Effect of sodium hexametaphosphate on nickel-containing pyrrhotite

Although sodium hexametaphosphate has strong complexation effect on iron and nickel, it enhances the hydrophilicity of minerals. But its complex is soluble. Butyl xanthate and sodium hexametaphosphate are competitive when they act on the surface of pyrrhotite containing nickel.

In order to eliminate or reduce the harmful effect of sodium hexametaphosphate on the flotation of nickel-containing pyrrhotite during flotation, the competitive ability of butyl xanthate to sodium hexametaphosphate on mineral surface was strengthened. First, the surface of nickel-containing pyrrhotite was activated by copper ion (its activation reaction constant K=1*1018). After the interaction between butyl xanthate and the surface of the mineral activated by copper ion, the addition of hexagonal xagonal was carried out. Sodium polymetaphosphate not only ensures that the activation of copper ions on mineral surface is not weakened, but also increases the competitiveness of butyl xanthate on mineral surface because butyl xanthate is added before sodium hexametaphosphate is added.

At the same time, according to the Lewis hard and soft acid-base rule, the complexation stability of sodium hexametaphosphate on copper (I) may be weaker than that of iron (II). Therefore, the complexation of sodium hexametaphosphate on the surface of nickel-containing pyrrhotite activated by copper ions will be weakened, and the floatability of nickel-containing pyrrhotite may be improved.

Therefore, two different dosing methods (sodium hexametaphosphate added before all other flotation agents and after all other flotation agents) were selected for comparative test. Experiments show that the recovery of nickel-containing pyrrhotite can be significantly improved after adding sodium hexametaphosphate to all other flotation agents in Zhengzhou Yucai Phosphate Chemical Plant.

Under the condition of medium PH=8, using copper sulfate as activator and butyl xanthate as collector, before adding sodium hexametaphosphate to other flotation agents, the planktonic properties of nickel-containing pyrrhotite are inhibited and weakened. The inhibiting mechanism may be that iron and nickel on the surface of sodium hexametaphosphate form hydrophilic complexes, and that sodium hexametaphosphate exists in pulp reacts with sodium hexametaphosphate added in pulp. The complex of copper ions weakens the activation of free copper ions on the surface of minerals.

To sum up, changing the order of dosing, adding sodium hexametaphosphate after other flotation agents is beneficial to the flotation of nickel-containing pyrrhotite.

Yucai Phosphate Chemical Plant specializes in producing: sodium hexametaphosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium hydrogen phosphate, industrial phosphoric acid, trisodium phosphate, aluminum dihydrogen phosphate, solid aluminum dihydrogen phosphate, liquid aluminum dihydrogen phosphate, sodium dihydrogen phosphate and other phosphate series products after more than 30 years of continuous pursuit and development, relying on skilled chemical technology and product development, equipment updating and many universities. Established a good cooperative and sharing relationship, in the chemical industry played a (Yucai phosphate) brand!