1. A method for efficiently and synergistically recovering zinc from low-grade refractory mixed zinc ore resources is characterized by comprising the following steps:

s1, carrying out flotation on the ore with low oxidation rate to obtain a sulfur zinc concentrate A and an oxygen zinc concentrate: firstly, carrying out primary coarse and secondary scavenging and secondary fine flotation to obtain a sulfur zinc concentrate A, wherein 2-5mg of copper sulfate, 1-3mg of butyl xanthate and 0.5-2mg of 2# oil are added into each liter of ore pulp; performing flotation by using three-coarse and three-fine flotation to obtain an oxygen zinc concentrate, wherein 20-60mg of sodium fluosilicate and 10-30mg of aliphatic hydroximic acid collecting agent are added into each liter of ore pulp;

s2, combining the zinc oxide concentrate and the high-oxidation-rate ore, and adding sulfuric acid for pretreatment to obtain a pretreated liquid and pretreated tailings; in the pretreatment, 20-30g of concentrated sulfuric acid is added into each liter of ore pulp, the pretreatment temperature is 20-30 ℃, the pretreatment time is 1-1.5h, and the end point pH is 1.5-1.7;

s3, performing preneutralization on the pretreated liquid obtained in the step S2 to obtain gypsum slag and preneutralized liquid, wherein 10-12g of limestone or lime is added into each liter of the pretreated liquid, the preneutralization temperature is 35-40 ℃, the preneutralization time is 1.5-2h, and the end-point pH is 4.5-4.7; performing sodium carbonate zinc precipitation on the pre-neutralized liquid to obtain zinc carbonate precipitate, wherein 10-12g of sodium carbonate is added into each liter of the pre-neutralized liquid, the zinc precipitation temperature is 35-40 ℃, the zinc precipitation time is 1-3h, and the end point pH is 7.8-8.0;

neutralizing the pretreated tailings to obtain neutralized tailings slurry, wherein 0.5-0.8g of lime is added into each liter of pretreated tailings, the neutralization temperature is 35-40 ℃, the reaction time is 1-2h, and the end-point pH is 8.2-8.3; performing one-coarse two-sweep three-fine flotation on the neutralized tailing slurry to obtain a sulfur zinc concentrate B, wherein 2-3mg of copper sulfate, 1-1.5mg of butyl xanthate and 0.5-1mg of No. 2 oil are added into each liter of neutralized tailing slurry;

s4, mixing the sulfur zinc concentrate A and the sulfur zinc concentrate B, and roasting to obtain roasted sand and sulfuric acid; the roasting temperature is 900 ℃, and the retention time is 0.5-1 h;

s5, combining the zinc carbonate precipitate produced in the step S3 with the calcine obtained in the step S4, and then carrying out two-stage leaching on the waste electrolyte; the first-stage leaching adopts second-stage leaching overflow liquid, the second-stage leaching adopts waste electrolyte, the first-stage leaching temperature is 85 ℃, the first-stage leaching time is 2 hours, and the pH value of the first-stage leaching end point is 4.7; the temperature of the second-stage leaching is 80 ℃, the time of the second-stage leaching is 2h, and the pH value of the end point of the second-stage leaching is 1.5-1.6;

s6, adding limestone or lime into the first-stage leaching solution produced in the step S5, and introducing mixed gas of sulfur dioxide and air for impurity removal and purification to obtain purified solution; wherein, 20-40g limestone or lime is added into one liter of first-stage leachate, the introduction amount of the mixed gas of sulfur dioxide and air is determined by the potential control in the impurity removal purification process, the potential is controlled to be 500-600mV, and the volume ratio of the sulfur dioxide to the air is 0.2-2: 98-99.8; the reaction temperature for impurity removal and purification is 70-75 ℃, the pH is 4.5-4.6, and the reaction time is 3-5 h;

and S7, electrolyzing the purified liquid obtained in the step S6 to obtain an electro-zinc product.

2. The method as claimed in claim 1, wherein in step S1, the specific process of the first and second sweep-through flotation is as follows:

roughing the low-oxidation-rate ore to obtain roughing concentrate and roughing tailings, feeding the roughing concentrate into primary fine concentration, and feeding the roughing tailings into primary scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain a zinc sulfide concentrate A and secondary concentration tailings, and returning the secondary concentration tailings to primary concentration; primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging;

and performing secondary scavenging to obtain secondary scavenged concentrate and secondary scavenged tailings, returning the secondary scavenged concentrate to the primary scavenging, and performing three-rough three-fine flotation on the secondary scavenged tailings to produce the zinc oxide concentrate.

3. The method according to claim 1 or 2, wherein in step S1, the specific process of triple rougher triple finer flotation is as follows:

performing three-level roughing on the second-level scavenged tailings produced by performing first-level roughing, second-level scavenged and second-level fine flotation on the low-oxidation-rate ores in the step S1, wherein the first-level roughing is performed to obtain first-level roughed concentrates and first-level roughed tailings, and the first-level roughed tailings enter second-level roughing; performing secondary roughing to obtain secondary roughing concentrate and secondary roughing tailings, and performing tertiary roughing on the secondary roughing tailings; the three-stage rough concentration is carried out to obtain three-stage rough concentration concentrate and three-stage rough concentration tailings, the three-stage rough concentration tailings are discharged to a tailing pond, the first-stage rough concentration concentrate, the second-stage rough concentration concentrate and the third-stage rough concentration concentrate are combined and then enter first-stage concentration, the first-stage concentration concentrate and the first-stage concentration tailings are obtained through first-stage concentration, the first-stage concentration concentrate enters second-stage concentration, the second-stage concentration concentrate and the second-stage concentration tailings are obtained through second-stage concentration, the second-stage concentration concentrate enters third-stage concentration, and the third-stage concentration is carried out to obtain zinc oxide concentrate and third-stage concentration tailings; the first-stage concentration tailings return to the third-stage rough concentration, the second-stage concentration tailings return to the first-stage concentration, and the third-stage concentration tailings return to the second-stage concentration.

4. The method as claimed in claim 1, wherein in step S3, the specific process of one rough two-sweep three-fine flotation is as follows:

roughing the neutralized tailing slurry to obtain roughed concentrate and roughed tailings, wherein the roughed concentrate enters first-stage concentration, and the roughed tailings enter first-stage scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain secondary concentrated concentrate and secondary concentrated tailings, returning the secondary concentrated tailings to primary concentration, and performing tertiary concentration on the secondary concentrated concentrate; obtaining third-stage concentration concentrate and third-stage concentration tailings by third-stage concentration, returning the third-stage concentration tailings to second-stage concentration, and obtaining the third-stage concentration concentrate, namely the sulfur zinc concentrate B;

primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging; and secondary scavenging is carried out to obtain secondary scavenging concentrate and secondary scavenging tailings, the secondary scavenging concentrate returns to the primary scavenging, and the secondary scavenging tailings are discharged to a tailing pond.

5. The method of claim 1, wherein the low-oxidation rate ore has a zinc oxidation rate of less than 60% and the high-oxidation rate ore has a zinc oxidation rate of greater than or equal to 60%.

6. The method according to claim 1, wherein in step S1, the low-oxidation-rate ore has a particle size of-200 mesh, and the number-mass ratio of particles is 65% or more.

7. The method according to claim 1, wherein in step S2, the high-oxidation-rate ore has a particle size of-200 mesh at a ratio of 30% or more by number mass.

8. The method as claimed in claim 1, wherein the steps of pre-neutralizing, zinc precipitating, and neutralizing the pre-treated tailings in the steps S2 and S3, the steps S5 and S6 are all performed under stirring at a stirring speed of 300-500 rpm.

Background

China is the first major zinc consuming country in the world, zinc ore resources are relatively rich in general, but with the exploitation and utilization for many years, the traditional zinc sulfide resources are used up, most of the rest zinc sulfide resources are mixed zinc ores which are difficult to select, the grades are different, and the zinc oxidation rate is 15-99%. At present, only high-grade zinc ore with low oxidation rate is generally utilized, and a flotation-sulfur zinc concentrate roasting-leaching-electrodeposition process is adopted to treat and recover zinc sulfide ore, wherein the zinc oxide ore is not fully recovered, the low-grade zinc ore with high oxidation rate is stripped and stockpiled, and is not utilized, so that the resource waste and the environmental risk are relatively high. Meanwhile, because the mine is remote, zinc smelting plants for processing zinc sulfide concentrate usually face the problem of surplus sulfuric acid produced. Therefore, how to efficiently recover low-grade refractory mixed zinc ore resources, completely dry-pressing the zinc resources in the ores, and simultaneously solving the problem of sulfuric acid surplus in a zinc smelting plant is a technical problem in the industry.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for efficiently and synergistically recovering zinc from low-grade refractory mixed zinc ore resources.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for efficiently and synergistically recovering zinc from low-grade refractory mixed zinc ore resources comprises the following steps:

s1, carrying out flotation on the ore with low oxidation rate to obtain a sulfur zinc concentrate A and an oxygen zinc concentrate: firstly, carrying out primary coarse and secondary scavenging and secondary fine flotation to obtain a sulfur zinc concentrate A, wherein 2-5mg of copper sulfate, 1-3mg of butyl xanthate and 0.5-2mg of 2# oil are added into each liter of ore pulp; performing flotation by using three-coarse and three-fine flotation to obtain an oxygen zinc concentrate, wherein 20-60mg of sodium fluosilicate and 10-30mg of aliphatic hydroximic acid collecting agent are added into each liter of ore pulp;

s2, combining the zinc oxide concentrate and the high-oxidation-rate ore, and adding sulfuric acid for pretreatment to obtain a pretreated liquid and pretreated tailings; in the pretreatment, 20-30g of concentrated sulfuric acid is added into each liter of ore pulp, the pretreatment temperature is 20-30 ℃, the pretreatment time is 1-1.5h, and the end point pH is 1.5-1.7;

s3, performing preneutralization on the pretreated liquid obtained in the step S2 to obtain gypsum slag and preneutralized liquid, wherein 10-12g of limestone or lime is added into each liter of the pretreated liquid, the preneutralization temperature is 35-40 ℃, the preneutralization time is 1.5-2h, and the end-point pH is 4.5-4.7; performing sodium carbonate zinc precipitation on the pre-neutralized liquid to obtain zinc carbonate precipitate, wherein 10-12g of sodium carbonate is added into each liter of the pre-neutralized liquid, the zinc precipitation temperature is 35-40 ℃, the zinc precipitation time is 1-3h, and the end point pH is 7.8-8.0;

neutralizing the pretreated tailings to obtain neutralized tailings slurry, wherein 0.5-0.8g of lime is added into each liter of pretreated tailings, the neutralization temperature is 35-40 ℃, the reaction time is 1-2h, and the end-point pH is 8.2-8.3; performing one-coarse two-sweep three-fine flotation on the neutralized tailing slurry to obtain a sulfur zinc concentrate B, wherein 2-3mg of copper sulfate, 1-1.5mg of butyl xanthate and 0.5-1mg of No. 2 oil are added into each liter of neutralized tailing slurry;

s4, mixing the sulfur zinc concentrate A and the sulfur zinc concentrate B, and roasting to obtain roasted sand and sulfuric acid; the roasting temperature is 900 ℃, and the retention time is 0.5-1 h;

s5, combining the zinc carbonate precipitate produced in the step S3 with the calcine obtained in the step S4, and then carrying out two-stage leaching on the waste electrolyte; the first-stage leaching adopts second-stage leaching overflow liquid, the second-stage leaching adopts waste electrolyte, the first-stage leaching temperature is 85 ℃, the first-stage leaching time is 2 hours, and the pH value of the first-stage leaching end point is 4.7; the temperature of the second-stage leaching is 80 ℃, the time of the second-stage leaching is 2h, and the pH value of the end point of the second-stage leaching is 1.5-1.6;

s6, adding limestone or lime into the first-stage leaching solution produced in the step S5, and introducing mixed gas of sulfur dioxide and air for impurity removal and purification to obtain purified solution; wherein, 20-40g limestone or lime is added into one liter of first-stage leachate, the introduction amount of the mixed gas of sulfur dioxide and air is determined by the potential control in the impurity removal purification process, the potential is controlled to be 500-600mV, and the volume ratio of the sulfur dioxide to the air is 0.2-2: 98-99.8; the reaction temperature for impurity removal and purification is 70-75 ℃, the pH is 4.5-4.6, and the reaction time is 3-5 h;

and S7, electrolyzing the purified liquid obtained in the step S6 to obtain an electro-zinc product.

Further, in step S1, the specific process of the first rough second sweep second fine flotation includes:

roughing the low-oxidation-rate ore to obtain roughing concentrate and roughing tailings, feeding the roughing concentrate into primary fine concentration, and feeding the roughing tailings into primary scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain a zinc sulfide concentrate A and secondary concentration tailings, and returning the secondary concentration tailings to primary concentration; primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging;

and performing secondary scavenging to obtain secondary scavenged concentrate and secondary scavenged tailings, returning the secondary scavenged concentrate to the primary scavenging, and performing three-rough three-fine flotation on the secondary scavenged tailings to produce the zinc oxide concentrate.

Further, in step S1, the specific process of triple-rougher triple-finer flotation is as follows:

performing three-level roughing on the second-level scavenged tailings produced by performing first-level roughing, second-level scavenged and second-level fine flotation on the low-oxidation-rate ores in the step S1, wherein the first-level roughing is performed to obtain first-level roughed concentrates and first-level roughed tailings, and the first-level roughed tailings enter second-level roughing; performing secondary roughing to obtain secondary roughing concentrate and secondary roughing tailings, and performing tertiary roughing on the secondary roughing tailings; the three-stage rough concentration is carried out to obtain three-stage rough concentration concentrate and three-stage rough concentration tailings, the three-stage rough concentration tailings are discharged to a tailing pond, the first-stage rough concentration concentrate, the second-stage rough concentration concentrate and the third-stage rough concentration concentrate are combined and then enter first-stage concentration, the first-stage concentration concentrate and the first-stage concentration tailings are obtained through first-stage concentration, the first-stage concentration concentrate enters second-stage concentration, the second-stage concentration concentrate and the second-stage concentration tailings are obtained through second-stage concentration, the second-stage concentration concentrate enters third-stage concentration, and the third-stage concentration is carried out to obtain zinc oxide concentrate and third-stage concentration tailings; the first-stage concentration tailings return to the third-stage rough concentration, the second-stage concentration tailings return to the first-stage concentration, and the third-stage concentration tailings return to the second-stage concentration.

Further, in step S3, the specific process of the first rough two-sweep three-fine flotation includes:

roughing the neutralized tailing slurry to obtain roughed concentrate and roughed tailings, wherein the roughed concentrate enters first-stage concentration, and the roughed tailings enter first-stage scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain secondary concentrated concentrate and secondary concentrated tailings, returning the secondary concentrated tailings to primary concentration, and performing tertiary concentration on the secondary concentrated concentrate; obtaining third-stage concentration concentrate and third-stage concentration tailings by third-stage concentration, returning the third-stage concentration tailings to second-stage concentration, and obtaining the third-stage concentration concentrate, namely the sulfur zinc concentrate B;

primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging; and secondary scavenging is carried out to obtain secondary scavenging concentrate and secondary scavenging tailings, the secondary scavenging concentrate returns to the primary scavenging, and the secondary scavenging tailings are discharged to a tailing pond.

Further, the zinc oxidation rate of the low-oxidation-rate ore is less than 60%, and the zinc oxidation rate of the high-oxidation-rate ore is greater than or equal to 60%.

Further, in step S1, the low-oxidation-rate ore has a particle size of-200 mesh and a mass-to-number ratio of 65% or more.

Further, in step S2, the high-oxidation-rate ore has a particle size of-200 mesh and a mass ratio of 30% or more in terms of number of particles.

Further, the pre-neutralization, zinc precipitation, neutralization of the pre-treated tailings, step S5 and step S6 in step S2, step S3 were all performed under stirring conditions at a stirring rate of 300-.

The invention has the beneficial effects that:

the method researches and develops the separation and metallurgy cooperative treatment process by aiming at the resource characteristics of the low-grade refractory mixed zinc ore. For the ores with high oxidation rate, a first-leaching and later-floating process is adopted to respectively obtain zinc carbonate precipitate and zinc sulfide concentrate; for low-oxidation-rate ores, flotation of 'sulfur first and then oxygen' is adopted, two flotation processes of first coarse second scavenging second concentrate and third coarse third concentrate are organically combined, zinc sulfide concentrate and zinc oxide concentrate are respectively obtained, recovery of different zinc is achieved, and the zinc oxide concentrate is merged into a leaching treatment system of high-oxidation-rate ores; zinc sulfide concentrate is sent into a smelting roasting system, and zinc carbonate precipitate is directly sent into a smelting leaching system.

The method can realize the high-efficiency recovery of low-grade refractory mixed zinc ore resources, the comprehensive recovery rate of zinc is more than 90%, and the surplus rate of sulfuric acid is reduced by more than 80%. The invention has high maturity of each unit, closed cycle of the whole process, clean production requirement, dry extraction of zinc resource in the ore and solution of the sulfuric acid surplus problem of zinc smelting plant.

Drawings

FIG. 1 is a schematic flow chart of a method according to various embodiments of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, and it should be noted that the present embodiment is based on the technical solution, and the detailed implementation and the specific operation process are provided, but the protection scope of the present invention is not limited to the present embodiment.

Example 1

The embodiment provides a method for efficiently and synergistically recovering zinc from low-grade refractory mixed zinc ore resources, which comprises the following steps of:

s1, carrying out 'sulfur first and oxygen second' flotation on the low-oxidation-rate ore: 1000g of low-oxidation-rate ore is taken, and the number of particles with the particle size of-200 meshes of the low-oxidation-rate ore accounts for 65 percent. Adding 2000g of clear water, and selecting the sulfur-zinc concentrate by adopting a first-coarse-second-sweep-second-concentrate process, wherein the total amount of copper sulfate, butyl xanthate and 2# oil added into each liter of ore pulp is 5mg, 3mg and 2mg respectively, so as to obtain sulfur-zinc concentrate A100 g; and selecting the zinc oxide concentrate by adopting three-coarse-three-fine process, wherein the total dosage of the sodium fluosilicate and the aliphatic hydroximic acid collecting agent added into each liter of ore pulp is 60mg and 30mg, and 20g of the zinc oxide concentrate is obtained.

It should be noted that the specific process of the first coarse-second sweep-second fine flotation is as follows:

roughing the low-oxidation-rate ore to obtain roughing concentrate and roughing tailings, feeding the roughing concentrate into primary fine concentration, and feeding the roughing tailings into primary scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain a zinc sulfide concentrate A and secondary concentration tailings, and returning the secondary concentration tailings to primary concentration; primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging;

and performing secondary scavenging to obtain secondary scavenged concentrate and secondary scavenged tailings, returning the secondary scavenged concentrate to the primary scavenging, and performing three-rough three-fine flotation on the secondary scavenged tailings to produce the zinc oxide concentrate.

Further, it should be noted that the specific process of triple-coarse triple-fine flotation is as follows:

performing three-level roughing on the second-level scavenged tailings produced by performing first-level roughing, second-level scavenged and second-level fine flotation on the low-oxidation-rate ores in the step S1, wherein the first-level roughing is performed to obtain first-level roughed concentrates and first-level roughed tailings, and the first-level roughed tailings enter second-level roughing; performing secondary roughing to obtain secondary roughing concentrate and secondary roughing tailings, and performing tertiary roughing on the secondary roughing tailings; the three-stage rough concentration is carried out to obtain three-stage rough concentration concentrate and three-stage rough concentration tailings, the three-stage rough concentration tailings are discharged to a tailing pond, the first-stage rough concentration concentrate, the second-stage rough concentration concentrate and the third-stage rough concentration concentrate are combined and then enter first-stage concentration, the first-stage concentration concentrate and the first-stage concentration tailings are obtained through first-stage concentration, the first-stage concentration concentrate enters second-stage concentration, the second-stage concentration concentrate and the second-stage concentration tailings are obtained through second-stage concentration, the second-stage concentration concentrate enters third-stage concentration, and the third-stage concentration is carried out to obtain zinc oxide concentrate and third-stage concentration tailings; the first-stage concentration tailings return to the third-stage rough concentration, the second-stage concentration tailings return to the first-stage concentration, and the third-stage concentration tailings return to the second-stage concentration.

S2, combining the zinc oxide concentrate and the high-oxidation-rate ore, and adding sulfuric acid for pretreatment: 20g of the zinc oxide concentrate was combined with 1000g of high oxidation rate ore, the amount of particles having a particle size of-200 mesh accounting for 30%. Adding 3000g of clear water, adding 20g of concentrated sulfuric acid into each liter of ore pulp, and carrying out pretreatment at the stirring speed of 300rpm, wherein the pretreatment temperature is 30 ℃, the pretreatment time is 1h, and the end point pH is 1.5;

s3, pre-neutralizing the pre-treated liquid: adding 10g of limestone into each liter of pretreated liquid, and carrying out preneutralization at the stirring speed of 300rpm, wherein the preneutralization temperature is 35 ℃, the preneutralization time is 2 hours, the end point pH is 4.5, and 10g of gypsum residue is produced; and (3) performing sodium carbonate zinc precipitation on the pre-neutralized liquid to obtain zinc carbonate precipitate: adding 10g of sodium carbonate into each liter of the pre-neutralized solution, and precipitating zinc at the stirring speed of 300rpm, wherein the zinc precipitation temperature is 35 ℃, the reaction time is 1h, the end point pH is 8.0, and 10g of zinc carbonate precipitate is produced;

neutralizing the pretreated tailings: adding 0.5g of lime into each liter of the pretreated tailings, neutralizing at the stirring speed of 300rpm, wherein the neutralization temperature is 35 ℃, the neutralization time is 1h, and the end point pH is 8.2;

and (3) carrying out flotation on the neutralized tailing slurry: performing flotation on zinc sulfide ore by adopting a first-coarse-second-sweep three-fine flow process, wherein the concentration of ore pulp is about 33 percent, 2mg of copper sulfate, 1mg of butyl xanthate and 0.5mg of No. 2 oil are added into each liter of neutralized tailing pulp, and then zinc sulfide concentrate B10g is produced;

it should be noted that the specific process of the one-rough two-sweep three-fine flotation is as follows:

roughing the neutralized tailing slurry to obtain roughed concentrate and roughed tailings, wherein the roughed concentrate enters first-stage concentration, and the roughed tailings enter first-stage scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain secondary concentrated concentrate and secondary concentrated tailings, returning the secondary concentrated tailings to primary concentration, and performing tertiary concentration on the secondary concentrated concentrate; obtaining third-stage concentration concentrate and third-stage concentration tailings by third-stage concentration, returning the third-stage concentration tailings to second-stage concentration, and obtaining the third-stage concentration concentrate, namely the sulfur zinc concentrate B;

primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging; and secondary scavenging is carried out to obtain secondary scavenging concentrate and secondary scavenging tailings, the secondary scavenging concentrate returns to the primary scavenging, and the secondary scavenging tailings are discharged to a tailing pond.

S4, combining the sulfur zinc concentrate A and the sulfur zinc concentrate B, and roasting: and (3) combining 100g of the sulfur zinc concentrate A and 10g of the sulfur zinc concentrate B, roasting at 900 ℃ for 1h, and preparing acid by using flue gas to produce 60g of roasted product and 80g of sulfuric acid.

S5, combining zinc carbonate precipitate and calcine and leaching: and (3) combining the 10g of zinc carbonate precipitate produced in the step S3 with the 60g of calcine produced in the step S4, adding 700mL of waste electrolyte, and carrying out two-stage leaching at the stirring speed of 300 rpm. The first-stage leaching temperature is 85 ℃, the first-stage leaching time is 2 hours, and the first-stage end point pH is 4.7; the temperature of the second-stage leaching is 80 ℃, the time of the second-stage leaching is 2 hours, and the pH value of the second-stage end point is 1.5.

S6, impurity removal and purification: 20g of limestone is added into the first-stage leaching solution produced in the step S5, meanwhile, mixed gas of sulfur dioxide and air (the volume ratio of the sulfur dioxide to the air is 0.2: 99.8) is introduced, impurity removal and purification reaction is carried out under the conditions that the stirring speed is 300rpm and the potential is 500-550mV, the reaction temperature is 75 ℃, the reaction time is 5h, and the end-point pH is 4.5.

And S7, electrolyzing the purified liquid to obtain the electrolytic zinc product.

In the present example, the overall recovery rate of zinc was 91.5%, and the sulfuric acid surplus rate was reduced by 83.0%.

Example 2

The embodiment provides a method for efficiently and synergistically recovering zinc from low-grade refractory mixed zinc ore resources, which comprises the following steps of:

s1, carrying out 'sulfur first and oxygen second' flotation on the ore with low oxidation rate: 2000g of low-oxidation ore is taken, and the number of particles with the particle size of-200 meshes of the low-oxidation ore accounts for 80 percent. Adding 4000g of clear water, selecting the sulfur-zinc concentrate by adopting a first-coarse-second-sweep-second-concentrate process, wherein the total amount of copper sulfate, butyl xanthate and 2# oil added into each liter of ore pulp is respectively 2mg, 1mg and 0.5mg, so as to obtain sulfur-zinc concentrate A250 g; selecting the zinc oxide concentrate by adopting three-rough three-fine process, wherein the total dosage of the added sodium fluosilicate and the aliphatic hydroximic acid collecting agent is 20mg and 10mg, and obtaining 30g of zinc oxide concentrate;

it should be noted that the specific process of the first coarse-second sweep-second fine flotation is as follows:

roughing the low-oxidation-rate ore to obtain roughing concentrate and roughing tailings, feeding the roughing concentrate into primary fine concentration, and feeding the roughing tailings into primary scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain a zinc sulfide concentrate A and secondary concentration tailings, and returning the secondary concentration tailings to primary concentration; primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging;

and performing secondary scavenging to obtain secondary scavenged concentrate and secondary scavenged tailings, returning the secondary scavenged concentrate to the primary scavenging, and performing three-rough three-fine flotation on the secondary scavenged tailings to produce the zinc oxide concentrate.

Further, it should be noted that the specific process of triple-coarse triple-fine flotation is as follows:

performing three-level roughing on the second-level scavenged tailings produced by performing first-level roughing, second-level scavenged and second-level fine flotation on the low-oxidation-rate ores in the step S1, wherein the first-level roughing is performed to obtain first-level roughed concentrates and first-level roughed tailings, and the first-level roughed tailings enter second-level roughing; performing secondary roughing to obtain secondary roughing concentrate and secondary roughing tailings, and performing tertiary roughing on the secondary roughing tailings; the three-stage rough concentration is carried out to obtain three-stage rough concentration concentrate and three-stage rough concentration tailings, the three-stage rough concentration tailings are discharged to a tailing pond, the first-stage rough concentration concentrate, the second-stage rough concentration concentrate and the third-stage rough concentration concentrate are combined and then enter first-stage concentration, the first-stage concentration concentrate and the first-stage concentration tailings are obtained through first-stage concentration, the first-stage concentration concentrate enters second-stage concentration, the second-stage concentration concentrate and the second-stage concentration tailings are obtained through second-stage concentration, the second-stage concentration concentrate enters third-stage concentration, and the third-stage concentration is carried out to obtain zinc oxide concentrate and third-stage concentration tailings; the first-stage concentration tailings return to the third-stage rough concentration, the second-stage concentration tailings return to the first-stage concentration, and the third-stage concentration tailings return to the second-stage concentration.

S2, combining the zinc oxide concentrate and the high-oxidation-rate ore, and adding sulfuric acid for pretreatment: 30g of the zinc oxide concentrate was combined with 2000g of high oxidation rate ore, the number of particles with-200 mesh size of high oxidation rate ore accounting for 35%. Adding 3000g of clear water, adding 30g of concentrated sulfuric acid into each liter of ore pulp, and carrying out pretreatment at the stirring speed of 500rpm, wherein the pretreatment temperature is 20 ℃, the pretreatment time is 1.5h, and the end point pH is 1.7;

s3, pre-neutralizing the pre-treated liquid: adding 12g of limestone into each liter of pretreated liquid, and carrying out preneutralization at the stirring speed of 300rpm, wherein the preneutralization temperature is 40 ℃, the preneutralization time is 1.5h, the end point pH is 4.7, and 15g of gypsum residue is produced; and (3) performing sodium carbonate zinc precipitation on the pre-neutralized liquid to obtain zinc carbonate precipitate: adding 12g of sodium carbonate into each liter of the pre-neutralized liquid, and precipitating zinc at the stirring speed of 300rpm, wherein the zinc precipitation temperature is 40 ℃, the reaction time is 1h, the end point pH is 7.8, and 12g of zinc carbonate precipitate is produced;

neutralizing the pretreated tailings: adding 0.8g of lime into each liter of pretreated tailings, neutralizing at the stirring speed of 300rpm, wherein the neutralization temperature is 40 ℃, the neutralization time is 1h, and the end point pH is 8.3; and (3) carrying out flotation on the neutralized tailing slurry: performing flotation on zinc sulfide ore by adopting a first-coarse-second-sweep three-fine flow process, wherein the mass concentration of ore pulp is about 33 percent, 3mg of copper sulfate, 1.5mg of butyl xanthate and 1mg of No. 2 oil are added into each liter of neutralized tail pulp, and then zinc sulfide concentrate B15g is produced;

it should be noted that the specific process of the one-rough two-sweep three-fine flotation is as follows:

roughing the neutralized tailing slurry to obtain roughed concentrate and roughed tailings, wherein the roughed concentrate enters first-stage concentration, and the roughed tailings enter first-stage scavenging;

the first-stage concentration is carried out to obtain first-stage concentration concentrate and first-stage concentration tailings, the first-stage concentration concentrate enters second-stage concentration, and the first-stage concentration tailings return to roughing; performing secondary concentration to obtain secondary concentrated concentrate and secondary concentrated tailings, returning the secondary concentrated tailings to primary concentration, and performing tertiary concentration on the secondary concentrated concentrate; obtaining third-stage concentration concentrate and third-stage concentration tailings by third-stage concentration, returning the third-stage concentration tailings to second-stage concentration, and obtaining the third-stage concentration concentrate, namely the sulfur zinc concentrate B;

primary scavenging is carried out to obtain primary scavenging concentrate and primary scavenging tailings, the primary scavenging concentrate returns to roughing, and the primary scavenging tailings enter secondary scavenging; and secondary scavenging is carried out to obtain secondary scavenging concentrate and secondary scavenging tailings, the secondary scavenging concentrate returns to the primary scavenging, and the secondary scavenging tailings are discharged to a tailing pond.

S4, combining the sulfur zinc concentrate A and the sulfur zinc concentrate B, and roasting: and combining 250g of the sulfur zinc concentrate A and 15g of the sulfur zinc concentrate B, roasting at 900 ℃ for 1h, and preparing acid from flue gas to produce 150g of roasted product and 180g of sulfuric acid.

S5, combining zinc carbonate precipitate and calcine and leaching: the 12g zinc carbonate precipitate produced in step S3 was combined with the 150g calcine produced in step S4, 800mL of waste electrolyte was added, and two-stage leaching was carried out at a stirring rate of 300 rpm. The first-stage leaching temperature is 85 ℃, the first-stage leaching time is 2 hours, and the first-stage end point pH is 4.7; the temperature of the second-stage leaching is 80 ℃, the time of the second-stage leaching is 2 hours, and the pH value of the second-stage end point is 1.6.

S6, impurity removal and purification: 40g of limestone is added into the first-stage leaching solution produced in the step S5, meanwhile, mixed gas of sulfur dioxide and air (the volume ratio of the sulfur dioxide to the air is 2:98) is introduced, impurity removal and purification reaction are carried out under the conditions that the stirring speed is 300rpm and the potential is 550-600mV, the reaction temperature is 70 ℃, the reaction time is 3h, and the end-point pH is 4.6.

And S7, electrolyzing the purified liquid to obtain the electrolytic zinc product.

The comprehensive recovery rate of zinc in the embodiment is 90.6%, and the sulfuric acid surplus rate is reduced by 87.0%.

Various corresponding changes and modifications can be made by those skilled in the art based on the above technical solutions and concepts, and all such changes and modifications should be included in the protection scope of the present invention.