What are the methods used in gold ore beneficiation production line?

Faced with complex and diverse gold ore resources, how to efficiently carry out mineral processing design, improve gold recovery rates, select suitable equipment, and control key process nodes are key concerns for every enterprise.

Gold ore types

Gold ore can be classified based on multiple factors, including their origin, mineral composition, the state of gold occurrence, degree of oxidation, industrial type, and the difficulty of beneficiation processes. Gold ore of different origins vary greatly in their properties, and beneficiation methods also vary accordingly.

Gold Ore Beneficiation Processes

Gold ore beneficiation processes primarily include gravity separation, flotation, and cyanidation. The choice between a single process or a combined process depends on the type of gold ore, particle size, and the state of gold occurrence, aiming to achieve efficient recovery.

1) Gravity Separation

Gravity separation utilizes the density differences between minerals to form loose layers under the combined action of medium fluid and mechanical force, thereby separating gold from other minerals. This method is primarily suitable for the initial separation of placer gold deposits, alluvial gold deposits, and certain oxidized gold deposits. It can also be used for the recovery of coarse-grained free gold in vein gold deposits before or after flotation or cyanidation.

2) Flotation 

Flotation is widely applied to process gold-bearing sulfide ores with strong floatability, particularly those containing copper, lead, and other base metals, enabling the comprehensive recovery of multiple metals. The process typically includes flotation – cyanide leaching of concentrate, flotation – thiourea leaching of concentrate, flotation – roasting of concentrate – high-acid washing – cyanide leaching, etc. By first concentrating gold in sulfide concentrate and then extracting it, the comprehensive utilization rate of gold is improved.

3) Cyanidation Method

Cyanidation is one of the primary methods for gold ore beneficiation, categorized into stirred cyanidation and leaching cyanidation.

Stirred cyanidation is suitable for processing flotation gold concentrates or whole-ore slurry. It involves leaching gold ore with a dilute cyanide solution and then recovering gold using activated carbon adsorption. The process primarily includes two types of flows:

Cyanide-zinc replacement process (CCD method and CCF method): This involves continuous counter-current washing, followed by the use of zinc powder (or zinc wire) to replace and precipitate gold for recovery.

Non-filtered cyanide carbon slurry process (CIP method and CIL method): This method does not require filtration or washing, instead using activated carbon to directly adsorb and recover gold from the cyanide slurry.

The leaching cyanidation method is primarily used for low-grade gold-bearing oxide ores. It involves permeating cyanide solution through ore piles to dissolve gold, followed by recovery through ion exchange resins, activated carbon adsorption, or zinc powder replacement. Common processes include tank leaching and heap leaching.