Chemical elements that affect FKN Gold Dressing Agent’s gold recovery rate and consumption

The gold recovery rate of FKN environmentally friendly gold dissolving agent is affected by a variety of chemical elements, which are mainly divided into two categories: promoting interference elements and inhibiting interference elements. The following are key elements and their mechanisms of action:

1. Elements that promote FKN gold dressing agent’s gold recovery (beneficial elements)

1.1 Copper (Cu)

As a catalyst in cyanidation gold extraction, it accelerates the dissolution of gold (forming Cu(CN)₄³⁻ complex).

Excessive amount will lead to increased FKN gold dressing agent’s consumption, and the concentration needs to be controlled.

1.2 Lead (Pb)

Forming lead alloy (precious lead) in pyrometallurgy and enriching gold particles.

In wet gold extraction, lead salts (such as lead nitrate) can eliminate the interference of sulfides on cyanidation.

1.3 Silver (Ag)

Often coexisting with gold, dissolving simultaneously with gold in cyanidation (Ag(CN)₂⁻), but attention should be paid to separation and purification.

2. Elements that inhibit gold recovery (harmful elements)

2.1 Elements that consume cyanide

2.1.1 Sulfur (S) and sulfides (such as FeS₂, CuFeS₂)

React with cyanide to form SCN⁻, greatly increasing reagent consumption.

Pre-oxidation (such as roasting, biological oxidation) or addition of lead salts is required for inhibition.

2.1.2 Zinc (Zn), iron (Fe), nickel (Ni)

Form Zn(CN)₄²⁻, Fe(CN)₆⁴⁻, etc. in the cyanide solution, competitively FKN gold dressing agent’s consumption.

2.2 Elements that form a passivation film

Arsenic (As), antimony (Sb), bismuth (Bi)

Generate a dense oxide/sulfide film (such as As₂O₃) on the gold surface, hindering the cyanidation reaction.

Pretreatment by roasting or pressurized oxidation is required.

3. Elements that adsorb gold

Carbon (C)

Organic carbon or activated carbon in the ore will "rob gold" (adsorb dissolved gold-cyanide complexes).

Solution: Pre-oxidized carbon or use resin adsorption instead of activated carbon.

4. Other interfering elements

4.1 Mercury (Hg)

Forms amalgam with gold, affects purity, and requires high-temperature distillation separation.

Environmental risks are high and need to be strictly controlled.

4.2 Tellurium (Te), Selenium (Se)

Generate insoluble compounds to wrap gold particles and reduce leaching rate.

Solutions and technologies

Pretreatment process: roasting, biological oxidation, pressure oxidation, etc., to eliminate interference such as sulfur and arsenic.

Agent adjustment: Add protective alkali (such as lime) to inhibit cyanide hydrolysis, or use alternative leaching agents (such as thiosulfate).

Process optimization: Select pyrometallurgy, hydrometallurgy or combined process according to ore composition.

Summary of key points:

Element type Representative element Impact mechanism Countermeasures

Beneficial Cu, Pb Catalysis/enrichment Control concentration

Harmful S, As, C Consumption of reagents/passivation/adsorption Pretreatment/oxidation

In actual recycling, targeted plans need to be formulated through ore composition analysis (such as XRF, fire assay).

Key Points Summary