ESTUDO DO BENEFICIAMENTO DE UM MINÉRIO SULFETADO DE OURO DE BAIXO TEOR / STUDY OF THE PROCESSING OF SULPHIDE ORES OF GOLD WITH THE LOWEST GRADE OF GOLD

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The work involves the evaluation of physical and chemical factors that influence the processing of sulphide ores, with the lowest grade of gold known in the world. The studied sample is from Rio Paracatu Mining S.A. and is described as Calha Brava Cl-4, belonging to the 716 bench, block 508-B in the mine. Some industrial processing of gold include gravity concentration and flotation processes in order to reach the maximum gold recovery, aiming at raising production levels with lower costs. The selection of the mineral processing depends on several factors as mineralogy, particle size distribution and other minerals associated with the ore. The distribution of gold grades to the different size fractions in the studied ore, reveals that 80.48% of gold occur in the particle size fraction above 104 um, and 25% of gold occur in the fine fraction (<28 um). The global gold, sulphur and arsenic recoveries, obtained by centrifuge gravity concentration (Knelson) and flotation tests, were 80.44%, 64.90% and 58.22%, respectively. To these processes, the mass recovery was 10.14%. The total gold, sulphur and arsenic recoveries obtained in concentration processes by jig and flotation techniques were 88.91%, 86.82% and 49.07%, respectively. The mass recovery was 19.5%. In the flotation tests, the maximum gold recovery (87%) was obtained with the grounded ore (P80 = 86 um), using 30 g/t collector potassium amyl xanthate (PAX), 20 g/t methyl isobuthyl carbinol (MIBC), pH = 6.3 and potential of pulp 0.209 V vs Eh. The mass recovery was approximately 4%. When coarse particles (P80 = 130 um) were floated, the need of am increase in the collector concentration was observed. The maximum ore recovery (85.33%) was obtained at concentration of 60 g/t PAX, pH = 6.3 and potential of pulp 0.218 V vs Eh. The mass recovery was 9%.

ASSUNTO(S)

gold ore minerios de ouro flotation tamanho de particula minerios de baixo teor flotacao low grade ore gravity concentration particle size concentracao gravitica

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