Non-alkali beneficiation method of lead zinc sulfide ore

Abstract

The present application relates to the technical field of sulfide lead-zinc ore dressing, and discloses an alkali-free ore dressing method for sulfide lead-zinc ore. The method comprises the following steps: grinding to obtain ore slurry; performing lead flotation on the ore slurry to obtain lead concentrate and lead tailings; adding pyrite depressant, zinc activator and zinc flotation collector into the lead tailings slurry to perform zinc flotation, and obtaining zinc concentrate and final tailings; wherein, in the process of lead flotation, the added lead flotation depressant is a mixture of lignosulfonate and zinc sulfate; in the process of zinc flotation, the added pyrite depressant is composed of trithiocarbonate containing a hydrophilic group and a sulfur-containing inorganic salt. The present application can realize alkali-free flotation of sulfide lead-zinc ore, avoid the disadvantages of high-alkali lime process, and improve the lead-zinc separation efficiency.

Description

Technical Field

[0001] This invention relates to the field of lead-zinc sulfide ore beneficiation technology, and in particular to an alkali-free beneficiation method for lead-zinc sulfide ore. Background Technology

[0002] Lead-zinc sulfide ores, as important non-ferrous metal mineral resources, play a vital role in the national economy and are widely used in metallurgy, machinery, electrical engineering, military industry, chemical industry, light industry, and pharmaceuticals. These ores are complex in nature, often containing pyrite, marcasite, pyrrhotite, and other pyrite minerals. Due to the high content and relatively high floatability of pyrite minerals, they often enter the lead and zinc concentrates during flotation, affecting their grades. Therefore, in the beneficiation of lead-zinc sulfide ores, it is unavoidable to add pyrite depressants to improve the grades of lead and zinc concentrates.

[0003] Currently, the traditional sulfur suppression process uses a high-alkali beneficiation process, especially in the zinc flotation stage. The classic process involves adding a large amount of lime to adjust the pH of the slurry to above 11 to suppress pyrite, then adding copper sulfate to activate zinc sulfide, using xanthate as a collector to float zinc sulfide, or using xanthate collectors for zinc-sulfur co-selection, and then adding a large amount of lime for zinc-sulfur separation.

[0004] However, the inventors of this application recognize that the high-alkali lime process has the following problems: (1) A large amount of lime will have a negative impact on the flotation of lead and zinc minerals, and the impact is more obvious when the zinc sulfide mineral is iron sphalerite, and the recovery rate of zinc minerals will be greatly reduced; (2) Adding too much lime will lead to problems such as pipe scaling; (3) Adding a large amount of lime will inhibit the associated gold and silver, affecting the recovery rate of precious metals; (4) The tailings slurry has a high pH value, which puts great pressure on environmental protection. Summary of the Invention

[0005] According to one embodiment of the present invention, the objective is to provide an alkali-free beneficiation method for lead-zinc sulfide ore. This objective can be achieved through the following technical solutions:

[0006] According to one aspect of the present invention, an alkali-free beneficiation method for lead-zinc sulfide ore is provided, comprising: grinding to obtain a slurry;

[0007] The slurry is subjected to lead flotation to obtain lead concentrate and lead tailings; wherein the lead flotation inhibitor added during the lead flotation process is a mixture of lignin sulfonate and zinc sulfate in a ratio of 1:(1-3);

[0008] Add pyrite inhibitor, zinc activator and zinc flotation collector to lead tailings slurry to carry out zinc flotation and obtain zinc concentrate and final tailings; wherein, the pyrite inhibitor is composed of trithiocarbonate containing hydrophilic groups and sulfur-containing inorganic salt in a ratio of 1:(50-100).

[0009] Optionally, the trithiocarbonate containing hydrophilic groups in the pyrite inhibitor has the following structural formula:

[0010]

[0011] Where R is a hydrocarbon group containing 1 to 3 carbon atoms, X is a hydroxyl or carboxyl group, and Me is a metal ion.

[0012] Optionally, the sulfur-containing inorganic salt in the pyrite inhibitor is one or more of sulfites, metabisulfites, and thiosulfates. Further, the salt can be a sodium salt, potassium salt, etc.

[0013] Optionally, the zinc flotation collector is composed of a carbonyl-containing thiocarbamate, a carbonyl-containing dithiocarbonate, and an alcohol; wherein, the carbonyl-containing thiocarbamate in the zinc flotation collector has the following structural formula:

[0014]

[0015] Among them, R1 and R2 are hydrocarbon groups, which may be the same or different, and contain 2 to 6 carbon atoms.

[0016] Optionally, the carbonyl-containing dithiocarbonate in the zinc flotation collector has the following structural formula:

[0017]

[0018] Among them, R1 and R2 are hydrocarbon groups, which may be the same or different, and contain 2 to 6 carbon atoms.

[0019] Optionally, the alcohol in the zinc flotation collector is one or more of methanol, ethanol, and isopropanol.

[0020] Optionally, the ratio of the total amount of carbonyl-containing urethane and carbonyl-containing dithiocarbonate to alcohol is (90%–95%): (10%–5%).

[0021] Optionally, during lead flotation, the lead flotation collector added is a black powder collector, which includes one or more of butylammonium black powder, No. 25 black powder, and aniline black powder.

[0022] Optionally, the grinding fineness is 70-75% -0.074 mm.

[0023] Optionally, the lead flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage; the zinc flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage; the zinc activator is copper sulfate.

[0024] Optionally, the zinc concentrate recovery rate is ≥92%.

[0025] Beneficial effects: According to the above-described embodiments of the present invention, based on the principle of light pulling and light pressing, lignin sulfonate and zinc sulfate are mixed in proportion as lead flotation inhibitors during lead flotation, and pyrite inhibitors composed of trithiocarbonate containing hydrophilic groups and sulfur-containing inorganic salts are added in proportion during zinc flotation, along with zinc flotation collectors. Through the combination of the above inhibitors and collectors, alkali-free flotation of sulfide lead-zinc ore is achieved, avoiding a series of drawbacks of the high-alkali lime process and improving lead-zinc separation efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of an alkali-free beneficiation method for lead-zinc sulfide ore in one embodiment of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be clearly and completely described below with reference to embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Figure 1 The schematic diagram illustrates the flow of an alkali-free beneficiation method for lead-zinc sulfide ore according to an embodiment of the present invention. For example... Figure 1 As shown, the alkali-free beneficiation method for lead-zinc sulfide ore in this embodiment specifically includes the following steps:

[0029] 1) Grinding and pulping: The grinding fineness is -0.074mm, accounting for 70-75%.

[0030] 2) Lead flotation: Lead flotation depressants, lead flotation collectors, and frothers are added to the slurry. The lead flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage. Lead flotation yields lead concentrate and lead tailings.

[0031] The lead flotation inhibitor is a mixture of lignin sulfonate and zinc sulfate. The lignin sulfonate can be, for example, sodium, potassium, calcium, or ammonium salts. Lignosulfonate is a large organic molecule containing functional groups such as methoxy, hydroxyl, carbonyl, and phenolic hydroxyl groups, which can react with zinc and iron. When lignin sulfonate is mixed with zinc sulfate, some lignin reacts with zinc sulfate to form lignin sulfonate chelated zinc. This substance, together with lignin sulfonate and zinc sulfate, effectively inhibits the flotation of pyrite and zinc sulfide minerals. Lead flotation is performed based on this inhibitor. Further addition of pyrite inhibitor, zinc activator, and zinc flotation collector for zinc flotation improves lead-zinc separation efficiency and achieves alkali-free beneficiation, overcoming a series of drawbacks of the high-alkali lime process.

[0032] Furthermore, in the lead flotation depressant, the ratio of lignin sulfonate to zinc sulfate is 1:(1-3), which allows the generated lignin sulfonate to chelate zinc, and the lignin sulfonate and zinc sulfate to work together, further improving the effective suppression of pyrite and zinc sulfide minerals. In addition, the lead flotation collector is a distillate collector, which can be one or more of butanone distillate, No. 25 distillate, aniline distillate, etc. The frother is a commonly used flotation frother, such as No. 2 oil, grade methyl isobutyl methanol, sec-octanol, etc.

[0033] 3) Zinc flotation: A sulfur inhibitor (i.e., a pyrite inhibitor), a zinc activator, and a zinc collector (i.e., a zinc flotation collector) are added to the lead tailings slurry. The zinc flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage. Zinc flotation yields zinc concentrate and final tailings. In this example, the zinc activator is copper sulfate.

[0034] The pyrite inhibitor is composed of a trithiocarbonate containing a hydrophilic group and a sulfur-containing inorganic salt, in a ratio of 1:(50-100).

[0035] The structural formula of the trithiocarbonate containing hydrophilic groups is as follows:

[0036]

[0037] In this system, R can be a hydrocarbon group containing 1 to 3 carbon atoms, X is a hydroxyl or carboxyl group, and Me is a metal ion, such as Na. + K + In the above structural formula, the right-hand end group can be either H or Me. Furthermore, R is an alkyl group used to connect hydrophilic groups, and can also be an alkenyl group.

[0038] For example, the trithiocarbonate containing a hydrophilic group is sodium / potassium hydroxyethyl trithiocarbonate, where X is a hydroxyl group, R is an ethyl group, and the right-hand end group is a sodium / potassium metal ion, etc. Another example is sodium / potassium hydroxypropyl trithiocarbonate, sodium / potassium carboxyethyl trithiocarbonate, etc.

[0039] The sulfur-containing inorganic salt can be a sulfite, metabisulfite, thiosulfate, etc., and the corresponding salt can be a sodium salt, potassium salt, etc. For example, it can be one or more of sodium sulfite / potassium, sodium metabisulfite / potassium, sodium thiosulfate / potassium, etc.

[0040] For example, the pyrite inhibitor is sodium hydroxyethyl trithiocarbonate and sodium sulfite. The pyrite inhibitor is sodium hydroxypropyl trithiocarbonate and sodium metabisulfite. The pyrite inhibitor is sodium carboxyethyl trithiocarbonate and sodium thiosulfate, etc., and is not limited to these examples; they are not listed exhaustively.

[0041] In the described pyrite depressant, trithiocarbonates containing hydrophilic groups can undergo chemisorption on the surface of pyrite. Simultaneously, due to their inherent hydrophilic groups, they enhance the hydrophilicity of the pyrite surface. When combined with traditional sulfur-containing inorganic salts as pyrite depressants, the depressant effect is strengthened, especially against a small portion of easily floatable marcasite and pyrite. By applying the aforementioned pyrite depressant to lead tailings slurry obtained from lead flotation using lead flotation based on the above-mentioned lead flotation depressant, and employing a zinc flotation collector, alkali-free flotation of sulfide lead-zinc ore is achieved, improving lead-zinc separation efficiency.

[0042] Furthermore, the zinc flotation collector is composed of carbonyl-containing thiocarbamate, carbonyl-containing dithiocarbonate, and alcohol. The carbamate and dithiocarbonate can be in any proportion, with their total amount relative to the alcohol being (90%–95%):(10%–5%). This provides excellent dispersion for the carbamate and dithiocarbonate while fully utilizing their collecting effect on zinc sulfide minerals.

[0043] The structural formulas of the above carbonyl-containing thiocarbamates are as follows:

[0044]

[0045] In this structure, R1 and R2 are hydrocarbon groups, which may be the same or different, and generally contain 2 to 6 carbon atoms. Furthermore, the hydrocarbon group is an alkyl group; for example, R1 and R2 can be butyl, isopropyl, etc. The structural formula of the above carbonyl-containing dithiocarbonate is as follows:

[0046]

[0047] In this configuration, R1 and R2 are hydrocarbon groups, which may be the same or different, and generally contain 2 to 6 carbon atoms. Furthermore, the hydrocarbon group is an alkyl group; for example, R1 and R2 may be butyl, isopropyl, etc.

[0048] The alcohol can be one or more of methanol, ethanol, isopropanol, etc.

[0049] For example, the zinc flotation collector is composed of O-butyl-N-carbonylbutyl-thiocarbamate, O-butyl-S-carbonylbutyl-dithiocarbonate, and isopropanol. The zinc flotation collector may also be composed of O-isopropyl-N-carbonylbutyl-thiocarbamate, O-isopropyl-S-carbonylbutyl-dithiocarbonate, and isopropanol, etc., and is not limited to these examples; they are not listed exhaustively.

[0050] While carbamates and dithiocarbonates exhibit some selectivity for zinc sulfide and pyrite, the inventors discovered in their research that these collectors still collect a significant portion of pyrite when beneficiating zinc sulfide minerals. This results in the zinc concentrate obtained using these agents in alkali-free zinc beneficiation processes still containing a certain amount of pyrite. The carbonyl-containing thiocarbamates and dithiocarbonates used in this application involve adding a carbonyl group next to the collecting thiocarbonyl group, reducing the electron cloud density of the S atom in the thiocarbonyl group and significantly improving the selectivity of the aforementioned agents. The combination of these two sets of agents utilizes their synergistic effect to enhance the collection of zinc sulfide minerals. Simultaneously, the addition of alcohols promotes the dispersion of the ester agents in the pulp, further enhancing the agent's effectiveness.

[0051] In some embodiments of this application, a lead flotation inhibitor is used by mixing lignin sulfonate and zinc sulfate in a certain proportion during the lead flotation process. A pyrite inhibitor composed of trithiocarbonate containing hydrophilic groups and sulfur-containing inorganic salts in a certain proportion is added during the zinc flotation process. A zinc flotation collector composed of carbonyl-containing thiocarbamate, carbonyl-containing dithiocarbonate, and alcohol is also added. Through this combination of inhibitors and collectors, an alkali-free flotation process for sulfide lead-zinc ore is achieved, avoiding a series of drawbacks of the high-alkali lime process and improving lead-zinc separation efficiency. The final product can be lead concentrate with a lead grade >60% and a recovery rate >87%, and zinc concentrate with a zinc grade >47% and a zinc recovery rate >92%. Compared to the traditional alkali process, with similar concentrate grades, the zinc concentrate recovery rate is increased by at least 1.5 percentage points. Simultaneously, it overcomes problems such as pipe scaling and high environmental pressure caused by the use of large amounts of lime.

[0052] The preferred embodiments of this application will be described in more detail below with reference to specific examples:

[0053] Example 1:

[0054] A certain lead-zinc mine contains 1.67% lead, 4.50% zinc, and 19.34% sulfur. The main metallic minerals are pyrrhotite, sphalerite, galena, and other sulfide minerals.

[0055] Separation was carried out under the condition that 70% of the grinding fineness was -0.074mm. The depressant added in the lead flotation stage was sodium lignosulfonate 1:1 zinc sulfate, and the lead collector was No. 25 black reagent. The collector dosages for roughing, scavenging 1, and scavenging 2 were 25g / t, 15g / t, and 5g / t, respectively; the lead flotation depressant dosages for roughing, cleaning 1, and cleaning 2 were 200g / t, 50g / t, and 20g / t, respectively.

[0056] The depressant in the zinc flotation stage consists of sodium sulfite and sodium hydroxyethyl trithiocarbonate in a ratio of 80:1. The zinc collector is composed of O-butyl-N-carbonylbutyl-thiocarbamate, O-butyl-S-carbonylbutyl-dithiocarbonate, and isopropanol in a ratio of 45%:45%:10%.

[0057] The copper sulfate addition amounts for zinc roughing and zinc scavenging 1 are 250 g / t and 50 g / t, respectively. The collector dosages for zinc roughing, scavenging 1, and scavenging 2 are 40 g / t, 20 g / t, and 10 g / t, respectively. The depressant dosages for zinc roughing, cleaning 1, cleaning 2, and cleaning 3 are 500 g / t, 250 g / t, 100 g / t, and 50 g / t, respectively. This reagent system yields lead concentrate with a lead grade of 62.12% and a recovery rate of 90.34%, and zinc concentrate with a zinc grade of 47.34% and a zinc recovery rate of 92.13%.

[0058] If the traditional high-alkali process is used, No. 25 black reagent is used as the collector for lead flotation, zinc sulfate is used as the lead flotation depressant, and lime is added to control the pulp pH to 10. In the zinc flotation stage, butyl xanthate is used as the collector, copper sulfate is used as the activator, and lime is added to control the pulp pH to 11.5. Because the iron sphalerite is inhibited by lime, the zinc concentrate recovery rate decreases by about 3 percentage points when the concentrate grade is similar.

[0059] Example 2:

[0060] A certain lead-zinc mine contains 0.67% lead, 3.50% zinc, and 10.34% sulfur. The main metallic minerals are marcasite, sphalerite, and galena.

[0061] Separation was carried out under the condition that 70% of the grinding fineness was -0.074mm. The depressant added in the lead flotation stage was sodium lignosulfonate 1:2 zinc sulfate, and the lead collector was No. 25 black reagent. The collector dosages for roughing, scavenging 1, and scavenging 2 were 20g / t, 10g / t, and 5g / t, respectively; the lead flotation depressant dosages for roughing, cleaning 1, and cleaning 2 were 200g / t, 50g / t, and 20g / t, respectively.

[0062] The depressant in the zinc flotation stage consists of sodium sulfite and sodium hydroxyethyl trithiocarbonate in a ratio of 50:1. The zinc collector is composed of O-butyl-N-carbonylbutyl-thiocarbamate, O-butyl-S-carbonylbutyl-dithiocarbonate, and isopropanol in a ratio of 45%:45%:10%.

[0063] The copper sulfate addition amounts for zinc roughing and zinc scavenging 1 are 200 g / t and 50 g / t, respectively. The collector dosages for zinc roughing, scavenging 1, and scavenging 2 are 30 g / t, 15 g / t, and 10 g / t, respectively. The depressant dosages for zinc roughing, cleaning 1, cleaning 2, and cleaning 3 are 600 g / t, 300 g / t, 100 g / t, and 50 g / t, respectively. This reagent system yields lead concentrate with a lead grade of 60.23% and a recovery rate of 87.34%, and zinc concentrate with a zinc grade of 51.23% and a zinc recovery rate of 93.56%.

[0064] If the traditional high-alkali process is used, No. 25 black reagent is used as the collector for lead flotation, zinc sulfate is used as the lead flotation depressant, and lime is added to control the pulp pH to 10. In the zinc flotation stage, butyl xanthate is used as the collector, copper sulfate is used as the activator, and lime is added to control the pulp pH to 11.5. Because the iron sphalerite is inhibited by lime, the zinc concentrate recovery rate decreases by about 1.5 percentage points when the concentrate grade is similar.

[0065] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for the non-alkali beneficiation of a lead-zinc sulfide ore, characterized in that, include: Grinding yields slurry; The slurry is subjected to lead flotation to obtain lead concentrate and lead tailings; wherein the lead flotation inhibitor added during the lead flotation process is a mixture of lignin sulfonate and zinc sulfate in a ratio of 1:(1-3); Add pyrite inhibitor, zinc activator and zinc flotation collector to lead tailings slurry to carry out zinc flotation and obtain zinc concentrate and final tailings. The pyrite inhibitor is composed of trithiocarbonate containing hydrophilic groups and sulfur-containing inorganic salt in a ratio of 1:(50-100). The zinc flotation collector is composed of a carbonyl-containing thiocarbamate, a carbonyl-containing dithiocarbonate, and an alcohol; wherein, the carbonyl-containing thiocarbamate in the zinc flotation collector has the following structural formula: Among them, R1 and R2 are hydrocarbon groups, which may be the same or different, and contain 2 to 6 carbon atoms.

2. The method of claim 1, wherein the method is characterized by, The pyrite inhibitor contains a trithiocarbonate with a hydrophilic group, and its structural formula is as follows: Where R is a hydrocarbon group containing 1 to 3 carbon atoms, X is a hydroxyl or carboxyl group, and Me is a metal ion.

3. The method of claim 1, wherein the method is characterized by, The sulfur-containing inorganic salt in the pyrite inhibitor is one or more of sulfites, metabisulfites, and thiosulfates.

4. The method of claim 1, wherein the method is characterized by, The zinc flotation collector contains a carbonyl-containing dithiocarbonate with the following structural formula: Among them, R1 and R2 are hydrocarbon groups, which may be the same or different, and contain 2 to 6 carbon atoms.

5. The method of claim 1, wherein the method is characterized by, The zinc flotation collector contains one or more of methanol, ethanol, and isopropanol.

6. The method of claim 1, wherein the method is characterized by, The ratio of the total amount of carbonyl-containing thiocarbamates and carbonyl-containing dithiocarbonates to alcohols is (90%–95%): (10%–5%).

7. The method of claim 1, wherein the method is characterized by, During lead flotation, the lead flotation collector added is a black powder collector, which includes one or more of butylammonium black powder, No. 25 black powder, and aniline black powder.

8. The method of claim 1, wherein the method is characterized by, The grinding fineness is -0.074 mm, accounting for 70-75%.

9. The method of claim 1, wherein the method is characterized by, The lead flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage; the zinc flotation stage includes a roughing stage, a scavenging stage, and a cleaning stage; the zinc activator is copper sulfate.

10. The method of claim 1, wherein the method is characterized by, The zinc concentrate recovery rate is ≥92%.

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