In the copper oxide flotation, direct flotation method usually can not achieve better results. Sulfuration flotation method is the main flotation method for treating copper oxide ore and mixed ore at home and abroad. For malachite, azurite, and red copper. Mine-based copper oxide ore can get better indicators. The method used to treat the mixed ore is the vulcanization-flotation method, and the individual plant uses the separation-flotation method. Under normal circumstances, copper oxide ore mostly has high oxidation rate, large mud content, high combined copper content, uneven grain intercalation, mixed oxygen and sulfur, coarse and fine mixing, coexistence of various minerals, etc. Copper ore contains low copper, which determines the difficulty of copper oxide ore beneficiation.
Copper oxide minerals are generally highly hydrophilic due to their molecular structure. They attract the dipoles of water in the slurry and cause the water dipoles to form aligned hydrated films on the mineral surface. Therefore, the collector is difficult to adsorb to the surface of the mineral, and after the vulcanization treatment, the surface of the oxidized mineral changes radically. The essence of the vulcanization flotation is to vulcanize the ground copper oxide slurry with a vulcanizing agent, and then add the xanthate collector to float. The vulcanizing agents are: sodium sulfide, sodium hydrosulfide, hydrosulfide ammonia, hydrogen sulfide, potassium sulfide, etc., and the most commonly used is sodium sulfide. A copper sulfide film is formed on the surface of the sulfided copper oxide ore to make the surface of the copper oxide mineral have the surface property of the copper sulfide mineral, and then floated by the action of the collector. The collectors used after vulcanization are: ethyl xanthate and high-grade (butyl, isobutyl, pentyl, etc.) xanthate, black medicine and fatty acid, etc., which are more commonly used as advanced xanthate. Therefore, the quality of the vulcanization process plays a key role in this method.
The degree of vulcanization increases with the increase of sodium sulfide concentration and the contact time with minerals; the vulcanization rate of malachite and chrysocolla increases with the decrease of pH value in solution, especially for cyanite. When the temperature is increased from 10 °C to 60 °C, the adsorption amount of sodium malachate to sodium sulfide is increased by 4.5 times, and the amount of chrysocolla is increased by 3 times; since the CuS film formed on the surface of malachite is not stable enough, when the slurry is too strong, If the time is too long, the copper sulfide film will easily fall off into colloidal copper sulfide, and the formation of colloidal copper sulfide is very harmful to flotation. Therefore, the selection of copper oxide ore is suitable for early harvesting and multi-receiving. The production process often carries out stage grinding and stage selection, which can achieve the fineness of grinding required for the selection of fine-grained copper oxide ore. Moreover, the easily floatable copper sulfide and partial copper oxide can be preferentially floated.