阅读说明：本技术 一种硫酸协同处理氰化尾渣脱氰浮选回收金银的方法 (Method for decyanating, flotation and recovery of gold and silver from cyanidation tailings treated by sulfuric acid in cooperation ) 是由 王建政 朱德兵 郭建东 于 2021-09-07 设计创作，主要内容包括：本发明涉及一种硫酸协同处理氰化尾渣脱氰浮选回收金银的方法,包括1)硫酸酸化及氧化脱氰处理,2)硫脲法浸金,3)微泡射流浮选,4)二次氰化浸出,5)金银制取等步骤回收金银产品。本发明实现了氰化尾渣中氰化物的脱除回收、贵金属金银的综合回收,并且整个过程液体全部得到了循环与利用,减少了试剂用量,降低处理成本,处理后尾矿用于水泥生产原料,从而实现了氰化尾渣有价元素的高效回收和资源化利用,为氰化尾渣的合理有效处置提供了新的技术途径。(The invention relates to a method for recovering gold and silver by decyanation flotation of cyanidation tailings through synergistic treatment of sulfuric acid, which comprises the steps of 1) sulfuric acid acidification and oxidative decyanation treatment, 2) gold leaching by a thiourea method, 3) micro-bubble jet flotation, 4) secondary cyanidation leaching, 5) gold and silver preparation and the like. The method realizes the removal and recovery of cyanide in the cyanidation tailings and the comprehensive recovery of precious metal gold and silver, recycles and utilizes all liquid in the whole process, reduces the reagent dosage and the treatment cost, and uses the treated tailings as the cement production raw material, thereby realizing the high-efficiency recovery and resource utilization of valuable elements in the cyanidation tailings and providing a new technical approach for the reasonable and effective treatment of the cyanidation tailings.)

1. A method for decyanating, floating and recovering gold and silver from cyanidation tailings subjected to sulfuric acid synergistic treatment is characterized by comprising the following steps:

1) sulfuric acid acidification and oxidation decyanation treatment: adding sulfuric acid into cyaniding tailings, and then adding powdered activated carbon and potassium permanganate for leaching to obtain hydrogen cyanide gas and ore pulp;

2) gold leaching by a thiourea method: adding thiourea into the ore pulp obtained in the step 1), stirring and leaching, adjusting the pH value of the leached ore pulp to 1-3, adding a flocculating agent, concentrating and settling to obtain a concentrated sediment and an acidification decyanation solution, and performing filter pressing, washing and discharging on the concentrated sediment to obtain a filter cake;

3) micro-bubble jet flotation: mixing the filter cake obtained in the step 2), adding a bubble agent, entering a micro-bubble jet flotation column, and rising and floating mineralized bubbles to the surface of mineral liquid to aggregate to form a foam layer to obtain gold-containing foam product concentrate;

4) secondary cyanidation leaching: carrying out filter pressing and discharging on the foam product concentrate obtained in the step 3), carrying out cyaniding leaching on the obtained filter cake to obtain first leaching filtrate and ore pulp, and carrying out filter pressing and washing on the leached ore pulp to obtain a filter cake; performing secondary cyanidation leaching on the obtained filter cake to obtain secondary leaching filtrate and ore pulp;

5) preparation of gold and silver: mixing leaching filtrates obtained by leaching twice in the step 4), and performing deoxidation, replacement and gold and silver refining processes to obtain gold ingot and silver ingot products.

2. The method for decyanation flotation of gold and silver from cyanidation tailings treated by sulfuric acid in coordination according to claim 1, characterized in that in step 1):

the concentration of the sulfuric acid is 10-50 wt%, and the temperature is 50-80 ℃; the mass ratio of the cyaniding tailings to the sulfuric acid is 1: (1-5); the adding amount of the powdery active carbon is 1-10 kg/t, the adding amount of the potassium permanganate is 1-10 kg/t, and the leaching time is 4-6 h.

3. The method for decyanation flotation of gold and silver from cyanidation tailings treated by sulfuric acid in coordination according to claim 1, characterized in that in step 2):

the temperature of the ore pulp is 30-40 ℃; according to the mass of the ore pulp, the adding amount of thiourea is 10-30 kg/t; the stirring speed is 100-200 r/min, and the stirring leaching time is 6-8 h.

4. The method for decyanation flotation of gold and silver from cyanidation tailings treated with sulfuric acid in coordination according to claim 1, characterized in that in step 3):

the concentration of the pulp is 5-15 wt%; the added air bubble agents are ammonium nitrate black powder and 25# black powder, and the addition amount of the ammonium nitrate black powder is 10-50 g/t25# black powder and is 50-100 g/t based on the mass of the pulp after pulp mixing.

5. The method for decyanation flotation of gold and silver from cyanidation tailings treated by sulfuric acid in coordination according to claim 1, characterized in that in step 4):

the two cyanidation leaching conditions are as follows: adding a sodium cyanide solution into the filter cake for cyanide leaching, wherein the liquid-solid mass ratio of the sodium cyanide solution to the filter cake is (3-10): 1, the concentration of the sodium cyanide solution is 3-10 wt%, the leaching temperature is 40-50 ℃, the stirring speed is 600-800 r/min, and the leaching time is 36 h.

6. The method for decyanating, floating and recovering gold and silver from cyanide tailings by synergistic treatment with sulfuric acid according to claim 1 or 2, characterized in that hydrogen cyanide gas generated in the step 1) is absorbed by 5-10 wt% of sodium hydroxide to obtain sodium cyanide, and the obtained sodium cyanide is recycled for the cyanidation gold extraction process.

7. The method for decyanating, floating and recovering gold and silver from cyanidation tailings by synergistic treatment of sulfuric acid according to claim 1 or 3, characterized in that in the step 2), flocculating agents are added, namely polyacrylamide and alum, and the adding amount of the polyacrylamide is 1-5 g/t and the adding amount of the alum is 50-100 g/t based on the mass of the ore pulp after thiourea is added.

8. The method for recovering gold and silver by decyanation flotation of cyanide tailings treated with sulfuric acid in synergy according to claim 3, wherein the acidified decyanation solution generated during step 2) is recycled for the gold concentrate roasting and cyaniding process.

9. The method for decyanation flotation of gold and silver from cyanide tailings treated with sulfuric acid in coordination according to claim 1 or 4, wherein tailings generated during step 3) are made into tailings filter cakes for use as raw materials in cement manufacturing enterprises.

10. The method for recovering gold and silver by decyanation flotation of cyanidation tailings through synergistic treatment of sulfuric acid according to claim 1 or 5, characterized in that the secondary leaching ore pulp generated in the step 4) is subjected to pressure filtration and washing to obtain a gold-containing secondary leaching tailings filter cake for a roasting cyanidation gold extraction process.

Technical Field

The invention belongs to the field of gold smelting, and particularly relates to a method for decyanation flotation recovery of gold and silver from cyanidation tailings treated by sulfuric acid in a synergistic manner.

Background

In the industrial production of gold, the gold extraction process by cyanidation is an extraction mode that cyanide reacts with gold in ore to generate gold-cyanide complex, and the gold-cyanide complex is separated from the ore. Because the cyanidation method has the advantages of high recovery rate, mature process, low cost and the like, the cyanidation method is dominant in the gold extraction industry, and about 85 percent of gold ores in the world adopt the cyanidation method gold extraction process at present. But a large amount of cyanidation tailings are discharged in the production of the gold extraction process by the cyanidation method, and the discharge amount of gold cyanidation tailings per 1 ton of gold produced is 2.5-3 ten thousand tons. China is one of the biggest gold producing countries in the world, the generated cyanided tailings are large, a large amount of cyanided tailings are accumulated, the environment is seriously polluted, and huge resource waste is generated.

The existing common acidification volatilization method, hydrogen peroxide oxidation method, sodium metabisulfite oxidation method and the like need to add a large amount of reagents, so that the treatment cost is high, the treatment is not thorough, and the treatment effect is poor; the combined application of a plurality of methods causes complex treatment flow and high energy consumption, and is difficult to comprehensively recover precious metals such as gold, silver and the like in cyanidation tailings; the tailings of arsenic-containing gold concentrate two-stage roasting dearsenification-calcine cyanidation leaching have high gold content, and the methods of adding copper and lead smelting systems as a manufacturing and checking agent by using a chloridizing roasting-volatilization method still face the problems of economy, environmental protection and the like; therefore, how to effectively treat and comprehensively utilize the cyanidation tailings and solve the problems caused by the method needs a new method to solve.

Disclosure of Invention

The invention aims to provide a method for decyanating, floating and recovering gold and silver from cyanidation tailings by synergistic treatment of sulfuric acid, so as to solve the technical problem of technical problems.

The technical scheme for solving the technical problems is as follows:

a method for decyanating, floating and recovering gold and silver from cyanidation tailings subjected to sulfuric acid synergistic treatment comprises the following steps:

1) sulfuric acid acidification and oxidation decyanation treatment: adding sulfuric acid into cyaniding tailings, and then adding powdered activated carbon and potassium permanganate for leaching to obtain hydrogen cyanide gas and ore pulp;

2) gold leaching by a thiourea method: adding thiourea into the ore pulp obtained in the step 1), stirring and leaching, adjusting the pH value of the leached ore pulp to 1-3, adding a flocculating agent, concentrating and settling to obtain a concentrated sediment and an acidification decyanation solution, and performing filter pressing, washing and discharging on the concentrated sediment to obtain a filter cake;

3) micro-bubble jet flotation: mixing the filter cake obtained in the step 2), adding a bubble agent, entering a micro-bubble jet flotation column, and rising and floating mineralized bubbles to the surface of mineral liquid to aggregate to form a foam layer to obtain gold-containing foam product concentrate;

4) secondary cyanidation leaching: carrying out filter pressing and discharging on the foam product concentrate obtained in the step 3), carrying out cyaniding leaching on the obtained filter cake to obtain first leaching filtrate and ore pulp, and carrying out filter pressing and washing on the leached ore pulp to obtain a filter cake; performing secondary cyanidation leaching on the obtained filter cake to obtain secondary leaching filtrate and ore pulp;

5) preparation of gold and silver: mixing leaching filtrates obtained by leaching twice in the step 4), and performing deoxidation, replacement and gold and silver refining processes to obtain gold ingot and silver ingot products.

The mechanism and thought of the treatment method for the synergistic roasting of the neutralized waste residues and the lead-containing gold concentrate are as follows:

the method comprises the steps of carrying out acidification decyanation and oxidation decyanation treatment on cyanidation tailings by using sulfuric acid, carrying out carbon adsorption recovery on soluble gold compounds in a solution, simultaneously carrying out gold leaching and carbon adsorption by a thiourea method to effectively recover the soluble gold compounds, effectively dissociating gold particles coated on alkali oxides, carbonates, iron compounds and metal minerals in the acidification decyanation process to fully expose the gold particles, effectively enriching precious metals such as gold and silver in flotation concentrate by microbubble jet flotation, and carrying out secondary cyanidation leaching, replacement and gold and silver refining on the flotation concentrate to obtain gold ingots and silver ingot products so as to comprehensively recover the gold and silver ingots.

Further, in step 1): the concentration of the sulfuric acid is 10-50 wt%, and the temperature is 50-80 ℃; the mass ratio of the cyaniding tailings to the sulfuric acid is 1: (1-5); the adding amount of the powdery active carbon is 1-10 kg/t, the adding amount of the potassium permanganate is 1-10 kg/t, and the leaching time is 4-6 h.

The further technical characteristics have the following technical effects:

the gold particles coated on the alkali oxide, the carbonate, the iron compound and the metal mineral are effectively dissociated by proper concentration, temperature and dosage of the sulfuric acid, so that the gold particles are fully exposed; the proper amount of the powdery active carbon and the potassium permanganate and the proper leaching time are favorable for sulfuric acid acidification and oxidation decyanation treatment, and the active carbon can adsorb and recover soluble gold compounds in the solution.

Further, absorbing hydrogen cyanide gas generated in the step 1) by using 5-10 wt% of sodium hydroxide to obtain sodium cyanide, and recycling the obtained sodium cyanide for a cyaniding gold extraction process;

the further technical characteristics have the following technical effects:

the method realizes the removal and recovery of cyanide in the cyanide tailings, reasonably and effectively treats the cyanide tailings, effectively recycles the cyanide, saves the reagent consumption, reduces the cyanide tailings and reduces the environmental pollution.

Further, in step 2): the temperature of the ore pulp is 30-40 ℃; according to the mass of the ore pulp, the adding amount of thiourea is 10-30 kg/t, the stirring rotating speed is 100-200 r/min, and the stirring leaching time is 6-8 h;

further, in the step 2), 1-5 g/t of polyacrylamide and 50-100 g/t of alum are added as a flocculating agent according to the mass of the ore pulp added with thiourea;

the further technical characteristics have the following technical effects:

is beneficial to gold leaching and carbon adsorption by a thiourea method, and effectively recovers the soluble gold compound.

Further, the acidified decyanation solution generated in the step 2) is recycled for the gold concentrate roasting and cyaniding process and is used as water for wet size mixing of the gold concentrate before roasting.

The further technical characteristics have the following technical effects:

the acidized decyanation liquid is recycled, the reagent consumption is saved, the acid liquor discharge is reduced, and the environment is protected.

Further, in step 3): the concentration of the pulp is 5-15 wt%; adding air bubble agents, wherein the mass of the ammonium nitrate black powder is 10-50 g/t and the mass of 25# black powder is 50-100 g/t based on the mass of the pulp after size mixing;

the further technical characteristics have the following technical effects:

is beneficial to mineralized bubbles of slurry in the micro-bubble jet flotation process and improves the gold content in gold-containing foam.

Further, tailings generated in the step 3) are prepared into a tailing filter cake which is used as a raw material for cement production enterprises.

The further technical characteristics have the following technical effects:

the tailings are used as raw materials for cement production enterprises, and reasonable and effective treatment and resource utilization of the cyanided tailings are realized.

Further, in the step 4), the two cyanidation leaching conditions are as follows: adding a sodium cyanide solution into the filter cake for cyanide leaching, wherein the liquid-solid mass ratio of the sodium cyanide solution to the filter cake is (3-10): 1, the concentration of a sodium cyanide solution is 3-10 wt%, the leaching temperature is 40-50 ℃, the stirring speed is 600-800 r/min, and the leaching time is 36 h;

the further technical characteristics have the following technical effects: effectively improves the recovery rate of the gold and silver.

Further, carrying out filter pressing and washing on the second leaching ore pulp generated in the step 4) to obtain a gold-containing second leaching tailing filter cake for a roasting, cyaniding and gold extraction process.

The further technical characteristics have the following technical effects:

the secondary leaching tailings are recycled again through roasting decarburization and cyaniding gold extraction processes, so that the high-efficiency recovery and resource utilization of valuable elements in the cyaniding tailings are realized.

The processing method for the synergistic roasting of the neutralized waste residues and the lead-containing gold concentrate has the beneficial effects that:

the method realizes the removal and recovery of cyanide in the cyanidation tailings and the comprehensive recovery of precious metal gold and silver, recycles and utilizes all liquid in the whole process, reduces the reagent dosage and the treatment cost, and uses the treated tailings as the cement production raw material, thereby realizing the high-efficiency recovery and resource utilization of valuable elements in the cyanidation tailings and providing a new technical approach for the reasonable and effective treatment of the cyanidation tailings.

Detailed Description

The principles and features of this invention are described below in conjunction with examples, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.

Example 1

Adding a certain amount of water into an acidification tank, and adding concentrated sulfuric acid, wherein the concentration of the sulfuric acid is regulated to 10 wt%, and the temperature of the sulfuric acid is kept at 50 ℃; carrying cyanide tailings containing 2g/t gold to an acidification tank by a forklift, wherein the solid-liquid mass ratio of the cyanide tailings to sulfuric acid is 1: 1; adding a certain amount of powdered activated carbon and potassium permanganate, wherein the adding amount of the powdered activated carbon is 1kg/t and the adding amount of the potassium permanganate is 1kg/t according to cyanidation tailings, and the leaching time is 4 hours; hydrogen cyanide gas generated in the process enters a countercurrent spray absorption tower, 5 wt% of sodium hydroxide is used as absorption liquid to absorb the generated hydrogen cyanide gas, and the sodium cyanide generated by absorbing the hydrogen cyanide gas is recycled for the cyaniding gold extraction process.

Cooling the temperature of the ore pulp after acid leaching to 30 ℃, adding thiourea, wherein the adding amount of the thiourea is 10kg/t according to cyanidation tailings, stirring the mixture at a rotating speed of 100r/min for 6 hours, and adjusting the pH value of the ore pulp after leaching to 1; adding 1g/t of flocculating agent polyacrylamide and 50g/t of alum, feeding the mixture into a thickener for concentration and sedimentation, conveying the bottom flow of the thickener to a blowing washing filter press through a pump, performing filter pressing, washing and discharging, and feeding a filter cake into a flotation system; the acidified decyanation liquid overflowing from the thickener is recycled for the gold concentrate roasting and cyaniding process as water for wet size mixing of the gold concentrate before roasting.

The filter cake is subjected to size mixing by adopting flotation system liquid, the concentration of the ore pulp is adjusted to be 5 wt%, the ammonium nitrate black powder is added for 10g/t and the No. 25 black powder is added for 50g/t, then the mixture enters a micro-bubble jet flow flotation column, mineralized bubbles rise and float to the surface of the ore liquid to be gathered to form a foam layer, and the foam layer is scraped out by a scraper to obtain a foam product concentrate containing 50g/t gold; the tailings are discharged from the column bottom by virtue of a lifting device, and are subjected to pressure filtration by a membrane filter press to obtain a tailing filter cake containing 0.5g/t of gold and 10 wt% of iron, which belongs to common solid wastes and is used as a raw material for cement production enterprises.

Sending the foam product concentrate into a diaphragm filter press through a pump, performing filter pressing, discharging, replacing barren liquor with cyanide gold extraction for pulp mixing of filter cakes, performing cyanide leaching for the first time, and controlling the liquid-solid mass ratio to be 3: 1, the concentration of sodium cyanide is 3 wt%, the temperature is 40 ℃, the stirring speed is 600r/min, the leaching time is 36h, and the leached ore pulp is subjected to filter pressing and washing; and (3) performing secondary cyaniding leaching on the filter cake by using cyaniding gold extraction displacement barren solution, and controlling the liquid-solid ratio to be 3: 1, the concentration of sodium cyanide is 3 wt%, the temperature is 40 ℃, the stirring speed is 600r/min, the leaching time is 36h, and the leached ore pulp is subjected to filter pressing and washing; and conveying the filter cake of the secondary leaching tailings containing 5g/t of gold to a roasting, cyaniding and gold extracting process by a belt conveyor, and recycling again by the roasting, decarbonizing and cyaniding gold extracting processes.

And (3) carrying out deoxidation and zinc powder replacement processes on the primary leaching filtrate and the secondary leaching filtrate to obtain gold mud containing 10 wt% of gold and 10 wt% of silver, and carrying out gold and silver refining to obtain gold ingot and silver ingot products.

Example 2:

adding a certain amount of water into an acidification tank, and adding concentrated sulfuric acid, wherein the concentration of the sulfuric acid is regulated to 50 wt%, and the temperature of the sulfuric acid is kept at 80 ℃; carrying cyanide tailings containing 10g/t gold to an acidification tank by a forklift, wherein the solid-liquid mass ratio of the cyanide tailings to sulfuric acid is 1: 5; adding a certain amount of powdered activated carbon and potassium permanganate, wherein the adding amount of the powdered activated carbon is 10kg/t and the adding amount of the potassium permanganate is 10kg/t according to cyanidation tailings, and the leaching time is 6 hours; hydrogen cyanide gas generated in the process enters a countercurrent spray absorption tower, 10 wt% of sodium hydroxide is used as absorption liquid to absorb the generated hydrogen cyanide gas, and the sodium cyanide generated by absorbing the hydrogen cyanide gas is recycled for the cyaniding gold extraction process.

Cooling the temperature of the ore pulp after acid leaching to 40 ℃, adding thiourea, wherein the adding amount of the thiourea is 30kg/t, the stirring speed is 200r/min, the stirring leaching time is 8 hours, and the pH value of the leached ore pulp is adjusted to 3 according to the cyaniding tailings; adding flocculating agents of polyacrylamide 5g/t and alum 100g/t, feeding the mixture into a thickener for concentration and sedimentation, conveying the underflow of the thickener to a blowing washing filter press through a pump, performing filter pressing, washing and discharging, and feeding a filter cake into a flotation system; the acidified decyanation liquid overflowing from the thickener is recycled for the gold concentrate roasting and cyaniding process as water for wet size mixing of the gold concentrate before roasting.

The filter cake is subjected to size mixing by adopting flotation system liquid, the concentration of the ore pulp is adjusted to 15 wt%, and the ammonium nitrate black powder is added into a micro-bubble jet flow flotation column after the ammonium nitrate black powder is added into the column and the No. 25 black powder is added into the column at 100g/t, mineralized bubbles rise and float to the surface of the ore liquid to be gathered to form a foam layer, and the foam layer containing 300g/t gold is obtained after overflowing; the tailings are discharged from the column bottom by virtue of a lifting device, and are subjected to pressure filtration by a membrane filter press to obtain a tailing filter cake containing 1.0g/t of gold and 30 wt% of iron, which belongs to common solid wastes and is used as a raw material for cement production enterprises.

Sending the foam product concentrate into a diaphragm filter press through a pump, performing filter pressing, discharging, replacing barren liquor with cyanide gold extraction for pulp mixing of filter cakes, performing cyanide leaching for the first time, and controlling the liquid-solid mass ratio to be 10: 1, carrying out filter pressing and washing on the leached ore pulp, wherein the concentration of sodium cyanide is 10 wt%, the temperature is 50 ℃, the stirring speed is 800r/min, the leaching time is 36 h; and (3) performing secondary cyaniding leaching on the filter cake by using cyaniding gold extraction displacement barren solution, and controlling the liquid-solid ratio to be 10: 1, carrying out filter pressing and washing on the leached ore pulp, wherein the concentration of sodium cyanide is 10 wt%, the temperature is 50 ℃, the stirring speed is 800r/min, the leaching time is 36 h; and conveying the secondary leaching tailings filter cake containing 10g/t of gold to a roasting, cyaniding and gold extracting process by a belt conveyor, and recycling again by the roasting, decarbonizing and cyaniding gold extracting processes.

And (3) carrying out deoxidation and zinc powder replacement processes on the primary leaching filtrate and the secondary leaching filtrate to obtain gold mud containing 50 wt% of gold and 20 wt% of silver, and carrying out gold and silver refining to obtain gold ingot and silver ingot products.

It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.