A Research Project in Hydrometallurgy

	PROJECT DESCRIPTION Pupils research ways of extracting metals from ores with support from industrial scientists.	AREAS OF SCIENCE Astronomy Chemistry Computing Engineering / Technology Environment Interdisciplinary Life Science / Medicine Physics	WHERE School Other institution Field / Expedition WHEN In curriculum Extra curricular Work experience	SCHOOL TYPE Primary Secondary to 16 Post 16 Independent Maintained Sixth Form College Further Education
	PROJECT ORGANISERS Shelagh Rogerson, Hulme Grammer School for Girls, Oldham. Drs Ray Dalton and Peter Tasker, with Alan Sugarman, from Zeneca Specialities, Blackley, as advisers.

Project Participants

Project work is open to girls in Year 12 studying Chemistry at A Level. Numbers are approximately 20-25 per year. The students work in teams but gain experience of all aspects of the analysis. Since the project began in 1990, over 60 pupils have been involved. Work is carried out after school on one or two evenings a week, a total time of about two hours per week.

Science Programme

The chemical principles involved are to a large extent covered by the A Level Chemistry syllabus. Topics include: transition metal chemistry (with particular emphasis on the study of copper); complex formation; ligand replacement; titrimetric analysis involving copper ions and sodium thiosulphate. General principles involved include the extraction of metals from their purified ores, including electrolytic reduction. Also included are aspects of chemical equilibria and the factors affecting equilibrium, dissociation constants, the concept of pH and the action of buffers.

The programme was set up with various aims in mind. These included giving chemistry a high profile in the science curriculum, giving the students a feel for the importance of chemistry in industry, providing contact with industry, and providing opportunities to meet professional chemists.

At the start of each year, technical advisers from Zeneca Specialities, Manchester, speak to the group and give an overview of the importance of hydrometallurgy in the extraction of copper. Training is then given after school on two evenings during the week.

Personal Development

The success of a scheme like this is measured not only in terms of the final experimental results but also in the wider aspect of capturing and maintaining the interest and enthusiasm of the sixth form research chemists. They cope well with the repetitive nature of the tasks and gain confidence in handling apparatus and chemicals. They can achieve a professional approach to the analysis. Interviews have been given to local press and visits have been made to the research laboratories at Zeneca.

Pupils benefit from the contact with industry and the open ended nature of the project, giving them a feel for the subject and a taste of what is actually involved in scientific research.

The link with the scientific advisers is a stimulating challenge for the staff. The project has been found to be a challenging, exciting and constructive way of doing investigative chemistry.

Outcomes

Students at work in the school lab Essentially the group aims to produce distribution curves (called isotherms). The gradient of the isotherm determines the number of stages involved in the extraction of the copper and to some extent the efficiency of the process. The extraction technique is pH sensitive and certain ions present may have a buffering action, which can alter the gradient of the isotherms. The effect of aluminium ions and of varying the initial pH of the feedstock have also been looked at.

Analytical results are usually processed by the Zeneca research team using their Mining Chemical software. The results are submitted annually to the Royal Society and a description of the project has been published (Rogerson, 1995).

Project Origin

The setting up of the research group began to take shape in 1989. The topic was intended to demonstrate chemical principles at work in modern industry and after discussion with professional chemists from the Research Centre of ICI Speciality Chemicals in Blackley (now Zeneca Specialities), it was decided to investigate some aspects of hydrometallurgy. The process concerns the recovery of copper by solvent extraction from low grade ores and from waste sources. In the mid 1970s, special extractant solvents were developed involving molecules designed specifically for copper extraction. The technique introduced by ICI has recently grown considerably and the major mining companies of the world have established new copper projects using these strong extractants.

Resources

The project requires use of one laboratory with a fume cupboard, storage cupboards and drawers.
Mr John Bibby, chemistry teacher at Hulme Grammar School assists with this project. Professional advice is provided by Zeneca Specialities, including Dr Ray Dalton, Dr Peter Tasker and Mr Alan Sugarman.
The project is funded through the Scientific Research in Schools Scheme.
Zeneca provide feedstock and the extractant.

Contact

Shelagh Rogerson, Hulme Grammar School for Girls, Oldham OL8 4BX.
Tel: +44 (0) 161 6242523.