Классификация упорных золотосодержащих руд и способы их переработки. Фоменко И. НИЦ Гидрометаллургия

Summary

The presentation discusses the complexities of extracting gold from stubborn ores, which contain only about 20% of the world's gold reserves. It highlights the challenges posed by sulfides, requiring advanced extraction techniques like bio-oxidation and autoclave processing to effectively release gold. Various methods are compared, emphasizing that autoclave processing is superior for breaking down sulfides. The speaker notes that over 90% of gold in some deposits is oxidized, complicating extraction. The discussion underscores the need for thorough testing of mineral properties to select the best processing method, showcasing the ongoing advancements in gold extraction technologies.

Takeaways

• 🌍 Approximately 20% of global gold reserves are found in refractory ores, which pose significant extraction challenges.
• ⚙️ Traditional extraction methods typically recover only about 70% of gold from refractory ores due to the presence of sulfides.
• 🔍 To access gold effectively, breaking down the sulfide matrices is crucial, as gold may be hidden within these structures.
• 🔥 Roasting is an effective technique that fully oxidizes sulfides, making gold available for cyanidation.
• 🦠 Biological and atmospheric oxidation methods are less effective for highly refractory ores compared to roasting and autoclave techniques.
• 🔬 Autoclave oxidation is highlighted as the most efficient method for gold extraction, allowing for near-total recovery rates.
• 🌱 Natural carbonaceous materials can interfere with gold extraction processes, necessitating specialized techniques to mitigate their effects.
• ⚗️ The choice of extraction method should be tailored to the specific mineralogy and characteristics of the ore being processed.
• 🔧 Technological advancements in extraction methods are essential for improving recovery rates from refractory ores.
• 🤔 A one-size-fits-all approach to gold extraction is ineffective; thorough testing and understanding of ore properties are vital for success.

Q & A

What percentage of the world's gold reserves are found in refractory ores?

Approximately 20% of the world's gold reserves are found in refractory ores.

What is the primary challenge in extracting gold from refractory ores?

The primary challenge is that gold is often trapped in sulfide matrices, which makes extraction difficult and typically yields less than 70% recovery using traditional methods.

How do sulfides affect gold extraction?

Sulfides can encapsulate gold particles, preventing effective recovery. Gold can be in the form of solid solutions or microscopic particles within the sulfide matrix.

What extraction methods are commonly used for refractory gold?

Common extraction methods include cyanidation, roasting, bio-oxidation, and autoclave oxidation.

What are the advantages of roasting as a gold extraction method?

Roasting allows for nearly 100% oxidation of sulfides, making all the gold accessible for cyanidation without significant problems.

How effective is bio-oxidation compared to other methods?

Bio-oxidation is less effective in fully breaking down sulfides compared to roasting and autoclave processes, which can limit gold recovery.

What is the significance of the Petropavlovsk deposit in terms of gold oxidation?

At the Petropavlovsk deposit, over 90% of the gold is oxidized, with only a small percentage being metallic and accessible for cyanidation.

What role do natural organic substances play in gold recovery?

Natural organic substances, such as organic carbon, can significantly affect gold recovery, sometimes hindering extraction processes.

What is the recommended approach for extracting gold from different ore deposits?

The recommended approach is to test various extraction methods tailored to the unique characteristics of each ore deposit to achieve optimal recovery.

How does the presence of chloride ions affect gold extraction in autoclave processes?

The presence of chloride ions can lead to the formation of gold complexes that can adsorb onto carbon, potentially resulting in gold losses during extraction.