Copper-lead separation inhibitor and preparation method and application thereof

Abstract

The invention belongs to the field of beneficiation reagents, and relates to a copper-lead separation inhibitor and a preparation method and application thereof. The main component of the inhibitor is sodium N-carboxyethyl dithiocarbamate, and the inhibitor contains sodium dihydrogen phosphate and hydroxyethyl cellulose. The N-carboxyethyl sodium dithiocarbamate is synthesized for the first time, the synthesis method is simple and convenient, carboxyethyl and thioamino groups in molecules are highly selectively adsorbed on the surface of galena, and competitive adsorption can be formed by a collecting agent; and the method has significance and universality, and is particularly suitable for flotation separation of copper and lead minerals. The main component sodium N-carboxyethyl dithiocarbamate and the secondary components sodium dihydrogen phosphate and hydroxyethyl cellulose of the inhibitor mixture play a synergistic inhibition role at the same time, the inhibition capacity of the inhibitor on galena is improved, the lead grade in copper concentrate in the copper-lead separation process is effectively reduced, and cyanide-free and chromium-free separation is achieved. The inhibitor is stable in effect and strong in inhibition capability, and has a relatively good process application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing agents, and in particular relates to a copper-lead separation inhibitor and a preparation method and application thereof. Background Art

[0002] In copper-lead polymetallic sulfide ores, chalcopyrite and galena are usually densely coexisting, with complex embedded particle sizes. Since the natural floatability of the two is similar, the process of mixed copper-lead flotation and separation is often used during flotation. The quality of the subsequent copper-lead separation effect is the key to the success of treating copper-lead polymetallic sulfide ores. At present, the copper-lead separation methods mainly include the "lead suppression copper floating" method, the "copper suppression lead floating" method, and the combined application of the two. In the lead suppression copper flotation separation process, galena is the main suppressed target mineral. Dichromate is a relatively mature type of galena inhibitor used in copper-lead separation. This is because dichromate is converted into chromate in weakly alkaline slurry, and then a hydrophilic lead chromate film is formed on the surface of galena, thereby increasing the hydrophilicity of galena. As we all know, dichromate has strong selectivity, wide applicability, and good copper-lead separation indicators, but it is a type of highly toxic substance that seriously pollutes the environment, and its use in production is gradually restricted.

[0003] In addition to dichromate, inorganic inhibitors mainly include sulfites, water glass and sodium sulfide. Production practice shows that the combination of two or more agents is conducive to enhancing the inhibitory effect of galena. Other combined inhibitors such as sodium sulfite / water glass, sodium sulfite / carboxymethyl cellulose, sodium sulfite, ferrous sulfate, sodium sulfite / zinc sulfate / sodium sulfide, sodium sulfite / zinc sulfate / carboxymethyl cellulose have good inhibitory effects on galena. Sodium sulfite can replace dichromate when mixed with carboxymethyl cellulose and water glass. Sodium thiosulfate and sodium pyrosulfite can also be used as galena inhibitors. Small molecule organic inhibitors mainly include ASC, polyhydroxy thiophosphates and polyhydroxy xanthates. Natural macromolecular compounds often have stronger inhibitory properties, such as lignin, humic acid, polysaccharides (cellulose, starch, dextrin and its derivatives). Such inhibitors are usually used in combination with inorganic inhibitors such as sulfites. Synthetic macromolecular inhibitors have been reported to confirm that sodium polyacrylate and polyacrylamide derivatives can be used as galena inhibitors.

[0004] In summary, the existing combined inhibitors have overcome the environmental pollution problems caused by dichromates and promoted the innovation and progress of copper-lead separation technology. However, the selective inhibition effect of this type of agent is still not ideal, and is subject to many interference factors and difficult to control in operation. At the same time, the agent needs to be removed during separation, which is not easy to control and affects the use effect of the inhibitor. It is difficult to effectively reduce the lead grade in copper concentrate. Therefore, the research and development of new clean and efficient copper-lead separation inhibitors still needs further in-depth research. Summary of the invention

[0005] In view of the defects of weak inhibition ability and low universality of copper-lead separation inhibitors in sulfide ores in the prior art, the object of the present invention is to provide a copper-lead separation inhibitor and a preparation method and application thereof; the copper-lead separation inhibitor provided by the present invention significantly improves the copper-lead separation effect and solves the problem of copper-lead separation.

[0006] In order to achieve the purpose of the present invention, the present invention adopts the following technical solutions.

[0007] A copper-lead separation inhibitor mainly comprises sodium N-carboxyethyldithiocarbamate and contains a certain proportion of sodium dihydrogen phosphate and hydroxyethyl cellulose.

[0008] A method for preparing a copper-lead separation inhibitor comprises the following steps: Step 1: Add a certain amount of water and sodium hydroxide into a container, add iminodiacetic acid under stirring and fully dissolve; Step 2, adding carbon disulfide dropwise into the container at a controlled temperature, and heating the container for a certain period of time to obtain a sodium N-carboxyethyl dithiocarbamate solution; Step 3: adding a certain amount of hydroxyethyl cellulose and sodium dihydrogen phosphate to the synthetic product sodium N-carboxyethyl dithiocarbamate solution, heating and reacting for a certain time to obtain a copper-lead separation inhibitor.

[0009] Furthermore, in step 1, the mass ratio of water to sodium hydroxide is 4:1.

[0010] Furthermore, the molar ratio of sodium hydroxide: iminodiacetic acid: carbon disulfide is 1: (1-1.5): (1-1.2).

[0011] Furthermore, in step 2, the temperature is controlled not to exceed 30°C, and after the dropwise addition is completed, the temperature is raised to 40-50°C and the reaction is carried out for 3-5 hours.

[0012] Furthermore, in step 3, the mass ratio of sodium N-carboxyethyl dithiocarbamate: hydroxyethyl cellulose: sodium dihydrogen phosphate is 70: (10-20): (5-15).

[0013] Furthermore, in step 3, the temperature is raised to 70-80° C. and the reaction is carried out for 2 hours.

[0014] The application of the copper-lead separation inhibitor in the separation of copper-lead mixed concentrate specifically comprises the following steps: (1) Adding a slurry adjuster and the above-mentioned inhibitor to the copper-lead mixed concentrate; the slurry adjuster is lime, the dosage is 200-1000 g / t; the dosage of the inhibitor is 200-2000 g / t; (2) Flotation includes one roughing selection, several scavenging selections and several concentrating selections. The copper collector is ethylthiocarbamate or allylthiocarbamate, and its dosage is 30-200 g / t. The dosage of inhibitor in copper-lead separation and concentrating operation is 1 / 30-3 / 5 of the dosage in roughing selection, the dosage of inhibitor in copper-lead separation and scavenging operation is 0-1 / 2 of the dosage in roughing selection, and the dosage of collector is 1 / 10-1 / 3 of the dosage in roughing selection.

[0015] According to the crystal chemical characteristics of galena mineral, the present invention develops an inhibitor with a specific structure and component, and the inhibitor has a new application in copper-lead separation and exhibits excellent inhibitory performance. The inhibitor component has a hydrophilic carboxyl group and a thioamino group in sodium N-carboxyethyl dithiocarbamate, which is used as a copper-lead separation inhibitor, can form a chelate with lead minerals, selectively adsorb on the surface of galena, and produce competitive adsorption with mixed collectors such as thiocarbamates, xanthates, and black drugs. Without de-drugation, the inhibitor of galena can be achieved, while the effect on chalcopyrite is weak. The copper-lead separation effect is significantly improved, and at the same time, the hydroxyl and carboxyl groups in the hydroxyethyl cellulose molecules in the inhibitor component are both strong polar groups. During the reaction with galena, the carboxyl group is adsorbed on the mineral surface, and the hydroxyl group extends into the aqueous solution to react with water molecules. A hydration film is formed on the mineral surface, thereby inhibiting the floatability of galena, and sodium dihydrogen phosphate can strengthen the inhibitory effect on galena.

[0016] Compared with the prior art, the invention has the following beneficial effects.

[0017] (1) In the separation of copper and lead, the inhibitor can achieve selective inhibition of lead ore without the need for a removal process.

[0018] (2) The inhibitor is a multi-component mixture. The sodium N-carboxyethyl dithiocarbamate solution is synthesized for the first time. It does not require a crystallization process and is directly mixed with sodium dihydrogen phosphate and hydroxyethyl cellulose to prepare a mixture. It is easy to use and has good selectivity. It can significantly improve the inhibitory effect on pyrite.

[0019] (3) Sodium N-carboxyethyl dithiocarbamate in the inhibitor component can remove the collector on the surface of galena in the mixed concentrate, and produce competitive adsorption with the collector. It can be adsorbed on the surface of galena without removing the collector from the mixed concentrate. The carboxyl group in the molecule ensures the hydrophilicity of galena, while the effect on chalcopyrite is very weak. Components such as sodium dihydrogen phosphate and hydroxyethyl cellulose contain hydrophilic groups and selectively adsorb on the surface of galena. They have a synergistic inhibitory effect on galena, enhance the inhibitor's inhibitory ability on galena, effectively reduce the lead grade in the copper concentrate during the copper-lead separation process, and realize cyanide-free and chromium-free separation. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited in any way. Any changes and substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0021] A method for preparing a copper-lead separation inhibitor comprises the following steps: (1) Add a certain amount of water and sodium hydroxide to a three-necked flask, the mass ratio of water to sodium hydroxide is 4:1, and add a certain amount of iminodiacetic acid to fully dissolve; (2) Add carbon disulfide to the three-necked flask and control the temperature not to exceed 30°C. After the addition is complete, raise the temperature to 40-50°C and react for 3-5 hours to obtain a sodium N-carboxyethyl dithiocarbamate solution; (3) Solid sodium dihydrogen phosphate and hydroxyethyl cellulose were added to the sodium N-carboxyethyl dithiocarbamate solution, the temperature was controlled at 70-80°C, and the reaction was carried out for 2 hours to obtain galena inhibition for copper-lead separation.

[0022] In the preparation of the inhibitor of the present invention, the molar ratio of sodium hydroxide: iminodiacetic acid: carbon disulfide is 1: (1-1.5): (1-1.2).

[0023] The inhibitor of the present invention has a mass ratio of sodium N-carboxyethyl dithiocarbamate: sodium dihydrogen phosphate: hydroxyethyl cellulose of 70: (10-30): (5-25).

[0024] The application of the copper-lead separation inhibitor in the separation of copper-lead mixed concentrate specifically comprises the following steps: (1) Adding a slurry adjuster and the above-mentioned inhibitor to the copper-lead mixed concentrate; the slurry adjuster is lime, the dosage is 200-1000 g / t; the dosage of the inhibitor is 200-2000 g / t; (2) Flotation includes one roughing selection, several scavenging selections and several concentrating selections. The copper collector is ethylthiocarbamate or allylthiocarbamate, and its dosage is 30-200 g / t. The dosage of inhibitor in copper-lead separation and concentrating operation is 1 / 30-3 / 5 of the dosage in roughing selection, the dosage of inhibitor in copper-lead separation and scavenging operation is 0-1 / 2 of the dosage in roughing selection, and the dosage of collector is 1 / 10-1 / 3 of the dosage in roughing selection.

[0025] Example 1.

[0026] In a three-necked flask equipped with a thermometer and a stirrer, add 160g of tap water, and under the action of the stirrer, add 40g of sodium hydroxide to obtain a sodium hydroxide aqueous solution; then add 160g of iminodiacetic acid and fully dissolve it; then add 76g of carbon disulfide to the reactant, and control the temperature not to exceed 30°C; after the dropwise addition is completed, the temperature is raised to 50°C, and the reaction time is 4 hours to obtain 220g of an effective ingredient, sodium N-carboxyethyl dithiocarbamate aqueous solution; add 63g of sodium dihydrogen phosphate and 31g of hydroxyethyl cellulose to the sodium N-carboxyethyl dithiocarbamate aqueous solution, stir evenly, control the temperature to 80°C, and react for 2 hours to obtain 530g of a copper-lead separation inhibitor.

[0027] Example 2.

[0028] In a three-necked flask equipped with a thermometer and a stirrer, 160g of tap water is added, and under the action of the stirrer, 40g of sodium hydroxide is added to obtain a sodium hydroxide aqueous solution; then 173g of iminodiacetic acid is added, and then 84g of carbon disulfide is added to the reactant, and the temperature is controlled not to exceed 30°C; after completion, the temperature is raised to 48°C, and the reaction time is 3 hours to obtain 225g of an effective ingredient, sodium N-carboxyethyl dithiocarbamate aqueous solution; then 48g of sodium dihydrogen phosphate and 48g of hydroxyethyl cellulose are added to the sodium N-carboxyethyl dithiocarbamate aqueous solution, the temperature is controlled to 75°C, and the reaction is carried out for 2 hours to obtain 553g of a copper-lead separation inhibitor.

[0029] Example 3.

[0030] In a three-necked flask equipped with a thermometer and a stirrer, add 160g of tap water, and under the action of the stirrer, add 40g of sodium hydroxide to obtain a sodium hydroxide aqueous solution; then add 200g of iminodiacetic acid, and then add 91g of carbon disulfide to the reactant, and control the temperature not to exceed 30°C; after completion, heat to 50°C, react for 5 hours, and obtain 230g of N-carboxyethyl dithiocarbamate sodium aqueous solution as an effective ingredient; then add 82g of sodium dihydrogen phosphate and 16g of hydroxyethyl cellulose to the N-carboxyethyl dithiocarbamate sodium aqueous solution, control the temperature to 70°C, and react for 2 hours to obtain 589g of copper-lead separation inhibitor.

[0031] Example 1.

[0032] The test ore is a copper-lead mixed concentrate of a lead-zinc mine in Inner Mongolia, which contains 5.42% copper and 33.90% lead. The inhibitor and copper-lead flotation separation method provided in Example 1 of the present invention are used to carry out a mineral processing test, and the specific steps are as follows: The mixed concentrate was ground in a ball mill, and the grinding fineness was controlled to be -0.037mm, accounting for 80%, to ensure that the copper-lead mineral monomers were fully dissociated, and at the same time, 1000g / t of lime and 800g / t of the inhibitor of Example 1 were added in the mill; flotation included one roughing selection, one scavenging selection, and two concentrating selections, and the mixed concentrate did not need to be de-doped, and 60g / t of the collector ethylthiocarbamate was added in the roughing selection; 400g / t of the inhibitor of Example 1 was added in the first concentrating selection; 200g / t of the inhibitor of Example 1 was added in the second concentrating selection, 300g / t of the inhibitor of Example 1 was added in the first scavenging selection, and the amount of the collector ethylthiocarbamate was 20g / t. The closed-circuit test obtained a copper concentrate with a copper grade of 19.56% and a copper recovery rate of 94.17%, and a lead concentrate with a lead grade of 42.55% and a lead recovery rate of 95.48%, as shown in Table 1.

[0033] Table 1. Test results of copper and lead separation (%).

[0034] Example 2.

[0035] The test ore is a copper-lead mixed concentrate of a lead-zinc mine in Inner Mongolia, which contains 4.64% copper and 45.30% lead. The inhibitor and copper-lead flotation separation method provided in Example 2 of the present invention are used to carry out a mineral processing test, and the specific steps are as follows: The copper-lead separation adopts a process flow of one roughing, one scavenging and one concentrating, as well as regrinding and allyl thiocarbamate as a copper collector; the mixed concentrate is ground in a ball mill, and the grinding fineness is controlled to be -0.037 mm, accounting for 90%, to ensure that the copper-lead mineral monomers are fully dissociated, and 500 g / t of lime and 1000 g / t of the inhibitor of Example 2 are added to the mill; flotation includes one roughing, one scavenging and one concentrating, and the mixed concentrate does not need to be de-doped. 80 g / t of the collector allyl thiocarbamate is added in the roughing; 400 g / t of the inhibitor of Example 2 is added in the first concentrating; 300 g / t of the inhibitor of Example 2 is added in the second concentrating, 300 g / t of the inhibitor of Example 2 is added in the first scavenging, and the collector allyl thiocarbamate is used in an amount of 20 g / t. The closed-circuit test obtained copper concentrate with a copper grade of 21.35% and a copper recovery rate of 90.88%, and lead concentrate with a lead grade of 55.13% and a lead recovery rate of 97.67%, as shown in Table 2.

[0036] Table 2 Copper-lead separation test results (%).

[0037] Example 3.

[0038] The copper-lead depressant and the copper-lead flotation separation method provided in Example 3 of the present invention were used to carry out a mineral processing test, and the specific steps are as follows: The test ore is a copper-lead polymetallic ore from Chifeng, Inner Mongolia. The ore contains 0.23% copper and 1.88% lead. The main copper mineral is chalcopyrite, and the main lead mineral is galena. The raw ore uses ethylthiocarbamate as a collector, and the copper-lead mixed selection process is adopted. The coarse concentrate is re-grinded twice to obtain a copper-lead mixed concentrate.

[0039] The mixed concentrate contains 4.60% copper and 36.62% lead. The copper-lead separation adopts the lead-suppression copper flotation process, with a roughing process, a scavenging process, and a secondary concentration process. The amount of lime added is 600g / t, the amount of roughing inhibitor is 900g / t, ethylthiocarbamate is 50g / t, the amount of primary concentration inhibitor is 400g / t, the amount of secondary concentration inhibitor is 250g / t, the amount of scavenging inhibitor is 300g / t, and the amount of collector ethylthiocarbamate is 15g / t. The closed-circuit test obtained a copper concentrate with a copper grade of 19.84% and a copper recovery rate of 95.11%, a lead concentrate with a lead grade of 53.01% and a lead recovery rate of 97.14%, as shown in Table 3.

[0040] Table 3 Copper-lead separation test results (%).

Claims

1. A copper-lead separation inhibitor, characterized in that The main ingredients include sodium N-carboxyethyldithiocarbamate, and contain a certain proportion of sodium dihydrogen phosphate and hydroxyethyl cellulose.

2. A method for preparing a copper-lead separation inhibitor, characterized in that: The specific steps include: Step 1: Add a certain amount of water and sodium hydroxide into a container, add iminodiacetic acid under stirring, and fully dissolve; Step 2, adding carbon disulfide dropwise into the container at a controlled temperature, and heating the container for a certain period of time to obtain a sodium N-carboxyethyl dithiocarbamate solution; Step 3: adding a certain amount of hydroxyethyl cellulose and sodium dihydrogen phosphate to the synthetic product sodium N-carboxyethyl dithiocarbamate solution, heating and reacting for a certain time to obtain a copper-lead separation inhibitor.

3. The method for preparing the copper-lead separation inhibitor according to claim 2, characterized in that: In the step 1, the mass ratio of water to sodium hydroxide is 4:

1.

4. The method for preparing the copper-lead separation inhibitor according to claim 2, characterized in that: The molar ratio of sodium hydroxide: iminodiacetic acid: carbon disulfide is 1: (1~1.5): (1~1.2).

5. The method for preparing the copper-lead separation inhibitor according to claim 2, characterized in that: In the step 2, the temperature is controlled not to exceed 30° C., and after the dropwise addition is completed, the temperature is raised to 40° C. to 50° C., and the reaction is carried out for 3 hours to 5 hours.

6. The method for preparing the copper-lead separation inhibitor according to claim 2, characterized in that: In the step 3, the mass ratio of sodium N-carboxyethyl dithiocarbamate: hydroxyethyl cellulose: sodium dihydrogen phosphate is 70: (10-20): (5-15).

7. The method for preparing the copper-lead separation inhibitor according to claim 2, characterized in that: In the step 3, the temperature is raised to 70° C. to 80° C. and the reaction is carried out for 2 hours.

8. The method for preparing the copper-lead separation inhibitor according to any one of claims 2 to 6, characterized in that: The application of the copper-lead separation inhibitor in the separation of copper-lead mixed concentrate specifically comprises the following steps: (1) Adding a slurry adjuster and the above-mentioned inhibitor to the copper-lead mixed concentrate; the slurry adjuster is lime, with an amount of 200 g / t to 1000 g / t; the inhibitor is used in an amount of 200 g / t to 2000 g / t; (2) Flotation includes one roughing selection, several scavenging selections and several concentrating selections. The copper collector is ethylthiocarbamate or allylthiocarbamate, with a dosage of 30 g / t to 200 g / t. The dosage of inhibitor in the copper-lead separation and concentrating operation is 1 / 30 to 3 / 5 of the dosage in the roughing selection. The dosage of inhibitor in the copper-lead separation and concentrating operation is 0 to 1 / 2 of the dosage in the roughing selection. The dosage of collector is 1 / 10 to 1 / 3 of the dosage in the roughing selection.

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