Froth Flotation Rule of Thumb

Here is a list of Rules of Thumb often used in Froth Flotation:

Clean metallic gold particles (free gold) finer than 200 microns (65 mesh) float readily with appropriate reagents. Gravity separation is desirable for larger particles. Source: Mining Chemicals Handbook (Cyanamid).
When designing the flotation circuit for a proposed mill, the scale-up factor for flotation retention times obtained from bench tests is approximately two. Source: Mining Chemicals Handbook (Cyanamid)
To determine a preliminary water balance for a proposed flotation circuit, the pulp density may be assumed to be 30% solids (by weight). Source: Rex Bull
As a rule, water-soluble collectors may be added anywhere in the circuit, but oily, insoluble promoters should always be added to the grinding mill. Source: Keith Suttill
For roasting to be exothermic to the extent that no fuel is required to sustain reaction, the flotation product must contain at least 17% sulfur. Therefore, the target is 18%. Source: Dickson and Reid
When designing the filters required for a proposed mill, the scale-up factor from bench tests is approximately 0.8. Source: Donald Dahlstrom
When determining vacuum pumps for filter installations required for a proposed mill, the scale-up factor from bench tests is approximately 1.1. Source: Donald Dahlstrom
The moisture content of concentrate measured by a custom smelter will invariably be 1% higher than was correctly measured by the mine when it was shipped. Source: Edouardo Escala