First Announcement- Sustainable Minerals '16

In closing last month's SRCR '14 conference, Outotec's Markus Reuter stressed that minerals are at the centre of sustainability. The aim of the Sustainable Minerals (formerly SRCR) series of conferences has been to transfer the rich source of mineral processing knowledge accumulated over the years to a wider community dealing with waste processing and utilisation, recycling etc.

Some of the delegates at SRCR '14, Falmouth

We would now like to invite scientists of all related disciplines to join us in Falmouth in June 2016 for Sustainable Minerals '16, which will immediately follow Biohydromet '16 at the same venue, the St. Michael's Hotel. There will be discounted rates for those attending both conferences.

As with all MEI Conferences, the papers presented at the meeting will form the basis of a special peer-reviewed issue of Minerals Engineering. Regular updates on the progress of the conference will be published on the conference website and on Twitter (#SustainableMinerals16 @barrywills).

You should plan ahead and try to spend a few days in Cornwall after the conference. There is much to see and do in this beautiful part of the world, as can be seen in the Cornwall section of the blog.

River Fal, Falmouth

MEI's consultant to Sustainable Minerals '16 will, as always, be Prof. Markus Reuter of Outotec, Finland, who is also Adjunct Professor at Aalto University, Finland, Professorial Fellow at the University of Melbourne and a Guest Professor at the Central South University, China. He is co-author of the very recently published Handbook of Recycling, which discusses the multifaceted field of metal and materials recycling, reuse and reclamation in one compact volume, uniquely synthesizing industrial application alongside policy and economic implications.

Eminent Biohydrometallurgist joins the Editorial Board of Minerals Engineering

There is little doubt that biohydrometallurgy will play an increasingly important role in future mineral processing operations. Recognising this, we have appointed one of the world's foremost practitioners to the Editorial Board of Minerals Engineering.

Dr. Corale Brierley, who presented a keynote lecture at Biohydrometallurgy '14, is one half, with husband Jim, of Brierley Consultancy LLC, USA, which provides consultation to the mining and chemical industries and government agencies.

In an internationally recognized career of over 30 years, Corale has spent 20 years as an international consultant; two years with Newmont Mining Corporation as Head of Environmental Process Development; eight years of managing Advanced Minerals Technology Inc., a metal's biotechnology company; and 10 years of applied research and development at New Mexico Institute of Mining and Technology. She was inducted in 1999 into the U.S. National Academy of Engineering for "innovations applying biotechnology to mine production and remediation". Dr. Brierley is the 2008 recipient of AIME’s James Douglas Gold Medal Award, which recognizes distinguished achievement in nonferrous metallurgy, and at the 2011 SME Meeting, was the recipient of the  Milton E. Wadsworth Award, which recognizes distinguished contributions that advance our understanding of the science and technology of non-ferrous chemical metallurgy. In December 2014 Corale and Jim Brierley will be inducted into the American Mining Hall of Fame (Medal of Merit award for transformative contributions to the mining industry).

We are very proud to have Corale involved with the future progress of Minerals Engineering.

Close shaves for a good cause

William and his grandpa, Barry, have just shaved their flowing locks for a very good cause. No great hardship for William "at least mine will grow back".

William before the shave

We are trying to achieve William's target of £500 towards the excellent Macmillan Cancer Support, in memory of William's Granddad David. If you would like to donate to this worthy cause, you can do so on our sponsorship page.

Drakelands, Britain's first new metal mine in over 40 years, prepares to open

During the late 1970s I was marginally involved with work carried out at the Camborne School of Mines (CSM) pilot plant into the feasibility of opening up the historic Hemerdon tungsten mine, situated on the edge of Dartmoor National Park near Plymouth. The work was undertaken by international mining company AMAX, under the supervision of Dr. Simon Meik and Dr. Gillian Hall. Simon, who I last met 4 years ago at Precious Metals '10, is now with Dundee Precious Metals, Bulgaria, and Gillian is with FLSmidth in Cornwall.

During this period at Camborne, a shy young man named Charlie Northfield was just commencing a honours degree course in Mineral Processing Technology. He graduated in 1980 and then commenced a very colourful career, which included, apart from working in tungsten mines in Thailand and Zimbabwe, imprisonment in Gambia under 'trumped up charges' and a daring escape into Senegal across a swollen river (MEI Online 2008).

Now Charlie is Process Plant Manager at Hemerdon (now known as Drakelands Mine), owned by Australian company Wolf Minerals. The mine is scheduled to open in September next year, 32 years after the end of the AMAX study, and 71 years after the mine's last closure at the end of World War 2. The collapse of the tungsten and tin prices in the mid-80s meant that the mine never made it into production despite the favourable feasibility study.

Now the time, and prices, are right and this will be Britain's first new metal mine for more than 40 years, exploiting the world's fourth-largest deposit of tungsten, and projected to be the world's largest producer of tungsten concentrate at about 3,450 tonnes of WO3 per year, amounting to 3-4 % of global tungsten production, compared with the 80% produced by China, which has dictated supply to the rest of the world. Drakelands will provide security of supply for tungsten and valuable export revenue for the UK.

The mine contains 23.5Mt of proven reserves grading 0.15% W as wolframite and 0.03% Sn as cassiterite. Saleable tungsten concentrate, grading 62-65% WO3 will be produced, as well as around 460 tonnes of tin concentrate per year, containing 40-60% Sn.

As this region of Dartmoor has been mined for well over 100 years and the local community is here because of that, the overwhelming reaction from the local community has been supportive, as this will bring around 200 much needed jobs, ranging from geologists, engineers and mining surveyors to truck drivers, to the area.

Yesterday I travelled the 75 miles from Falmouth to meet up with Charlie, and to see how things are progressing, and I was surprised and pleased to find so many CSM graduates involved with the operation.

With CSM graduates Nick Hall (Mining 2014), Andy Bond (Geology 1984 and Mining 1988),
Barnaby Hudson (Environmental 2002), Henry Chalcraft (Mining 2009),
Charlie Northfield (Mineral Processing 1980), Simon Holland (Mining 1987) and David Howourth (Mining 1984)

The processing plant site with the open pit in the background

The site is a hive of activity, the foundations are in place, and the equipment is on site ready for installation. It will be an interesting flowsheet, commencing with primary and secondary crushing in Sandvik hybrid toothed roll crushers, and tertiary cone crushing. Gravity concentration is the main method of beneficiation, by dense medium cyclones after crushing, and spirals and Holman-Wilfley shaking tables (MEI Online) for the finer fractions. Grinding is by ball mills in closed circuit with Derrick screens rather than hydrocyclones, to minimise overgrinding of the heavy minerals.

Charlie Northfield at the mill site

The flowsheet also includes flotation, in Outotec cells, to remove arsenopyrite and other sulphides from the gravity concentrates, high temperature reduction of hematite to magnetite, which will then be removed by low intensity magnetic separators, and high intensity magnetic separation to separate the final wolframite from cassiterite. The magnetic separators have been supplied by Eriez Europe.

I look forward to returning in a couple of years time when the mine will be in full operation, but in the meantime Charlie is hoping to present an overview of the operation at Physical Separation '15 next June in Falmouth.

First Announcement- Biohydrometallurgy '16

The recent Biohydromet '14 was a superb conference with a fairly small but very distinguished audience from academia, research institutions and industry, with a wide range of different disciplines.

Some of the delegates at Biohydromet '14

Prof Sue Harrison, of University of Cape Town (UCT), summarised the conference, which covered innovative technologies and the challenges for existing processes, including important trends, such as expanding the range of minerals treated by biohydrometallurgy. The biotreatment of tailings and WEEE is also becoming more important, as are remediation and water issues. One of the great challenges is transferring scientific developments from academia into industry, concerns which have been expressed at other recent MEI Conferences. She also felt that in future conferences we must address not only technological, but also social issues.

So there is much to look forward to in this rapidly evolving field, and we are pleased to announce that Biohydromet '16 will be held in Falmouth in June 2016. Once more MEI will be assisted by our three consultants, Prof. Sue Harrison, of UCT, South Africa, Dr. Chris Bryan, of University of Exeter, UK, and Dr. Patrick D'Hugues, of BRGM, France.

Chris Bryan, Sue Harrison and Patrick D'Hugues

Immediately following Biohydromet '16 will be Sustainable Minerals '16, and as there is some common ground between the two conferences, we will be offering discounted rates to those attending both conferences.

Cornwall is one of the world's most beautiful areas, so plan ahead to spend a few days here after the conferences. There is much to see and do, as can be seen in the Cornwall section of the blog.

Falmouth Bay

Regular updates on the progress of the conference will be published on the conference website and on Twitter (#Biohydromet16 @barrywills).

Interest in Rare Earth Element Separation Grows

It is not surprising that in the list of Minerals Engineering's most recently downloaded articles on ScienceDirect, papers on rare earth separation are in the top five. Rare earth elements (REE) have unique physicochemical properties that make them essential elements in many high-tech components. They are widely used for traditional sectors including metallurgy, petroleum, textiles, and agriculture but they are also becoming uniquely indispensable and critical in many other applications, such as hybrid cars, wind turbines, and compact fluorescent lights, flat screen televisions, mobile phones, disc drives, and defence technologies. Different rare earths are needed to supply the required functionality in these applications. In some cases, a single rare earth element may be required, such as La for nickel-metal hydride batteries, but other applications require a mixture of rare earths, for example Nd and Pr for rare earth magnets (see also posting of 11th February 2013) and Eu (or Tb) and Y for rare earth phosphors.

Bastnesite (La, Ce)FCO3, monazite, (Ce, La, Y, Th)PO4, and xenotime, YPO4, are the main commercial sources of rare earths. Increased demand for the different products manufactured from REE has resulted in a constriction of supply from China, which currently produces 97% of the world’s rare earths, via export quotas. Many new rare earth deposits are currently being developed to help meet the demand void created by the Chinese export quotas, however most of these developing deposits include rare earth minerals for which there is limited processing knowledge. A paper from McGill University Canada (see also posting of 1st February 2013) examines the separation techniques, usually flotation, gravity or magnetic, that are currently employed for rare earth mineral beneficiation and identifies areas in need of further research.

Rare earth mineral concentrates are leached with aqueous inorganic acids, such as HCl, H2SO4, or HNO3. After filtration or counter current decantation (CCD), solvent extraction is usually used to separate individual rare earths or produce mixed rare earth solutions or compounds. Rare earth producers follow similar principles and schemes when selecting specific solvent extraction routes. The use of cation exchangers, solvation extractants, and anion exchangers, for separating rare earths has been extensively studied. The choice of extractants and aqueous solutions is influenced by both cost considerations and requirements of technical performance. Commercially, D2EHPA, HEHEHP, Versatic 10, TBP, and Aliquat 336 have been widely used in rare earth solvent extraction processes. Up to hundreds of stages of mixers and settlers may be assembled together to achieve the necessary separations. It is a challenging process, and a paper by authors from Northeastern University, China, University of British Columbia, Canada, and University of California-Berkeley, USA, the most downloaded article in the past 3 months, reviews the chemistry of different solvent extractants and typical configurations for rare earth separations.

Expect to see many more papers on rare earths in future journal articles and conference presentations.