Landfill Treasure - Future Mining Opportunity?

Nigel AdamsSitting around in airports is tedious and boring and gets you wondering what you have done in life to deserve such punishment. At times like these I will inevitably start thinking of many things and even on occasions some work related issues which usually include considering how else can I apply the technology that I am so deeply involved in promoting and implementing. Machine control is so focussed on civil construction – just look at the advertorial content of this MCO -  that we tend to ignore the other applications that benefit from this technology and are even sometimes blinkered from its future uses.

What are the other applications where we can apply machine control ?  Well there are some applications that I can mention, but have no real knowledge of e.g agriculture, and others which I have a good working knowledge of e.g. Landfill compaction, tunnelling, specialist dredging to name a few, but don’t really want to detail at the moment. It might be worth having a more detailed focus on these particular subject areas at a later date (I’ll leave that to the Ed to decide)

So what about the future, where else can we apply this technology ? It’s always difficult to predict the future and I eagerly await the day that we develop crystal ball technology, but how’s about this for starters.

A recent headline in the Telegraph (UK Newspaper):

Britain' could be mining landfill for gold in a decade
Prospectors will be mining for gold from dumped circuit boards and mobile phones found in British landfill sites within the next decade, according to industry experts.

 the article went on to say ...

With commodity prices rising, landfill mining is an increasingly viable option for countries like Britain.

In Japan, the world leader in recovering plastic and metal from landfill sites, gold, silver and platinum are routinely excavated.

Robert McCaffrey, conference organiser, said there was no reason why Britain should not build a similar industry.

"I think we will certainly see landfill mining in the UK. I think it is an areas that will grow over the next five or ten years. There are a lot of regulatory hurdles that need to be jumped but when the landfills are dug up the people that do it will need to use all the revenue streams they can get and if gold is amongst them then I am sure they will think about doing it," he said.

Peter Jones OBE, an industry consultant and former director of waste services company Biffa, said Britain has thrown away 3.2 billion tonnes of material over the last 40 years, including £45 billion worth of plastic. He said companies will go in primarily to extract methane and recover plastic, that can be converted to liquid fuel or recycled, but could also mine precious metals.

He said the process, which will be carried out by men and women in "space suits" under an inflatable tent to protect the environment against asbestos and dangerous gases, is another 15 to 20 years away because of the costs involved.

But with rising commodity prices he predicted it would be a viable business.

"In an energy hungry world it is certainly something we need to keep an eye on," he said.

Britain faces fines that could be passed on to the tax payer for sending so much waste to landfill.

This led me to think back to when I attended a conference on Landfill mining a couple of years ago. It was obvious that the whole field was still in its infancy and the main thrust of the conference was about the practicalities and cost of implementation, as well as more important topics such as “what do we do with the extracted material ?” Some answers were based on sound ecological practices such as cleaning up the landfill site and the recycling of the extracted materials or using them to create energy – recycling being an area /crusade which just didn’t exist when the materials where originally “landfilled” all those years ago - and other answers were more directly involved in the reclamation of rare and valuable materials such as those identified in the Telegraph article. So what is landfill mining ?

Landfill mining and reclamation (LFMR) is a process whereby solid wastes which have previously been landfilled are excavated and processed. Processing typically involves a series of mechanical processing operations designed to recover one or all of the following: recyclable materials, a combustible fraction, soil, and landfill space. In addition, LFMR can be used as a measure to remediate poorly designed or improperly operated landfills and to upgrade landfills that do not meet environmental and public health specifications. Typical equipment used in simple LFMR operations are excavators, screens, and conveyors. Complex LFMR operations recover additional materials and improve the purity of recovered materials, and therefore have equipment in addition to that of simple operations.

Another headline, recently published in the Guardian (UK newspaper) :

It might sound like a load of old rubbish, but landfill mining could be the next resources idea to sweep Britain and the rest of Europe. UK company Advanced Plasma Power (APP) has formed a joint venture to dig up a giant landfill site in Belgium, and will recycle half the rubbish and convert the rest into renewable electricity. The project, which will become operational by 2014, is thought to be the first of its kind in the world.

The 30-year project will reuse 16.5m tonnes of municipal waste dumped since the 1960s at the landfill site near Hasselt in eastern Belgium. APP will use its plasma technology to convert the methane produced by the rubbish, which is more than 20 times more damaging to the environment than carbon dioxide, into usable gas. This will fuel a 60MW power plant capable of supplying 60,000 homes.

Why landfills are bad and what Europe is doing about them.

Landfill mining may not seem very pertinent to some as they still have an unquestioned landfill policy and enforced recycling and reclamation is way down the agenda. However within Europe there is a drive to remove landfill completely. Whether or not this is possible is open to question as regardless of any amount of recycling and reclamation policies there will always be material that needs to be disposed of in landfill. The introduction of the European Landfill Directive is seen as a positive measure in the attempt to reduce the amount of waste disposed via landfill and the associated environmental implications.

The Directive's overall aim is "to prevent or reduce as far as possible negative effects on the environment, in particular the pollution of surface water, groundwater, soil and air, and on the global environment, including the greenhouse effect, as well as any resulting risk to human health, from the landfilling of waste, during the whole life-cycle of the landfill".

The Directive has provisions covering location of landfills, and technical and engineering requirements for aspects such as water control and leachate management, protection of soil and water and methane emissions control.

The Landfill Directive targets are:

  • To reduce biodegradable waste going to landfill to 75% of 1995 figures by 2010 and to 35% by 2020. (This included paper, card, food, garden waste and organic textiles.)
  • In 2004 co-disposal of hazardous and non-hazardous waste was banned. Three separate landfill types are required for hazardous, non-hazardous and inert wastes
  • The requirement to treat most wastes before they are landfilled. From 2004, all hazardous wastes going to landfill have needed to be treated first.
  • Disposal of whole tyres at landfill sites was banned in 2003, and by 2006 tyre granules were also not permitted in landfills.
  • To ban landfilling of liquid wastes, certain clinical waste and certain hazardous wastes. Increase the level of control, monitoring and reporting at landfill sites.

The regulations aim to reduce the volume of waste and increase recycling rates. Composting and careful segregation of waste types for recycling will need to be encouraged to fulfill the targets.

Waste acceptable at landfills as inert waste includes

      · Waste glass based fibrous materials

      · Glass packaging

      · Concrete

      · Bricks

      · Tiles and ceramics

      · Glass

      · Soil and stones, excluding topsoil & peat

Some countries have already virtually eliminated landfill and others are well on their way with zero landfill targets within the next 25 years.

The Netherlands and Denmark dispose of almost no municipal waste to landfill, and Belgium, Sweden, Germany and Luxembourg all landfill less than a quarter of their municipal waste.

In Denmark, Sweden and Luxembourg incineration is the single main method of disposal and over half of Denmark’s municipal waste is treated in that way. The Netherlands and Austria recycle/compost around 60 per cent of their municipal waste and Belgium and Germany recycle/compost around half of theirs.

All these efforts are admirable, but this still leaves us with plenty of landfill sites (active and dormant) and as cited in the Telegraph, potential gold mines.

How can machine control help ?

Existing landfill sites may or may not have quality records that identify material content and location, it depends on their age, management methods, location etc. – remember many landfill sites were started many years ago when the policy of waste disposal was “anything goes”. Machine control may assist during the landfill mining by keeping records of extracted material versus location which can then be used as part of the documentation for the further processing and traceability of the materials extracted, but the application is fairly limited due to the lack of control employed through the life older landfill sites.  

Where it can offer great assistance is on existing landfill sites. Because of the diligence now required for taking material to landfill it is possible to geo-reference material types as they are deposited and compacted (using a suitable landfill GPS system on the compactor – much has been said about this type of machine control in some of my previous articles) allowing this data to be stored and used for the future – this operating method is referred to in the directive target –

“Increase the level of control, monitoring and reporting at landfill sites. “

and it virtually screams – application for machine control. Certainly some of the more enlightened landfill operators are looking at using this technology as a tool for not only improving landfill design and operation, but to also closely monitor and manage waste types and location in an attempt to “future proof” the site for later generations who will most certainly be employing mining and reclamation policies.

By using machine control this way then as and when the material is required in the future we have a complete data log of the landfill site allowing for precise extraction of the required materials. So machine control can be used as an effective part of the landfill mining operation, even if it is just as a means of virtual staking of the landfill site in preparation for future plundering.

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