Zwick has revealed that De Beers is using the company's compression testing machine to analyse how diamonds break during mining.
Using a Zwick compression testing machine, researchers at South African company DebTech, a research and development arm of De Beers, have been able to experimentally measure the breakage function of a diamond.
Dr Garry Morrison, senior research scientist at DebTech, said: 'Being able to measure the breakage function gives us a lot more confidence in our simulations.
'The Zwick compression testing machine also gives us a way of relating simulated breakage to actual diamond breakage.' As well as crushing diamonds, the Zwick machine is also used to fracture ceramic cylinders, which are used by diamond mines to periodically assess the effectiveness of its mining processes.
These ceramic cylinders are put through the mining process and their fragments are collected and analysed at the other end.
Morrison added: 'Diamond mining is a trade-off between doing things as quickly and therefore as severely, as possible and not damaging the product.
'The Zwick machine is helping us to better understand the effects our processes have on our product.' Morrison uses a Zwick Z030 Allround-Line Table-Top Machine for his experiments.
This is equipped with a 30 kN load cell and features Zwick's TestXpert software, which is easy to use and modular in design.
Intelligent assistants help the customer to set up or change test procedures and it is compatible with all commercially available PCs and laptops without the need for an additional connection card.
It adopts industry-specific terminology and can easily export data to a company's central laboratory database.
The software also enables frame synchronization of video recordings and features a Laboratory Information Management System (LIMS).
This is a database that can be used to administer test results spanning a number of test series.
Its graphical sequence editor enables the customer to design customised test procedures by combining test events, parameters and results.
It analyses the test procedure and can filter out errors in the early stages without destroying a single specimen.
The tests are run at 5mm/min load rate and each sequence is filmed with a high-speed video camera.
Loads can vary from tens of Newtons to thousands of Newtons and each diamond behaves differently depending on its shape, its flaws and inclusions.
Some break into two or three larger fragments and others fracture into vast numbers of tiny fragments.
Morrison said: 'We can typically test 30 diamonds a day using the Zwick.
'The time-consuming part is the characterization of the size and shape of all the fragments after each test.' An analysis of the size and shape distributions of the broken fragments gives the breakage function.
Morrison added: 'The fact that I can measure loads at a resolution of less than 1 N is useful.
'Another plus is the ease of set-up.
'This is important, since in both our applications we attach our own custom anvils.
'The software enables me to do this easily thus allowing us to change between configurations quickly.'
