Application of combined inhibitor in flotation separation of associated gold, silver, lead and zinc sulfide ore

Abstract

The invention discloses an application of a combined inhibitor in flotation separation of associated gold, silver, lead and zinc sulfide ore, the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of zinc sulfate to methionine is 2: 1; the combined inhibitor is used for achieving flotation separation of the associated gold and silver low-copper lead-zinc polymetallic sulfide ore in a low-alkali environment, the separation effect is good, the concentrate grade is high, the zinc content of the lead concentrate is effectively reduced, the recovery rate of gold and silver in the lead concentrate is increased, and the combined inhibitor has important significance on quality improvement and efficiency improvement of flotation separation of the associated gold and silver low-copper lead-zinc polymetallic sulfide ore. Besides, methionine in the combined inhibitor is a small-molecular organic matter, is non-toxic and pollution-free and is easy to degrade, so that the problems that a traditional inhibitor is toxic and unfriendly to the environment and human bodies are solved. The combined inhibitor is small in dosage, stable in effect and good in process application prospect.

Description

Technical Field

[0001] The invention relates to application of a combined depressant in flotation separation of associated gold, silver, lead and zinc sulfide ores, and in particular to a mixture of zinc sulfate and methionine in a mass ratio of 2:1 as a sphalerite combined depressant, belonging to the technical field of mineral processing. Background Art

[0002] Copper, lead and zinc are common nonferrous metals that play a vital role in aerospace, electricity, electronic components, ships, medical and other fields. With the advancement of science and technology and the development of economic construction, the demand for copper, lead and zinc has gradually expanded. Gold and silver are common precious metals, and the demand in production and life is also increasing. Therefore, the comprehensive recovery and utilization of polymetallic sulfide ores associated with gold and silver is of great significance.

[0003] Polymetallic sulfide ores often use high-alkali processes to suppress iron sulfide minerals (including pyrite and pyrrhotite). Although lime has low cost and good suppression effect, it will cause pipeline pulp compaction and pipeline blockage when used in large quantities, resulting in a series of problems such as sticky flotation foam, difficulty in activating suppressed sulfur, and difficulty in treating ore dressing wastewater. Therefore, it is necessary to select a method that can achieve flotation separation of polymetallic sulfide ores in a low-alkali environment.

[0004] The associated gold and silver low-copper lead-zinc polymetallic sulfide ore, galena is the main carrier mineral of silver, gold mainly exists in the form of sulfide wrapped gold, mainly in chalcopyrite, galena and pyrite. The useful minerals of this type of ore are mainly galena, chalcopyrite, sphalerite and pyrite.

[0005] The difficulties in using existing flotation processes to beneficiate this type of ore are: (1) high alkali suppresses sulfur, resulting in a low recovery rate of associated precious metals gold and silver, most of which are lost in the tailings; (2) the zinc blende suppression effect is poor, the lead concentrate contains a high zinc content, resulting in zinc loss. The above problems have seriously affected the economic benefits. Summary of the invention

[0006] The purpose of the present invention is to provide an application of a combined depressant in the flotation separation of associated gold, silver, lead and zinc sulfide ores. The combined depressant has a small dosage, is safe and environmentally friendly, and is a new type of depressant for sphalerite. The combined depressant is combined with zinc sulfate in a ratio of 1:2 to inhibit sphalerite under low alkalinity, thereby achieving the flotation separation of lead-zinc sulfide ores.

[0007] The structural formula of methionine in the combined inhibitor of the present invention is as follows:

[0008]

[0009] Under low-alkali conditions, the silver content in lead concentrate is increased, the zinc content is reduced, the silver content in zinc concentrate is reduced, and the economic benefit indicators of the product are comprehensively improved. The application of this combined inhibitor in the flotation separation of associated gold, silver, lead and zinc sulfide ores is as follows:

[0010] (1) Grinding the ore to be selected, the grinding mass concentration is 64% to 67%, and grinding to a mass particle size of less than 0.074 mm, accounting for 60-65%;

[0011] (2) adding lime, a combined depressant, and a combined collector to the ore pulp after grinding in step (1) in sequence, and performing lead roughing after slurry adjustment to obtain a lead roughing concentrate and a lead roughing tailings, respectively;

[0012] (3) The lead roughing tailings obtained in step (2) are subjected to two scavenging operations, lime and a combined collector are added in the first scavenging operation, and a combined collector is added in the second scavenging operation, and the concentrate of each scavenging operation is returned to the previous operation in sequence to form a closed loop, and the final lead tailings are obtained after two scavenging operations;

[0013] (4) subjecting the lead rougher concentrate obtained in step (1) to three concentration operations, wherein lime and combined depressants are added in the first and second concentration operations, and only combined depressants are added in the third concentration operation, and the tailings of each concentration operation are returned to the previous operation in sequence to form a closed loop, and a final lead concentrate is obtained after three concentration operations;

[0014] The combined collector is a combination of No. 25 black medicine and aniline black medicine, and the mass ratio of the two is 3:1; the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two is 2:1; lime is used as a pyrite inhibitor and pH adjuster.

[0015] In step (2), the amount of lime used is 1000-2000 g / t, the amount of combined inhibitor used is 700-1000 g / t, and the amount of combined collector used is 120-150 g / t.

[0016] In step (3), the amount of lime used in the first sweeping operation is 300-500 g / t, the amount of combined collector used is 40-60 g / t, and the amount of combined collector used in the second sweeping operation is 10-20 g / t.

[0017] In step (4), the amount of lime used in the first concentration operation is 300-500 g / t, and the amount of combined inhibitor used is 400-600 g / t. The amount of lime used in the second concentration operation is 100-200 g / t, and the amount of combined inhibitor used is 200-300 g / t. The amount of combined inhibitor used in the third concentration operation is 100-200 g / t.

[0018] The roughing operation time of lead is 4 minutes, the first and second sweeping operation time are 4 minutes and 3.5 minutes respectively, and the first, second and third concentrating operation time are 3.5 minutes, 3 minutes and 2.5 minutes respectively.

[0019] In combination with the above scheme, the principles and beneficial effects of the present invention are as follows:

[0020] The present invention uses No. 25 black medicine and aniline black medicine as a combined collector, which utilizes the strong collection performance of No. 25 black medicine on copper and lead sulfide minerals under low alkaline conditions and the selective collection of copper and lead by aniline black medicine in the presence of sphalerite and iron sulfide ore, and has a significant effect on improving the recovery rate of gold and silver. The combined use of the two has both coordinated promotion of collection and high selectivity. The combined inhibitor of sphalerite of the present invention inhibits sphalerite in a low alkaline environment to achieve efficient separation of lead-zinc sulfide ores. The methionine molecule has amino and carboxyl groups, and has a strong chelating ability with metal ions. It can also complex with zinc ions on the surface of sphalerite, exposing the hydrophilic carboxyl groups to the outside to make the mineral surface hydrophilic, thereby inhibiting sphalerite. The Ca generated by lime dissolving in water 2+ and Ca(OH) + It can also adsorb on the surface of sphalerite, making it hydrophilic. Under alkaline conditions, zinc sulfate generates zincate ions that adsorb on the surface of sphalerite to inhibit sphalerite. In addition, methionine reacts with zinc sulfate to produce methionine zinc that adsorbs on the surface of sphalerite, making the surface of sphalerite hydrophilic and inhibiting it.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention provides a combined depressant and a combined collector for use in a flotation separation method for lead-zinc sulfide minerals under low alkalinity, which solves a series of problems such as environmental pollution caused by the traditional high-alkali method and difficulty in treating mineral processing wastewater.

[0023] (2) The present invention improves the recovery rate of gold and silver in lead concentrate, reduces the zinc content of the lead concentrate, and improves the economic benefits of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the described contents.

[0026] Implementation 1:

[0027] The associated gold and silver are low-copper, lead-zinc polymetallic sulfide ores. Galena is the main carrier mineral of silver. Gold mainly exists in the form of sulfide-encapsulated gold, mainly in chalcopyrite, galena and pyrite. The lead grade of the original ore is 3.07%, the zinc grade is 4.44%, the silver grade is 60.42g / t, and the gold grade is 0.21g / t. The useful minerals are mainly galena and sphalerite. Figure 1 The specific steps are as follows:

[0028] Step (1), grinding the mineral to be selected, the grinding mass concentration is 64%, and the mineral particle size after grinding is -200 mesh accounts for 60%;

[0029] Step (2), adding lime, a combined depressant, and a combined collector to the ore pulp after grinding in step (1) in sequence, and then performing lead roughing to obtain a lead roughing concentrate and a lead roughing tailings, respectively;

[0030] Step (3), subjecting the lead roughing tailings obtained in step (2) to two scavenging operations, adding lime and a combined collector in the first scavenging operation, and adding a combined collector in the second scavenging operation, and returning the concentrate of each scavenging operation to the previous operation in sequence to form a closed loop, and obtaining the final lead tailings after two scavenging operations;

[0031] Step (4), subjecting the lead roughing concentrate obtained in step (2) to three concentration operations, wherein lime and combined depressants are added in the first and second concentration operations, and only combined depressants are added in the third concentration operation, and the tailings of each concentration operation are returned to the previous operation in sequence to form a closed loop, and a final lead concentrate is obtained after three concentration operations;

[0032] The combined collector is a combination of No. 25 black medicine and aniline black medicine, and the mass ratio of the two is 3:1; the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two is 2:1; lime is used as a pyrite inhibitor and pH adjuster.

[0033] In the step (2), the amount of lime used is 2000 g / t, the amount of combined inhibitor used is 1000 g / t, and the amount of combined collector used is 150 g / t.

[0034] In the step (3), the amount of lime used in the first sweeping operation is 500 g / t, the amount of combined collector used is 60 g / t, and the amount of combined collector used in the second sweeping operation is 20 g / t.

[0035] In the step (4), the amount of lime used in the first concentration operation is 500 g / t, and the amount of combined inhibitor used is 600 g / t, the amount of lime used in the second concentration operation is 200 g / t, and the amount of combined inhibitor used is 300 g / t, and the amount of combined inhibitor used in the third concentration operation is 150 g / t.

[0036] The flotation time is 4 minutes for rough selection, 4 minutes for the first, second and third sweeping selections, and 3.5 minutes for the first and second concentration selections, respectively. 3.5 minutes, 3 minutes and 2.5 minutes.

[0037] The above experimental reagent system is shown in Table 1, the lead and zinc experimental results are shown in Table 2, and the gold and silver experimental results are shown in Table 3.

[0038] According to the above experimental process, the amount of lime was changed to 6000g / t for roughing operation, and the other reagent systems were kept unchanged for the experiment. The experimental reagent system is shown in Table 1, the lead and zinc experimental results are shown in Table 2, and the gold and silver experimental results are shown in Table 3.

[0039] Table 1. Dosage system of Example 1, Comparative Example 1 and Comparative Example 2, unit (g / t)

[0040]

[0041] Table 2. Experimental results of lead and zinc in Example 1 and Comparative Example 1.

[0042]

[0043] Table 3. Experimental results of gold and silver in Example 1 and Comparative Example 1.

[0044]

[0045] From Table 1, Table 2 and Table 3, it can be seen that under low-alkali conditions, using zinc sulfate + methionine as an inhibitor can obtain a lead grade of 71.49% and a recovery rate of 90.59%; a silver grade of 1147.65g / t, a silver recovery rate of 73.89%; a gold grade of 2.21g / t, a gold recovery rate of 40.94%; and a lead concentrate containing 5.69% zinc. The experiment using this scheme under high-alkali conditions found that although the high-alkali conditions improved the quality of the lead concentrate, the zinc content of the lead concentrate increased, and the addition of a large amount of lime suppressed most of the pyrite, resulting in some gold and some silver being suppressed along with the pyrite, greatly limiting the recovery of gold and silver.

[0046] Example 2

[0047] A silver-associated low-copper lead-zinc polymetallic sulfide ore in Yunnan, galena is the main carrier mineral of silver. The lead grade of the ore is 1.58%, the zinc grade is 2.03%, and the silver grade is 27.41g / t. Figure 1 The specific steps are as follows:

[0048] Step (1), grinding the mineral to be selected, the grinding mass concentration is 67%, and the mineral particle size after grinding is -200 mesh accounts for 65%;

[0049] Step (2), adding lime, a combined depressant, and a combined collector to the ore pulp after grinding in step (1) in sequence, and then performing lead roughing to obtain a lead roughing concentrate and a lead roughing tailings, respectively;

[0050] Step (3), subjecting the lead roughing tailings obtained in step (2) to two scavenging operations, adding lime and a combined collector in the first scavenging operation, and adding a combined collector in the second scavenging operation, and returning the concentrate of each scavenging operation to the previous operation in sequence to form a closed loop, and obtaining the final lead tailings after two scavenging operations;

[0051] Step (4), subjecting the lead roughing concentrate obtained in step (2) to three concentration operations, wherein lime and combined depressants are added in the first and second concentration operations, and only combined depressants are added in the third concentration operation, and the tailings of each concentration operation are returned to the previous operation in sequence to form a closed loop, and a final lead concentrate is obtained after three concentration operations;

[0052] The combined collector is a combination of No. 25 black medicine and aniline black medicine, and the mass ratio of the two is 3:1; the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two is 2:1; lime is used as a pyrite inhibitor and pH adjuster.

[0053] In the step (2), the amount of lime used is 1500 g / t, the amount of combined inhibitor used is 800 g / t, and the amount of combined collector used is 130 g / t.

[0054] In the step (3), the amount of lime used in the first sweeping operation is 400 g / t, the amount of combined collector used is 50 g / t, and the amount of combined collector used in the second sweeping operation is 15 g / t.

[0055] In the step (4), the amount of lime used in the first concentration operation is 400 g / t, and the amount of combined inhibitor used is 500 g / t, the amount of lime used in the second concentration operation is 150 g / t, and the amount of combined inhibitor used is 250 g / t, and the amount of combined inhibitor used in the third concentration operation is 150 g / t.

[0056] The flotation time is 4 minutes for rough selection, 4 minutes for the first, second and third sweeping selections, and 3.5 minutes for the first and second concentration selections, respectively. 3.5 minutes, 3 minutes and 2.5 minutes.

[0057] The above experimental reagent system is shown in Table 4, and the lead and zinc experimental results are shown in Table 5.

[0058] Comparative Example 2

[0059] According to the above experimental process, the combined inhibitor was changed to zinc sulfate + sodium sulfite. The experimental reagent system is shown in Table 4, and the experimental results are shown in Table 5.

[0060] Table 4. Dosage system of Example 2 and Comparative Example 2, unit (g / t)

[0061]

[0062]

[0063] Table 5. Experimental results of Example 2 and Comparative Example 2.

[0064]

[0065] From Table 4 and Table 5, it can be seen that under low-alkali conditions, using zinc sulfate + methionine as inhibitors can obtain a lead grade of 65.32% and a recovery rate of 93.85%; a silver grade of 885.12 g / t, a silver recovery rate of 73.30%; and a lead concentrate containing 4.76% zinc. The use of zinc sulfate + sodium sulfite combination inhibits the increase in the amount of sphalerite lime, while the quality and recovery rate of the lead concentrate are reduced, which also leads to a decrease in the recovery rate of silver. The zinc sulfate + methionine solution improves production efficiency, and its technical solution is feasible.

[0066] Example 3

[0067] A polymetallic sulfide ore with associated gold, silver, lead and zinc in Yunnan. Galena is the main carrier mineral of silver. Gold mainly exists in the form of sulfide-encapsulated gold, mainly in chalcopyrite, galena and pyrite. The lead grade of the original ore is 1.98%, the zinc grade is 1.54%, the silver grade is 51.67g / t, and the gold grade is 0.18g / t. Figure 1 The specific steps are as follows:

[0068] Step (1), grinding the mineral to be selected, the grinding mass concentration is 65%, and the mineral particle size after grinding is -200 mesh accounts for 63%;

[0069] Step (2), adding lime, a combined depressant, and a combined collector to the ore pulp after grinding in step (1) in sequence, and then performing lead roughing to obtain a lead roughing concentrate and a lead roughing tailings, respectively;

[0070] Step (3), subjecting the lead roughing tailings obtained in step (2) to two scavenging operations, adding lime and a combined collector in the first scavenging operation, and adding a combined collector in the second scavenging operation, and returning the concentrate of each scavenging operation to the previous operation in sequence to form a closed loop, and obtaining the final lead tailings after two scavenging operations;

[0071] Step (4), subjecting the lead roughing concentrate obtained in step (2) to three concentration operations, wherein lime and combined depressants are added in the first and second concentration operations, and only combined depressants are added in the third concentration operation, and the tailings of each concentration operation are returned to the previous operation in sequence to form a closed loop, and a final lead concentrate is obtained after three concentration operations;

[0072] The combined collector is a combination of No. 25 black medicine and aniline black medicine, and the mass ratio of the two is 3:1; the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two is 2:1; lime is used as a pyrite inhibitor and pH adjuster.

[0073] In the step (2), the amount of lime used is 1000 g / t, the amount of combined inhibitor used is 700 g / t, and the amount of combined collector used is 120 g / t.

[0074] In the step (3), the amount of lime used in the first sweeping operation is 300 g / t, the amount of combined collector used is 40 g / t, and the amount of combined collector used in the second sweeping operation is 10 g / t.

[0075] In the step (4), the amount of lime used in the first concentration operation is 300 g / t, and the amount of combined inhibitor used is 400 g / t, the amount of lime used in the second concentration operation is 100 g / t, and the amount of combined inhibitor used is 200 g / t, and the amount of combined inhibitor used in the third concentration operation is 100 g / t.

[0076] The flotation time is 4 minutes for rough selection, 4 minutes for the first, second and third sweeping selections, and 3.5 minutes for the first and second concentration selections, respectively. 3.5 minutes, 3 minutes and 2.5 minutes.

[0077] The above experimental reagent system is shown in Table 6, the lead and zinc experimental results are shown in Table 7, and the gold and silver experimental results are shown in Table 8.

[0078] Comparative Example 3

[0079] According to the above experimental process, the inhibitor of sphalerite was changed to zinc sulfate + sodium metabisulfite. The experimental reagent system is shown in Table 6, the lead and zinc experimental results are shown in Table 7, and the gold and silver experimental results are shown in Table 8.

[0080] Table 6: Dosage system of Example 3 and Comparative Example 3, unit (g / t) (

[0081]

[0082] Table 7. Experimental results of lead and zinc in Example 3 and Comparative Example 3.

[0083]

[0084] Table 8. Experimental results of gold and silver in Example 3 and Comparative Example 3.

[0085]

[0086] From Table 7 and Table 8, it can be seen that under low-alkali conditions, using zinc sulfate + methionine as an inhibitor can obtain a lead concentrate with a lead grade of 72.32% and a recovery rate of 93.87%; a silver grade of 1468.34g / t and a silver recovery rate of 73.03%; a gold grade of 2.88g / t and a gold recovery rate of 41.12%; and a zinc content of 2.85%. Compared with the use of zinc sulfate + sodium metabisulfite, the recovery rates of gold and silver are improved while ensuring the quality of the lead concentrate, which is of great significance to production practice.

[0087] In summary, the use of zinc sulfate + methionine as a combined inhibitor to inhibit sphalerite can achieve the effective separation of gold, silver, low-copper, lead and zinc polymetallic sulfide ores in a low-alkali environment. This combined inhibitor is green and environmentally friendly, can be naturally degraded, and is environmentally friendly. When used under low-alkali conditions, it avoids a series of hazards caused by the large-scale use of lime.

[0088] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. Application of a combined depressant in flotation separation of associated gold, silver, lead and zinc sulfide ores, characterized in that: The specific steps of flotation separation are as follows: (1) Grinding the ore to be selected, the grinding mass concentration is 64% to 67%, and grinding to a mass particle size of less than 0.074 mm, accounting for 60-65%; (2) adding lime, a combined depressant, and a combined collector to the ore pulp after grinding in step (1) in sequence, and performing lead roughing after slurry adjustment to obtain a lead roughing concentrate and a lead roughing tailings, respectively; (3) The lead roughing tailings obtained in step (2) are subjected to two scavenging operations, lime and a combined collector are added in the first scavenging operation, and a combined collector is added in the second scavenging operation, and the concentrate of each scavenging operation is returned to the previous operation in sequence to form a closed loop, and the final lead tailings are obtained after two scavenging operations; (4) subjecting the lead rougher concentrate obtained in step (1) to three concentration operations, wherein lime and combined depressants are added in the first and second concentration operations, and only combined depressants are added in the third concentration operation, and the tailings of each concentration operation are returned to the previous operation in sequence to form a closed loop, and a final lead concentrate is obtained after three concentration operations; The combined collector is a combination of No. 25 black medicine and aniline black medicine, and the mass ratio of the two is 3:1; the combined inhibitor is a combination of zinc sulfate and methionine, and the mass ratio of the two is 2:1; lime is used as a pyrite inhibitor and pH adjuster.

2. The use of the combined depressant according to claim 1 in the flotation separation of associated gold, silver, lead and zinc sulfide ores, characterized in that: In step (2), the amount of lime used is 1000-2000 g / t, the amount of combined inhibitor used is 700-1000 g / t, and the amount of combined collector used is 120-150 g / t.

3. The use of the combined depressant according to claim 1 in the flotation separation of associated gold, silver, lead and zinc sulfide ores, characterized in that: In step (3), the amount of lime used in the first sweeping operation is 300-500 g / t, the amount of combined collector used is 40-60 g / t, and the amount of combined collector used in the second sweeping operation is 10-20 g / t.

4. The use of the combined depressant according to claim 1 in the flotation separation of associated gold, silver, lead and zinc sulfide ores, characterized in that: In step (4), the amount of lime used in the first concentration operation is 300-500 g / t, and the amount of combined inhibitor used is 400-600 g / t. The amount of lime used in the second concentration operation is 100-200 g / t, and the amount of combined inhibitor used is 200-300 g / t. The amount of combined inhibitor used in the third concentration operation is 100-200 g / t.

5. The use of the combined depressant according to claim 1 in the flotation separation of associated gold, silver, lead and zinc sulfide ores, characterized in that: The rough selection time of lead is 4 minutes, the first and second sweeping selection time are 4 minutes and 3.5 minutes respectively, and the first, second and third concentration selection time are 3.5 minutes, 3 minutes and 2.5 minutes respectively.

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