Mineral Processing

Treatment And Utilization Of Gold Mine Tailings

What Are Gold Tailings

To be shortly saying, tailings are ground up rock minus the gold. The placer or rocks mined from underground which contains gold is called ore.

The gold mining process involves crushing the ore into sand and dust to liberate and recover the gold. What’s leftover is called tailings.

Gold Mine tailings
Ballarat Gold Mine uses its robust management and monitoring processes to make sure its produced gold tailings comply with all license conditions and permits necessary for the safe storage of tailings.

Overall, there is approximately 95% of the tailings are generated from gravity separation methods, which are chemical-free and exploit the difference in density between gold and quartz, just as the old-timers did with their pans and sluices.

The remaining tailings are generated via a chemical leaching process that uses small quantities of Cyanide to extract fine gold from sulphide minerals that co-exist in the ore.

In this article, we only talk about how to recycle and reuse the gold tailings in solid-state, like sand, dirt, and dust. Those tailings are mostly produced by gravity separations. For gold tailings generated by chemical leaching processing, these processes are water-based, meaning tailings from the mill are pumped as a slurry to the Tailings Storage Facility (TSF) where they are stored in fully engineered clay lined dams.

Gold mine tailings dust can be easily blown up in the wind and could easily lost in the presence of water. And long-term stacking will not only occupy a lot of land but also cause harm to the nearby environment. So in this article, we would like to propose several simple management methods for the current situation of tailings pollution.

 

The Fact About Gold Tailing Pollution

Because the gold mine tailings are fine in particle size and contain mineral processing agents and metal ions, in the event of strong winds, especially from March to June in the dry season, the tailings will be scraped into yellow sand and dust, and fall into villages, farmlands and orchards, causing It is violated by pollution, and the resulting pollution disputes will directly affect the stability and unity of the society.

There are generally three ways for tailings to pollute the environment: 

one is that the tailings escape some harmful gases during the weathering process and are polluted by the atmosphere; the other is that the extremely fine tailings sand particles are affected by the wind ( It can even form sandstorms), causing serious harm to the nearby environment; third, in the flood season, tailings and rainwater flow into farmland and rivers, causing damage to groundwater.

To sum up, tailings pollution occupies land, damages landscapes, destroys soil, harms organisms, silts rivers, and pollutes the atmosphere.

 

Methods to Control Tailings Pollution

The three most feasible approaches to tailings management and utilization are:

One is to cover the soil to create fields. In areas with sufficient soil, the method of pressing 10-20 cm of soil can be used for planting, covering the soil to create fields, and expanding the area of ​​cultivated land. This method is suitable for valley-shaped tailings ponds. This approach has been affirmed over the years. However, there are also cases of secondary dust hazards due to the thin soil layer being pressed.

The second is to use organic waste to solidify and block the dust of gold mine tailings with degradability, and select appropriate seeds and substrates to make plants germinate and grow quickly to achieve the purpose of vegetation utilization. This method of tailings management has been tested through several years of practice, especially in the selection of degradable solidified waste, substrate, seed selection, and seed germination time. Some experiments have been successful. It overcomes the disadvantages of occupying a lot of soil layers and being inconvenient to manage due to the shape of tailings. At the same time, it also has great potential in desert management.

The third is to use tailings to develop building materials. Certain silica sands, sandstones, or vein quartz from gold mine tailings can be utilized. Bricks are the most common building materials. It is also a good way to use tailings to make bricks. A certain amount of lime is added to make bricks, which are then sent to the carbonization chamber, and carbon dioxide gas is introduced to carbonize them into bricks, which not only increases the pressure of bricks, Reduces land use and destroys land, and the economic benefits are also considerable. The tailings can also manufacture flat glass and various thermal insulation, thermal insulation, and sound insulation materials. In addition, techniques for extracting useful metals from tailings have also been utilized.

 

Our Recommendations on Tailings Management 

Gold production produces a lot of tailings, so there are a few things to keep in mind.

First, the site selection of tailings ponds must be reasonable, which is the basis for the management and utilization of tailings ponds.

Second, the exhausted tailings pond will be immediately overturned and reclaimed. Generally, the thickness of the covering soil should be more than 400-600 mm, and the planting should be used together, so that the tailings are no longer polluted.

The third is to plant plants that can cover the dam surface, such as plants with dense branches and leaves, well-developed rhizomes and easy reproduction, which can protect the soil and stabilize the embankment and achieve a thorough management effect.

The fourth is to formulate a strict management system for gold mine tailings, whoever pollutes will manage it, whoever reclaims it will use it, and rewards and penalties will be honored to ensure the smooth implementation of tailings management.