Micro-fine Refractory Oxide Copper Minerals Flotation Mechanism

The main characteristic of copper ore resources in our country is low-grade, and the majority of the copper ores are copper oxides. Most of them have not been exploited efficiently.As all we know, the basic condition of mineral flotation is the liberation of intergrown constituent of monomers, so the operation of grinding must be intensified. But the floatation of the fine particles is very different from the conventional floatation. The characteristics of fine particles are low-mass, large-specific surface area and high-surface energy. The floatation of fine particles of copper oxide ore is more difficult than the conventional floatation.The floatation experimentation of different dimension particles shows that the particles of copper oxide ores which diameters are -10μm are not easy to be floated. It shows that fine particles are not easy to be processed indeed. So we decide to use the method of vacuum floatation to process fine particles, the particles can float by the micro bubbles which produced by themselves. The result of the test is better. The particles which diameters are +74μm are not easy to be floated, too. It tells us that the liberation of intergrown constituent of monomers is also a key factor for the floatation. The result of the experimentation also shows that the less range of dimensions of the particles, the higher recovery will be obtained.Nowadays, the main method which can be used in the floatation of copper oxides ores is using the sodium sulfide, so the dosage of sodium sulfide and some other correlative conditions influence the result of the floatation.The experimentation of using different dosages of sodium sulfide in the flotation shows that the more sodium sulfide used, the higher recovery can be obtained, just when the concentration of the sodium sulfide is low. When the concentration comes to be some certain high level, the more sodium sulfide used, the lower recovery can be obtained. The sodium sulfide overused restrains the floatation of the copper oxide ores. The right concentration of the sodium sulfide is about 1.0×10^-3 mol/L for the malachite ores and 1500g/t for the Dongchuan tangdan copper oxide ores. The using of the butyl xanthates is important to the floatation of the copper oxide ores ,too. More butyl xanthenes used , higher recovery can be obtained, just when the concentration is low. When the concentration of butyl xanthenes comes to be some certain level, the influence of concentration is weak. The experimentation tells us the activation of the sodium sulfide can carry out when the range of pH level is 6-12 in the pulp. The recovery of the floatation can get to the highest when the range of pH level is 8⁹.5.Using XRD, SEM etc. to observe the change on surface of the malachite ores when the reagent acts. From the pictures of SEM, we can see clearly that overused sodium sulfide changes the configuration of ores surface, and the two extremes of the malachite particles absorb more butyl xanthates than the middle does. The result of the XRD shows that when the concentration of the sodium sulfide comes to 10^-1mol/L, a new substance CU7S4 created.