Copper-lead separation inhibitor, preparation method and usage method thereof

Abstract

The present invention provides a copper-lead separation inhibitor, a preparation method thereof and a using method thereof, belonging to the technical field of ore dressing agents and flotation technology. The preparation method of the inhibitor includes: providing a chitosan raw material with a deacetylation degree of ≥90%; providing mercaptoacetic acid, which is used as a mercaptoylation reagent to prepare mercaptochitosan with the chitosan raw material; providing acrylonitrile, which is used as a cyanation reagent to prepare cyanoethyl chitosan polymer with the chitosan raw material; and mixing the mercaptochitosan and the cyanoethyl chitosan polymer to obtain the copper-lead separation inhibitor; the weight ratio of the mercaptochitosan to the cyanoethyl chitosan polymer is 1:1-5. This inhibitor can be used in the flotation separation process of copper-lead mixed concentrate and copper-molybdenum mixed concentrate. The copper-lead separation inhibitor of the present invention can solve the problems of strong toxicity of cyanide in existing copper inhibitors, large environmental pollution, difficult treatment of wastewater, high price of mercaptoacetate salts, and difficult control of separation effect in production.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing agents and flotation technology, and particularly to a copper-lead separation inhibitor, a preparation method thereof, and a using method thereof. Background Art

[0002] As important mineral resources for China's national production, most non-ferrous metals such as copper and lead exist in the form of symbiotic and associated ores, and the grades are relatively low, making it difficult to recycle this part of resources. However, with the gradual depletion of easily mined and processed ores in recent years, the research on the effective recovery of symbiotic and associated metals in polymetallic ores has attracted more and more attention. How to effectively separate the mixed concentrate obtained by flotation of low-grade polymetallic ores has become an urgent technical problem to be solved.

[0003] China has rich copper-lead ore resources. Copper and lead belong to the copper-type ion structure, so the surface properties of copper and lead minerals existing in the earth's crust are similar, and their floatabilities are extremely close. In industrial production, a bulk flotation process is usually adopted to obtain a copper-lead mixed concentrate, and then copper-lead separation is carried out. Copper-lead separation is the main problem in the flotation of copper-lead ores and has always been a major problem in the ore dressing industry. The scheme can be to inhibit lead and float copper, or to inhibit copper and float lead. Which scheme is better needs to be determined through specific tests, but the general principle is: when the lead content in the ore is much higher than that of copper, lead should be inhibited and copper should be floated; conversely, when the copper content is close to or more than that of lead, copper should be inhibited and lead should be floated.

[0004] The traditional method for inhibiting copper and floating lead is specifically: using the sodium cyanide method and sodium thioglycolate or its upgraded agent to inhibit copper minerals and float lead minerals. Cyanide can inhibit pyrite, chalcopyrite, etc., and has no inhibitory effect on galena. Although cyanide has the advantages of less dosage and strong inhibitory ability, cyanide is a highly toxic substance, inconvenient for transportation, difficult to treat wastewater, and has great harm to the human body and the environment. With the strict national environmental protection requirements, cyanide is not suitable for large-scale use. And sodium thioglycolate is particularly sensitive to the de-drug effect and the dosage of the agent, which is difficult to control in actual production, resulting in difficult control of the copper-lead separation effect, and the price is relatively high, affecting the ore dressing cost.

[0005] Therefore, in the face of increasingly stringent environmental protection requirements and depleted mineral resources, the research on green, efficient, and low-cost copper-lead separation inhibitors has attracted more and more attention from industry personnel. New copper-lead separation inhibitors, preparation methods, and using methods are of great significance for the effective separation of mixed concentrates and the development of the ore dressing industry. Summary of the Invention

[0006] The present invention provides a copper-lead separation inhibitor, a preparation method thereof, and a using method thereof to solve the problems of strong toxicity of cyanide in existing copper inhibitors, great environmental pollution, difficult wastewater treatment, high price of thioglycolate salts, and difficult control of separation effect in production.

[0007] In a first aspect, the present invention provides a method for preparing a copper-lead separation inhibitor, comprising:

[0008] Providing a chitosan raw material with a deacetylation degree of ≥90%; providing thioglycolic acid, which is used as a mercapto group-introducing reagent to prepare mercapto chitosan with the chitosan raw material; providing acrylonitrile, which is used as a cyanoethylation reagent to prepare cyanoethyl chitosan polymer with the chitosan raw material; and mixing the mercapto chitosan and the cyanoethyl chitosan polymer to obtain a copper-lead separation inhibitor; the weight ratio of the mercapto chitosan to the cyanoethyl chitosan polymer is 1:1-5.

[0009] The present invention prepares a copper-lead separation inhibitor using chitosan as the matrix. The hydrophilic polar groups (-OH and -CONH) in chitosan are used to form a hydrophilic film on the surface of mineral particles, and the ore-loving polar groups (mercapto group and cyanoethyl group) are selectively adsorbed on the surface of copper-containing mineral particles, so that the copper-containing mineral particles are inhibited, achieving the effect of copper-lead separation. In addition, when the copper-lead separation inhibitor is used in combination with zinc sulfate, it can give full play to the synergistic effect, separate secondary copper minerals, and improve the copper-lead separation accuracy.

[0010] Chitosan is a natural organic polymer material, which is the product of chitin deacetylation, rich in amino and hydroxyl groups. The atoms in these groups have lone electron pairs and can coordinate with metal ions. Therefore, using chitosan as the matrix to prepare mercapto chitosan and cyanoethyl chitosan polymer has the advantages of simple preparation method, easy availability of raw materials and low production cost.

[0011] According to the present invention, the preparation steps of mercapto chitosan are as follows: Take chitosan, thioglycolic acid and concentrated sulfuric acid with a concentration of 75% and mix them, then carry out a water bath stirring reaction. After the reaction is completed, filter, and wash the obtained reaction product with distilled water and ethanol in turn until neutral, and then dry it under vacuum to obtain mercapto chitosan.

[0012] Furthermore, the weight ratio of chitosan, mercapto group-introducing reagent and concentrated sulfuric acid is 1:5-15:0.05-0.1; the temperature of the water bath stirring reaction is 35-45°C, the stirring speed is 300-1000 r / min, and the time is 8-16 h; the vacuum drying temperature is 40-60°C, and the time is 24-48 h.

[0013] Introducing a mercapto group on the chitosan matrix, the introduced mercapto group and the amino and hydroxyl groups of chitosan itself can form a chelate with Cu 2+ to form a chelate, so as to strongly adsorb and complex with the surface of copper-containing mineral particles, fix on the surface of mineral particles, and then use the hydrophilic groups (-OH and -CONH) of chitosan itself to greatly increase the hydrophilicity of mineral particles, so that the copper-containing mineral particles are inhibited, and the copper inhibition effect is remarkable.

[0014] According to the present invention, the preparation steps of the cyanoethyl chitosan polymer are as follows:

[0015] a) Add acrylonitrile to chitosan, stir, and add a 5% NaOH solution during stirring. After reacting at a constant temperature of 25 - 40 °C for 6 - 12 h, perform suction filtration, wash with acetone until neutral, and then dry to obtain cyanoethyl chitosan;

[0016] b) Add a copper sulfate solution with a concentration of 100 - 150 mg / L and a pH of 3 - 4 to cyanoethyl chitosan, then stir at 25 - 40 °C for 6 - 8 h, perform suction filtration and wash with water 2 - 3 times. Then make the precipitate obtained by suction filtration into a suspension with a solid content of 18 - 25% by adding water. Next, add a crosslinking agent solution with a concentration of 20 - 30% to the suspension, stir and react at 30 - 45 °C for 5 - 8 h, perform suction filtration, and then wash the obtained crosslinked product successively with water, ethanol, and ether, and dry to obtain crosslinked cyanoethyl chitosan;

[0017] c) Add a 0.1 mol / L hydrochloric acid solution to the crosslinked cyanoethyl chitosan, soak for 10 - 12 h, then wash successively with water, ethanol, and ether, and dry under vacuum to obtain the cyanoethyl chitosan polymer.

[0018] The cyanoethyl chitosan polymer uses cyanoethyl chitosan as a functional monomer, and during the polymerization process, Cu 2+ leaves "holes" that can match with Cu 2+ in the spatial structure and binding sites of the polymer. This enables the cyanoethyl chitosan polymer to selectively adsorb and accommodate Cu 2+ on the one hand using these "holes", and on the other hand, form chelates with Cu 2+ using its own amino and hydroxyl groups. As a result, the cyanoethyl chitosan polymer binds tightly to the copper - containing ore particles, and the hydrophilic groups of chitosan are used to increase the hydrophilicity of the ore particles, making the floatability of the copper - containing ore particles worse, thereby achieving the effect of copper inhibition. In addition, after the cyanoethyl chitosan polymer adsorbs the copper - containing ore particles, it is also easy to elute. Therefore, the cyanoethyl chitosan polymer can be reused repeatedly and is not easily deactivated.

[0019] Furthermore, the solid - liquid ratio of chitosan to acrylonitrile is 1 g∶40 - 50 mL, and the addition amount of the NaOH solution is 4 - 5% of the weight of acrylonitrile; the solid - liquid ratio of crosslinked cyanoethyl chitosan to the hydrochloric acid solution is 1 g∶50 - 70 mL.

[0020] Furthermore, the solid - liquid ratio of cyanoethyl chitosan to the copper sulfate solution is 1 g∶40 - 50 mL; the crosslinking agent solution is a glutaraldehyde solution, and the weight ratio of the crosslinking agent solution to the suspension is 1.5 - 2∶1.

[0021] Second aspect, the present invention provides a copper-lead separation inhibitor prepared by the aforementioned preparation method. The copper-lead separation inhibitor in the present invention is an easily soluble powdery solid, with stable chemical properties, not easily oxidized and inactivated, strong inhibition effect and small dosage, which can greatly enhance the wettability of ore particles, thus greatly increasing the difficulty of ore particles adhering to bubbles, not polluting the concentrate after flotation, and at the same time not causing problems of difficult foam control, making the flotation process easier to carry out and the concentrate after flotation have higher value.

[0022] Third aspect, the present invention provides an application of the copper-lead separation inhibitor prepared by the aforementioned preparation method in the flotation separation process of copper-lead mixed concentrate and copper-molybdenum mixed concentrate. The addition method of the copper-lead separation inhibitor is: directly add the solid copper-lead separation inhibitor, or, prepare the copper-lead separation inhibitor into a solution with a mass concentration of 1-10% and then add it.

[0023] The copper-lead separation inhibitor of the present invention can be used for copper-lead separation, copper-molybdenum separation, etc., and can obtain copper concentrate and lead concentrate with better quality and higher grade. The separation effect of the copper-lead separation inhibitor is good, and it can completely replace traditional agents such as sodium cyanide and sodium mercaptoacetate. It has little harm to the human body in the on-site production process, and the production wastewater is convenient to treat, which can protect the environment and improve the on-site production efficiency.

[0024] In a specific example, when the raw ore contains secondary copper, the copper-lead separation inhibitor can be used in combination with zinc sulfate, and the flotation separation effect will be better.

[0025] Fourth aspect, the present invention provides a usage method of the copper-lead separation inhibitor prepared by the aforementioned preparation method. Add the copper-lead separation inhibitor in the roughing, cleaning and scavenging of the flotation separation process of copper-lead mixed concentrate; in the flotation separation process, it includes one roughing, three cleanings and two scavengings.

[0026] The copper-lead separation inhibitor of the present invention has less pollution to the concentrate during use, has high environmental friendliness, and also has the characteristics of small dosage, good selectivity, good inhibition effect and not easily oxidized and inactivated.

[0027] According to the present invention, the usage method includes the following steps:

[0028] 1) Add the copper-lead separation inhibitor, collector BK902 and foaming agent BK204 to the copper-lead mixed concentrate. After one roughing, obtain the lead roughing concentrate and the lead roughing tailings; the dosage of the copper-lead separation inhibitor is 100-1000 g / t, the dosage of the collector is 10-30 g / t, and the dosage of the foaming agent is 2-5 g / t;

[0029] 2) The lead rougher concentrate is further concentrated three times to obtain lead concentrate. During the first cleaning process, 50 - 500 g / t of copper - lead separation inhibitor, 1 - 5 g / t of collector BK902, and 0.5 - 1 g / t of frother BK204 are added. During the second cleaning process, 25 - 60 g / t of copper - lead separation inhibitor and 0.5 - 2.5 g / t of collector BK902 are added. During the third cleaning process, 15 - 30 g / t of copper - lead separation inhibitor is added.

[0030] 3) The lead rougher tailings are scavenged twice to obtain copper concentrate. During the first scavenging process, 60 - 600 g / t of copper - lead separation inhibitor, 5 - 10 g / t of collector BK902, and 1 - 3.5 g / t of frother BK204 are added. During the second scavenging process, 30 - 60 g / t of copper - lead separation inhibitor, 2.5 - 5 g / t of collector BK902, and 0.5 - 1.5 g / t of frother BK204 are added.

[0031] 4) The middlings produced in each step of cleaning and scavenging are sequentially returned to the previous step.

[0032] The copper - lead separation inhibitor, its preparation method and its use method provided by the present invention achieve the following beneficial effects by providing a means of preparing a copper inhibitor with chitosan as the matrix and introducing ore - philic polar groups (mercapto and cyanoethyl):

[0033] 1) The copper - lead separation inhibitor prepared by the present invention is a copper inhibitor with green environmental protection, good selectivity and low comprehensive cost. During use, it can utilize the synergistic effect of groups with different functions, adsorb on the surface of copper - bearing ore particles through the solid - affinity groups, and enhance the hydrophilicity of copper - bearing ore particles through its hydrophilic groups, making the floatability of copper - bearing ore particles worse, exerting the selective inhibition ability, and significantly reducing the mutual metal content in the concentrate products obtained by flotation separation (such as lead concentrate and copper concentrate obtained by copper - lead separation), with good separation effect.

[0034] 2) The raw materials of the copper - lead separation inhibitor in the present invention are easily available, with good copper - inhibiting effect, easy to store and promote, reducing the ore - dressing cost, and improving the problems of strong toxicity of cyanide, large environmental pollution and difficult wastewater treatment in existing copper inhibitors, and high price of mercaptoacetates and difficult control of separation effect in production, providing a new means for the development and utilization of multi - metal copper - bearing ore resources and the separation of copper - containing polymetallic mixed concentrates.

[0035] 3) The copper - lead separation inhibitor of the present invention has a strong inhibition effect and a small dosage, will not pollute the concentrate after flotation, and will not cause problems of difficult foam control. When used in combination with zinc sulfate, it can give full play to the synergistic effect, separate secondary copper minerals, improve the copper - lead separation accuracy, can be used for copper - lead separation, copper - molybdenum separation, etc., and can obtain concentrate products with better quality and higher grade. Description of the Drawings

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 This is the process flow diagram of the closed-circuit test in Test Example 2 of the present invention. Specific embodiments

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts also fall within the scope of protection of the present invention.

[0039] In specific embodiments, the preparation method of the copper-lead separation inhibitor of the present invention includes the following steps:

[0040] 1) Preparation of mercapto chitosan: Chitosan, mercaptoacetic acid, and concentrated sulfuric acid with a concentration of 75% are mixed, and then subjected to a water bath stirring reaction at a temperature of 35 - 45°C and a stirring speed of 300 - 1000 r / min for 8 - 16 h. After the reaction is completed, filtration is carried out, and the obtained reaction product is washed with distilled water and ethanol in sequence until neutral, and then vacuum dried at a temperature of 40 - 60°C for 24 - 48 h to obtain mercapto chitosan. The weight ratio of chitosan, mercapto reagent, and concentrated sulfuric acid is 1∶5 - 15∶0.05 - 0.1.

[0041] 2) Preparation of cyanoethyl chitosan polymer:

[0042] a) Add acrylonitrile to chitosan, stir, and add a 5% NaOH solution during the stirring process. After reacting at a constant temperature of 25 - 40°C for 6 - 12 h, filtration is carried out, and it is washed with acetone until neutral and then dried to obtain cyanoethyl chitosan.

[0043] The solid-liquid ratio of the above chitosan and acrylonitrile is 1 g∶40 - 50 mL, and the addition amount of the NaOH solution is 4 - 5% of the weight of acrylonitrile.

[0044] b) Add a copper sulfate solution with a concentration of 100 - 150 mg / L and a pH of 3 - 4 to cyanoethyl chitosan, then stir at 25 - 40 °C for 6 - 8 h, followed by suction filtration and washing with water 2 - 3 times. Then, add water to the precipitate obtained by suction filtration to make a suspension with a solid content of 18 - 25%. Next, add a crosslinking agent solution with a concentration of 20 - 30% to the suspension, stir and react at 30 - 45 °C for 5 - 8 h, then perform suction filtration. Subsequently, wash the obtained crosslinked product successively with water, ethanol, and ether, and dry it to obtain crosslinked cyanoethyl chitosan.

[0045] The solid - liquid ratio of the above - mentioned cyanoethyl chitosan to the copper sulfate solution is 1 g∶40 - 50 mL; the crosslinking agent solution is a glutaraldehyde solution, and the weight ratio of the crosslinking agent solution to the suspension is 1.5 - 2∶1.

[0046] c) Add a 0.1 mol / L hydrochloric acid solution to the crosslinked cyanoethyl chitosan, soak for 10 - 12 h, then wash successively with water, ethanol, and ether, and dry under vacuum to obtain a cyanoethyl chitosan polymer.

[0047] The solid - liquid ratio of the above - mentioned crosslinked cyanoethyl chitosan to the hydrochloric acid solution is 1 g∶50 - 70 mL.

[0048] 3) Take mercapto chitosan and the cyanoethyl chitosan polymer and mix them in a weight ratio of 1∶1 - 5 to obtain a copper - lead separation inhibitor.

[0049] As a further improvement to the foregoing implementation, the crosslinking agent solution used for preparing the cyanoethyl chitosan polymer also includes 1 - 2 wt% of 6 - aminohexanoic acid and 0.5 - 1 wt% of sodium fumarate. The hydrophobicity and structural density of the polymer crosslinked by glutaraldehyde will increase as the crosslinking proceeds, which will cause it to be difficult for Cu 2+ to approach the polymer, resulting in a deteriorated copper - inhibiting effect. After adding 6 - aminohexanoic acid and sodium fumarate to the crosslinking agent, the two cooperate to connect with the groups of chitosan using their own hydroxyl, carboxyl, and amino groups, enabling more hydrophilic groups to be exposed during chitosan crosslinking, enhancing the hydrophilicity and dispersibility of the cyanoethyl chitosan polymer. At the same time, it can also provide more binding sites for complexing Cu 2+ , enhancing the adsorption capacity for Cu 2+ , thus making the copper - inhibiting effect of the cyanoethyl chitosan polymer more significant.

[0050] It should be noted that before the rough - selection step, it is necessary to perform a de - medicating treatment on the copper - lead mixed concentrate. Preferably, the de - medicating treatment adopts mechanical de - medicating or combined de - medicating.

[0051] The above - mentioned mechanical de - medicating step is: Add water to the copper - lead mixed concentrate to be floated according to a solid - liquid ratio of 2∶2.5 - 3.5 for grinding until the fineness of the pulp is - 400 mesh ≥85%, and the de - medicating is completed.

[0052] The above-mentioned combined reagent removal uses a combination of activated carbon and sodium sulfide. The steps are as follows: Add 800 - 1600 g / t of activated carbon and 500 - 1000 g / t of sodium sulfide to the copper-lead mixed concentrate to be floated, and then stir for 10 - 30 min to complete the reagent removal.

[0053] Before performing the copper-lead flotation separation, it is necessary to remove the reagents (collectors or excess reagents in the pulp) used in the previous process (the flotation separation of copper-lead mixed concentrate and other impurity minerals) from the surface of copper-lead metal minerals to avoid affecting the copper-lead flotation separation. The reagent removal treatment must be clean and thorough, and it is considered qualified when there are no metal minerals attached to the bubbles after flotation aeration.

[0054] In specific examples, the reagent removal treatment can also adopt at least one of regrinding reagent removal, stirring and washing reagent removal, sodium sulfide reagent removal, activated carbon adsorption reagent removal, and heating reagent removal.

[0055] The present invention will be further described in detail below with reference to the embodiments.

[0056] Example 1:

[0057] A preparation method of a copper-lead separation inhibitor includes the following steps:

[0058] 1) Take chitosan, mercaptoacetic acid, and concentrated sulfuric acid with a concentration of 75% and mix them. Then, carry out a water bath stirring reaction at a temperature of 40°C and a stirring speed of 700 r / min for 12 h. After the reaction is completed, filter, and wash the obtained reaction product successively with distilled water and ethanol until neutral. Then, vacuum dry it at a temperature of 55°C for 36 h to obtain mercaptochitosan. The weight ratio of chitosan, mercaptoylation reagent, and concentrated sulfuric acid is 1∶15∶0.07.

[0059] 2) Add acrylonitrile to chitosan, stir, and add a 5% NaOH solution during the stirring process. After reacting at a constant temperature of 40°C for 10 h, perform suction filtration, wash it with acetone until neutral, and then dry it to obtain cyanoethyl chitosan. The solid-liquid ratio of the above-mentioned chitosan and acrylonitrile is 1 g∶45 mL, and the addition amount of the NaOH solution is 4.5% of the weight of acrylonitrile.

[0060] 3) Add a copper sulfate solution with a concentration of 150 mg / L and a pH of 3.5 to cyanoethyl chitosan, and then stir at 40°C for 6 h. Then, perform suction filtration and wash it with water 3 times. Then, add water to the obtained precipitate to make a suspension with a solid content of 25%. Then, add a 25% cross-linking agent solution to the suspension, stir and react at 35°C for 6 h, perform suction filtration, and then wash the obtained cross-linked product successively with water, ethanol, and ether, and dry it to obtain cross-linked cyanoethyl chitosan.

[0061] The solid-liquid ratio of the above-mentioned cyanoethyl chitosan to the copper sulfate solution is 1 g∶50 mL; the crosslinking agent solution is a glutaraldehyde solution, and the weight ratio of the crosslinking agent solution to the suspension is 1.5∶1.

[0062] 4) Add 0.1 mol / L hydrochloric acid solution to the crosslinked cyanoethyl chitosan, soak for 12 h, then wash successively with water, ethanol and ether, and dry in vacuum to obtain the cyanoethyl chitosan polymer. The solid-liquid ratio of the above-mentioned crosslinked cyanoethyl chitosan to the hydrochloric acid solution is 1 g∶60 mL.

[0063] 5) Take mercapto chitosan and cyanoethyl chitosan polymer and mix them in a weight ratio of 1∶1.5 to obtain the copper-lead separation inhibitor.

[0064] Example 2:

[0065] In this example, a preparation method of a copper-lead separation inhibitor is only different from that of Example 1 in that:

[0066] In step 3), when preparing crosslinked cyanoethyl chitosan by adding a crosslinking agent solution with a total concentration of 25% to the suspension, the weight ratio of the crosslinking agent solution to the suspension is 1.5∶1, and the crosslinking agent solution is a mixed solution of glutaraldehyde, 6-aminocaproic acid and sodium fumarate, wherein the concentration of 6-aminocaproic acid is 1.5 wt% and the concentration of sodium fumarate is 1 wt%.

[0067] Example 3:

[0068] A method for using a copper-lead separation inhibitor includes the following steps:

[0069] 1) Add the copper-lead separation inhibitor, collector BK902, and frother BK204 prepared in Example 1 to the copper-lead mixed concentrate. After one rough selection, lead rough concentrate and lead rough tailings are obtained. The dosage of the copper-lead separation inhibitor is 600 g / t, the dosage of the collector is 30 g / t, and the dosage of the frother is 3 g / t.

[0070] 2) The lead rough concentrate is subjected to three times of cleaning to obtain lead concentrate. Among them, 300 g / t of copper-lead separation inhibitor, 5 g / t of collector BK902, and 1 g / t of frother BK204 are added in the first cleaning, 50 g / t of copper-lead separation inhibitor and 2.5 g / t of collector BK902 are added in the second cleaning, and 20 g / t of copper-lead separation inhibitor is added in the third cleaning.

[0071] 3) The lead rough tailings are subjected to two times of scavenging to obtain copper concentrate. Among them, 500 g / t of copper-lead separation inhibitor, 8 g / t of collector BK902, and 2.5 g / t of frother BK204 are added in the first scavenging, and 60 g / t of copper-lead separation inhibitor, 4 g / t of collector BK902, and 1 g / t of frother BK204 are added in the second scavenging.

[0072] 4) The middlings produced in each step of rough selection and scavenging are sequentially returned to the previous step.

[0073] Example 4:

[0074] In this example, a method for using a copper-lead separation inhibitor is different from that in Example 3 only in that: in the steps of one rough selection, three fine selections, and two scavengings, the copper-lead separation inhibitor used is prepared from Example 2.

[0075] Example 5:

[0076] A method for using a copper-lead separation inhibitor includes the following steps:

[0077] 1) Chitosan, mercaptoacetic acid, and concentrated sulfuric acid with a concentration of 75% are mixed, and then subjected to a water bath stirring reaction at a temperature of 45 °C and a stirring speed of 800 r / min for 16 h. After the reaction is completed, filtration is carried out, and the obtained reaction product is washed with distilled water and ethanol in sequence until neutral, and then vacuum dried at a temperature of 60 °C for 48 h to obtain mercaptochitosan. The weight ratio of chitosan, mercaptoylation reagent, and concentrated sulfuric acid is 1:10:0.1.

[0078] 2) Acrylonitrile is added to chitosan, stirred, and a 5% NaOH solution is added during the stirring process. After reacting at a constant temperature of 35 °C for 12 h, suction filtration is carried out, and after washing with acetone until neutral, it is dried to obtain cyanoethyl chitosan. The solid-liquid ratio of the above chitosan and acrylonitrile is 1 g:45 mL, and the addition amount of the NaOH solution is 5% of the weight of acrylonitrile.

[0079] 3) A copper sulfate solution with a concentration of 100 mg / L and a pH of 4 is added to cyanoethyl chitosan, and then stirred at 40 °C for 6 h, followed by suction filtration and washing with water twice. Then, the precipitate obtained by suction filtration is added with water to make a suspension with a solid content of 20%. Then, a 20% crosslinking agent solution is added to the suspension, and after stirring and reacting at 35 °C for 8 h, suction filtration is carried out, and then the obtained crosslinked product is washed with water, ethanol, and ether in sequence and dried to obtain crosslinked cyanoethyl chitosan.

[0080] The solid-liquid ratio of the above cyanoethyl chitosan to the copper sulfate solution is 1 g:40 mL; the crosslinking agent solution is a glutaraldehyde solution, and the weight ratio of the crosslinking agent solution to the suspension is 2:1.

[0081] 4) A 0.1 mol / L hydrochloric acid solution is added to crosslinked cyanoethyl chitosan, soaked for 10 h, and then washed with water, ethanol, and ether in sequence and vacuum dried to obtain a cyanoethyl chitosan polymer.

[0082] The solid-liquid ratio of the above crosslinked cyanoethyl chitosan to the hydrochloric acid solution is 1 g:50 mL.

[0083] 5) After mixing mercapto chitosan and cyanoethyl chitosan polymer in a weight ratio of 1:2.5, a copper-lead separation inhibitor is obtained.

[0084] 6) Add water to the copper-lead mixed concentrate to be floated according to a solid-liquid ratio of 2:2.5 for grinding until the fineness of the pulp is -400 mesh ≥ 85%, then the de-drugging is completed.

[0085] 7) Add a copper-lead separation inhibitor, a collector BK902, and a frother BK204 to the copper-lead mixed concentrate. After one rough selection, a lead rough concentrate and a lead rough tailing are obtained. The dosage of the copper-lead separation inhibitor is 800 g / t, the dosage of the collector is 30 g / t, and the dosage of the frother is 5 g / t.

[0086] 8) The lead rough concentrate is subjected to three cleanings to obtain a lead concentrate. Among them, 400 g / t of copper-lead separation inhibitor, 4 g / t of collector BK902, and 1 g / t of frother BK204 are added in the first cleaning, 50 g / t of copper-lead separation inhibitor and 2 g / t of collector BK902 are added in the second cleaning, and 25 g / t of copper-lead separation inhibitor is added in the third cleaning.

[0087] 9) The lead rough tailing is subjected to two scavengings to obtain a copper concentrate. Among them, 500 g / t of copper-lead separation inhibitor, 8 g / t of collector BK902, and 3.5 g / t of frother BK204 are added in the first scavenging, 50 g / t of copper-lead separation inhibitor, 4 g / t of collector BK902, and 1.5 g / t of frother BK204 are added in the second scavenging.

[0088] 10) The middlings generated in each step of cleaning and scavenging are sequentially returned to the previous step.

[0089] Comparative Example 1:

[0090] In this example, a preparation method of a copper-lead separation inhibitor is different from that of Example 2 only in that:

[0091] In step 3), when preparing crosslinked cyanoethyl chitosan by adding a crosslinking agent solution with a total concentration of 25% to the suspension, the weight ratio of the crosslinking agent solution to the suspension is 1.5:1, and the crosslinking agent solution is a mixed solution of glutaraldehyde and 6-aminocaproic acid, in which the concentration of 6-aminocaproic acid is 1.5 wt%.

[0092] Comparative Example 2:

[0093] In this example, a preparation method of a copper-lead separation inhibitor is different from that of Example 2 only in that:

[0094] In step 3), when preparing crosslinked cyanoethyl chitosan by adding a crosslinking agent solution with a total concentration of 25% to the suspension, the weight ratio of the crosslinking agent solution to the suspension is 1.5:1. The crosslinking agent solution is a mixed solution of glutaraldehyde and sodium fumarate, and the concentration of sodium fumarate is 1 wt%.

[0095] Comparative Example 3:

[0096] In this example, a method for using a copper-lead separation inhibitor is different from that in Example 3 only in that: in the steps of one rough selection, three fine selections and two scavenging selections, the copper-lead separation inhibitor used is prepared from Comparative Example 1.

[0097] Comparative Example 4:

[0098] In this example, a method for using a copper-lead separation inhibitor is different from that in Example 3 only in that: in the steps of one rough selection, three fine selections and two scavenging selections, the copper-lead separation inhibitor used is prepared from Comparative Example 2.

[0099] Comparative Example 5:

[0100] In this example, a method for using a copper-lead separation inhibitor is different from that in Example 3 only in that: in the steps of one rough selection, three fine selections and two scavenging selections, the inhibitor used is sodium cyanide.

[0101] Test Example 1:

[0102] Actual mineral flotation test (copper-lead ore)

[0103] Test method: The raw material is a certain copper-lead mixed concentrate, in which the copper content is 23.15%, the lead content is 13.23%, copper mainly exists in the form of chalcopyrite, and lead mainly exists in the form of galena; the gangue minerals are mainly silicate minerals. Take 500 g of the copper-lead mixed concentrate and mix it with 900 mL of water, then grind it to a pulp fineness of -400 mesh ≥ 85%, and then send it into a flotation machine for flotation test. Add the copper-lead separation inhibitors prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention respectively according to the amount of 600 g / t (mixed concentrate), then stir for 3 min, and then add the collector BK902 at 25 g / t (mixed concentrate) respectively and stir for 5 min. Finally, add 5 g / t of the foaming agent BK204. After one rough selection for 5 min, collect the concentrate and tailings products respectively, filter, dry and weigh. Under the same other conditions, add the same amount of sodium cyanide as the control group. Each test example has 3 parallels and the average value is taken. The copper grade and copper recovery rate in the concentrate obtained by rough selection are measured, and the results are shown in Table 1.

[0104] Table 1 Results of copper inhibition test of copper-lead mixed concentrate with different inhibitors

[0105] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Control Group Copper Grade % 4.71 4.07 4.69 4.54 5.03 Copper Recovery Rate % 5.40 4.67 5.38 5.20 5.77

[0106] The results show that the copper-lead separation inhibitor of the present invention can effectively reduce the copper grade and copper recovery rate in copper-lead ore. Compared with traditional copper inhibitors, the copper inhibition effect and recovery effect of the copper-lead separation inhibitor of the present invention are slightly better, indicating that the inhibition effect of the copper-lead separation inhibitor of the present invention is strong and it is more environmentally friendly than sodium cyanide. It can be seen that the copper-lead separation inhibitor of the present invention can effectively achieve the flotation separation of copper-lead ore. At the same time, the results also show that the inhibition effect of Example 2 is better than that of Example 1, and the inhibition effects of Comparative Example 1 and Comparative Example 2 have no significant difference from that of Example 1, indicating that the cross-linking agent components in Example 2 act synergistically, making the copper-lead separation inhibitor prepared in Example 2 have a better copper inhibition effect.

[0107] Test Example 2:

[0108] Closed-circuit test

[0109] Test method: The raw materials are the same as those in Test Example 1. The process flow of the closed-circuit test is shown in Figure 1 . Among them, the copper-lead separation inhibitors of the test groups were respectively selected as the copper-lead separation inhibitors prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention, and the control group was sodium cyanide with the same dosage. Each test example had 3 parallels and the average value was taken. The grades and recovery rates of copper and lead in the concentrate obtained by flotation were measured, and the results are shown in Table 2.

[0110] Figure 1 It is the process flow chart of the closed-circuit test in Test Example 2 of the present invention.

[0111] Table 2 Results of closed-circuit test

[0112]

[0113] The results show that the copper inhibition effect and recovery effect of the copper-lead separation inhibitor of the present invention are significant, slightly better than traditional copper inhibitors, and the copper-lead separation inhibitor of the present invention significantly reduces the mutual inclusion of metals in the lead concentrate and copper concentrate, the concentrate products obtained by flotation separation, and the separation effect is good. The results also show that the copper grade and copper recovery rate in the lead concentrate of Example 2 are significantly lower than those of Example 1, and the results of Comparative Example 1 and Comparative Example 2 have no significant difference from those of Example 1, indicating that the cross-linking agent components in Example 2 act synergistically, making the copper-lead separation inhibitor prepared in Example 2 have a better copper inhibition effect, exerting a selective inhibition ability, significantly reducing the mutual inclusion of metals in the lead concentrate and copper concentrate, the concentrate products obtained by flotation separation, and the copper inhibition effect is better.

[0114] It should be noted that in the present invention, concentrations, ratios, etc. without special instructions are all weight concentrations, weight ratios, etc., which are common writing habits of those skilled in the art, so they will not be elaborated in the present invention.

[0115] It should be noted that in the present invention, the detailed steps of some operations are not described in detail, but are prior arts known to those skilled in the art, so they will not be elaborated herein.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A preparation method of a copper-lead separation inhibitor, characterized in that, Including: Providing a chitosan raw material with a deacetylation degree of ≥90%; Providing thioglycolic acid, which is used as a mercapto group reagent to prepare mercapto chitosan with the chitosan raw material; Providing acrylonitrile, which is used as a cyanation reagent to prepare cyanoethyl chitosan polymer with the chitosan raw material; and, Mixing the mercapto chitosan and the cyanoethyl chitosan polymer to obtain the copper-lead separation inhibitor; The weight ratio of the mercapto chitosan to the cyanoethyl chitosan polymer is 1:1 - 5; The preparation steps of the cyanoethyl chitosan polymer are as follows: a) Adding acrylonitrile to chitosan, stirring, and adding a 5% NaOH solution during the stirring process. After reacting at a constant temperature of 25 - 40°C for 6 - 12 h, filtering, washing with acetone until neutral, and then drying to obtain cyanoethyl chitosan; b) Adding a copper sulfate solution with a concentration of 100 - 150 mg / L and a pH of 3 - 4 to the cyanoethyl chitosan, then stirring at 25 - 40°C for 6 - 8 h, filtering and washing with water 2 - 3 times. Then, adding water to the filtered precipitate to make a suspension with a solid content of 18 - 25%. Next, adding a cross-linking agent solution with a concentration of 20 - 30% to the suspension, stirring and reacting at 30 - 45°C for 5 - 8 h, filtering, and then washing the obtained cross-linked product with water, ethanol, and ether in sequence, and drying to obtain cross-linked cyanoethyl chitosan. The cross-linking agent solution is a glutaraldehyde solution, and the weight ratio of the cross-linking agent solution to the suspension is 1.5 - 2:1; c) Adding a 0.1 mol / L hydrochloric acid solution to the cross-linked cyanoethyl chitosan, soaking for 10 - 12 h, then washing with water, ethanol, and ether in sequence, and drying under vacuum to obtain the cyanoethyl chitosan polymer; The cross-linking agent solution for preparing the cyanoethyl chitosan polymer also includes 1 - 2 wt% of 6 - aminohexanoic acid and 0.5 - 1 wt% of sodium fumarate; The copper-lead separation inhibitor is used after being formulated into a solution with a mass concentration of 1 - 10%; 2. The preparation method of the copper-lead separation inhibitor according to claim 1, characterized in that, The preparation steps of the mercapto chitosan are as follows: Mixing chitosan, thioglycolic acid, and concentrated sulfuric acid with a concentration of 75%, then carrying out a water bath stirring reaction. After the reaction is completed, filtering, washing the filtered reaction product with distilled water and ethanol until neutral, and drying under vacuum to obtain mercapto chitosan.

3. The preparation method of the copper-lead separation inhibitor according to claim 2, characterized in that, The weight ratio of the chitosan, the mercapto group reagent, and the concentrated sulfuric acid is 1:5 - 15:0.05 - 0.1; The temperature of the water bath stirring reaction is 35 - 45°C, the stirring speed is 300 - 1000 r / min, and the time is 8 - 16 h; The temperature of the vacuum drying is 40 - 60°C, and the time is 24 - 48 h; 4. The preparation method of the copper-lead separation inhibitor according to claim 1, characterized in that, The solid-liquid ratio of the chitosan and acrylonitrile is 1 g:40 - 50 mL, and the addition amount of the NaOH solution is 4 - 5% of the weight of acrylonitrile; the solid-liquid ratio of the cross-linked cyanoethyl chitosan and the hydrochloric acid solution is 1 g:50 - 70 mL.

5. The preparation method of the copper-lead separation inhibitor according to claim 1, characterized in that, The solid-liquid ratio of the cyanoethyl chitosan and the copper sulfate solution is 1 g:40 - 50 mL.

6. A copper-lead separation inhibitor prepared by the preparation method according to any one of claims 1 - 5.

7. Use of a copper-lead separation inhibitor prepared by the preparation method according to any one of claims 1-5 in the flotation separation process of copper-lead mixed concentrate and copper-molybdenum mixed concentrate, characterized in that, The adding method of the copper-lead separation inhibitor is: Add the solid copper-lead separation inhibitor directly, or, Prepare the copper-lead separation inhibitor into a solution with a mass concentration of 1-10% and then add it.

8. A method for using a copper-lead separation inhibitor prepared by the preparation method according to any one of claims 1-5, characterized in that, Add the copper-lead separation inhibitor in the roughing, cleaning and scavenging processes of the flotation separation process of the copper-lead bulk concentrate; In the flotation separation process, it includes one roughing, three cleanings and two scavengings.

9. The method of use according to claim 8, wherein The usage method includes the following steps: 1) Add the copper-lead separation inhibitor, collector BK902, and foaming agent BK204 to the copper-lead bulk concentrate. After one roughing, obtain the lead roughing concentrate and the lead roughing tailings; the dosage of the copper-lead separation inhibitor is 100-1000 g / t, the dosage of the collector is 10-30 g / t, and the dosage of the foaming agent is 2-5 g / t; 2) The lead roughing concentrate is cleaned three times to obtain the lead concentrate. Among them, 50-500 g / t of the copper-lead separation inhibitor, 1-5 g / t of the collector BK902, and 0.5-1 g / t of the foaming agent BK204 are added in the first cleaning. 25-60 g / t of the copper-lead separation inhibitor, 0.5-2.5 g / t of the collector BK902 are added in the second cleaning, and 15-30 g / t of the copper-lead separation inhibitor is added in the third cleaning; 3) The lead roughing tailings are scavenged twice to obtain the copper concentrate. Among them, 60-600 g / t of the copper-lead separation inhibitor, 5-10 g / t of the collector BK902, and 1-3.5 g / t of the foaming agent BK204 are added in the first scavenging. 30-60 g / t of the copper-lead separation inhibitor, 2.5-5 g / t of the collector BK902, and 0.5-1.5 g / t of the foaming agent BK204 are added in the second scavenging; 4) The middlings generated in each step of the cleaning and scavenging are sequentially returned to the previous step.

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