Lead zinc cyanide tailings Comprehensive Recovery Technology price of metal has been a problem. As more cyanide tailings remaining in pharmaceutical processing, resulting in lead-zinc flotation froth was sticky and pyrite flotation separation of gangue minerals and more difficult; In addition, as inhibition Cyanide Leaching and long CN- The aerated agitation of time destroys the surface properties of lead-zinc minerals and deactivates the natural floatability of sulfide minerals, thus causing great difficulty in flotation recovery [1, 2] .
Entrusted by a company in Shandong, the Beijing Research Institute of Mining and Metallurgy conducted a comprehensive study on the tailings of the company after the cyanide gold extraction, and improved the lead and zinc beneficiation process test to improve the lead and zinc grade of the cyanide tailings flotation concentrate. And recovery rate.
The original flotation process of the company cyanide tailings is a rough selection, three sweeps, three selections, and the lead-zinc mixed concentrate (lead + zinc) grade ≤ 48%, the recovery rate is about 70%, and the pole Unstable. In view of the characteristics of the cyanide tailings, our institute adopted YO as the activation regulator through experimental research, and adopted the asynchronous mixing and selection process twice through two rough selections, two sweeps, and three selected processes to finally obtain lead-zinc mixing. Concentrate (lead + zinc) grade 52.56%, of which lead 20.89%, zinc 31.67%, lead recovery rate of 85.15%, zinc recovery rate of 97.5l%, lead and zinc recovery rate has been greatly improved.
First, the cyanide tailings properties
The metal cyanide tailings minerals include pyrite, sphalerite, galena, followed limonite ore brass, zinc tennantite, a small amount of titanium manganese, hematite and trace copper blue; gangue minerals are quartz, followed by feldspar, mica, clay minerals, silicate minerals, chlorite, amphibole small amount, carbonaceous material, apatite, rutile. The main mineral content is shown in Table 1.
(1) Main chemical components of cyanide tailings
The main chemical composition analysis results of cyanide tailings are shown in Table 2.
(2) Analysis of lead and zinc phases
The results of chemical phase analysis of cyanide tailings are shown in Table 3.
(III) Characteristics of particle size distribution of lead and zinc
The distribution characteristics of lead and zinc in each particle size are shown in Table 4.
It can be seen from Table 4 that the material has a fine particle size, the content of +74 μm is only 5.21%, the content of -30+74 μm is only 17.72%, and the content of -30 μm is as high as 77.07%.
(4) Main mineral inlay characteristics
The galena in cyanide tailings mainly exists in the form of monomer, and its monomer dissociation degree is 84.93%. The minerals associated with galena are mainly gangue and pyrite, with the occupancy rates being 4.08% and 3.42%, respectively. In addition, 1.01% and 1.51% of galena are associated with chalcopyrite and various minerals respectively; sphalerite is mainly in the form of monomer, and its monomer dissociation degree is 84.79%, which is associated with sphalerite. The raw minerals are mainly gangue, pyrite, chalcopyrite, and their occupation rates are 3.43%, 3.17% and 2.33%, respectively, and 1.68% of sphalerite is associated with various minerals.
Second, mineral processing test research
The cyanide tailings are tailings after gold cyanide leaching. During the cyanidation leaching process, various metal sulfides are subjected to the action of cyanide CN- and long-term stirring, and the floatability is greatly reduced. In comparison, galena is less affected. Therefore, when lead and zinc are mixed, the difference in floatability of lead and zinc minerals should be utilized, and the asynchronous mixed process should be adopted, that is, the rough selection in two steps, the first step is to select lead, and the second step is to select zinc; By changing the original process to two rough selections, two sweeps, and three selections, it is possible to use less flotation reagents and to obtain more adequate recovery of lead and zinc minerals.
(1) Process test of rough selection I
1. Adjusting agent YO dosage test
Before the cyanide tailings enter the flotation, although it has been filtered, cyanide CN- remains in the cyanide residue, especially on the mineral surface. Their presence is very harmful to sulfide flotation. For this reason, the adjusting agent YO is added. To eliminate the impact of CN-. The test procedure is shown in Figure 1, and the test results are shown in Figure 2.
It can be seen from the test results in Figure 2 that the lead and zinc recovery rates in the coarse concentrate are also increasing with the increase in the amount of YO. When the YO dosage is more than 1500g/t, the lead and zinc recovery rates do not change much. Considering comprehensively, it is advisable to determine the crude IYO dosage of 1500g/t.
2, lime dosage test
Lead and zinc flotation requires a suitable pH value, usually using lime to adjust the pH of the slurry and inhibit pyrite. The test procedure for the amount of use is shown in Figure 1, and the results of the crude concentrate test are shown in Figure 3. It can be seen from the test results of Fig. 3 that the amount of lime is preferably 700 g/t.
3, collector type test
The rough selection I is mainly lead-selected, and there are many kinds of lead collectors. Commonly used are ethyl sulphide, aniline black, butyl xanthate, etc., the test process is shown in Figure 1, the test results are shown in Table 5.
It can be seen from the test results in Table 5 that the butyl xanthate has better trapping power for lead and zinc minerals than the other four collectors. The aniline black drug has better selectivity for lead. Considering the lead and zinc indicators, the combination of butyl xanthate and aniline black medicine is used as a collector for lead and zinc mixed selection.
4, butyl yellow medicinal amount test
By comparing the results of the collector type test, butyl xanthate was selected as the collector of crude selection I and an appropriate amount of aniline black medicine (20 g/t) was selected. The results of the butyl yellow medicinal amount test are shown in Fig. 4.
It can be seen from the test results in Fig. 4 that, at the same time, the lead and zinc flotation indexes are comprehensively considered, and the butyl yellow dosage is preferably 30 g/t.
(2) Rough selection II condition test
Rough selection II is based on zinc-selective operation, because sphalerite is affected by cyanide CN- during cyanide leaching of gold concentrate, and the floatability of some sphalerite is strongly inhibited by CN- There is no floating in the first stage of flotation. In order to restore the floatability of the sphalerite, the influence of CN- must be eliminated first, followed by the addition of an activator and a suitable pH value of the slurry.
1. Adjusting agent YO dosage test
The results of the rough selection I test show that YO is an agent that can effectively eliminate the residual CN-effect in the slurry. In order to further float the hard-to-float zinc ore, it is still necessary to add YO to the rough selection II. The coarse selection I coarse concentrate was used as the ore-bearing for the rough selection II YO dosage test. The test procedure is shown in Fig. 5, and the test results are shown in Fig. 6.
It can be seen from the test results in Fig. 6 that with the increase of YO dosage, the lead and zinc grades and the recovery rate of the operation in the coarse concentrate are increasing, and the dosage is preferably 500-700 g/t.
2, lime dosage test
Taking lime as the pH adjuster, the lime dosage test procedure is shown in Figure 5, and the test results are shown in Figure 7. It can be seen from the test results in Fig. 7 that when the amount of lime is 1000g/t, the lead and zinc flotation indexes are the best, so it is determined that the amount of coarsely selected II lime is 1000g/t.
3, copper sulfate dosage test
Copper sulfate is a universal activator of sphalerite, and the test results of copper sulfate dosage are shown in Fig. 8. It can be seen from the test results of Fig. 8 that the amount of copper sulfate is preferably 1200 g/t.
4, rough selection of II butyl yellow drug amount test
The rough selection II is mainly zinc-selective, the collector is mainly butyl xanthate, and a small amount of aniline black medicine (20g / t) is used to further recover lead. The test procedure of butyl yellow medicinal amount is shown in Fig. 5, and the test results are shown in Fig. 9. It can be seen from the test results that the amount of butyl yellow is preferably 80 g/t.
Third, closed circuit test
The flotation closed circuit test was carried out on the basis of the optimized test conditions, and the test flow chart 10 was carried out. The test results are shown in Table 6. It can be seen from the closed-circuit test results in Table 6 that the lead-zinc mixed concentrate (lead + zinc) grade is 52.56%, which is obtained by asynchronous mixed selection through two rough selection, two sweeping, and three selection processes. 20.89%, zinc 31.67%; lead recovery rate 85.15%, zinc recovery rate 97.51%.
Fourth, the conclusion
(1) The metal minerals in cyanide tailings mainly include pyrite, sphalerite and galena, followed by limonite, chalcopyrite, zinc arsenide bismuth ore, and a small amount of manganese ilmenite and red iron. Minerals and trace copper and blue; gangue minerals mainly include quartz, followed by feldspar, mica, clay minerals, silicate minerals, chlorite, etc., as well as a small amount of amphibole, carbonaceous matter, apatite, rutile, etc. .
(2) The mineral size of the cyanidation tailings is fine, and the -30μm particle size reaches 77.07%; the minerals are seriously over-grinded, and a large amount of muddy gangue minerals and residual cyanide in the pulp will deteriorate the flotation and eventually affect the lead. , zinc flotation indicators.
(III) Beneficiation test research shows that YO is used as the activation regulator, and the new process of asynchronous mixing is used to obtain the lead-zinc mixed concentrate (lead + zinc) through two rough selection, two sweeps, and three selected processes. The grade of lead and zinc is 85.15% and 97.51%, respectively, and the lead and zinc recovery rate is greatly improved.
(4) The new pharmaceutical system and process have been applied to industrial production, which has greatly improved the economic benefits of the concentrator.
references
[1]He Zheng. Study on zinc flotation of cyanide tailings [J]. Mining and Metallurgy, 2002, 11 (3): 30-34.
Anvil Cylinder,High Precise Anvil Cylinder,Hardened Anvil Cylinder,Durable Anvil Cylinder
Jetfly High Precision Manufacturing Co.,Ltd , https://www.jetflytech.com