Yellow copper ore, pyrite is typical of sulfide ore minerals, they are typically referred to as a job separator copper sulfur separation. In the separation of copper and sulfur, the flotation method is of great significance, and the research of inhibitors in flotation is a very important direction. The traditional method of copper-sulfur flotation separation is to add a large amount of lime to the slurry and to carry out sulfur-inhibiting float copper in a high alkalinity environment. The process is quite mature and the separation effect is good, but it is also easy to scale during use. Consolidation, blockage of pipelines, corrosion of equipment, and serious pollution of mine wastewater are not conducive to the contradiction of comprehensive recovery of valuable associated components. Therefore, it is of great theoretical and practical significance to research and develop high-efficiency pyrite inhibitors to achieve lime-free copper-sulfur flotation separation under low alkali conditions and improve the comprehensive utilization of mineral resources.

I. Single mineral test study

(1) Preparation of single mineral ore sample

The pyrite (FeS ₂ ) used in the test was taken from a mine to break the ore. The pyrite is crushed, selected, and porcelain ball milled to below 100 mesh, and then sieved to remove fine ore particles with a 250-mesh sieve, and the obtained mineral of 100-250 mesh size is used as a test sample, and stored in a vacuum dryer. spare. The purity of pyrite was 95.74%, and the chemical analysis results of the main elements are shown in Table 1.

Table 1 Chemical analysis results of main elements of pyrite

The chalcopyrite (CuFeS ₂ ) used in the test was taken from the chalcopyrite flotation concentrate of Dexing Copper Mine. After degreasing, the drug was removed and sieved to remove -250 mesh fine ore. The obtained ore sample was used as a test. Samples were stored in a vacuum desiccator for later use. The purity of chalcopyrite was 99.05% after analysis. The main elemental composition analysis results are shown in Table 2.

Table 2 Chemical analysis results of main elements of chalcopyrite %

(II) Effect of calcium hypochlorite on the floatability of pyrite and chalcopyrite

Calcium hypochlorite (Ca (ClO) _2), dissolved in water and release oxygen while simultaneously decomposing and Ca ^{2 +,} it has a strong oxidation resistance, and when the solution was at pH <9, Ca ^{2 +} in the aqueous solution hardly occurs Hydrolysis, which exists mainly in the form of ions, in view of this, the test of the influence of the amount of Ca(ClO) ₂ on the floatability of chalcopyrite and pyrite was carried out. The test conditions and results are shown in Fig. 1.

Fig.1 Effect of Ca(ClO) ₂ dosage on the floatability of chalcopyrite and pyrite

â—†-Chalcopyrite; â– -Pyrite

Dinghuang medicine 60g / t, 2 ^# oil 90g / t, NaOH adjust the pH to 7 ~ 8

It can be seen from Fig. 1 that Ca(ClO) ₂ does not change the floatability of chalcopyrite when the pH of the slurry is 7-8, but it has a good inhibitory effect on pyrite. With the increase of its dosage, the floating rate of pyrite is greatly reduced. When the dosage is 1000g/t, the recovery rate of pyrite is only 19.20%. When the dosage continues to increase, the recovery rate does not change much.

(III) Flotation separation test of artificial mixed ore

According to the previous single mineral test, Ca(ClO) ₂ showed good inhibition performance to pyrite in the low alkalinity environment of pH=7-8, but did not change the floatability of chalcopyrite. In order to further study the inhibitory effect of Ca(ClO) ₂ on pyrite and the possibility of copper and sulfur separation, the experiments of artificial mixed ore flotation separation of different copper-sulfur ratios were carried out under low alkalinity conditions. The pH of the slurry was adjusted to 7-8 with NaOH, 60 g/t of butyl xanthate, 1000 g/t of Ca(ClO) _{2 and} 90 g/t of 2 ^# oil. The test results are shown in Table 3.

Table 3 Flotation separation results of chalcopyrite and pyrite mixed ore

It can be seen from Table 3 that Ca(ClO) ₂ has good inhibitory performance on pyrite and has strong adaptability. Under the low alkali condition of slurry pH 7-8, Ca(ClO) _{2 is} used as an inhibitor of pyrite. It can realize the separation of copper and sulfur flotation and obtain better separation index.

2. Analysis of inhibition mechanism of Ca(ClO) ₂ on pyrite

According to the basic theory of mineral flotation, the main way of suppressing minerals is to activate the activated film or collector film on the mineral surface, and form a hydrophilic film on the mineral surface. In order to further understand the role of Ca(ClO) ₂ in the separation of copper and sulfur, better guide the separation process of copper and sulfur, through the surface chemical reaction and Raman spectroscopy analysis, the Ca(ClO) in the separation process of low alkalinity copper and sulfur was studied. ₂ inhibition mechanism of pyrite.

(I) Effect of Ca(ClO) ₂ on the chemical composition of pyrite mineral surface

Studies have shown that under alkaline or neutral conditions, pyrite indicates that (1) to (3) oxidation reactions may occur, and they have also detailed the properties and effects of elemental sulfur on the surface of sulfide minerals. Studies have shown that zero-valent (S ⁰ ) on the surface of sulfide ore is a very unstable substance that is oxidized under oxidizing conditions. , , .

,(1)

,(2)

, (3)

, (4)

, (5)

.(6)

Ca (ClO) ₂ is a strong oxidant, adding a small amount of Ca (ClO) ₂ in the floating mineral slurry, the slurry was able to make a strong oxidizing atmosphere. At this time, in addition to the oxidation reaction shown in the formula (1) to (6), the surface of the pyrite may be further oxidized. , , In addition, it is more important that a large amount of Fe(OH) ₂ formed by the surface reaction is further oxidized to Fe(OH) ₃ as shown in the formula (7). Fe(OH) ₃ is a slightly water-soluble compound, and its solubility product K _{sp is} much smaller than Fe(OH) ₂ , and it can be stably present in an alkaline medium. Therefore, it is possible to determine a large amount of Fe(OH) ₃ produced on the surface of pyrite, which is a major cause of inhibition of pyrite.

2Fe(OH) ₂ +ClO ^- +H ₂ O=2Fe(OH) ₃ ↓+Cl ^- .(7)

On the other hand, Ca (ClO) ₂ was dissolved in a large amount of water will be ionized Ca ^{2 +,} studies have shown that, when the solution pH at 9, Ca ^{2 +} difficult to hydrolyze <in aqueous solution, is present in substantially ionic form. Accordingly, the Ca ^{2 +} will pyrite oxidation of the surface Combine to form a precipitate. In addition, the slurry will absorb part of the CO ₂ during the flotation and aeration process, producing a certain amount of , because K _{sp calcium carbonate} <K _{sp calcium sulfate} <K _{sp calcium hydroxide} <K _{sp calcium chloride} , then the reaction shown in formula (8), (9), (10), and finally The calcium component on the mineral surface is mainly CaCO ₃ , and CaCO ₃ is very stable in alkaline environment, and its solubility product K _sp is only 2.8×10 ^{- 9} , which is a sparingly soluble compound and is firmly wrapped in yellow iron. The surface of the ore is therefore considered to be another cause of the deterioration of the floatability of pyrite.

,(8)

,(9)

, (10)

Through the above series of chemical reaction analysis, it can be considered that the inorganic oxidant Ca(ClO) ₂ inhibits pyrite, and the mechanism of achieving low alkalinity and no lime, copper and sulfur separation is under the low alkali condition of pulp pH=7-8, Ca ( ClO) ₂ so that the surface oxidation reaction, a large amount of Fe (OH) ₃ hydrophilic substance; the other hand, with a solution of Ca ^{+ 2} (ClO) ₂ in an aqueous solution of ionized Ca cation Combined, the combined product is stably adsorbed on the surface of pyrite, so that Fe(OH) ₃ and CaCO ₃ synergistically act on the surface of the pyrite, resulting in the formation of the main components of the pyrite surface as Fe(OH) ₃ and CaCO ₃ . The water film greatly enhances the hydrophilicity of the surface of the pyrite, so that it is inhibited in the slurry, and the separation of lime-free copper and sulfur is achieved.

In order to further clarify the inhibition mechanism of Ca(ClO)2 on pyrite, it is confirmed that the above-mentioned series of chemical reactions exist on the surface of pyrite minerals. The Raman spectra of the pyrite mineral surface before and after the action of Ca(ClO) _{2 were} studied under low alkali conditions with a slurry pH of 7-8. Fig. 2(a) is a Raman spectrum of the mineral surface of the pyrite after soaking with the xanthate solution; Fig. 2(b) is the soaking effect of the pyrite after the soaking of the xanthate and then Ca(ClO) ₂ solution After the final mineral surface Raman spectrum.

Fig. 2 Raman spectroscopy of pyrite mineral surface before and after Ca(ClO) ₂ treatment

(A) seen from Figure 2, low-alkali conditions 7-8 PH = in the pulp, the view of the Raman spectrum of pyrite surface is only xanthate 343cm ^{- 1,} cm 379 ^{- 1} at a peak value, which Both peaks are caused by pyrite Fe-[S ₂ ] stretching vibration. Therefore, it can be inferred that Dinghuang is difficult to chemically react on the surface of pyrite. (B) 2 shows that, the addition of Ca (ClO) _2, pyrite undergone significant changes, in addition to the Raman spectrum 343cm ^{- 1,} 379 cm ^{- 1} pyrite occur near the Fe- [ outer _2] of the two stretching vibration S, also 282 cm ^- more than ¹ near one peak, which peak is a typical CaCO ₃ activity peaks, in addition to other vibration peak does not appear. Therefore, it can be explained that under the low alkali condition of pulp pH=7-8, pyrite shows that after Ca(ClO) ₂ solution, a hydrophilic film of CaCO _{3 is} newly produced, so that it is Sufficiently suppressed.

Third, the conclusion

(1) Single mineral flotation test shows that Ca(ClO) ₂ does not affect the floatability of chalcopyrite under low alkali conditions of pulp pH=7-8, and shows good inhibition performance to pyrite.

(2) The flotation separation test of artificial mixed ore shows that Ca(ClO) ₂ has good selectivity in the process of copper-sulfur flotation separation under the low alkali condition of slurry pH=7-8, and the adaptability is strong. Successfully realized the separation of lime-free copper-sulfur flotation of artificial mixed ore with various copper-sulfur ratios, and obtained better indicators.

(3) Mineral surface chemical reaction and Raman spectroscopy analysis show that under low alkalinity conditions, Ca(ClO) ₂ oxidizes the surface of the ore to form a hydrophilic film with Fe(OH) ₃ and CaCO ₃ as main components. The hydrophilicity of the mineral surface of pyrite is improved, which is fully suppressed in the copper-sulfur flotation separation operation, thereby successfully achieving the separation of lime-free copper and sulfur.

heat pipe heat sink

Heat Pipe Heat Sink,Copper Pipe Heat Sink,Heatsink With Heatpipe,Heat Sink With Copper Tube

Suzhou Wint Electric Co., Ltd , https://www.wintocool.com