Sprinkler Irrigation VS. Drip Irrigation in Heap Leaching, Which One Is Better?

Heap leaching is an important technical method for extracting gold from gold mines. In order to achieve the goal of making gold ore particles fully contact with NaCN or eco-friendly gold leaching reagent, it is very important to use advanced technical methods in beneficiation and smelting.

In addition to looking for new high-efficiency or non-toxic gold leaching reagents (such as CNLITE eco-friendly gold leaching reagent), applying chemical oxidation, pressurized oxidation, bacterial oxidation, and sulfur-containing reagent oxidation method and chlorination method, etc. We should also improve the method of adding reagent, for example: using sprinkler irrigation or drip irrigation to add cyanide or eco-friendly gold leaching reagent through the pipeline.

Which method is better? Sprinkler irrigation or drip irrigation? We will compare sprinkler irrigation and drip irrigation below.

1. The Difference between Sprinkler Irrigation and Drip Irrigation

1) Differences in Environmental Protection

When using the sprinkler irrigation, the cyanide contained in the gold leaching reagent would be sprayed into the air in the form of tiny water beads, which is easy to spread, causing pollution and injury to the environment and human body, and would severely pollute the water environment and the atmosphere.

While using the drip irrigation, the gold leaching reagent drops into the mine pile in the form of water droplets, which is not easy to diffuse. It can greatly reduce the pollution of the cyanide in the reagent to the air and water environment, and can significantly reduce the amount of gold leaching reagent and save costs.

2) Difference in the Amount of Gold Leaching Reagent

When using the sprinkler irrigation, the gold leaching reagent is sprayed on the mine heap, which causes difficulty in the controlling of the amount of gold leaching reagent. Excessive use of cyanide will increase the cost of sewage treatment in the mining area, thereby increasing the cost of environmental treatment and even increasing the production cost.

Modern drip irrigation equipment has clogging prevent and pressure compensation devices. The optimal gold leaching reagent concentration and dripping strength can be used according to the ore composition, grade and crushing degree. And the outflow is uniform.

In addition, the drip irrigation system can accurately control the concentration of the cyanide solution and reduce the amount of sodium cyanide loss in the air. Therefore, using the drip irrigation method can optimize the ratio of gold leaching reagent; significantly reduce the amount of gold leaching reagent, and save costs.

3) Difference in Leaching Efficiency

During the heap leaching, if the traditional sprinkler irrigation method is used, at the beginning, because the spraying strength does not exceed the infiltration capacity of the mineral powder, no water layer would be formed on the surface of the mineral powder. This infiltration is called free infiltration. The infiltration rate of mineral powder is comparable to the intensity of rainfall.

But with the increase of spraying time and intensity, the surface of the mineral powder will soon form a water layer and get hardened. The infiltration process is changed from free infiltration to pressure infiltration, and the efficiency of leaching is also reduced.

However, using the drip irrigation method can make the reagent act directly on the surface of the mineral powder pile, the surface of the mineral powder would not form a water layer, so the infiltration would be fast, the gold leaching reagent can fully contact the mineral powder and wash the surface of the mineral powder. This will greatly facilitate the leach of gold powder.

In addition, drip irrigation can increase the amount of air in the solution, which means increasing the oxygen content participating in chemical reactions and thus increasing the activity of gold leaching. And the temperature control equipment can be easily added to the drip irrigation system to achieve the purpose of increasing the temperature of the heap leaching reaction.

2. Other Advantages of Drip Irrigation

In addition, according to the manufacturer’s summary, drip irrigation method also has the following advantages:

• 1) High performance and high reliability, easy to install;
• 2) Can reduce production costs;
• 3) Eliminate the influence of wind;
• 4) Can run all year round;
• 5) Reduce the damage of solar ultraviolet rays to chemical substances;
• 6) Reduce the loss of gold leaching reagent;
• 7) Save the construction cost of diversion channel and liquid storage pool;
• 8) Automatic dripper cleaning and anti-blocking;
• 9) Reducing the impact on the surrounding environment, operating workers and land.
• 10) Eco-friendly.

3. Conclusion

In conclusion, after many comparisons, the drip irrigation system is easy to operate, has little impact on the environment, high production efficiency, high degree of automation, relatively low production cost and high reliability. It is more advanced and has more advantages. The use of drip irrigation method can improve the efficiency of gold mine heap leaching and reduce costs. Combined with eco-friendly gold leaching reagent, it can make the gold leaching plant more eco-friendly and efficient.