1. Lead and zinc flotation collector
Commonly used collectors for lead-zinc ores include:
1. Xanthate. This type of agent includes xanthate, xanthate ester, etc.
2. Sulfur nitrogen, such as ethyl sulfur nitrogen, has stronger collection ability than xanthate. It has strong collection ability for galena and chalcopyrite, but weak ability to collect pyrite, good selectivity, fast flotation speed, and fewer uses than xanthate. It has a strong collection ratio for the coarse particles of sulfide ore. When it is used for sorting copper-lead-sulfur specific ores, it can obtain better sorting effects than xanthate.
3．Black medicine
Black powder is an effective collector of sulfide ores, and its collection ability is weaker than that of xanthate. The solubility product of dihydrocarbyl dithiophosphate of the same metal ion is larger than that of xanthate of the corresponding ion. Black medicine has foaming properties.
Commonly used black powders in industry include: No. 25 black powder, butylammonium black powder, amine black powder, and naphthenic black powder. Among them, butylammonium black powder (dibutyl ammonium dithiophosphate) is a white powder, easily soluble in water, turns black after deliquescing, and has certain foaming properties. It is suitable for the flotation of sulfide ores such as copper, lead, zinc, and nickel. . In weakly alkaline slurry, the collection ability of pyrite and pyrrhotite is weak, but the collection ability of galena is strong.
2. Lead and zinc flotation regulator
According to their role in the flotation process, adjusters can be divided into: inhibitors, activators, medium pH adjusters, slime dispersants, coagulants and re-coagulants.
Adjusters include various inorganic compounds (such as salts, bases and acids) and organic compounds. The same agent often plays different roles under different flotation conditions.
Inhibitors:
1. Lime lime (CaO) has strong water absorption and reacts with water to form hydrated lime Ca(OH)2. It is difficult to dissolve in water and is a strong alkali. The reaction when added to the flotation slurry is as follows:
CaO+H2O=Ca(OH)2
Ca(OH)2=CaOH++OH-
CaOH+=Ca2++0H-
Lime is often used to increase the pH value of the slurry and inhibit iron sulfide minerals. In copper sulfide, lead, and zinc ores, they are often accompanied by iron sulfide ores (pyrite, pyrrhotite, marcasite, and pyroarsenite (such as arsenopyrite)). In order to better flotate copper, lead, and zinc Minerals, lime is often added to inhibit iron sulfide minerals.
2. Cyanide (NaCN, KCN)
Cyanide is an effective inhibitor during lead and zinc sorting. Cyanide is mainly sodium cyanide and potassium cyanide, and calcium cyanide is also used.
Cyanide is a salt generated by strong base and weak acid. It is hydrolyzed in the slurry to generate HCN and CN-
KCN＝K++CN-
CN+H2O＝HCN++OH-
It can be seen from the above balanced equation that in alkaline slurry, the concentration of CN- increases, which is beneficial to inhibition. If the pH is lowered, HCN (hydrocyanic acid) is formed and the inhibitory effect is reduced. Therefore, when using cyanide, the alkaline nature of the slurry must be maintained.
3．zinc sulfate
The pure product of zinc sulfate is white crystal, easily soluble in water, and is an inhibitor of sphalerite. It usually has inhibitory effect only in alkaline slurry. The higher the pH of the slurry, the more obvious its inhibitory effect. Zinc sulfate produces the following reaction in water:
ZnSO4＝Zn2++SO42-
Zn2++2H20=Zn(OH)2+2H+
Zn(OH)2 is an amphoteric compound that dissolves in acid to form a salt.
Zn(OH)2+H2S04＝ZnSO4+2H2O
In alkaline medium, HZnO2- and ZnO22- are obtained. Their adsorption to minerals enhances the hydrophilicity of mineral surfaces.
Zn(OH)2+NaOH=NaHZnO2+H2O
Zn(OH)2+2NaOH=Na2ZnO2+2H2O
When zinc sulfate is used alone, the inhibitory effect is poor. It is usually used in combination with cyanide, sodium sulfide, sulfite or thiosulfate, sodium carbonate, etc.
The combined use of zinc sulfate and cyanide can enhance the inhibitory effect on sphalerite. The commonly used ratio is: cyanide: zinc sulfate = 1:2-5. At this time, CN- and Zn2+ form colloidal Zn(CN)2 precipitate.
Post time: May-30-2024
