Thermal Technologies – overcoming the variability of waste by Dr Tim Johnson

One of the most difficult aspects of waste treatment is that ‘waste’ is a highly variable thing.  By its very nature, waste comes from an almost unlimited number of sources and in a huge range of compositions and forms.  Unfortunately, this inherent variability makes it harder to select the right waste treatment process for each pile of waste.  Thankfully, many wastes can be kept separate as they are being produced and this makes finding the right treatment option much easier.  For example, catalytic converters, old tyres and used engine oil all come from cars that end up in scrap yards, but they are pretty easy to keep separate from each other during the dismantling process.  This general principle of keeping wastes separate, or ‘segregation’ as it is known in technical-speak, can be seen spreading to most areas of waste management, as anyone will testify who (like me) has the weekly excitement of feeding multiple green bins, brown bins, black boxes and blue sacks with the correct parts of their household waste.  Not bothering to segregate your waste certainly makes throwing things away much easier, but since all the goods we use are produced in separate industrial processes it is not very surprising that recycling those things at the end of their useful lives works best when the waste is also separated into piles of similar objects.

In several of my previous blogs I have explained how Tetronics’ plasma technology can be used to treat specific waste streams and often to extract valuable materials or energy from them, so that ‘disposal of waste’ becomes ‘recovery from waste’.  Naturally, each of these processes depends on someone making sure those waste streams are kept nicely segregated from other things.  The good news is that the list of wastes suitable for a ‘recovery’ process is growing all the time, as Tetronics and other waste treatment innovators roll out new technologies.  However, it is clear that eventually, after all materials suitable for recycling and recovery have been picked out, there will still be a motley collection of unwanted wastes with no elegant and economic treatment solution.  For these wastes a more generic treatment solution is required, one that can accept everything from liquids to solids, flammable or non-flammable, hazardous or benign. 

There are very few such treatment processes available and historically the choices have tended to be restricted to landfilling and high-temperature incineration, both of which have their drawbacks.  In the case of landfilling of generalised hazardous and industrial wastes this was often preceded by mixing various different types of waste together in an attempt to create a mixture that was less hazardous than the sum of its starting materials.  For some years now regulators have frowned on such practices because in many cases the ‘treatment’ amounted to little more than dilution of hazardous materials rather than rendering the waste non-hazardous in any true sense of the word.  Even when materials are encased in concrete (a process known as ‘cementation’) the hazardous aspects of the material often still remain for future generations, it is just that the materials are contained more effectively in the short term.

Happily, Tetronics plasma technology offers the sort of generic waste treatment solution that many local authorities, waste operators and communities are looking for.  Plasma furnaces are very ‘omnivorous’ animals and will eat more or less anything, since using plasma to heat waste up to 1600°C results in almost everything melting or being vaporised.  Plasma’s combination of high temperatures and high ultra-violent light leads to efficient destruction of organic pollutants and the capturing of heavy metals in a glassy non-leaching material suitable for inert disposal or reuse as aggregate.  The fact is, all materials look fairly similar at plasma furnace temperatures, which means that although treating a mixed bag of very different wastes in a single process will never be easy, the enormous versatility and effectiveness of Tetronics’ plasma technology looks certain to make it an increasingly obvious choice for the treatment of hazardous and industrial wastes around the World.

Tetronics will be attending 'Investing in Resource Recovery' at the London Stock Exchange on Friday 28th October.

The purpose of the conference, which is part of the London Environmental Investment Forum (LEIF), is to connect capital with environmental innovation.

As concerns mount over the price and security of so many crucial commodities, it is becoming imperative to reclaim the abundant resources and energy contained in our municipal and industrial waste streams.

UK and EU regulations are also increasingly requiring that less waste go to landfill and more go to recycling/recovery operations. In response, companies are developing and applying innovative solutions to extract value from waste.

‘Investing in Waste and Resource Recovery’ will assemble leading investors and companies in the waste management and resource recovery industries to present and discuss the issues and investment opportunities.

Plasma Treatment of Spent Potliner ~ Tetronics featured in Aluminium International Today

Aluminium is the second most widely used metal in the World today. During the production of Aluminium there are two wastes in particular that arise that continue to present serious challenges to both the aluminium and waste treatment communities.  The first of these is red mud, for which the standard method of disposal at present is storage in large lagoons until such time as regulatory changes and technical developments drive the industry to adopt alternative solutions to the problem.  A similar situation exists for its sister waste, ‘Spent Pot Liner’ (SPL).  Although SPL is produced in much smaller quantities (around 20 kilogrammes per tonne of aluminium compared with 1.2 to 1.5 tonnes of red mud per tonne of aluminium), it is even more problematic from an environmental point of view and the existing treatment methods do not provide a universal solution, leaving much of it to be simply stored in warehouses. 

This article looks closely at Spent Pot Liner and its challenges, and how Tetronics’ plasma technology provides an innovative solution to this escalating waste management problem.

To read the full article, please click here.

Harsco Metals Forms Strategic Alliance with Tetronics

Tetronics Ltd., a global leader in the supply of Direct Current (DC) plasma waste recovery plants for the treatment of hazardous waste and metal recovery, today announced that it has signed a Strategic Alliance Agreement with Harsco Metals Group Ltd, an established and well respected globally operating services company.  Through this alliance Harsco will seek to extend their technical offering with the addition of Tetronics’ DC plasma arc technology to the many potential areas of hazardous waste treatment and metal recovery as well as into new applications and territories. 

Harsco has a wide global presence in over 50 countries and an interest to invest in commercially viable plasma arc facilities involving the build, ownership and operation of such facilities for the benefit of Harsco’s existing and new customers. 

Harsco and Tetronics have a long history of successful collaboration with Harsco having 20 years of experience in operating and maintaining Tetronics’ technology at their Plasminox project at Terni in Italy. The project has seen Tetronics DC plasma arc solutions recovering valuable metals from the Electric Arc Furnace dust that is generated from an adjacent stainless steel manufacturing process to then be re-used back into the steel production process. Both companies recognise the combined strength of Tetronics, as an established technology provider and Harsco as a global operator.

The process chemistry in Tetronics’ plasma technology is designed to symbiotically and preferentially separate and recover the valuable material in a range of wastes whilst destroying any hazardous components. The remaining non-valuable material is vitrified into an inert, safe disposable, non‐hazardous material, called Plasmarok®, in a single processing step. The robust level of construction and minimal number of moving components within the plasma systems delivers outstanding plant longevity. The recovery process also has exceptional environmental and commercial credentials and can be considered as a future‐proof solution for waste management problems.

Speaking about the alliance, Jeremy Makepeace, Vice President Global Solutions (Non ferrous) at Harsco Corporation explains;

“The reality is that how we manage waste today will change dramatically in the next 5-10 years, with traditional waste management solutions being increasingly challenged on regulatory compliance, corporate & social responsibility and economic cost grounds.

The Tetronics technology will enable our customers to recover valuable resources from waste that they can reuse in their manufacturing processes in a sustainable “closed loop model” thereby ensuring security of supply of key resources, or that they can sell to achieve additional revenue streams.

We have first-hand experience and trust in Tetronics and the effectiveness of their DC plasma arc technology.”

Stephen Davies, CEO for Tetronics comments;

“We are delighted to have formed this alliance with Harsco.

Harsco is already a major player in the services sector with a presence on all continents across the globe. The new alliance will see the benefits of our plasma technology being promoted not only in our traditional areas of operation, but also into new sectors and territories.”

The alliance will see Harsco Metals expanding its technical portfolio by offering the Tetronics DC plasma arc technology through an extended service offering.

Furuya Metal Selects Tetronics Plasma Technology to Recover Platinum Group Metals from Waste Catalysts

The technology will be used to reclaim high levels of Platinum Group Metals from chemical, automotive and other industrial waste catalysts. London, July 31st, 2012 – Tetronics Ltd., the global leader in the supply of Direct Current (DC) plasma waste recovery plants for the treatment of hazardous waste and metal recovery, today announced that it has been selected by Furuya Metal Co. Ltd., Japan to supply a new plasma system for the reclamation of Platinum Group Metals (PGM’s) from spent catalysts. Preparations for the project are now underway and the plasma recovery plant will be delivered to Japan in early 2013. Following comprehensive due-diligence, including test work at Tetronics comprehensive UK trials facility, the plant will allow technical recovery rates in excess of 98% of PGM’s from the spent catalysts. Catalyst wastes, including automotive catalytic converters and industrial catalysts, for example from the chemical and petrochemical industries, contain Precious Metals and specifically the PGMs that are valuable as a result of their low natural abundance, unique properties and the complex processes that are required for their extraction and refining from primary sources. The principal advantages of Tetronics patented plasma technology are that it couples the highest technical recovery/operational flexibility with the lowest environmental impacts and cost base. The process chemistry in Tetronics’ plasma waste recovery technology is designed to smelt and preferentially separate the precious metals from the less valuable material, which is vitrified into an inert, safe reusable product called Plasmarok®, in a single processing step. The technology will also destroy any hazardous organic material, such as dioxins etc. that may be contained within the waste material. Speaking about the project, Furuya comments; “We selected Tetronics as they are considered the world leader in the supply of plasma systems and have extensive experience in the delivery of metal recovery solutions specifically designed for the recovery of PGMs from catalyst wastes.” Stephen Davies, CEO for Tetronics comments; “We are delighted to be working with Furuya Metals on this project, it is an application we know very well and we have a number of systems that have been running for many years. Our objective on the project is to ensure Furuya maximises their return from the plant as well as providing them with a competitive advantage that the recovery performance makes possible.” ENDS For more information about Tetronics please contact Kate Colclough on +44 (0)1793 238 500 or visit: NOTES FOR EDITORS About Tetronics • Tetronics – the global leader in the supply of Waste Recovery Plants. Tetronics’ patented Direct Current (DC) Plasma Arc plant technology provides the closest solution to Zero Waste currently available. • This sustainable “green” alternative for waste management uses ultra-high temperatures to melt, gasifiy or vaporise any waste material, in order to treat, recover or generate valuable commercial products. • Tetronics’ technology has been tried and tested over five decades and has been used globally in more than 80 plants across a wide and varied range of applications. About Furuya Metal Co., Ltd. FURUYA METAL produces industrial-use precious metal products, employing rare and valuable precious metals belonging to platinum group metals (PGM), including platinum (Pt), iridium (Ir) and ruthenium (Ru). These precious metals are extremely difficult to work with, which is why the number of industrial precious metal manufacturers specializing in PGM worldwide is limited. For more information about FURUYA METAL please visit their website:
The technology will be used to reclaim high levels of Platinum Group Metals from chemical, automotive and other industrial waste catalysts.

Securing secondary commodities from waste by Dr Tim Johnson

These days it’s difficult to avoid noticing inflation.  Every time you pull up at the pump or buy food at the supermarket, every time you pay for your heating or you buy yourself some new clothes it’s right there – prices have gone up. 

Now I know it might seem a difficult argument to make right now, but it’s easy to forget that the pain isn’t universal.  Just as these rising prices bring falling income for some, so they also bring rising income and profit for others.  Yes, as consumers we are paying more for our food, but the other side of the coin is that it’s a better time to be a farmer now than at many points in the last 20 years.  More widely, you don’t see many executives of oil and gas companies on the news programmes bewailing the terrible state of their profits right now because they are actually doing very nicely thank you and the same could also be said of mining, metals and many other similar industries.   And what is the thing that links these various sectors of our economy that seem to be bucking the trends that we see in our wallets?

The answer is, of course, they are all sectors that produce commodities – the fundamental raw materials used in the production of almost everything, whether fuel, food, minerals, metals and a host of other things besides.

As with everything in the financial sector, there are graphs to show how the prices of commodities have changed over the years.  According to these graphs, although the prices of commodities varied by perhaps ±50% or more from year to year in the decade or so leading up to 2003, the overall trend was one of prices remaining largely flat.  However, from 2003 onwards the prices increased spectacularly until in mid-2008 when they reached a peak four times higher than the previous long term average. Perhaps even more surprisingly, even at the deepest point of the credit crunch, commodity prices were still around double that long term average and they have been rising rapidly ever since and are now back to a level similar to that seen in 2008. 

Ultimately, these rises have been driven by the increasing demand for raw materials from the developing economies of the World.  One consequence of this is that as the prices of raw materials increase, so it becomes increasingly economic to obtain materials from more difficult or less conventional sources, such as in the extraction of oil from deep sea wells or oil sands.  However, in a double benefit to both the economy and the environment it has also been promoting the recovery of valuable materials from waste and Tetronics is well placed to help companies all round the World in their efforts to do just that.

The main problem with waste is that any value it contains is usually locked up with less valuable materials, which makes it frustratingly unobtainable.  Tetronics plasma arc technology is designed to unlock waste by separating it into specific fractions using a combination of chemical reactions and temperature.  Typically a waste material will be split into several phases:

– A gas phase, containing volatile metals like zinc which can be sold for zinc production, or acid gases which can be condensed and sold to the chemical or metals industry;

– A slag phase, which can be granulated for use as an aggregate or in construction; and

– A metal phase, which can contain metals such as platinum group metals from catalysts or iron, nickel and chromium from steel plant dust.

Tetronics has many long term reference plants that use plasma arc technology to make waste safe and extract value for the benefit of companies and local communities.  So at this time of historically high commodity prices, if you have a waste or process by-product which contains some difficult to get at valuable commodity and needs a treatment solution please contact us and let us extract some value for you as well.

Dr Tim Johnson from Tetronics speaking at the 11th International Electronics Recycling Congress (IERC) 2012

Dr Johnson’s speaker session will focus on the recovery of metals from electronics waste using DC plasma arc technology.

Date: 18th – 20th January 2012

Time: TBC


Dr Johnson will be presenting at the 11th International Electronics Recycling Congress (IERC) in January 2012 in Salzburg. Dr Johnson’s speaker session will focus on the range of electronics wastes that can be treated in Tetronics’ DC plasma arc systems, and also of the plasma equipment and process for the treatment of spent catalysts and WEEE.  The unique combination of design and operational benefits of the technology has ensured that industry-leading technical recovery rates have been demonstrated for a wide range of PGMs at both a pilot and full commercial scale for treating Auto Cats.  Building on this long-established success, this same equipment and process is now being applied at a commercial scale to the recovery of other precious metals (gold, silver etc.) from pre-treated Waste Electronic & Electrical Equipment (WEEE) at a plant now under construction in Taiwan. 


Dr Tim Johnson – Technical Director

A technical director with a plasma and engineering focus particularly in the areas of waste reuse/recovery and clean heating. Tim obtained a PhD from the University of Birmingham in 1990 before spending eight years as a research fellow operating and coordinating the work of the university’s large plasma melting facility. Since joining Tetronics, he has focused on technology development and the delivery of commercial plants. Tim is a Fellow of the Institute of Materials, Minerals and Mining.
Dr Johnson’s speaker session will focus on the recovery of metals from electronics waste using DC plasma arc technology

The Use of Thermal Plasma Technology for Treating Air Pollution Control Residues ~ Tetronics featured in Waste Advantage Magazine

The growth in EfW plant capacity is leading to a corresponding increase in the generation of Air Pollution Control (APC), making it one of the fastest growing waste sectors in the UK.

This Waste Advantage Magazine article discusses how Tetronics’ plasma technology is a solution to the increasing quantity of APC residue generated from these EfW plants, which is officially classed as a hazardous waste.

To read the full article click here, The use of Thermal Plasma Technology – Waste Advantage Magazine

Big Step Forward for EnergyPark Peterborough As Technology Licence Agreement signed with Tetronics

Peterborough Renewable Energy Ltd (PREL) is delighted to announce that a Technology Licence Agreement has been signed with Tetronics Ltd, the world leaders in DC plasma arc systems. The Agreement gives PREL permission to use Tetronics’ patented technology to deal with Air Pollution Control (APC) residues created onsite at EnergyPark Peterborough.

The ground-breaking EnergyPark Peterborough project, which was granted consent by the Department for Energy and Climate Change (DECC) in November 2009, will be the first sustainable biomass-from-waste powerstation of its kind in Europe. Drawing upon a mix of best available technologies, PREL will achieve maximum diversion of waste from landfill, creating renewable energy and recycled products at the same time. Tetronics’ plasma-enhanced waste recovery systems will play a vital role in achieving that sustainable cycle and ensuring that the greatest value is taken from the waste input.

Following the gasification of a clean biomass fuel, the hazardous Air Pollution Control (APC) residues, which would traditionally be sent to landfill, will instead be collected and safely transferred to the co-located plasma unit. Tetronics’ plasma technology will then separate and destroy all the hazardous components in the residue, generating a totally safe inert product, similar to granite. This non-hazardous product called Plasmarok® can then be re-used as a glass or building aggregate in a range of applications, achieving close to zero residues remaining.

Commenting on the deal, CEO of Tetronics, Stephen Davies, added:

“We are delighted to sign the Technology Licence Agreement with PREL, a pioneering company leading the way in waste management in this country.

“Tetronics has decades of experience in the UK, Europe and Asia, processing problematic wastes, such as APC residues, in a stable and cost-effective way.

“We are very confident that this development will be a trailblazer for others to follow.”

Speaking about the Agreement, Chris Williams, Managing Director for PREL said:

“Tetronics’ plasma-enhanced waste treatment technology has been the final piece to the puzzle of ensuring that the absolute minimum of residues from the treatment process needs to be processed offsite.

Tetronics’ contribution has been vital in guaranteeing that a sustainable, practically zero waste facility is achieved. Through this partnership, we hope to see many more developments like EnergyPark Peterborough in years to come.”

To download the full article, please click here.


For further information please contact the PREL Press Office

on 07590477985 or
Peterborough Renewable Energy Ltd (PREL) is delighted to announce that a Technology Licence Agreement has been signed with Tetronics Ltd, the world leaders in DC plasma arc systems.

DC Plasma Arc Technology – Unlocking Value from Mining Waste by Dr Tim Johnson

Entry by Dr Tim Johnson, Technical Director at Tetronics

As you read this blog, take look around you and see just how many man-made objects there are in your little patch of World. From the screen in front of you and the chair you’re sitting on, to the building surrounding you, from the car, train or shoes that got you there to the money you had to pay for them with – almost all man-made objects are made from (or made by) something that used to be in the ground. Almost everything that our modern lives depend on exists only because minerals have been hacked, mined or dug from the Earth.

It is one of the wonders of the modern World that the long chain from extraction of raw materials to finished goods in our shops functions so seamlessly for so much of the time, but behind this lies a stark truth – we are utterly dependent on the minerals that come from under our feet.

The balance between the supply of these raw materials and the demand for the finished goods that rely on them is delicate. Consumer demand can change quickly before mining companies have a chance to catch up. As a result, when demand increases rapidly, prices of commodities tend to respond by rising steeply, as we saw between the beginning of 2006 and the middle of 2008, when world commodity prices rose by around 2.5 times (until the credit crunch caused them to plunge so spectacularly).

When you add to this our increasing environmental awareness, the increasing scarcity of many high quality ores and the growing list of strategic raw materials that are in short (or politically restricted) supply, it is not surprising that there are growing calls to reduce our consumption of these primary resources. One of the ways in which mining companies are responding to this is to make the maximum use of all the material they extract from the ground, including the wastes generated by mining itself that have tended to be overlooked in the past as uneconomic or an annoying distraction from core business.

Throughout its existence, Tetronics has used its plasma technology to recover valuable material from mining and metallurgical extraction wastes and very effective it is too. Indeed, here is a small selection we have investigated in some detail over the past 30 years.

– Chromite ore fines, recovered as ferrochrome for the steel industry
– Ilmenite ore tailings, recovered as an enriched slag for the titanium industry
– Basalt tailings, recovered for use in mineral wool production
– Copper smelting slag, recovered for recycling into the copper industry
– Lead blast furnace slag, recovered as a lead/zinc concentrate for recycling to the smelter

However, like all good ideas such reworking of old mining waste is not a new phenomenon. A quick surf around the web reveals a wide range of historical examples where the spoil heaps of yesteryear become the ore bodies of today, with coal, copper, diamonds, fluorspar, iron ore and silver all being relevant examples. The most common one in the UK is that of lead mining, where the ore and slag spoil heaps of Roman lead mines were worked over from medieval times through to the 19th Century and in the Balkans an astonishing 3,000 tonnes of lead was extracted from old Roman lead workings shortly before the Great War.

Tetronics DC Plasma arc technology is ideally suited to continue this noble tradition of recovering valuable raw materials from mining wastes and we have seen a strong upturn in interest recently from organisations in this area. The combination of flexible operation, small physical footprint and tight control of smelting conditions make it highly efficient in separating the valuable components from the waste and it seems certain that DC plasma furnaces will continue to play a major role in helping to reduce consumption of primary raw materials for the foreseeable future.