracts early.”

“We anticipate that our steady focus and additional resources will keep us on schedule and possibly put us ahead of schedule,” says Van Niekerk.

ASA Metals’ Chief Operating Officer, Herman Smith says that ASA is extremely impressed with the approach followed by Metix during the tendering, contract negotiation and construction phases of the project. “I have not encountered a company as willing as Metix to meet our specific needs and requirements for quite some time. Their site management has been exceptional. Good project management skills have allowed them to not only maintain the construction schedule, but also remain within budgeted cost, notwithstanding certain changes requested by our project team during the design review stages of the project. Their professional approach and general attitude to create a safe construction site have now culminated in the milestone of 250 000 injury free hours.”

Another Metix project currently underway is the Middelburg Ferrochrome (MFC) EPCM contract for Samancor Chrome, one of the largest ferrochrome producers in the world.

“Metix started this project in September 2007, and has a Ready for Hot Commissioning (RHC) target towards the beginning of the 2009 second quarter. We are responsible for the engineering, procurement, construction and management of this 600 000 ton per annum sinter plant,” says Van Niekerk.

In complying with Samancor’s unique SHERQC (safety, health, environment, risk, quality and community) requirements, Metix added another 250 000 Classified Injury-free hours. Working together to incorporate Samancor Chrome’s high level of standards and specifications into our own has been a positive and rewarding experience for us. It’s a company that has been around a long time, and we are happy to have been able to learn so much from its team.”

Van Niekerk adds that Metix plans to complete all civil and structural construction work early next year and has installed 60% of the major mechanical items. Electrical and instrumentation (E&I) and piping construction has already begun and should finish close to the RHC target.”

MFC’s General Manager, Roelof Retief says “working with the Metix organisation and especially their plant construction management has been a very positive experience. The main contribution being the attitude of the Metix personnel on site, in buy in and adopting Samancor.”

Chrome’s/MFC’s emphasis has been on frontend loading and continuous monitoring by Line Management. Metix also contributed hugely in convincing the contracting companies and their leadership to also have the same attitude. The only way they could do this was to become part of the MFC team, which they did. Together with Metix, I would like to congratulate all service providers on this project for their commitment to ZERO HARM,” Retief notes.

Metix is looking forward to an interesting array of projects in 2009. Negotiations are currently underway for finalising the award of a furnace upgrade in Zimbabwe. “Metix is currently also working on enclosing Hernic’s furnaces 1 and 2, leading to a safer and more environmentally-friendly operation. We started work in early 2008, and look set to complete the project at the beginning of 2009,” says Van Niekerk. “We are also busy with our final contractual negotiations on a 600 000 ton per year international sinter plant, which should start in 2009.

What’s more, an exciting development for Metix is the company’s involvement in co-generation projects. According to Van Niekerk, Metix recently completed a tender for a 15 MW Jenbacher facility. “This is a relatively new application for reliable and proven technology that combusts cleaned closed furnace off-gas in reciprocating engines to generate electricity”. The project forms part of the internationally-authorised clean development mechanism (CDM) that allows project financing through the sale of certified emission reductions (CER’s or carbon credits).

Binding emission reduction targets have been agreed to by numerous industrialised countries.  Countries struggling to meet these targets can trade carbon with countries that have achieved theirs. Most countries choose to do so by maintaining a balanced portfolio encompassing various developing countries and types of carbon reduction projects.  Very few African CDM projects have been implemented, making prospective CDM projects from Africa a sought after portfolio addition. South Africa, and particularly the metallurgical industry in Southern Africa, is well positioned to capitalise on this potential, Van Niekerk explains.

Metix aims to assist clients in this field by offering them a technical and commercial solution, unbiased by carbon trading interest.  Metix offers a LSTK or EPCM plant, while assisting third party consultants to structure carbon financing according to the client’s requirements. 

This approach increases the range of products that Metix can provide to its smelter clients, putting the company top-of-mind when clients are looking for a professional concern that offers creditable engineering solutions across all areas of its business.