Study On Flotation Behavior And Flotation Mechanism Of Witherite

Witherite belongs to the rare minerals.Due to unreasonable exploitation,high-grade witherite will be run out,and low-grade witherite cannot be be used directly because of too many gangue minerals.The main problem is that the separation of witherite has been little investigated and that systematic research has not yet seen.The study of thesis fills the domestic blank and provides a way for the rational development of low-grade witherite.The main purpose of the thesis is the basic research on flotation behavior of witherite,which includes that the floatation performance of witherite with different collector is studied and that the inhibition or activation of witherite with different modifying agent is studied.The dissertation takes the witherite from the Daba Mountains as the study object.From the collecting agent,pH,inhibitor,activator,contact angle and solution chemistry,this dissertation has systematically studied the flotation behavior and mechanism of witherite.The collector test showed that sodium oleate and laurylamine collector has good performance of witherite.In the sodium oleate flotation system,experimental results show that there is no inhibitory effect of sodium carbonate,sodium sulfate,calgon,water glass,tannic acid and citric acid have good inhibition effect,barium chloride,calcium chloride,ferric chloride and lead nitrate has good activation effect.In the laurylamine system,experimental results show that there is no inhibitory effect of sodium carbonate,sodium sulfate,calgon,tannic acid and citric acid have good inhibition effect,the inhibition effect of water glass is not obvious,barium chloride,calcium chloride,ferric chloride and lead nitrate have a weak activation effect.Through solution chemical analysis,in the flotation of witherite,Ol^-ions may play a major role in the sodium oleate flotation system.RNH₃⁺and（RNH₃⁺）₂²⁺ions may play a major role in the laurylamine system.In the sodium oleate flotation system,the cationic activation effect on witherite mainly increases the activite particle of witherite surface.Due to the formation of barium sulfate,sodium sulfate shows strong inhibition effect.Because of the large number of anions produced by the hydrolysis of calgon,which can compete with sodium oleate,calgon shows good inhibition effect.Because of the formation of BaL-complex ion,reducing the active particle of witherite surface,citric acid shows a strong inhibitory effect on witherite.In the laurylamine flotation system,laurylamine is adsorbed on the surface of witherite by electrostatic interaction.Sodium sulfate and calgon can be adsorbed on the surface of witherite through chemical reaction of barium ion on the surface of witherite,which increases the hydrophilicity of witherite and results in inhibitory action of witherite.The hydrolysis of water glass builds up Si（OH）₄ molecules with a strong adsorption,enhancing hydrophilic minerals,resulting in the inhibitory effect of witherite;citric acid can inhibit witherite because of the presence of a large number of BaH₂L⁺complex ions,which is not conducive to the adsorption of laurylamine.