What types of adsorption are the flotation agents on the surface of the mineral?
Many flotation agents are adsorbed on the surface of the mineral. But different flotation reagents are different for different minerals. The adsorption way of flotation reagent on mineral surface is uncertain. Today, flotation reagent manufacturers will briefly introduce several common ways of adsorption.
(1) molecular adsorption, that is, an agent is adsorbed on the surface of a mineral in the form of molecules. Such as the adsorption of neutral oil on non-polar minerals (graphite, molybdenite and so on), adsorption of xanthate on the surface of sulfide minerals, adsorption of some foaming agents (such as pine alcohol oil, fatty alcohol, etc.) at the interface of gas and liquid.
(2) ion adsorption, that is, the agent is adsorbed on the surface of minerals in the form of ions. As the adsorption of xanthate on the galena surface, a carboxylic acid collectors in adsorption of fluorite, scheelite surface.
(3) ion exchange adsorption means that some ions on the surface of the mineral are charged on the surface of minerals. For example, when an activated sphalerite is used to adsorb on the surface of the sphalerite from the solution, the surface of the sphalerite is dissolved into the solution.
(4) the adsorption of electricity by electrostatic force. For example, the adsorption of twelve alkyl sulfate on the surface of goethite and the adsorption of twelve amine on the surface of quartz.
(5) semi micellar adsorption. When the mass fraction of long hydrocarbon chain is high, when the mass fraction in the solution is high, if their molecules or ions are adsorbed on the mineral surface, under the action of van Edward force, the non-polar basis will be associated with each other. This adsorption is called half micelle adsorption. For example, when the mass fraction of the twelve amine is high, a semi micellar adsorption can be formed on the surface of the quartz.
In some cases, the formation of semi micellar adsorption is beneficial to flotation. The hydrophobicity produced by the collector in the formation of a semi micelle on the surface of the mineral is stronger than that produced by a single collector ion or molecule. However, if we increase the mass fraction of collectors, it will be possible to form multilayer adsorbents on the surface of minerals, which will decrease the surface hydrophobicity and reduce the recovery rate.
(6) characteristic adsorption. The surface of a mineral has a special affinity to a certain component in the solution and thus produces adsorption. The adsorption can not be affected by the electrical properties of the surface of the mineral, and the charged ions can also be adsorbed on the surface of the mineral with the same symbol charge by the properties.
The absorption of this characteristic can create conditions for the adsorption of certain minerals on some mineral surfaces. For example, at pH=6, as the corundum surface is positively charged (the zero point of the corundum is pH=9.1), the cationic collector can not be used to collect the corundum. However, after the adsorption of SO4 on the surface of corundum, the surface can be changed from positive to negative, and can be collected by cationic collector amines.