Improved Settling Properties of Iron Silicate Slag by CaO Modifications

• One of the most significant sources of copper losses from pyrometallurgical copper extraction is attributed to dissolved and entrained copper in the discarded slag. The entrained copper can be recovered via pyrometallurgical slag cleaning in a settling furnace. Reduced copper losses mean increased smelter profits by improved raw material efficiency, and, in addition, the slag will become a more environmentally safe by-product. One way to increase the copper recovery during the settling process is to modify the slag to improve the properties that decrease copper solubility and slag viscosity. In this study, iron silicate slag was modified using CaCO3 on an industrial scale to evaluate its effect on the settling process. More specifically, the changes in settling were related to the modifications and measurements of slag viscosity and copper droplet size distributions in the slag. The trial was evaluated by comparing the copper content in different batches, the size distribution of copper-containing droplets using automated scanning electron microscopy, and performing rheological studies using a high-temperature rheometer. The results showed that increasing the CaO content of the slag by modification with CaCO3 has a positive effect on the settling process and is thus a possible method to improve the industrial settling process of valuable metals in slag.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Metallurgi och metalliska material (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Metallurgy and Metallic Materials (hsv//eng)

Keyword

Slag modifications

CaO

Rheology

Viscosity

Copper droplets

Size distribution

Process Metallurgy

Processmetallurgi

Mineral Processing

Mineralteknik

Centrumbildning - Centrum för avancerad gruvteknik och metallurgi (CAMM)

Centre - Centre for Advanced Mining & Metallurgy (CAMM)

Publication and Content Type

vet (subject category)

kon (subject category)