Is the end of the world of mineral processing nigh?

Here's some food for thought for the new year:

An article in the December issue of Materials World may have passed many people by, but it discussed a topic which would be of profound significance to the world, and, closer to home, to the minerals industry.  Eoin Redahan asked "How close are we to a nuclear fusion reactor?", a carbon-free process that produces four times more power than nuclear fission, with no waste disposal problems, and a fuel, isotopes of hydrogen, which is abundant.

Despite billions of dollars having been thrown at it, fusion’s imposing challenge has not yet been met. For atoms to fuse, a huge amount of energy must be generated. As such, materials must be developed that can withstand hundred of millions of degrees. To create fusion energy, light atomic nuclei are fused within high-pressure, high-temperature plasma, which is contained by a magnetic field. As yet, scientists haven’t refined this magnetic confinement efficiently enough to reach a break-even point – where the energy output equals the energy input.

As discussed in the article, billions of euros have already been spent on just one facility, the International Thermonuclear Experimental Reactor (ITER) in the south of France. The aim of the ITER project, which is funded by the EU, India, Japan, China, Russia, South Korea and the USA, is to prove that nuclear fusion is commercially viable.  However, the goal of having its deuterium-tritium facility operational by 2027 is looking increasingly optimistic, but encouraging noises are being made about several smaller projects. According to researchers at Sandia Laboratories in Albuquerque, USA, their huge electric pulse generator is progressing in its pursuit of the fusion dream. In September 2014, the team reported significant by-products of fusion reactions in one of its experiments. Sandia’s approach involves putting fusion fuel inside a tiny metal can and passing a pulse of 19 million amps through it from top to bottom for 100 nanoseconds. The powerful magnetic field created crushes the can inwards at a speed of 70km/second. At the same time, the researchers pre-heat the deuterium fuel with a laser pulse and apply a steady magnetic field, which holds the fusion fuel in place.  The team reports that it has produced significantly more fusion neutrons than previous methods, though there is still a long way to go – 100 times more neutrons will have to be produced to achieve break-even point.

Lockheed Martin is a major American global aerospace, defence, security and advanced technology company, which caused a stir recently with claims that its compact fusion reactor, which will fit "on the back of a truck" and produce a 100 MW output, enough to power a town of 80, 000 people, will be developed and deployed within 10 years. The company claims that the key to the success of its reactor concept lies in a magnetic bottle that withstands 150 million-degree temperatures while offering 90% size reduction over previous concepts.  Lockheed Martin's plan is to "build and test a compact fusion reactor in less than a year with a prototype to follow within five years, operational reactors being available in 10 years time.

Lockheed Martin reactor: neutrons released from plasma (purple)
transfer heat through reactor walls to power turbines

There is obviously a lot of skeptism about these claims, but there is little doubt that the intent is there, and it could be a fair bet that sometime this century nuclear fusion will become a reality, If it does it will change civilisation as we know it, and will certainly have a profound effect on our industry.

Ironically in the same issue of Materials World I authored a short article where I put a case (as I have done many times before) for froth flotation being the most important technological development since the discovery of smelting. But what would be the future for flotation if nuclear fusion became a practical proposition? Would its use be confined just to the production of industrial minerals? Would there be any need to comminute and concentrate metallic ores, and concentrate them prior to smelting? Maybe the metal mines of the future might crush the mined ores to make them easier to handle, and then transport them to huge on-site or custom smelters where the ore would be direct smelted, the energy being supplied by the smelter's on-site fusion reactor? The advantages of pyrometallurgy are of course that reactions are much faster at high temperatures than they are in slurries or aqueous solutions, and mineral characteristics are lost in melts, making the reactions controllable by known universal thermodynamic and kinetic laws. Separation by differential melt solubility or volatilisation permits recoveries that are impossible by mineral processing methods.

It would be a strange new world, little comminution, no concentration, no need for process mineralogy and expensive automated scanning electron microscopes, and more seriously no further editions of Wills' Mineral Processing Technology!  And probably quite a dreary one- what would be the technological challenges once complex ores are no longer complex and when we are all pyrometallurgists?

So what do you think? Is this likely to happen in this century?  My bet is that it will, although within 10 years might be optimistic.  Never underestimate the ingenuity of man; if great minds get together to solve a problem there is a fair chance that they know that the problem can eventually be solved.

There are great parallels with the Large Hadron Collider at CERN. Particle physicists have their various theories of the origin of matter, much of it hinging on the quest for the Higgs boson, but to find proof protons must be collided at near light speeds to basically see what happens. The science behind the LHC experiment is therefore fairly simple, but the engineering problems are immense, but were overcome despite much opposition. Questions were asked about the possible benefits to humanity, and I like the answer of one of the project leaders who said that when radio waves were discovered they were not called radio waves, as there were no radios!

Similarly the science behind nuclear fusion is simple- smashing hydrogen atoms together to produce helium and lots of energy. The engineering problems are, however, truly formidable, but the fact that billions of dollars are being spent on the quest for controlled nuclear fusion suggests that these might eventually be overcome.