MEI Blog: Thanks for your support

Just a note to thank you all for your continued interest and support for the MEI blog, which is currently averaging over 22,000 page views per month. Much of the success of the blog can be attributed to your interactions with discussions, both on the blog and the associated Minerals Engineering group on LinkedIn, which now has over 5300 members.

If you regularly dip into the blog you may not be aware that you can receive alerts of new postings via email, by submitting your email address in the box in the right hand column.

Thanks again for your involvement, and please do send me photos and updates of anything that you feel might be of interest to mineral processors worldwide.

Nominations invited for the MEI Young Person's Award 2014

Do you know a young minerals engineer who you feel has made outstanding contributions to the profession in 2014?

If so we invite you to submit your nomination by email to bwills@min-eng.com by 6th February 2015 and the name of the recipient will be announced at the end of that month.

Nominations must be for persons under 35 years of age at December 31st 2014, and should include the name, age and affiliation of the nominee, and reasons for the nomination.

The recipient will receive an engraved award and a complimentary registration to any MEI Conference in 2015/16, with the option of presenting an MEI Award lecture.

Previous award winners are shown below.

Rodrigo Carvalho (Brazil) 2013

Randall Zahn (USA) 2012

Peter Amelunxen (Chile) 2011

 

Carne Beach to Portloe

If you are based in Falmouth, I can thoroughly recommend this 7.5 mile hike, which Barbara and I undertook last Sunday. Although only a stone's throw from Falmouth, it is a 24 mile drive to the starting point at the Nare Hotel at Carne Beach, unless you take the short cut by ferry across the River Fal from Feoch.

Gerrans Bay

With a total elevation gain of 1120 feet, this is classed as 'Challenging', but you will be rewarded by great cliff scenery around the 310 feet high Nare Head.

Looking back to Carne Beach

Gull Rock

As we left Gerrans Bay and climbed to the top of Nare Head, I got my first view of Gull Rock in Veryan Bay in 37 years!  It was a familiar sight in the mid 1970s when I would regularly come out by boat with the Camborne School of Mines diving club, to collect wonderful white scallops in the deep gullies, and dive on the wreck of the German steel barque Hera, which struck Gull Rock in 1914.

After 4.5 miles of hard walking we reached the small fishing village of Portloe, where we had a quick drink at the Ship Inn, before taking the short cut across country lanes back to Carne.

Approaching Portloe

Portloe

More Cornish Walks
More on Cornwall

 

Towards the next generation of mineral processing plants

These are exciting times in mineral processing. Probably not since the development of froth flotation has there been such intensive debate on the need to focus on a specific area for research. Reduction in energy consumption has to be the major thrust of future mineral processing research, particularly in respect to comminution machines and circuits.

A recent Canadian paper in Minerals Engineering introduces an energy benchmarking model for mineral comminution for assessing the energy performance of different crushing and grinding technologies. In the same volume researchers from Australia's JKMRC surveyed the comminution energy requirements of gold and copper producing mines  to provide reliable benchmarking data which can be used to compare comminution energy consumption across different mine sites. The study showed that comminution of gold and copper ores can be expected to consume about 0.2% of global, and 1.3% of Australia’s electricity consumption.  Analysis of the contribution of circuit efficiency, ore competence, grind size and ore grade showed that ore grade was the greatest determinate of specific comminution energy.

The best way to reduce comminution energy is not to comminute, therefore concentrating the ore via gangue rejection prior to grinding is likely to achieve the largest positive effect on comminution energy efficiency. Dense medium separation has long been used to do this on amenable ores, such as Pb-Zn vein deposits, but electronic ore sorting is showing great potential, by identifying the metal values in a run-of-mine stream and separating the rock containing valuable mineralization from barren material. This branch of technology has been the subject of papers at virtually every recent mineral processing conference, and will be the subject of Dr. Rob Morrison's keynote lecture at Physical Separation '15 next June.  Another Canadian paper in Minerals Engineering provides quantitative discussion on the impact of this technology. Dual-energy X-ray transmission was used to sort ore from different mines, and an analysis identifying the economic impact of these results presented.  Ore sorting has been identified as a technology with potentially broad reaching impacts on the mining industry. With the implementation of ore sorting significant energy savings or throughput increases are realized during comminution, and these effects are then felt throughput the plant.

Another technique which I am sure we will hear more of is gangue rejection within the comminution circuit via coarse flotation in fluid-bed separators, such as the Eriez HydroFloat separator (see posting of 5 August 2013).

In our recent conversation, Prof. Alban Lynch felt strongly that mineral processing in the future needs to be linked to mining. As early as 1975 the JKMRC extended their comminution modelling research to blasting because that was the first in the sequence of size reduction processes. The feasibility study was carried out with support from Mount Isa and Mount Newman and the blasting project became a large and long running AMIRA project. The research was very useful to blasting engineers but it was many years before the link between blasting and crushing and grinding was developed.

It is interesting that this year's Coalition for Eco-Efficient Comminution (CEEC) Medal has been awarded to Orica’s Dr. Geoff Brent and his research team for ground-breaking research using a novel method of Ultra-High Intensity Blasting to improve mine productivity. Orica Managing Director Ian Smith said the quest to use the chemical energy in explosives to improve ore fragmentation and deliver a step change in mine processing efficiency was a priority for the global resources sector. “Independent modelling has indicated that increasing the explosive energy by several fold can lead to increases in mill circuit throughput of up to 40% and savings of tens of millions of dollars annually.”  Speaking on behalf of the research team, Dr. Brent said: “By utilising explosive energy in the pit to produce much finer ore we can dramatically increase the efficiency and throughput of the downstream comminution processes of crushing and milling. The overall energy consumption across the mining and milling cycle can be reduced with a consequent reduction in emissions. This is a step-change in ore processing.”

It has been announced recently that Metso has signed a 5-year strategic research agreement with The University of Queensland's JKTech division to develop next-generation technologies and services for energy-efficient minerals concentration (MEI Online). The agreement is part of a program where Metso and JKTech SPA will cooperate with the leading Chilean mining companies to develop Chile as a regional innovation hub for minerals processing.  The program's four principal research themes are primary grinding, ball mill grinding, classification and coarse particle flotation; the main operational targets are productivity, energy and water efficiency.

"The goal of this unique research program is to take some serious steps forward in the development of equipment and methods that will enable the construction of the next-generation mineral concentrator. A very attractive feature of the program is that each technology offers a retrofit possibility to improve existing plant performance and can be utilized at other mines around the world as well" says João Ney Colagrossi, President of Metso's Mining and Construction (as of October 1, 2014 President, Minerals, Metso).

"We are delighted to partner with Metso in this exciting Program. The 'Next-Generation Concentrator' will provide a step change in the energy, capital efficiency and production signatures of process plants for the global minerals industry.  Our time frames for implementation are aggressive and we look forward to a suite of innovation outcomes for our co-creation industry partners," states Dr. Ben Adair, Deputy Director, Sustainable Minerals Institute at UQ.

It is clear that there are fundamental changes taking place in the approach to mineral processing research and it is our aim at MEI to reflect these forthcoming paradigm shifts in the content of future MEI Conferences.

International Mineralogical Association (IMA '14) Day 5

I thank Dr. Megan Becker for her excellent daily (Monday, Tuesday, Wednesday, Thursday) updates and photos from IMA '14. Now I invite those of you who attended the conference to submit your views and comments- what were the highlights for you?

Below is Megan's report on the last day of the conference:

And so the last day of the conference finally arrived….after a morning focused on the more technical aspects of the conference, I was involved in running the final afternoon session on Education and skills development. I think this was a very well timed session since it changed from the technical to the more philosophical and was a fun way to end the week. There were 5 talks in this final session, 3 of them devoted to newly developed programmes teaching mineralogy to undergraduate and graduate students: Dr Desh Chetty from Mintek presented on their graduate development programme, Prof Eric Pirard presented on the Emerald Geometallurgy Masters programme (an EU Erasmus Mundus programme run through Universities of Liege, Nancy, Freiburg and Luleå), and Prof Dee Bradshaw presented on behalf of Ilkay Celik and Metin Can from Hacettepe University in Turkey (where she recently spent a sabbatical) on a new undergraduate process mineralogy course for mineral processing engineers.

Lunga Bam (NECSA), Wilma Clark (Mintek), Keshree Pillay (Mintek) and
Bertus Smith (University of Johannesburg) at the Mintek stand

The other 2 talks covered novel initiatives at teaching high school learners in South Africa. Rene Toerien from the University of Cape Town spoke on the interactive and accessible teaching material that she helped develop for high school teachers enabling them to educate learners on mining and mineral processing (bearing in mind that many of the teachers are from underprivileged schools and were faced with teaching curriculum that they have no previous experience on). The success of this initiative really spoke to the partnerships between school teachers, university and the local mining industry (sponsored by Anglo American).

Dr Jodie Miller (Stellenbosch University), Dr Phil Harris and Paul Linton at the Geospectral Imaging Stand

The other presentation was from Dr Tanya Reinhardt from the Science Centre affiliated to the University of Kwazulu Natal in South Africa. 2014 is the International year of Crystallography and as such, all local science centres were tasked with developing appropriate material that could be used as workshops for high school learners. On the basis of developing something accessible, easy to roll out, low cost and illustrative, she developed a workshop teaching learners about crystals and their internal structures (atoms and bonds). The heart of the workshop was building crystal models using jelly tots (sweets) and tooth picks! Tanya kindly prepared several of these “crystal model packs” which she distributed at the end of the session for delegates to build. The final built version of the “low cost” crystal model of galena (or halite) was simple and sufficiently engaging even for my own 5 yr old daughter (although eating the jelly tots was potentially problematic).

Dr Tanya Reinhardt setting up her “low cost” mineralogy workshop

Overall, this final Friday afternoon session was well attended (this was my favourite session of the conference), and we had lots of constructive discussion even though many delegates were probably exhausted by the end of the week. This really highlights the fact that there are many dedicated teachers around who are passionate about finding ways to educate the next generation, be they scientists and or engineers. We are also reminded that mineralogy is not a simple subject to teach since it forces all learners to visualize from 2D into the world of 3D. Lastly, it also affirmed the need for process mineralogy courses within the current education of those involved in the global mining industry.

The next meeting of the International Mineralogical Association will be held in Melbourne in 2018.

International Mineralogical Association (IMA '14) Day 4

Megan Becker reports on Thursday in Johannesburg:

This morning I chose to devote the day to the computed tomography session – pushing frontiers in imaging in the 3rd and 4th dimension. This is the first time that this conference has had a full day session devoted to this topic which reflects the growing popularity of this technique for imaging rocks and minerals samples in 3D. The plenary for the morning was Prof Richard Ketcham from the University of Texas, who back in 1997 was responsible for running the 1st industrial grade CT scanner in an academic science department (Geosciences) in the world. During the course of the day it really came through that this technology is progressively reaching maturity, becoming routinely available, and is starting to deliver some really exciting possibilities for future research imaging solid systems into the nano-scale. I was really impressed by the research coming out of the University of Gent in Belgium where they have built a CT device with an environmental cell allowing them to visualise pore flooding over time (minutes), crack expansion over sequential freeze – thawing cycles (hours), and so the possibilities are endless. 

However, in terms of CT technology delivering direct value into the field of process mineralogy with respect to providing routine information on bulk mineralogy, mineral liberation and association, I suspect it will be several more years before this technology will start replacing auto-SEM technology (QEMSCAN, MLA, TIMA, Mineralogic etc). For the moment though, auto-SEM and CT really do complement one another providing valuable information that can be used in the design and optimisation of various minerals beneficiation operations. 

Igor Tonzetic from Zeiss South Africa demonstrating the “Mineralogic” system to students

The conference dinner was held in the ball room of the Sandton Convention Centre and the organisers of the conference really put on a good show and gave it an African flavour with the decorations and entertainment, providing local music and even a mini-live drama set in the local “shebeen” (beer tavern) that reflected on some of the social – political aspects of the mining industry.

Following the formal proceedings of the dinner, the mood of the dinner changed when dancing and the DJ got going. I initially thought Wednesday’s casual dinner was quite something, but now I’ve changed my opinion and indeed have seen a new side to many of the conference delegates (I’m not sure if this is a good or a bad thing!). Anyway, the party broke up around midnight and we will see how many make it to the morning plenary starting at 09.00.