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IMPROVEMENT OF COMPLEX SULPHIDE FLOTATION UTILIZING NEW REAGENT CHEMISTRY.

Objective

MOST CURRENT ATTEMPTS AT FLOTATION IMPROVEMENTS INVOLVE CIRCUIT OPTIMISATION WITH CURRENTLY AVAILABLE COLLECTOR AND DEPRESSANT CHEMISTRIES.THE RESEARCH IS INNOVATIVE IN THAT NEW POLYMERIC DEPRESSANTS WILL BE DEVELOPED TO IMPROVE SEPARATION OF VALUABLE SULPHIDES AND IMPROVE DEPRESSION OF UNWANTED GANGUE MINERALS. THESE NEW CHEMISTRIES PERHAPS IN ASSOCIATION WITH MODIFIED PROCESS CONDITIONS WILL THEN BE USED TO MAXIMISE METAL PRODUCTION.
It has been demonstrated that approximately 10% improvement in copper recovery should be possible with finer grinding but at the expense of lower lead recoveries.

The primary objective of the project was to determine whether new flotation reagents would be capable of providing improvements in metallurgical performance.

Initial studies ofplant operation and mineralogy established that potential existed for further metal recoveries from liberated minerals in the fine size fractions. However, extensive laboratory flotation studies of copper flotation and lead flotation with an extremely wide range of alternative collectors and various process chemistry changes failed to improve on the performance obtained with the collector currently in use, potassium amyl xanthate. Promising laboratory results, operating the copper rougher at netural pH, could not be sustained when transferred to plant operation.

The poor flotation performance (in the copper and lead circuits) was attributed to nonselective flotation in the slime fractions and poor liberation in the coarser material. Quantitative mineralogical examinations of the tailings confirmed the latter and some success was obtained with improving comminution practice. It has been demonstrated that approximately 10% improvement in copper recovery should be possible with finger grinding but at the expense of lower lead recoveries. Translation of this finding to plant operation would require significant process alterations.

It is concluded that no commerical benefit is currently possible by alteration of collector of other reagents. Some attention should, however, be focused on improving the performance of the copper cleaning circuit. The greatest potential for extra recovery of copper involves finer grinding but this must be carefully controlled.
THIS PROJECT IS INTENDED TO IMPROVE THE GRADES AND RECOVERIES OF CONCENTRATES PRODUCED AT MINAS DE ALMAGRERA SA BY THE USE OF NOVEL FLOTATION REAGENTS. IT IS ALSO PLANNED TO STUDY THE SURFACE-CHEMICAL MECHANISMS OF FLOTATION IN THE PRESENCE OF THESE REAGENTS THUS IMPROVING THE GENERAL UNDERSTANDING OF COMPLEX SULPHIDE SEPARATIONS. PERSONNEL AT ALMAGRERA WILL ASSUME OVERALL PROJECT MANAGEMENT, SUB-CONTRACTING MOST OF THE LABORATORY INVESTIGATIONS TO UNIVERSITY COLLEGE, CARDIFF.
CYANAMID LTD WILL PROVIDE AND CHARACTERISE THE RELEVANT CHEMICALS AND PURE MINERAL SPECIMENS, ASSIST WITH LABORATORY STUDIES AND ALSO SUPPLY SUFFICIENT QUANTITIES OF CANDIDATE REAGENTS FOR MEANINGFUL PLANT TRAILS.
WE AT THE MINE WILL ALSO PROVIDE THE SUB-CONTRACTORS WITH HISTORICAL DATA ON PLANT PERFORMANCE, PROVIDE SAMPLES FOR STUDY AT THE UNIVERSITY AND COORDINATE PLANT-BASED TRIALS ON A CONTINUOUS BASIS WITH NEW CHEMICALS AND MODIFIED PROCESS CONDITIONS.

PLAN OF WORK:
COMPUTER LITERATURE SEARCHES
BASE-LINE PLANT STUDY
LABORATORY STUDIES:
A) PROCESS MINERALOGY
B) PURE MINERAL SPECIMENS (SURFACE CHEMISTRY, ADSORPTION MICROFLOTATION)
C) BATCH FLOTATION (ORIGINAL VERSUS NOVEL REAGENTS AND PROCESS CONDITIONS).
PROVISION AND CHARACTERIZATION OF NEW REAGENTS
PLANT TRIALS WITH NEW REAGENTS

THE POTENTIAL FOR IMPROVEMENTS IN BOTH GRADE AND RECOVERY OF METAL CONCENTRATES DERIVED FROM COMPLEX SULPHIDE ORES WITHIN THE EUROPEAN COMMUNITY IS HIGH. THIS RESEARCH AND DEVELOPMENT PROJECT IS INTENDED TO IMPROVE THE FLOTATION PERFORMANCE AT MINAS DE ALMAGRERA SA, WHERE COPPER, LEAD AND ZINC CONCENTRATE PRODUCTION IS CURRENTLY 10.000, 8.500 AND 40.000 TONNES PER ANNUM RESPECTIVELY.
REALISTIC ESTIMATES OF TARGET GRADES AND RECOVERIES AT PROJECT COMPLETION WOULD RESULT IN EXTRA METAL PRODUCTION WITH A VALUE IN EXCESS OF 2.7 MPOUNDS PER ANNUM.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

CARDIFF UNIVERSITY
Address
Newport Road 30-36
Cardiff
United Kingdom

Participants (2)

Almagrera SA
Spain
Address
Centro Sotiel
21300 Calañas
Cyanamid of Great Britain Ltd
United Kingdom
Address

PO13 0AS Gosport