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Contenido archivado el 2019-03-12

MODIFIED POLYSACCHARIDES TO PROMOTE THE FLOTATION OF LOW GRADE SULPHIDIC ORES AND PHOSPHATE

Objetivo

DEVELOPMENT OF POLYSACCHARIDIC DERIVATIVES FOR THE APPLICATION AS SELECTIVE FLOCCULANT ACTIVATOR AND DEPRESSANT IN BENEFICIATION OF LOW GRADE FINELY DISSEMINATED SULPHIDIC ORES AND PHOSPHATE ORES TO IMPROVE THE RECOVERY AS WELL AS THE GRADE.

THE PROBLEMS IN FLOTATION OF LOW GRADE, FINELY DISSEMINATED SULPHIDIC ORES AND PHOSPHATE ORES ARE INTERRELATED. FLOTATION RECOVERY OF FINELY GROUND PARTICLES DECREASES CONSIDERABLY AS RESULT OF A LOW MOMENTUM. THE EFFECTIVE SIZE OF THE FINES CAN BE INCREASED BY FLOCULATION.

THE APPLICATION OF CONVENTIONAL SYNTHETIC FLOCCULANTS, SUCH AS POLY-ACRILAMIDE FAIL IN SELECTIVITY AS WELL AS IN RESISTANCE AGAINST THE HIGH-SHEAR CONDITIONS OF THE FLOTATION PROCESS. POLYSACCHARIDES - NOTABLY CELLULOSE -
HAVING A STIFF BACKBONE ARE MUCH MORE RESISTENT AGAINST THE HIGH SHEAR CONDITIONS IN THE CELL COMPARED TO THE FLEXIBLE OIL-BASED POLYMERS.

HYDROPHOBIC GROUPS CAN BE INCORPORATED IN THE POLYSACCHARIDIC BACKBONE TO DECREASE THE HYDROPHYLICITY.

IT CAN BE ANTICIPATED THAT DISPERSANTS HAVE TO BE APPLIED ALSO.

SHORT CHAIN POLYSACCHARIDE HAVE DISPERSING PROPERTIES WHEREAS LONG CHAIN POLYSACCHARIDES HAVE FLOCCULATING PROPERTIES. DISPERSING PROPERTIES CAN BE IMPROVED BY INCORPORATION OF ANIONIC GROUPS (E.G. CARBOXYLIC GROUPS).

SELECTIVE ABSORPTION OF THE POLYMER IS THE KEY FOR THE SUCCESSFUL APPLICATION.

SELECTION OF THE ACTIVE GROUPS TO BE ATTACHED TO THE POLYSACCHARIDIC MOLECULE WILL BE BASED ON :

1. CHELATING GROUPS SPECIFIC TO (METAL) IONS IN THE CLEAVAGE PLANES

2. STEREOMETRIC CONSIDERATIONS RELATING TO THE STRUCTURE OF THE RUPTURE PLANE

3. EXPERIENCE WITH CHEMICALS THAT HAVE BEEN PROVEN TO BE SPECIFIC.

A NEW PROCESS HAS BEEN DEVELOPED TO DISSOLVE THE CELLULOSE IN LICL-METHYL ACETAMIDE TO BE APPLIED IN YARN SPINNING. THIS TECHNIQUE CAN BE USED ALSO TO PREPARE CELLULOSE DERIVATIVES.

GUAR MOLECULE IS MORE FLEXIBLE COMPARED TO CELLULOSE BUT IT IS MORE ACCESSIBLE FOR CHEMICAL MODIFICATION. THEREFORE IT WILL BE INCLUDED IN THE RESEARCH PROGRAM AS WELL.

THE HYDROPHYLIC BACKBONE OF POLYSACCHARIDIC DERICATIVES IS ABLE TO BUILD UP IMMOBILISED WATERLAYERS AROUND THE MINERALS TO BE DEPRESSED BUT ALSO TO PREVENT ABSORPTION OF COLLECTOR MOLECULES ON THE MINERAL SURFACE.

THEREFORE THESE POLYMERS CAN BE APPLIED ALSO FOR DEPRESSION OF E.G. PYRITE IN POLYSULPHIDIC ORE OR CALCITE IN PHOSPHATE ORES.

Tema(s)

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Régimen de financiación

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Coordinador

ENKA B.V. , INDUSTRIAL COLLOIDS
Aportación de la UE
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Dirección
VELPERWEG 76 NL-6824 BM ARHEM

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