| In this paper,eight kinds of new regulators were designed and synthesized based on the crystal structure of aluminosilicate as well as the designing theory of flotation reagents.By means of micro-flotation tests of pure minerals,the inhibition behavior of eight kinds of regulators has been compared,and three agents,that were ZMD-1,ZMD-4,ZMD-6,exhibited better properties and were used to explore the mechanism.Micro-flotation experiments and zeta potential measurements were conducted to explore the effect of these three regulators on the flotation performance of pyrophyllite,and the mechanism of these phenomena was investigated.Besides,flotation tests of bauxite that was real ore from Xiaoguan in Henan province and Kelan in Shanxi province were explored to validate the above results.The main contents were briefly summarized as below.(1)The results of mineralogical study showed that the purity of the pure mineral pyrophyllite used can satisfy the test requirements.Two kinds of real ore showed fine disseminated extent and contained aluminum ore which was mainly present as diaspora.Pyrophyllite and kaolinite was major gangue mineral containing silicon.(2)The results of micro-floation tests showed that ZMD-1,ZMD-4,and ZMD-6 exhibited effective inhibition for bauxite during these eight kinds of compound phosphate agents.And the inhibition of the regulators descended in order of ZMD-4>ZMD-1>ZMD-6.(3)The results of zeta potential measurements indicated that zeta potential of pyrophyllite in test pH range were negative.After adding sodium oleate,zeta potential of pyrophyllite slightly moved negatively in a certain pH range.However,zeta potential of pyrophyllite moved to negative significantly when agent ZMD-1,ZMD-4,and ZMD-6 were introduced respectively.(4)When pure mineral tests and zeta potential analysis were combined,it was found that oleic acid made the potential on the surface of the pure mineral pyrophyllite reduced.The regulators ZMD-1,ZMD-4,and ZMD-6 can make the zeta potential of pyrophyllite obviously move negatively.Thus,it could be inferred that the above regulators were competed with oleic acid when adsorbed on surface of the mineral.(5)The actual mineral tests showed the following results.For the bauxite ore with A/S=4.99 from Xiaoguan,the float behavior of sodium hexametaphosphate and ZMD regulators was compared with sodium oleate as collector and the test proceess of " selective grinding-positive flotation".ZMD regulators showed more effective float behavior than sodium hexametaphosphate.And ZMD-1 was the most excellent regulator with the A/S of 9.74 and recovery rate of 74.96%for Al2O3,which was much more improved than sodium hexametaphosphate with the A/S of 8.33and recovery rate of 59.03%for Al2O3.For the bauxite ores with A/S=4.14,sodium oleate collector was used for positive flotation,ZMD-1 was used as inhibition agent,and the test process of "selective grinding-positive flotation" was carried out.After one roughing and two scavengings,the obtained A/S of final concentrate was 7.68 and recovery rate for Al2O3 was 33.39%.The float behavior of ZMD-1 was comparable with that of the inhibition agent of sodium hexametaphosphate,but ZMD-1 showed high economic value.Therefore,ZMD reagents were effective regulators for bauxite positive flotation.(6)In the actual mineral experiments,the Al-O bonds on the surface of diaspore were much more than pyrophyllite.The surface activity on the surface of diaspore and pyrophyllite was obviously different with the addition of oleic acid.And ZMD regulators could enlarge the difference,which benefited the flotation separation between diaspore and pyrophyllite. |
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