The core goal of environmentally friendly gold beneficiation agents isSafely and efficiently extract gold from ores without relying on or significantly reducing highly toxic cyanidesThe principle varies depending on the specific type of agent (such as thiourea, thiosulfate, halide, polysulfide, or special organic chelating agent) and application scenario, but the logic is consistent.

The following is a detailed explanation of the working principle for different application scenarios:

Scenario 1: Directly replacing traditional sodium cyanide (applicable to most oxidized ores and some primary ores)

This is the most direct application. As a substitute for sodium cyanide, environmentally friendly chemicals work in the leaching tank, but their mechanism of action is more environmentally friendly.

• Traditional cyanide principleCN ⁻ forms an extremely stable bond with gold ions (Au ⁺)Cyanogen gold complex [Au (CN) ₂⁻]Dissolve the gold.

• Principles of Environmental Protection Agents (Taking Common Systems as Examples)：

• Thiourea methodIn an acidic oxidizing environment, thiourea molecules form stable bonds with gold ionsCationic complex [Au (CS (NH ₂) ₂) ₂⁺]This reaction is fast, more effective for certain impurity containing ores, and has extremely low toxicity.

• Thiosulfate methodIn an ammonia solution, thiosulfate ions form stable complexes with gold ionsAnionic complex [Au (S ₂ O ∝) ₂³ ⁻]Its biggest advantage is its high tolerance for impurities such as copper and other base metals, and it is non-toxic and harmless.

• core differenceAlthough the stability of complexes formed by environmentally friendly agents may be slightly inferior to cyanide gold complexes, theirExtremely low environmental toxicity, faster kinetic speed(In some cases), andBetter selectivityThis constitutes its core advantage. The entire leaching adsorption process (carbon slurry CIP or carbon leaching CIL) is similar to traditional methods, except that the chemical environment (pH value, oxidant) needs to be adjusted.

Scenario 2: Environmental Protection Renovation and Upgrade of Existing Cyanide Plants

This scenario aims to utilize the existing equipment foundation to reduce environmental risks and improve efficiency by adding or replacing some chemicals.

• Principle of synergy：

1. Reduce toxicity and increase efficiencyAdd specific environmentally friendly catalysts or auxiliary leaching agents in proportion to the cyanide system. These additives themselves are low toxic, but they canSignificantly accelerate the cyanide leaching reaction for goldThusReduce the total amount and residue of cyanide。

2. Release package goldFor gold encapsulated in sulfides (such as pyrite) with fine particles, environmentally friendly additives can preferentially react with the surface of sulfides to make themPassivation or slight dissolutionExpose the encapsulated gold particles, allowing subsequent cyanide or main leaching agents to come into contact with the gold, thereby improving the recovery rate. This achieves' partial substitution, overall optimization '.

Scenario 3: Dealing with "Difficult to Handle" Gold Mines (Core Advantage Scenario)

This is the field where environmentally friendly chemicals shine, especially for ores that are almost ineffective with traditional cyanide methods.

• The principle of "robbing gold" (for "robbing gold" carbonaceous gold mines)：

• problemThere is "gold robbing" active organic carbon in the ore, which can adsorb dissolved gold cyanide complexes like activated carbon, resulting in the inability to recover gold.

• Solution: UsePassivation type environmental protection agentThese medicines canPrioritize adsorption or reaction with activated carbon dots to 'seal' themMake it lose its ability to adsorb gold. Subsequently, whether using cyanide or other environmentally friendly leaching agents, gold can dissolve smoothly and be adsorbed by recovered carbon.

• Principle of "package" release (for stubborn sulfide ore wrapped in gold)：

• problemGold is encapsulated in minerals such as pyrite and arsenopyrite in an ultra microscopic form, which cannot be exposed by physical grinding.

• Solution: Use withMild oxidation and selective dissolution abilityEnvironmentally friendly chemicals (such as polysulfide systems or special oxidizing agents). They canSlow etching of sulfide mineral latticeOpen the package channel like a minimally invasive surgery to release gold while avoiding the production of large amounts of acidic wastewater or toxic gases such as sulfur dioxide and arsine.

• Principle of interference elimination (for complex minerals such as high copper, high arsenic, and high antimony)：

• problemThese harmful elements will consume a large amount of cyanide and oxygen, produce interfering ions, and seriously hinder the leaching of gold.

• Solution: Usehighly selectiveEnvironmentally friendly chemicals. For example, the thiosulfate system is not sensitive to the interference of copper. Some organic chelating agents are specifically designed toThe ability to form complexes with gold ions is much stronger than the binding ability with copper and iron ionsThus, gold can be accurately extracted from the "impurities" surrounding it, greatly reducing the consumption of reagents and the difficulty of subsequent processing.

Scenario 4: Recovery of Gold from Tailings and Electronic Waste

This scenario emphasizes safe operation in low-grade and complex materials.

• Principle of gentle and efficient extraction：

• The gold in tailings and electronic waste may have partially oxidized or taken on special forms, and contain various unknown impurities.

• Environmental protection agents due to theirLow toxicity and low corrosivenessIt can be operated under milder conditions (such as near neutral pH, room temperature), making the operation safer.

• itsGood permeability and affinity for specific forms of gold (such as flake gold attached to the surface)So that it can effectively leach residual gold from these "waste materials", achieve safe mining of "urban mines", and avoid secondary pollution.

Summary: Common working principle logic of environmentally friendly mineral selection agents

1. Selective complexationUsing the electronic layer properties of gold ions (Au ⁺/Au ³ ⁺), design specific organic or inorganic ligands to formStable and soluble complex compoundsTransport it from solid ore to liquid phase.

2. Create dynamic advantagesBy optimizing the molecular structure, a faster reaction rate can be achieved than cyanide, or equivalent efficiency can be achieved under less stringent chemical conditions (strong base).

3. Avoid or passivate interfering substancesUsing chemical design to create pharmaceuticals'Invisible' or 'Priority Processing' 矿石中的有害杂质，从而在复杂环境中保持对金的高效提取。

4. Environmentally friendly designThe molecular structure of the drugs and their reaction products used is prone to oxidation, hydrolysis, or biological action in the natural environmentDegradation into harmless substancesFundamentally eliminating persistent toxic pollution like cyanide.

In short, the principle of environmentally friendly gold beneficiation agents is to use more sophisticated and intelligent "molecular keys" to safely unlock the "lock" of gold elements in ores, while avoiding damaging the "big lock" of the environment. 它是化学、矿物学和环境科学交叉创新的成果。