Analysis of Gold Ore Slime Cyanide Process

Gold ore slime refers to the fine-grained residue or residue produced by gold ore after crushing and grinding. The cyanide process is the most commonly used method for gold extraction, but the high-grade slime is usually difficult to cyanide, resulting in a low gold recovery rate. In this context, this article will analyze the reasons why gold ore slime is difficult to cyanide and the corresponding improvement measures.

Reasons for the difficulty in cyaniding gold ore slime

1.1 High slime content

Gold ore slime has a high slime content, which causes difficulties in the cyanide process. The slime content of gold ore is generally 15%-20%, and some are even higher, which makes the surface of gold particles covered with a layer of fine-grained mud, making the gold particles difficult to dissolve.

1.2 Gold particle size

The gold particle size in gold ore slime is generally finer, and the content of fine-grained gold is higher. Fine-grained gold is difficult to dissolve in cyanide solution, which affects the gold recovery rate.

1.3 Mineral composition

The mineral composition of gold ore slime is complex, and the presence of minerals such as iron oxide, sulfide, and carbonaceous matter will affect the gold recovery rate. For example, iron oxide minerals consume a large amount of cyanide, and carbonaceous matter will adsorb gold in the solution, making it difficult to dissolve.

Improvement measures

2.1 Gravity separation

Gravity separation is an effective method for separating fine-grained gold in gold ore slime. By using a centrifugal concentrator, a shaker table, or a spiral chute, the gold particles can be effectively enriched and separated from the slime. After gravity separation, the gold particles are larger and the cyanide dissolution is more complete, which can improve the gold recovery rate.

2.2 Flotation

Flotation is another effective method for separating fine-grained gold. By adding appropriate flotation reagents, the gold particles can be selectively floated to achieve the purpose of separation. In addition, flotation can also remove impurities such as iron oxide and sulfide, which is beneficial to the subsequent cyanide process.

2.3 Magnetic separation

Magnetic separation is an effective method for removing iron oxide minerals in gold ore slime. By using a magnetic separator, the iron oxide minerals can be effectively removed, reducing the consumption of cyanide and improving the gold recovery rate.

2.4 Roasting

Roasting is a method of removing carbonaceous matter in gold ore slime. By heating the slime to a certain temperature, the carbonaceous matter can be decomposed and removed, which is beneficial to the subsequent cyanide process.

In summary, the cyanide process is still the most widely used method for gold extraction. However, the gold recovery rate of gold ore slime is low due to the complex composition and fine particle size. Gravity separation, flotation, magnetic separation, and roasting are effective methods for improving the gold recovery rate of gold ore slime.