Is heap leaching ore required to have certain physical properties?

In heap leached ore, the following three physical properties are important:
① Fine grain content;
② Saturated water capacity;
③ Loose density, i.e. bulk density.

The fine-grained content in the ore generally refers to materials less than 74 μm or less than 149 μm, which has a great influence on the permeability of ore heap leaching: the higher the fine-grained content, the lower the permeability. Generally less than 74μm, when the content exceeds 5%, granulation heap leaching is required.

A saturated water capacity for an ore is the percentage of the water content of the ore to the total mass of the ore saturated with water (dry ore weight plus water absorption). It is another important factor affecting the permeability of ore. This value is not only related to the particle size of the ore, but also more closely related to the mineral composition of the ore. Minerals such as kaolin, chlorite and sericite contained in the ore have strong water absorption. When a solution passes between the ore particles, these minerals absorb a large amount of water and expand, so that the original high-strength ore particles are broken, even pulverized and sludged, so that the permeability of the ore is significantly deteriorated.

The loose density of ore, this value is directly related to the relationship between the volume of the ore pile and the quality of the ore. Therefore, it is also a more important parameter in heap leaching.