Study on flotation process of a copper-lead-zinc sulfide ore in Liaoning

Liaoning a conventional mine a scale of 120t / d beneficiation plant small, since the major metal ore minerals disseminated fine-grained, close symbiosis, production of lead and zinc concentrates containing copper, zinc lead concentrates severely overweight As a result, the quality of the products is not high and the sales are not smooth. Finally, the low-value products such as copper-lead mixed concentrates have to be sold, which seriously affects the economic benefits of the enterprises. The new process effectively solves the problem of copper-lead separation and the serious excess of the concentrate, and obtains high-quality copper concentrate, lead concentrate and zinc concentrate.

First, the nature of minerals

(1) Multi-element analysis of raw ore

The results of multi-element analysis of raw ore are shown in Table 1.

Table 1 Multi-element analysis results of raw ore %

Element

Cu

Pb

Zn

TFe

S

Au*

Ag*

Content

0.55

1.68

4.15

11.05

10.72

1.0

311

Element

C

As

Sb

CaO

MgO

Al 2 O 3

SiO 2

Content

2.48

0.03

0.13

5.25

6.22

6.35

42.80

* The content of Au and Ag is g/t.

(2) The material composition of the ore

The main metal ore minerals pyrite, sphalerite, galena, chalcopyrite, chalcocite small amount, magnetite, gray silver ore, tetrahedrite silver, silver hoof, occasionally natural silver And resulfur salts. Non-metallic minerals are mainly quartz , feldspar and a small amount of mica .

(3) Embedding characteristics of major metals

Sphalerite is mainly embedded in the cracks of pyrite, and is closely connected with chalcopyrite. It also forms a crystal with galena and gangue. It is mostly semi-self-type - it is granular, and it is disseminated in a fast-like shape, with little pulse-like output. Galena is closely related to silver minerals. It is closely related to pyrite and gangue. It is mainly embedded in the cracks of pyrite. It is also connected with gangue. It is mostly semi-self-type. It is granular and is a group. It is rapidly dip-dyed and has little pulse-like output. Pyrite is mainly semi-self-type - it is granular, with strong fragmentation and fissure development. It is often filled with polymetallic sulphides in the later stage. It is mostly in the form of lumps or clusters in the ore. It is less disseminated and has more continuation with gangue. The second is chalcopyrite, sphalerite, and galena. Silver minerals were found among the pyrite particles (micro-cracks), mainly the hoof silver ore, the silver-silver ore, and the natural silver. The main mineral particle size distribution results are shown in Table 2.

Table 2 % of main mineral particle size distribution results

Size/mm

Pyrite

Sphalerite

Chalcopyrite

Galena

〉0.3

11.1

28.9

40.4

/

0.3-0.1

17.5

14.7

19.2

/

0.1-0.074

23.2

12.2

11.8

18.2

0.074-0.037

25.7

18.6

17.2

35.8

0.037-0.01

17.6

18.4

5.1

40.4

<0.01

4.9

7.2

6.3

5.6

total

100

100

100

100

Second, conditional exploration and program selection

The copper lead in this mine has a low grade, finely immersed granules, and a variety of useful minerals are densely symbiotic. Exploratory experiments with priority float copper indicate that copper mineral recovery is extremely low and that most of the concentrate is lead-zinc minerals. According to this situation, it was decided to adopt the technical route of copper-lead mixed float-copper-lead separation-mixed floating tailings to suppress sulfur and float zinc.

(1) PH value test of copper-lead mixed floating pulp

The pH value of the slurry is an important factor influencing the flotation of copper-lead minerals. The test uses lime to adjust the pH value of the slurry. The test procedure and test conditions are shown in Figure 1. According to the grain size of the copper, lead and zinc minerals in the sample and considering the site conditions, for the rough selection operation, the grinding fineness is determined to be -74μm, accounting for 75%. The test results are shown in Table 3.

Table 3 Ph test results of copper-lead mixed floating pulp

pH

product

Yield

grade

Recovery rate

Cu

Pb

Zn

Cu

Pb

Zn

8

Coarse concentrate

6.86

3.87

17.67

20.54

48.21

72.14

33.95

9.5

Coarse concentrate

6.37

4.53

20.11

18.67

52.26

76.24

28.66

10.5

Coarse concentrate

5.84

5.31

23.14

17.58

56.48

80.43

24.74

11

Coarse concentrate

5.58

6.03

25.04

15.34

61.24

83.15

20.62

11.5

Coarse concentrate

5.42

6.45

26.18

13.85

63.56

84.46

18.09

12

Coarse concentrate

5.03

6.53

26.56

13.24

59.71

79.53

16.04

It can be seen from Table 3 that as the pH value of the slurry increases, the copper and lead grades in the copper-lead mixed coarse concentrate increase simultaneously, and the recovery rate also increases. However, when the pulp pH is 11.5, the zinc grade in the coarse concentrate is limited. The copper recovery rate begins to decline. Therefore, the pH of the suitable flotation slurry is about 11.5.

(1) Effect of inhibitors on copper-lead mixing

Copper-lead-zinc sulfide ore is a complex sulfide ore. It is difficult to separate copper-lead and zinc. In addition to the suitable pH value of the slurry, ZnSO 4 and Na 2 SO 3 are used in combination as inhibitors, copper-lead and lead, and zinc inhibition. To a good effect, it can reduce the zinc content in the copper-lead mixed concentrate. Therefore, the amount of copper-lead mixed-frozen ZnSO 4 +Na 2 SO 3 combination inhibitor was tested at a slurry pH of 11.5. The test results are shown in Table 4.

Table 4 % of copper and lead mixed flotation inhibitors

Inhibitor dosage / (g · t -1 )

product

Yield

grade

Recovery rate

Cu

Pb

Zn

Cu

Pb

Zn

600+600

Coarse concentrate

5.62

5.76

24.29

16.84

59.95

82.73

23.03

Tailings

94.38

0.23

0.30

3.35

40.05

17.27

76.97

Raw ore

100.00

0.54

1.65

4.11

100.00

100.00

100.00

1500+600

Coarse concentrate

5.43

6.45

26.27

13.82

63.68

84.41

18.39

Tailings

94.57

0.21

0.28

3.52

36.32

15.59

81.61

Raw ore

100.00

0.55

1.69

4.08

100.00

100.00

100.00

1500+1000

Coarse concentrate

5.16

6.68

27.06

12.57

60.47

83.11

15.62

Tailings

94.84

0.24

0.29

3.69

39.53

16.89

84.38

Raw ore

100.00

0.57

1.68

4.15

100.00

100.00

100.00

The test results show that when the amount of ZnSO 4 +Na2 2 SO 3 is increased, the inhibition capacity is enhanced, the yield of coarse concentrate is reduced, and the recovery rate of copper and lead is reduced. The comprehensive analysis shows that the amount of ZnSO 4 +Na2 2 SO 3 is controlled at 1,500 g. / t + 600 g / t is more suitable.

(2) Selection of copper-lead mixed-floating collector

Using lime as pulp pH adjuster, fixed slurry Ph between 10.5-11, investigated the combination of ethyl xanthate, butyl xanthate, ethyl sulphide, aniline black drug, and other collectors and ethyl sulphide + aniline black drug The effect of the agent on the copper-lead mixed flotation showed that the above collectors had certain catching effects on copper-lead minerals. However, in terms of harvesting capacity and selectivity, ethyl sulphide + aniline black medicine is more suitable. The combined collector can not only ensure the recovery rate of copper and lead, but also greatly reduce the zinc content in the coarse concentrate. Therefore, the ethyl sulphide + aniline black drug was chosen as the collector for the copper-lead floatation.

(3) The amount of copper-lead mixed-floating collector

(ZnSO 4 + Na 2 SO 3 ) was used as an inhibitor of zinc mineral. The pH value of the pulp was about 11.5, and the dosage of the collector (ethylsulfide nitrogen + aniline black drug) was changed. The test results are shown in Table 5. It can be seen from Table 5 that when the amount of collector is controlled at 40g/t, the yield of coarse concentrate decreases, the grade of copper and lead increases, the recovery rate increases, and the zinc content decreases with the decrease of ethyl sulfide and the increase of aniline. Comprehensive analysis showed that the dosage of the drug was 15 g/t of ethyl sulphide nitrogen and 30 g/t of aniline black drug.

Table 5 Test results of copper and lead mixed flotation collector

Collector dosage / (g·t -1 )

product

Yield

grade

Recovery rate

Cu

Pb

Zn

Cu

Pb

Zn

Ethyl sulfide 30

Aniline 15

Coarse concentrate

6.62

4.37

20.57

18.04

53.57

82.53

29.05

Tailings

93.38

0.27

0.31

3.12

46.43

17.47

70.95

Raw ore

100.00

0.54

1.65

4.11

100.00

100.00

100.00

Ethyl sulfide 20

Aniline 20

Coarse concentrate

6.15

5.06

22.56

15.46

55.56

82.01

23.19

Tailings

93.85

0.27

0.32

3.36

44.44

17.99

76.81

Raw ore

100.00

0.56

1.69

4.10

100.00

100.00

100.00

Ethyl sulfide 15

Aniline 30

Coarse concentrate

5.43

6.45

26.27

13.82

63.68

84.41

18.39

Tailings

94.57

0.21

0.28

3.52

36.32

15.59

81.61

Raw ore

100.00

0.55

1.69

4.08

100.00

100.00

100.00

2.4 Copper and lead separation test

Traditional copper

The method of separation is the main lead weight chromium with cyanide or potassium suppressing floating lead and copper, these methods result in a small amount of dissolved noble metal and cause environmental pollution, so this test uses a combination of sodium silicate, sodium sulfite and carboxymethylcellulose Inhibitors to inhibit galena. The inhibitory effects of the three agents in the separation of copper and lead have different characteristics: carboxymethyl cellulose has a good inhibitory effect on the lead ore, but it also has a greater impact on the floatation of chalcopyrite, which is not conducive to the improvement of recovery rate. The inhibition effect of the water glass on the other side is slightly weaker, but the effect on the floatation of the copper mineral is also small, and the copper recovery rate is high; the sodium sulfite activates the copper mineral, and the hydrophilic lead sulfate inhibits on the surface of the galena. Galena. The synergistic effect of the combination of the three agents is used to suppress lead-free copper. After multiple ratio tests, the optimal ratio of the three agents is determined: water glass: sodium sulfite: carboxymethyl fiber The prime is 2:6:1. In order to improve the sorting index, the activated carbon is used for drug removal before the copper-lead separation operation. The test results show that the separation effect is better when the amount of activated carbon is 800g/t. After determining the above conditions, a closed circuit test for copper and lead separation was carried out. The test procedure is shown in Figure 2, and the test results are shown in Table 6.

Table 6 Copper and lead separation closed-circuit process results%

product

Yield

grade

Recovery rate

Cu

Pb

Zn

Cu

Pb

Zn

Copper concentrate

30.51

28.34

7.28

6.01

93.89

4.87

28.12

Lead concentrate

69.49

0.81

62.38

7.38

6.11

95.13

71.82

Copper and lead mixing

100.00

9.21

45.57.

6.52

100.00

100.00

100.00

(5) Zinc selection test

Copper sulphate is used as an activator, diced yellow syrup as a collector, and lime is used as an inhibitor to suppress sulphur and float zinc. According to the optimization test, the suitable conditions for the rough selection of zinc were as follows: copper sulfate 400 g / t, dianthus 80 g / t, No. 2 oil 30 g / t, pulp pH 12.5. Under this condition, a zinc coarse concentrate containing Zn 51.24%, containing Pb 0.24%, containing Cu 0.12%, and a Zn recovery rate of 78.36% is obtained.

Third, the whole process closed circuit test and results analysis

On the basis of the above tests, the whole process closed-circuit test of copper-lead mixed-copper-lead separation-mixed floating tailings sulphur-spraying zinc was carried out. The closed-circuit process copper-lead mixed-mixed was a coarse two-sweeping fine, and copper-lead was separated. One coarse and two sweeping two fines, zinc is selected as a coarse three sweeping two fines, and the middle mine returns in sequence. The results are shown in Table 7.

Table 7 % of closed circuit test results

product

Yield

grade

Recovery rate

Cu

Pb

Zn

Cu

Pb

Zn

Copper concentrate

1.32

28.54

7.05

5.83

65.62

5.54

1.85

Lead concentrate

2.51

0.89

55.69

6.74

4.06

83.21

4.08

Zinc concentrate

7.38

0.56

0.73

51.09

7.51

3.21

90.87

Tailings

88.79

0.14

0.15

0.15

22.81

8.04

3.20

Raw ore

100.00

0.55

1.68

4.15

100.00

100.00

100.00

Closed-circuit test obtained copper concentrate with Cu grade 28.54%, Cu recovery rate 65.62%, Pb grade 55.69%, Pb recovery rate 83.21% lead concentrate and Zn grade 51.09%, Zn recovery rate 90.87% zinc concentrate mine.

Fourth, the conclusion

(1) For the nature of the ore, the flotation process of copper-lead mixed-copper-lead separation-mixed floating tailings sulphur-spraying zinc is used, and the mixed flotation uses ethyl sulphide nitrogen + aniline black drug as collector, ZnSO4 + Na 2 SO 3 is an inhibitor, and the pH value of the pulp is controlled at about 11.5 to realize the separation of copper-lead minerals and zinc-sulfur minerals.

(2) The use of non-toxic water glass, sodium sulfite and carboxymethyl cellulose combination inhibitors instead of cyanide and potassium dichromate has successfully achieved separation of copper and lead, which is conducive to environmental protection.

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