Tailings are the material in the concentrator that have a low content of useful components and cannot be used at present. And the tailings disposal is one of the important links in mineral processing.
At present, the tailings disposal methods are generally divided into tailing reprocessing, tailing dehydration and tailing filling goaf. We will explain these three tailings disposal methods separately.
Use the table of contents below to navigate through the guide:
Although the content of useful components in tailings is relatively low, using the advanced and reasonable mineral processing technology to reprocess tailings can also recover the useful components in tailings to a large extent, so as to fully recover and utilize resources, reduce the output of final tailings and relieve the pressure of tailings on the environment. At present, the common tailings reprocessing methods mainly include:
Due to the development of new flotation reagents and froth flotation processes, some tailings produced by the simple mineral processing processes, especially the old tailings, can be recycled to obtain the concentrate products by the froth flotation and method.
After the improvement, many gravity separators can be used in the fine and ultrafine tailings reprocessing, such as vertical centrifugal concentrator, shake table with the compound force field, the centrifugal machine with the compound force field.
This tailings disposal method mainly uses the biochemical action of microorganisms to improve the tailing properties and extracts the harmful metal ions in the tailing by means of microbial leaching or microbial mineralization, so as to avoid the environmental pollution.
There is a large amount of water in the pulp during the separation stage. And the tailings water content is too high, which can easily lead to the tailings dam break. Therefore, tailings thickening and dehydration are important links in the concentrator. The common tailings dehydration methods include:
As a kind of equipment for solid-liquid separation by centrifugal force, the hydrocyclone has the characteristics of small floor area and high bottom flow concentration. This kind of tailings disposal method mainly uses hydrocyclone and thickener to form a series or closed-circuit process for obtaining concentrated products with high concentration.
For the tailings disposal method in gold mines, pressure filtration is widely used. This tailings disposal method has the characteristics of low water content of filter cake and the filtrate can be returned to use, but it is difficult to use alone for large-scale tailings dehydration because of its low single processing capacity.
Tailings dry stacking is a new tailings disposal method, which mainly uses the dehydrating hydrocyclone, high-frequency dewatering screen, high-efficiency deep cone thickener. This tailings disposal method can reduce the water content in tailings to less than 15%, save cost and effectively avoid environmental pollution.
Tailing filling goaf uses the tailing waste to fill back to the mined area after treatment, which can protect the landform, reduce the cost of tailing dam. At present, there are two main methods of tailing filling goaf:
This tailings disposal method mixes the dewatering tailings with cement and flies ash to form the filling aggregate. Then, the filling pulp is sent into the goaf by the pipeline armature, thus filling the goaf.
This tailings disposal method is similar to the non-dewatered and cemented full tailings filling. This difference is that this tailings disposal method uses the high water material as the binding material, rather than the cement.
The above are three tailings disposal methods. In the practice, the selection of tailings disposal methods shall be determined according to the size and investment of the concentrator, etc. It is suggested to consult the mineral processing equipment provider with mine research and design qualification to select the suitable tailings disposal method for the concentrator.