Friday, 9 October 2015

Pictures from Bali

Amanda has had a great week at the International Biohydrometallurgy Symposium (IBS '15) in Bali.

Hopefully she will be reporting on the conference next week.

In the meantime she has sent me a few photos taken on her mobile phone- looks like it has been a fun week:

Delegates at the dinner on Tuesday evening had the opportunity
to play some traditional Balinese instruments

Delegates from Chile at the dinner
Thursday's social event involved a trip to the Uluwatu Temple, where delegates
saw a traditional Kecak dance, after which they enjoyed a seafood beach BBQ at Jimbaran,
with traditional dancing and a roaming band


Thursday, 8 October 2015

Fred Bond inducted into International Mining Hall of Fame

Fred Bond, 1972
Everyone involved with mineral processing has heard of the Bond Work Index, synonymous with grinding circuit design. Now the man behind this, Fred Chester Bond, is being inducted into the International Mining Technology Hall of Fame in the comminution category for 2015.
Fred Bond’s work on circuit design occurred from the late 1930s to the mid 1960s and it changed the method of design completely. In the pre-Bond era the prediction of the power required per tonne to grind material to a known product size was based on experience and judgment, but in the post Bond era the method of prediction has become engineering practice based on measurement and calculation.

Bond’s work defined the relationship between ore hardness, tonnage processed, size reduction achieved and power required. It set the standard for circuit design in the 1950s and it is widely used today, although modifications have been made to handle the large increases which have occurred in mill sizes, feed sizes and feed rates. The Bond Work Index approach is the standard method of selecting ball mills to grind from about 3 mm to 25 µm provided that correction factors are used if necessary.

A graduate and former professor of the Colorado School of Mines, Bond worked in the mining and ore milling equipment business of Allis-Chalmers from 1930 to 1964, and he knew the limitations of design techniques which were current at the time. During the late 1930s and the 1940s he studied the relationship between energy and size reduction and in 1952 he proposed a “Third” theory of comminution to define this relationship, Rittinger and Kick having proposed the first two. To apply it he defined “Work Index” for an ore as the specific energy (kWh/tonne) required to reduce the ore from infinite grain size to 100 µm and he showed that for any ore the Work Index can be calculated from plant data and determined in a laboratory test in a specified Bond Mill. The power prediction is fairly accurate for devices that produce a product with a size distribution parallel to that of the feed. It does not work well for devices such as the AG/SAG mill and high pressure grinding rolls where the product size distribution is not parallel to that of the feed. For SAG mills methods such as the Starkey SAGDesign mill, the SAG equivalent of the Bond Mill, are used.

Bond, who died in 1977, was inducted with first class into the National Mining Hall of Fame in 1988 and received a Distinguished Achievement Medal by his alma mater, the Colorado School of Mines, in 1952. He received the 1965 AIME Robert H. Richards Award "for major contributions to increased knowledge of crushing and grinding processes and for achievement in industrial application of this knowledge to advancement of the milling industry."

Monday, 5 October 2015

Amanda sends greetings from Bali

Just received a couple of photos from Amanda, who is at the opening keynote lecture at the International Biohydrometallurgy Symposium in Bali, Indonesia.

She will be in Bali all week, reporting on this important event, for which MEI is a media partner.

Royal visit to Wheal Jane, Cornwall

My recent visits to Wardell Armstrong International and SGS at the Wheal Jane site have shown me that exciting things are going to be happening for Cornish mining over the next few years (posting of 31 August).

Unfortunately I was on my way to Vancouver for the SAG '15 conference, and so missed the Wheal Jane Earth Science Park project receiving the Royal seal of approval from HRH the Duke of Kent, who spent over an hour touring newly completed workspace occupied by various companies.

According to Bernard Ballard, Director of Marketing and Property, the Duke was surprised by the diversity and scope of work taking place on site. During his tour he was able to see archive mine plans dating back to the 18th century, rare mineral specimens mined at Wheal Jane and ingots of Cornish tin salvaged from shipwrecks being restored after over a century on the sea bed.

In the Wheal Jane Laboratory the Duke was introduced to advanced analytical techniques used to provide minerals analysis for projects worldwide and in Wardell Armstrong's pilot plant facility aspects of a European minerals research project.

The Duke (centre) in the Wardell Armstrong pilot plant
The visit was concluded with HRH unveiling a plaque to mark the occasion and being presented with a limited edition set of tin coins by staff in the jewellery production workshop.

Saturday, 3 October 2015

Comminution '16: Abstracts due by the end of this month

A final reminder to all you crushing and grinding specialists that abstracts for Comminution '16 are due by the end of this month.

And for all comminution circuit operators out there- if you would like to present a 10 minute presentation on your operations, without the need to submit a formal paper, then we encourage you to do so.

Full details of what to expect at the conference in Cape Town can be found on the posting of 7th September.

Thursday, 1 October 2015

Exploring the Wheal Coates Towanroath Vugga

One of the best short walks on the north Cornwall coastal path is that between Porthtowan and Chapel Porth (posting of 3 September). But if you walk this when the tide is low, you have an added bonus, as you can make the return trip on a pristine stretch of sand, one and a half miles long, which opens up between the two coves.

We took advantage of the October sunshine this afternoon and continuing north-east from Chapel Porth beach we met up with CSM geologist Dr. Charlie Moon and a party of MSc geologists on an afternoon field trip (do they know how lucky they are?). There are a number of impressive caves on this stretch of coast, but the most interesting of these lies directly beneath the Towanroath pumping engine house of the old Wheal Coates mine (posting of 20 August). This is the Towanroath Vugga, an ancient working of a vein beneath Wheal Coates, which has been enlarged by the sea. It is possible, with care, to venture deep into this partially man-made cave, which contains an adit which was used to drain Wheal Coates.

The geologists at the entrance to the Vugga

Inside the Vugga