Many sulfide ores often coexist with talc and other magnesium silicate minerals, talc due to its good flotation affects the separation of sulfide ore flotation, affecting the comprehensive index of sulfide ore dressing, for this type of sulfide ores are often through the inhibition of talc to achieve the separation of the two flotation.
The following is a brief analysis of the characteristics of copper-nickel sulfide ore flotation, and how to solve the problem of talc in the process of copper-nickel sulfide ore flotation, so as to improve the recovery of the metal.
Overview of Copper-nickel ore
http://How to Depress Talc in Flotation of Copper-Nickel Sulfide Ores?
In copper-nickel sulphide ores, nickel-containing minerals mainly include nickel pyrite, acicular nickel sulphide, red nickel ore, and nickel-containing magnetopyrite.
Flotation of nickel minerals requires acidic, neutral or weakly alkaline media. Thecollector is a high-grade yellowing agent, such as butyl or pentyl yellowing agent. Nickel-bearing magnetopyrite is more difficult to float than other nickel minerals, and the best flotation medium is weakly acidic or acidic and very slow. In the alkaline medium caused by lime, all of the above nickel minerals can be depressed, but the degree of depression is different, the most easily depressed is nickel-containing magneto-pyrite, such as PH = 8.2~8.5, needle sulphide nickel ores can still be floated, while nickel-containing magneto-pyrite is depressed.
Copper-nickel ore flotation characteristics
http://How to Depress Talc in Flotation of Copper-Nickel Sulfide Ores?
The main factors to be considered in the selection of flotation scheme for copper-nickel ore are the floatability of minerals; the symbiotic relationship of minerals; the oxidation and sludging of nickel minerals; and the types of veinstone minerals. Selection is described as follows:
1. The flotation properties of copper and nickel minerals. Copper minerals and nickel minerals flotation speed difference is large, copper minerals flotation speed is faster, while nickel minerals slower. Production practice has proved that when copper nickel ore flotation, the first 5 min can float about 90% of the chalcopyrite. Nickel mineral flotation speed is slower, especially nickel-containing magnetite pyrite, often 20-30 min to float.
Difference in flotation speed of copper and nickel minerals, has been used in the practice of copper and nickel priority flotation, priority flotation of copper, copper ‘fast’ flotation. The process is characterised by increasing the speed of the slurry through the flotation machine, the collector with low-grade yellow drug, and the use of ‘starvation’ way of drug delivery. The tailings of copper flotation with copper sulfate activation of nickel minerals, and then use high-level yellow drug, such as d yellow drug and e yellow drug flotation nickel minerals.
2. Existence form of nickel minerals in the ore. Nickel minerals seldom form separate aggregates, mostly dispersed in other sulphide ores, mainly magnetite pyrite and chalcopyrite. Nickel is also often in the form of homogeneous impurities, exist in other sulfide ores, especially with magnetic pyrite, nickel minerals and copper sulfide, iron minerals symbiosis close, so it brings two problems: one is the nickel concentrate nickel content is relatively low, generally contains Ni3% ~ 5%, the lowest limit of 2% ~ 2.5%.
Therefore, if the original ore contains Ni>2%. Can be directly smelted; the second problem is that affects the separation of copper and nickel. Copper and nickel minerals are closely symbiotic, and even grinding to a very fine can not be dissociated alone, only to get a mixed copper and nickel concentrate, after smelting, and then copper and nickel separation. If the nickel-bearing minerals are only closely symbiotic with magnetopyrite, and the relationship with chalcopyrite is relatively simple, it is possible to get a copper concentrate, and the so-called iron-nickel concentrate with lower nickel content.
3. Oxidation and sludging of nickel-bearing minerals. Nickel-bearing minerals such as nickel pyrite and nickel-bearing magnetopyrite are not only easy to oxidise, but also easy to sludge. Therefore, when the sulfide minerals in the ore are not uniformly embedded, the stage grinding and floating process is particularly important. Generally, copper-nickel mixed flotation is carried out under the condition of coarse grinding, resulting in waste tailings. The mixed concentrate is then regraded and ground, followed by selection or copper-nickel separation. Enhanced classification before and after the regrind operation is important.
In order to eliminate the interference of nickel-bearing magnetic pyrite, at the Lake of the Woods concentrator in Canada, the magnetic properties of nickel-bearing magnetic pyrite are exploited, and after coarse grinding (65% – 0.074 mm), a 15% magnetic product is selected by a magnetic separator, and then refined as a nickel concentrate. The non-magnetic portion is reground and subjected to copper-nickel mixed flotation.
The plant used SO2 gas in the non-magnetic part of the copper-nickel mixed flotation in order to improve the floatability of the difficult-to-float nickel sulphide ore. The natural pH of the original pulp is 8.8, and after SO2 gas treatment, the pH value drops to 5.6. After SO2 gas treatment, the floatability of nickel sulphide minerals is improved.
4. The influence of vein minerals. Copper nickel ore often contains some easy to float veins, such as chlorite, sericite, serpentine and talc. They are easy to mud, easy to float. Magnesium-containing sludge into the concentrate, not only reduce the grade, but also affect the smelting. General requirements for nickel concentrate containing magnesium oxide not more than 5 to 9%.
Eliminate easy to float vein sludge method has two kinds: the first is to add a small amount of foaming agent pre-floating. This method is not always effective, especially the use of return water, because the return water contains trapping agent, will increase the loss of copper and nickel in the sludge; The second method is to use inhibitors, such as water glass, dextrin and carboxymethyl cellulose.
Especially in copper-nickel separation is usually to inhibit nickel flotation copper as the principle of flotation, widely used lime, sodium sulfite or its combination of agents as nickel inhibitors in the separation stage. Cyanide-based agents as nickel inhibitors also have a certain application, but with the promotion of the construction of green mines, this type of agent is gradually replaced.
For example, the Copper-nickel ore talc depressant D417 developed by Y&X Company can achieve effective separation through the principle of hydrophilicity between polar groups and mineral surface. The product has been tested in Russia, Kazakhstan, South Africa and Southeast Asia and has been used in the field.
In addition, Y&X company in the flotation of copper-nickel sulphide ore research found that the main problems are as follows:
- Difficult to depress Mg-silicate containing chalcopyrite minerals.
The sludge produced in the process of natural alteration and crushing and milling of chalcopyrite minerals has good natural floatability, and the effect of sludge suppression in flotation will directly affect the quality of the flotation concentrate.
Generally speaking, the requirement for flotation concentrate is MgO content less than 6.8%. - Difficulty in dissociation of copper-nickel mineral monomer.
The embedded relationship between copper and nickel sulphide minerals is close, and nickel pyrite and chalcopyrite are often accompanied by symbiotic relationship. - The copper-nickel intergrowth is more serious.
Due to the similarity of the floatability of copper-nickel sulphide minerals and the presence of congeners in the mixed concentrate, the large amount of lime will often inhibit chalcopyrite.
In addition, in the strong alkaline slurry environment, chalcopyrite surface will form hydrogen bonds to reduce the floatability, often resulting in high copper recovery in nickel concentrates, so the efficient separation of copper and nickel minerals needs further in-depth research.
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