Technical requirements for cyanide tailings backfilling

The gold cyanidation method will produce a large amount of cyanide tailings during the gold production process. This has become one of the major issues in the gold industry. After harmless treatment, the cyanide tailings are filled into the underground goaf using paste filling technology, which provides a new idea for the treatment of cyanide tailings.

If the cyanide tailings produced by the mineral processing plant are backfilled underground through mineral processing technology, a large amount of water will need to be added to make the pulp. After pulping, the concentration of the slurry is low. After backfilling the ground, the heavy metal ions in the slurry may contaminate the groundwater. If the cyanide tailings produced by the mineral processing plant are full of paste, due to the high concentration of the paste and the low leakage rate, the heavy metal ions in the cyanide tailings will not diffuse with the sewage, thus avoiding the pollution of groundwater resources. . Therefore, when cyanide tailings are used to backfill underground goafs, paste filling technology should be preferred.

The slurry filling operation of underground mining plants is mainly to prepare one or more types of mining solid waste and water into a paste-like slurry with certain stability, fluidity and plasticity. Under the action of external force (pump pressure) or gravity, the shape of the structural flow is transported to the underground goaf through pipelines to achieve the purpose of filling.

Cyanide gold tailings should be decyanized before backfilling. The technical requirements are as follows:

1. Cyanide tailings slurry should first be decyanized through solid-liquid separation and precipitation.

2. The filter residue after solid-liquid separation and washing should be deeply decyanized using ozone oxidation, hydrogen peroxide oxidation and other methods that are less likely to cause secondary pollution.

3. It is not suitable for decyanization in cyanide tailings.

Non-hazardous cyanide tailings are a relatively stable, inert material that can be used as the primary aggregate for fill slurries in underground gold mines.