Copper sulfate, with the appearance of blue or blue-green crystals, is a widely used activator in sulfide ore flotation. It is mainly used as an activator, regulator and inhibitor to adjust the pH value of the slurry, control foam generation and increase the surface potential of the mineral. It has an activating effect on sphalerite, stibnite, pyrite and pyrrhotite, especially sphalerite inhibited by lime or cyanide.
The role of copper sulfate in mineral flotation:
1. Used as an activator
It can change the electrical properties of the mineral surface and make the mineral surface hydrophilic. This hydrophilicity can increase the contact area between the mineral and water, making the mineral easier to float. Copper sulfate can also form cations in the slurry, which are further adsorbed on the mineral surface, increasing its hydrophilicity and buoyancy.
The activation mechanism includes the following two aspects:
①. Double decomposition reaction occurs on the surface of the activated mineral to form an activation film. For example, sphalerite is activated with copper sulfate. The radius of the divalent copper ion is similar to that of the zinc ion, and the solubility of copper sulfide is much smaller than that of zinc sulfide. Therefore, a copper sulfide film can be formed on the surface of sphalerite. After the copper sulfide film is formed, it is easy to react with xanthate collectors, so that the sphalerite is activated.
②. Remove the inhibitor first and then generate the activation film. When sodium cyanide inhibits sphalerite, a stable zinc cyanide complex ion is formed on the surface of sphalerite, and the copper cyanide complex ion is more stable than the zinc cyanide complex ion. If copper sulfate is added to the sphalerite slurry inhibited by cyanide, the cyanide on the surface of the sphalerite will fall off, and the free copper ions will react with the sphalerite to form an activation film of copper sulfide, thereby activating the sphalerite.
2. Used as a regulator
It can adjust the pH value of the slurry. At an appropriate pH value, copper sulfate can react with hydrogen ions on the surface of the mineral to form chemical substances that bind to the mineral surface, increase the hydrophilicity and buoyancy of the mineral, and thus promote the flotation effect of gold ore.
3. Used as a depressant
It can form anions in the slurry and adsorb on the surface of other minerals that do not need to be floated, reduce their hydrophilicity and buoyancy, and thus prevent these minerals from being floated together with gold minerals. Copper sulfate depressants are usually added to the slurry to keep the minerals that do not need to be floated at the bottom.
4. Used as a mineral surface modifier
Change the chemical and physical properties of the mineral surface. In gold ore flotation, the electrical properties and hydrophilicity of the mineral surface are key flotation factors. Copper sulfate can form copper oxide ions in the slurry, react with metal ions on the surface of the mineral, and change its surface chemical properties. Copper sulfate can also change the hydrophilicity of the mineral surface and increase the contact area between the mineral and water, thereby promoting the flotation effect of gold ore.
Post time: Mar-17-2025