Mineral process chemistry: Samples A and B

Please order Samples A and B via Sarah Codrington at the Nuffield Curriculum Centre, and give at least 4 weeks' notice.

Sample A: this will continue to be unroasted £25.00 per pack
Sample B: please recycle this as much as possible
because supplies are very limited £25.00 per pack
top-ups of wolframite for Sample B £7.00 per pack

Orders to:
Sarah Codrington
Nuffield Curriculum Centre, 28 Bedford Square, London WC1B 3JS
fax 020 7436 1869
email: Sarah Codrington

Sample A
This is supplied in 3-kg packs price £25.00 including post and packing.
This quantity is sufficient for 14 students or pairs of students.

There is no difference between the material for roasting and that which is treated ‘unroasted’. This is a change from the samples provided between November 1996 and November 1998.

The four minerals, chalcopyrite, malachite, sphalerite, and smithsonite have been added to the material collected from the waste tips at Ecton Hill. This is to ensure a sufficiently high copper and zinc content for extraction purposes. It also ensures that the first three minerals can be easily observed during microscopic examination. Smithsonite has no notable visual characteristics and is therefore difficult to identify.

Roasting must be carried out in a fume cupboard. The most appropriate technique is to spread the material thinly over a metal tray supported on tripods. Heating with a Bunsen burner should bring about a darkening in colour. This is generally accompanied by sparks and glowing of particles as oxidation and decomposition of minerals occur. It helps to turn the material over from time to time, using a spatula to ensure that air can circulate around all the particles.
Note that pieces of the hot ore sometimes shatter and shoot off the metal tray, so eye protection is essential throughout the process.

Sample B
This is supplied in 5 x 1-kg bags price £25.00 including post and packing.

This is sufficient for 5 students or pairs of students, and you are encouraged to recycle the material once or twice. A small quantity of the mineral wolframite has been added to each bag to ensure that there is some to be found by students.

Recycling Sample B: if all the residues are recovered and mixed after processing, fresh wolframite can be added to each well-mixed kilogram of residue.

Wolframite for recycling the samples is supplied in packs sufficient for addition to 5 x 1-kg samples price £7.00 including post and packing.