With the development of the national economy, mineral resources have received more and more attention, and mining has been increasing. Mineral processing is facing a situation of poor, fine and miscellaneous raw materials. Complex and difficult copper ore ore is one of them. Due to the high pyrite content is difficult to suppress, and secondary copper ore mainly copper-based, easily oxidized, there is more copper ions into the slurry after oxidation, activates pyrite, copper sulfur separation more difficult. According to the characteristics of the ore, the ore dressing process research was carried out, and the copper partial priority and mixed concentrate re-grinding process were adopted. The rational chemical system was adopted to realize the separation of copper and sulfur, and a good sorting index was obtained.
First, the nature of the ore
The sample was taken from a copper core ore combination sample taken from a copper mine in southern China. The ore body is a medium-fine grain granite , fine-grained granite or cryptoexplosive breccia type ore. Gangue minerals as quartz, mica and the like; metal minerals include pyrite, followed chalcocite, blue chalcocite, bornite, covellite and a small amount, into a useful set of associated gold. The main metal minerals and non-metallic minerals are granular, vein-like, disseminated, reticular, massive, crumb-like, gelatinous and other structures. The ore chemical composition, phase composition and particle size distribution are shown in Tables 1-3.
Table 1 Multi-element analysis results of ore /%
ingredient | Au | Cu | Pb | Zn | Ag | As | S | SiO 2 | Al 2 O 3 | CaO | MgO | Fe 2 O 3 |
content | 0.17g/t | 1.16 | 0.02 | 0.01 | 4.76g/t | 0.05 | 8.36 | 63.05 | 11.17 | 0.03 | <0.01 | 5.02 |
name | Primary copper sulfide | Secondary copper sulfide | Copper oxide | Total steel |
content | 0.12 | 0.70 | 0.32 | 1.15 |
Occupancy rate | 10.43 | 60.87 | 28.70 | 100.0 |
Table 3 Raw ore screening results /%
Size/μm | Yield | Grade copper grade | Copper metal distribution | ||
Granular grade | Grand total | Granular grade | Grand total | ||
+450 | 14.24 | 14.24 | 0.95 | 11.66 | 11.66 |
-450+280 | 18.51 | 32.75 | 0.97 | 15.48 | 27.14 |
-280+150 | 20.45 | 53.20 | 1.32 | 23.27 | 50.41 |
-150+74 | 13.84 | 67.04 | 1.55 | 18.49 | 68.90 |
-74+45 | 13.34 | 81.38 | 1.30 | 16.07 | 84.97 |
-45 | 18.62 | 100.0 | 0.93 | 15.03 | 100.0 |
total | 100.0 | 1.16 | 100.0 | ||
Second, the determination of the beneficiation process
The main purpose of this test is to select copper, comprehensively recover sulfur, and associated gold is recovered with copper concentrate. The reason why the ore is difficult to choose is that the oxidation rate of copper is high; the secondary copper is dominant, the mineral solubility changes greatly; the copper mineral is not thick. Uniformly embedded; copper ions activate pyrite minerals , which are difficult to separate. Based on the above reasons, the process of copper partial priority and mixed-concentration re-grinding and sorting process is proposed, which is to preferentially float some of the easy-to-float monomer copper minerals, and to mix floating copper minerals with pyrite. The concentrate is reground to separate the copper and sulfur and then sorted.
Third, the test results and discussion
The sample was crushed in two stages in the laboratory. After the sieve size was controlled to -0.6mm, the sample was mixed and bagged. The unit sample weighed 500g. The test was carried out using the XMB-70 three-roll four-cylinder ball mill. The XFD series was suspended. Selective flotation, all of the flotation reagents use industrial grade reagents.
(1) Copper partial priority flotation test
In order to obtain a higher quality copper concentrate in the copper portion preferential flotation, a rough grinding fineness test and a rough selection collector type and amount test were carried out. The results of the grinding fineness test are shown in Figure 1. The test results of the types and dosages of the collector are shown in Table 4. The test flow is shown in Figure 2. Considering the grade and recovery rate of copper, the grinding fineness is selected to be -74μm, accounting for 60%. It can be seen from the test results in Table 4 that Zj-02 has strong selectivity to copper and precious metals and weaker capture of sulfur; and PAC/butyl xanthate, ethylthiocarbamate/butylammonium black drug combination agent for copper The ability to capture is strong, but at the same time, some of the sulfur is floating at this stage, which is not conducive to the improvement of copper concentrate grade and comprehensive recovery of sulfur. After comprehensive consideration, Zj-02 was selected as the collector, and its dosage was 10g/t.
Figure 1 Grinding fineness test results
Figure 2 Test procedure for collector type and dosage
Table 4 Types and dosages of collectors Test conditions and results /%Collector type and dosage / (g·t -1 ) | product name | Yield | Copper grade | Copper recovery |
Zj-02/10 butyl xanthate/10 pine oil 10 | Copper concentrate | 7.57 | 12.24 | 74.72 |
Tailings | 92.43 | 0.34 | 25.28 | |
Raw ore | 100.0 | 1.24 | 100.0 | |
PAC/10 butyl xanthate/10 pine oil 10 | Copper concentrate | 6.76 | 11.70 | 64.30 |
Tailings | 93.24 | 0.48 | 35.70 | |
Raw ore | 100.0 | 1.23 | 100.0 | |
Ethylsulfide/40 butyl xanthate/10 pine oil 20 | Copper concentrate | 8.04 | 11.16 | 72.95 |
Tailings | 91.96 | 0.36 | 27.05 | |
Raw ore | 100.0 | 1.23 | 100.0 | |
Zj-02 10 Pine Oil 10 | Copper concentrate | 7.94 | 11.22 | 74.24 |
Tailings | 92.06 | 0.34 | 25.76 | |
Raw ore | 100.0 | 1.20 | 100.0 |
(2) Copper-sulfur mixed re-grinding separation test
The copper-sulfur mixed float was treated with butyl xanthate as a collector. It was determined by experiments that when the amount of butyl yellow was 60g/t, the copper-sulfur mixed concentrate contained 7.71% copper and the copper recovery rate was 53.84%. Up to 59.51%. The copper-sulfur separation was tested by regrind fineness test and copper-sulfur separation CaO dosage. The purpose of re-grinding of copper-sulfur mixed coarse concentrate is to increase the monomer dissociation degree of the mineral and to create a new dissociation surface on the surface of the coarse concentrate to facilitate the separation of sulfur from copper minerals and the full inhibition of pyrite by CaO. Improve the separation effect of copper and sulfur. The separation effect of copper-sulfur separation rough re-grinding on copper-sulfur mixed coarse concentrate is shown in Fig. 3. When the re-grinding degree of copper-sulfur mixed coarse concentrate is -74μm, 95%, the separation effect of copper and sulfur is better, and The reduction in copper recovery is not significant. Lime is cheap and has a wide range of sources. It is the most widely used copper and sulfur separation method. The effect of the amount of CaO used in the separation of copper and sulfur on the separation index of copper and sulfur is shown in Fig. 4. It can be seen from the results of Fig. 4 that the amount of CaO used for the separation of copper and sulfur is preferably 2000 g/t.
Fig. 3 Effect of grinding fineness on separation index of copper and sulfur
Figure 4 Effect of lime dosage on separation index of copper ore
(3) Small closed circuit process test results
The laboratory closed-circuit test was carried out on the basis of the comprehensive condition open circuit test. The test procedure and the drug system are shown in Figure 5. The closed circuit test results are shown in Table 5. The results show that copper concentrate contains 19.30% copper and 2.52 g/t copper in the ore containing 1.16% copper and 0.17 g/t gold. The recovery rates of copper and gold are 88.51. %, 78.71%; sulfur concentrate contains 32.16% sulfur, sulfur recovery rate is 39.40%, and the selection effect is better. The copper grade and impurity content of copper concentrates meet the requirements of the developer. Copper minerals in closed tailings mainly exist in the form of fine particles and inclusions, and flotation is difficult to recover, which is an important cause of copper loss in tailings.
Table 5 Flotation closed circuit test results /%
product name | Yield | grade | Recovery rate | ||||
Cu | Au/(g·t -1 ) | S | Cu | Au | S | ||
Copper concentrate | 5.32 | 19.30 | 2.52 | 40.40 | 88.51 | 78.71 | 27.66 |
Sulfur concentrate | 9.52 | 0.80 | 0.14 | 32.16 | 6.56 | 7.84 | 39.40 |
Tailings | 85.16 | 0.07 | 0.027 | 3.00 | 4.93 | 13.45 | 32.94 |
Raw ore | 100.0 | 1.16 | 0.17 | 7.77 | 100.0 | 100.0 | 100.0 |
Figure 5 closed circuit test process
Fourth, the conclusion
(1) The ore has a high oxidation rate of copper, and is mainly composed of secondary copper. The mineral floatation changes greatly, the copper mineral is unevenly embedded in thickness, and the activation of copper ions on pyrite is caused by copper. The main reason for the difficulty in sulfur separation.
(2) Under the condition that the copper part priority process does not add lime, the selective strong Zj-02 collector is used to recover some of the copper minerals with good floatability in time, which improves the copper concentrate grade. And is conducive to the recovery of associated gold.
(3) Small closed-circuit test results obtained copper concentrate containing 19.30% copper, 2.52g/t gold, copper and gold recovery rates of 88.5l% and 78.71%, and sulfur concentrate sulfur concentration of 32.16%, recovery rate 39.40% The sorting effect is better.
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