Antimony Oxide Ore Beneficiation Process

Antimony oxide ore, as an important antimony resource, is difficult to select because of its easy sludging, strong solubility, and similar nature with vein minerals. At present, the mainstream beneficiation process includes re-election method, sulphide flotation method and direct flotation method.

 1. Antimony ore re-election process

Re-election method uses the density difference between antimony oxide ore (density about 6.5 g/cm³) and quartz, calcite and other vein minerals for sorting, which is the conventional method for coarse-grained antimony oxide recovery. However, microfine-grained antimony oxide is prone to sludging, and the recovery efficiency of conventional re-election equipment is low. In recent years, research has focused on the development of efficient micro-fine grained re-election equipment:

•  Countercurrent sorting column: by adjusting the parameters of slurry flow, rising water flow, etc., it can achieve the pre-enrichment of fine-grained antimony oxide. Tests show that 80% of vein stones can be thrown out when the grade of raw antimony is 0.75%, and the recovery rate reaches 73.91%, but the concentrate grade is only 2.54%.

•  Stirred Countercurrent Sorting Column: Stirring blades are added on the basis of countercurrent sorting column to enhance particle dispersion and fluidised bed stability. For the flotation tailings of 0.15~0.023 mm particle size, the recovery rate is increased to 73.13%, and the concentrate particle size is more uniform.

2. Antimony Ore Sulfide Flotation Process

Sulfide flotation is a commonly used method for the sorting of oxidised ores by converting antimony oxide into antimony sulphide (Sb₂S₃) and then flotation. The key technologies include the selection of sulphiding agent and the optimisation of sulphidation conditions:

•  High temperature sulphidation roasting: at 450°C, antimony oxide is mixed and roasted with monolithic sulphur to produce antimony sulphide phase, and the flotation recovery can be increased from 5% to 95%. For example, flotation of actual ore after sulphide roasting can obtain an antimony grade of 21.8% and a recovery of 82.35%.

•  Alternative sulphiding agent research: adopt cheap sulphiding agent such as pyrite or co-ground copper sulphate to explore low temperature sulphiding process to reduce energy consumption and environmental impact.

3. Antimony ore direct flotation process

Direct flotation does not need sulphide pretreatment, but it needs to strengthen the research on the selectivity of pharmaceuticals and flotation mechanism:

• Optimization of collector: sodium oleate, dodecylamine, sodium dodecyl sulphate and so on have significant effect on the flotation of antimony oxide monomineral. For example, after the activation of copper ions, sodium oleate can achieve the separation of antimony oxide and quartz at pH=6.

• Combination of pharmaceutical applications: octyl hydroxamic acid combined with hydrocarbon oil and emulsifier to enhance the recovery of fine-grained antimony oxide through hydrophobic polymerisation; manganese ion activation can eliminate the harmful effects of hydrolysis products in the pulp.

Direct flotation of oxide ores.