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CHARACTERISATION OF RARE MINERALS IN COMPLEX ORES AND MINERAL PRODUCTS.

Objective

1. THE DEVELOPMENT OF NEW ANALYTICAL PROCEDURE WHICH WILL BE CAPABLE OF SWIFTLY LOCATING AND MEASURING VALUABLE, "RARE" MINERALS IN A WIDE VARIETY OF SPECIMENS AND THE INFORMATION OBTAINED WILL BE OF CONSIDERABLE, AND IMMEDIATE, VALUE TO GEOLOGISTS DURING MINERAL EXPLORATION WORK, TO MINERAL ENGINEERS FOR PROCESS DESIGN AND PROCESS CONTROL PURPOSES, AND TO METALLURGISTS FOR THE STUDY OF SLAGS AND INCLUSIONS IN METALS AND ALLOYS.
2. THE EXISTING MEASURING SYSTEM IS BASED ON A COMMERCIALLY-AVAILABLE ELECTRON PROBE X-RAY MICROANALYSER. THIS INSTRUMENT WAS DESIGNED AND MANUFACTURED BY A FRENCH COMPANY (CAMECA LTD.) AND, AS A RESULT OF THIS PROJECT, THE COMPANY MAY BENEFIT FROM ADDITIONAL SALES OF AUTOMATED INSTRUMENTS TO THE MINERAL INDUSTRY.
3. THE MEASURING PROCEDURE IS BEING SPECIALLY DESIGNED BY THE PROJECT TEAM FOR STUDYING THE KIND OF COMPLEX, FINE GRAINED ORES THAT ARE FOUND IN PORTUGAL, SPAIN, GERMANY AND CORNWALL. IN PARTICULAR, IT WILL BE ESPECIALLY SUITABLE FOR STUDYING THE NEWLY DEVELOPED, COMPLEX SULPHIDE ORES OF SOUTHERN PORTUGAL. THE SOFTWARE PROGRAMMES FOR CONTROLLING THE MICROANALYSER FOR HANDLING THE MEASURED DATA WILL BE DEVELOPED IN CONJUNCTION WITH THE INSTRUMENT MANUFACTURER AND THESE PROGRAMMES WILL BE COMPATIBLE WITH ALL PRESENT AND FUTURE VERSIONS OF THEIR INSTRUMENTS. THE PROGRAMMES WILL ENHANCE THE VALUE OF THE EXISTING EQUIPMENT SINCE IT CAN THEN BE USED FOR STUDYING LOW GRADE MINERALOGICAL MATERIALS DISCARDED BY EARLIER MINING OPERATION, AND FOR CHARACTERISING THOSE MINERALS WHICH ONLY OCCUR AS VERY SMALL PROPORTIONS IN CURRENTLY WORKED ORES.
A new, automatic analytical system for finding rare mineral phases in rocks, and other mineral based materials, has been developed. It is based on the use of a commercially available electron probe X-ray microanalyser for which user friendly, menu driven software has been developed.
The analytical procedure is an area scanning system in which the intensity of the back scattered electron (BSE) signal from each point on the specimen surface is compared with a preset value. At points where the signal exceeds this value the identities of the minerals are confirmed by measuring their characteristic X-ray signals. The maximum analytical speed achieved is 3.25 cm{2} per hour with a spatial resolution of 1 um.
The software has already been fitted to a number of microanalysers and specimens containing: trace amounts of gold with copper and iron sulphides; gold with galena; native bismuth; bismuth bearing minerals with gold; the platinoid element bearing minerals; diamonds; silver bearing minerals and other rare minerals have been successfully analysed.
1. REFINEMENT AND EXTENSION OF THE RARE PHASE ANALYTICAL PROCEDURES (SO THAT THEY WILL BE ABLE TO LOCATE ANY TYPE OF RARE MINERALS), USING MODIFIED ELECTRON PROBE X-RAY MICROANALYSER AND THE NEW, PROTOTYPE, SYSTEM WITH AN AREA-MEASURING DEVICE.

2. IMPROVEMENT OF THE SOFTWARE USED TO CONTROL THE AREA ANALYSES FACILITY TO PROVIDE USER-FRIENDLY PROGRAMMES.
INCORPORATION OF THESE PROGRAMMES INTO AN OVERALL ANALYTICAL SYSTEM WHICH WILL ALSO INCLUDE PROVISION FOR CARRYING OUT LINEAR ANALYSIS, WHICH HAS TO BE USED FOR SWIFTLY MEASURING THE MAJOR MINERAL COMPONENTS.

3. TESTING THE SYSTEM ON A VARIETY OF INDUSTRIAL SPECIMENS.

4. SPECIFICATIONS OF THE MEASURING SYSTEM IN A FORM THAT CAN BE PASSED TO AN EQUIPMENT MANUFACTURER FOR CONVERSION INTO A COMMERCIALLY SALEABLE INSTRUMENT.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

IMPERIAL COLLEGE OF SCIENCE, TECHNOLOGY AND MEDICINE
Address
South Kensington Campus
London
United Kingdom

Participants (6)

BILLITON RESEARCH
Netherlands
Address

Arnhem
BP Minerals
United Kingdom
CAMECA
France
CGF
United Kingdom
Mineral Industry Research Organisation
United Kingdom
Address

London
RTZ Metals Ltd
United Kingdom