Lead and zinc are key basic raw materials for the development of modern social economy. With the rapid economic growth, the demand for lead and zinc continues to increase, and the efficient recycling of complex and difficult-to-select lead and zinc mineral resources has become increasingly urgent. In this context, new mineral processing agents, especially collectors with strong collection performance and good selectivity, as well as environmentally friendly, low-cost, and efficient inhibitors and activators, are of great significance to the clean and efficient separation and recycling of lead-zinc ores. The following will give you a comprehensive understanding of the types of reagents used in lead-zinc ore flotation.
Lead and zinc flotation collector
xanthate
Such agents include xanthate, xanthate esters, etc.
Sulfur and nitrogen
For example, ethyl sulfide 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 strong collecting power for coarse particles of sulfide ores, and when used for sorting copper-lead-sulfur specific ores, it can achieve better sorting results than xanthate.
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.
Lead and zinc flotation regulator
Adjusters can be divided into inhibitors, activators, media pH adjusters, slime dispersants, coagulants and flocculants according to their role in the flotation process. 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.
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 hydrolyzes in the slurry to generate HCN and CNˉ
KCN＝K⁺+CNˉ CN+H₂O＝HCN⁺+OHˉ
From the above balanced equation, it can be seen that in alkaline pulp, the concentration of CNˉ 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. Cyanide is a highly toxic agent, and research on cyanide-free or cyanide-less inhibitors has been ongoing for many years.
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⁺+SO₄
Zn²⁺+2H₂O=Zn(OH)₂+2H⁺Zn(OH)₂ is an amphoteric compound that dissolves in acid to form a salt
Zn(OH)₂+H₂SO₄=ZnSO₄+2H₂O
In alkaline medium, HZnO₂ˉ and ZnO₂²ˉ 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, CNˉ and Zn²⁺ form colloidal Zn(CN)₂ precipitate.
Post time: Oct-16-2024
