A method for efficiently desorbing gold from gold-containing sulfide ore by carbon leaching

Abstract

The present invention relates to a method for efficiently desorbing gold-loaded carbon from gold-containing sulfide ore by carbon leaching, which belongs to the field of gold smelting. The specific steps are as follows: (1) dispersing and desludging the gold-loaded activated carbon obtained in the carbon leaching process, and separating the gold-loaded activated carbon from muddy water by a vibrating screen; (2) transporting the activated carbon obtained in the above step (1) to a circulating conversion column, treating it with a conversion agent, and obtaining calcium carbonate-containing gold-loaded activated carbon, wherein the conversion agent is a mixed solution of sodium carbonate and sodium hydroxide; (3) transporting the gold-loaded activated carbon obtained in the above step (2) to a circulating desorption column, transporting the obtained gold-containing precious liquid to an electrolysis system, and transporting the lean activated carbon to acid washing and decalcification, wherein the desorbent is a mixed solution of sodium carbonate, sodium hydroxide and sodium cyanide. The present invention avoids the normal operation of the gold-loaded activated carbon circulating desorption system by calcium sulfate or calcium hydroxide; at the same time, the difficult-to-desorb calcium auric cyanate is also converted into easily desorbable sodium auric cyanate, thereby improving the gold desorption rate of the gold-loaded activated carbon.

Description

Technical Field

[0001] The invention relates to a method for efficiently desorbing gold-loaded carbon by carbon-based leaching of gold-containing sulfide ores, belongs to the field of gold smelting, and relates to the field of gold smelting carbon-based leaching. Background Art

[0002] In gold smelting, most low-grade gold ore extraction methods use carbon-in-slurry method or carbon-in-leaching method. Activated carbon adsorption is a key step. During this process, activated carbon will also non-selectively adsorb impurity ions in the ore pulp, and the adsorption amount is positively correlated with the concentration of impurity ions in the ore pulp. This process mostly uses lime as a protective base, but the properties of the ore have a great influence on the amount of lime used. In particular, when this process is used to treat gold-containing sulfide ores, the amount of lime used increases sharply. At the same time, under the catalytic oxidation and adsorption of sulfides or dissolved sulfur ions by activated carbon, the SO4 adsorbed by activated carbon 2- With Ca 2+ The reaction generates calcium sulfate, which blocks the pores of activated carbon and seriously affects the desorption of gold. Calcium sulfate is slightly soluble. After entering the desorption system together with activated carbon, as the temperature of the desorption liquid increases and the number of cycles increases, the calcium ions in the solution gradually increase. When it reaches or exceeds the solubility product of calcium carbonate, hard scale (mainly composed of calcium carbonate, calcium sulfate, etc.) is formed on the walls of system pipes, gate valves, etc., affecting the normal desorption of gold from gold-loaded activated carbon. At present, the desorption methods of gold-loaded activated carbon include the Zadra desorption method, the high temperature and high pressure desorption method, and the alkaline ethanol solution desorption method. The Zadra desorption method is to add 1.0% sodium hydroxide to a 0.1% sodium cyanide mixture and heat it to 90℃~95℃. In actual production, it usually takes 50~70 hours to achieve a high desorption rate. The high temperature and high pressure desorption method is to place the gold-loaded carbon in a pressure vessel and use a 0.4%~1% sodium hydroxide and 0.1% sodium cyanide mixture at a temperature of 130℃~160℃ and a pressure of 3.6~5.9kg / cm 2 pressure, desorption time 6~8 hours; alkaline ethanol solution desorption method is to add 20% ethanol to a mixture of 1% sodium hydroxide and 0.1~0.2% sodium cyanide, desorb at normal pressure for 6~8 hours at 83℃, but ethanol is flammable and explosive. Using these methods, the gold desorption rate of activated carbon gold extracted by carbon leaching of gold-bearing sulfide ore is low, the production cost increases sharply, and the pipeline and gate valve of the desorption system are seriously blocked, the desorption process cannot be carried out normally, and some of them have safety hazards; at the same time, when the lean carbon is returned to the leaching-adsorption operation for gold extraction after desorption, the gold adsorption rate drops sharply, and the gold content of the tail liquid increases, resulting in a decrease in the total gold recovery rate. Therefore, seeking a scientific and effective treatment method is the key to solving the existing problems. Summary of the invention

[0003] The invention provides a method for extracting gold from gold-containing sulfide ore by carbon leaching and efficiently desorbing gold-loaded carbon, thereby improving the gold desorption rate of the gold-loaded activated carbon.

[0004] The specific steps are as follows:

[0005] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0006] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2%~3% sodium carbonate and 1%~1.5% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 5:1~6:1, and the conversion treatment time is 1~3 hours; sodium hydroxide is added to increase the pH value, because when the pH value is low, most of the sodium carbonate solution is bicarbonate, and bicarbonate reacts very slowly with calcium sulfate. On the contrary, when the pH value is high, most of the sodium carbonate solution is carbonate, which reacts quickly with calcium sulfate. The reaction principle with calcium hydroxide is the same.

[0007] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to a circulating desorption column and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to acid washing and decalcification. In this process, the desorbent is a mixture of 2% to 3% sodium carbonate, 1% to 1.5% sodium hydroxide and 0.3% sodium cyanide, the desorption temperature is 140°C to 165°C, and the desorption time is 16 to 18 hours. Adding sodium hydroxide has the effect of increasing the pH value and desorption, because at a low pH value, sodium cyanide will turn into hydrogen cyanide gas, overflow from the solution, and lose its effect; adding sodium hydroxide and sodium cyanide at the same time has a strong ability to desorb gold from the activated carbon. The purpose of adding sodium carbonate is to increase the carbonate concentration in the desorption solution and reduce the solubility of calcium carbonate, thereby reducing the calcium ion concentration and avoiding excessive calcium ion concentration, which will lead to scaling on the walls of pipelines or gate valves and affect continued production.

[0008] The mass concentration is 2%~3% sodium carbonate and 1%~1.5% sodium hydroxide; if the concentration is low, the effect is reduced. If the concentration is high, the cost is high and the adsorption and durability of activated carbon to gold are reduced.

[0009] The solubility product of calcium carbonate is much smaller than that of calcium sulfate or calcium hydroxide. Therefore, a mixture of sodium carbonate and sodium hydroxide is added to convert the slightly soluble calcium sulfate or calcium hydroxide on the surface and pores of the gold-loaded activated carbon into insoluble calcium carbonate through a cyclic replacement conversion system, removing sulfate (i.e., SO4 2-). Its effect is to prevent calcium sulfate or calcium hydroxide from entering the circulating desorption system with the gold-loaded activated carbon. As the temperature of the desorption liquid increases and the number of cycles increases, the calcium ions gradually increase, reaching or exceeding the solubility product of calcium carbonate, forming hard scale (mainly composed of calcium carbonate, calcium sulfate, etc.) on the walls of the system pipes, gate valves, etc., affecting the normal operation of the gold-loaded activated carbon circulating desorption system. In addition, calcium carbonate on the surface and pores of the lean activated carbon is easily removed by pickling (hydrochloric acid, nitric acid, etc.), while calcium sulfate is difficult to remove; at the same time, the difficult-to-desorb calcium auranate in the gold-loaded activated carbon is also converted into easily desorbed sodium auranate. Then, a mixed desorption liquid composed of sodium carbonate, sodium hydroxide and sodium cyanide is added to the converted gold-loaded activated carbon, and gold is desorbed through the circulating desorption system at a temperature of 140℃~165℃. In this process, due to the common ion effect of sodium carbonate, the calcium ion concentration in the circulating desorption liquid is greatly reduced, making it difficult to form scale on the walls of the system pipes, gate valves, etc. The finally obtained precious gold-containing desorption liquid is then electrolyzed, and the lean desorption carbon is washed with acid to remove calcium.

[0010] The current desorption methods are all aimed at the desorption of gold-loaded activated carbon other than gold-containing sulfide ores. One reason is that when sulfate enters the electrolysis, it will affect the electrolysis and subsequent gold mud treatment. Another reason is that during desorption, the calcium ion concentration is high, which will form scale on the pipes and systems, making it difficult to continue desorption.

[0011] Advantages and positive effects compared with existing methods

[0012] (1) Improved the gold desorption rate of gold-loaded activated carbon;

[0013] (2) The gold desorption rate of gold-loaded activated carbon was increased and the gold desorption rate was reduced;

[0014] (3) Reduce the production cost of the desorption process;

[0015] (4) Ensure the safe and smooth progress of the desorption process;

[0016] (5) Improved the adsorption rate of gold by the regenerated lean activated carbon during the leaching-adsorption process;

[0017] (6) The process has strong adaptability and is particularly suitable for the desorption of gold from gold-bearing activated carbon in gold-bearing sulfide ores using carbon-in-slurry or carbon-in-leach methods, and has good commercial promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A flow chart of a method for efficiently desorbing gold from gold-bearing sulfide ores by carbon leaching;

[0019] Figure 2 A schematic diagram of a highly efficient desorption device for gold-bearing carbon from gold-bearing sulfide ores using carbon leaching to extract gold;

[0020] Figure 2-1 Schematic diagram of desorption liquid heating system cycle;

[0021] Figure 2-2 Schematic diagram of the gold-loaded carbon desorption system cycle;

[0022] Figure 2-3 Schematic diagram of electrolysis cycle;

[0023] Among them, 1: stirring barrel, 2: vibrating screen, 3: conversion liquid tank, 4: conversion circulation pump; 5: carbon storage tank, 6: circulating conversion column, 7: circulating desorption column, 8: filter, 9: electrolytic cell, 10: desorption liquid tank, 11: 1# electric heater, 12: 2# electric heater, 13: 1# desorption liquid circulation pump, 14: 2# desorption liquid circulation pump. DETAILED DESCRIPTION

[0024] Figure 2 The illustrated system is a gold-containing sulfide ore carbon leaching method for gold extraction and gold-loaded carbon high-efficiency desorption system, comprising a stirring barrel 1, a circulating conversion column 6 and a circulating desorption column 7;

[0025] The circulating conversion column 6 is a cylindrical cavity structure, with a feed inlet and a circulating discharge port at the upper end of the cavity structure, and a circulating feed inlet, a discharge port and a waste conversion agent discharge port at the lower end;

[0026] The circulating desorption column 7 is a cylindrical cavity structure, with a feed inlet and two discharge ports at the upper end of the cavity structure, and two circulating feed inlets and a lean carbon outlet at the lower end;

[0027] A stirring barrel 1, a vibrating screen 2 is arranged below the stirring barrel 1, and the solids discharged from the vibrating screen are connected to a carbon storage tank 5, and the lower end of the carbon storage tank 5 is connected to a circulating conversion column 6 through a pipeline;

[0028] The discharge port at the lower end of the circulating conversion column 6 is connected to the feed port at the upper end of the circulating desorption column 7 through a pipeline;

[0029] The circulation discharge port at the upper end of the circulation conversion column 6 is connected to the conversion liquid tank 3, the conversion circulation pump 4 and the circulation feed port at the lower end of the circulation conversion column 6 through a pipeline;

[0030] A discharge port at the upper end of the circulating desorption column 6 is connected to the desorption liquid tank 10 through a pipeline;

[0031] Another discharge port at the upper end of the circulating desorption column 6 is connected to the electrolytic cell 9 through the filter 8, wherein the filtrate outlet of the filter 8 is connected to the electrolytic cell 9, and the solids of the filter 8 are processed separately;

[0032] The electrolyte outlet of the electrolytic cell 9 is divided into two paths, one of which is connected to the inlet of the desorption liquid tank 10, and the other (waste electrolyte) is connected to the desorption liquid circulation pump together with the outlet pipe of the desorption liquid tank 10;

[0033] The outlet of the desorption liquid circulation pump is divided into two paths, one path enters the circulation desorption column 7 from the bottom after being heated by the 1# electric heater 11 and the 2# electric heater 12, and the other path goes to the leaching tank; the 1# electric heater 11 and the 2# electric heater 12 are connected in series;

[0034] The pipeline from the upper end of the circulating desorption column 7 to the desorption liquid tank is connected to the pipeline at the outlet of the 1# electric heater 11. The pipeline connection is divided into two paths, one enters the circulating desorption column 7 from the bottom, and the other is connected to the pipeline to the leaching tank;

[0035] The above-mentioned devices are connected by pipelines, and a valve is provided at the outlet of each pipeline or device. The valve of the leaching tank pipeline is provided at the end, and each cycle of the whole system is used separately. The conversion liquid tank 3 is provided with a conversion agent addition port for adding the conversion agent; the desorption liquid tank 10 is provided with a desorption liquid addition port for adding the desorption liquid. In the circulating conversion column 6 and the circulating desorption column 7, except for the inlet and outlet of the gold-loaded carbon, other conversion agent or desorption liquid inlets and outlets are provided with screens to prevent the gold from entering the pump and crushing the gold-loaded carbon.

[0036] Furthermore, the desorption liquid circulation pumps include two 1# desorption liquid circulation pumps 13 and 2# desorption liquid circulation pumps 14, and the 1# desorption liquid circulation pumps 13 and 2# desorption liquid circulation pumps 14 are connected in parallel, one for backup and the other for use.

[0037] Running process:

[0038] like Figure 2 As shown, the gold-loaded activated carbon to be treated is fully stirred in a stirring barrel 1 and then separated into muddy water and gold-loaded carbon by a vibrating screen 2 , and the gold-loaded carbon enters a circulating conversion column 6 through a carbon storage tank 5 .

[0039] Open the valves between the circulating conversion column 6, the conversion liquid tank 3, and the conversion circulation pump 4, close the other valves, add the conversion agent to the conversion liquid tank 3, and then use the conversion circulation pump 4 to make the conversion agent and the gold-loaded carbon fully contact in the circulation, so that the calcium sulfate-loaded gold activated carbon is converted into the calcium carbonate-loaded gold activated carbon, and the sulfate SO4 is removed. 2- , and obtain gold-loaded activated carbon containing calcium carbonate. Open the valve of the waste conversion agent discharge port, close other valves, and release the waste conversion agent.

[0040] Open the valve between the circulating conversion column 6 and the circulating desorption column 7 to allow the converted gold-loaded carbon to enter the circulating desorption column 7 (in the actual production process, the circulating conversion column 6 is above the circulating desorption column 7, and the pipeline has a large angle, which is convenient for utilizing the drop to allow the wet gold-loaded carbon to enter the circulating desorption column 7. The wet gold-loaded carbon has good fluidity and can flow into the circulating desorption column 7. If necessary, negative pressure is applied to the upper end discharge port of the circulating desorption column 7 to facilitate the gold-loaded carbon to flow into the circulating desorption column 7. Figure 2 Schematic diagram only).

[0041] like Figure 2-1 As shown, the temperature of the desorption liquid is increased: the desorption liquid is added to the desorption liquid tank 10, the pipeline valves between the desorption liquid tank 10, the desorption liquid circulation pump (13 or 14) and the 1# electric heater 11 and the 2# electric heater 12 are opened, and the remaining valves are closed to increase the temperature of the desorption liquid.

[0042] like Figure 2-2 As shown, gold-loaded carbon desorption: when the temperature of the desorption liquid rises to the required temperature (140°C~165°C), open the pipeline valves between the circulating desorption column 7, the desorption liquid tank 10, the desorption liquid circulating pump (13 or 14) and the 1# electric heater 11 and the 2# electric heater 12, close the remaining valves, and carry out desorption.

[0043] like Figure 2-3 As shown, electrolysis: after the desorption is completed, open the pipeline valves between the circulating desorption column 7, the filter 8, the electrolytic cell 9, the desorption liquid tank 10, the desorption liquid circulation pump (13 or 14) and the 1# electric heater 11 and the 2# electric heater 12, close the remaining valves, and carry out electrolysis.

[0044] After the electrolysis is completed, the desorbed lean liquid in the electrolytic cell 9 and the desorbed lean carbon in the circulating desorption column 7 are removed, and the next cycle is awaited.

[0045] like Figure 1 A method for efficiently desorbing gold from gold-bearing sulfide ore by carbon leaching is shown, and the specific steps are as follows:

[0046] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0047] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2%~3% sodium carbonate and 1%~1.5% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 5:1~6:1, and the conversion treatment time is 1~3 hours; sodium hydroxide is added to increase the pH value, because when the pH value is low, most of the sodium carbonate solution is bicarbonate, and bicarbonate reacts very slowly with calcium sulfate. On the contrary, when the pH value is high, most of the sodium carbonate solution is carbonate, which reacts quickly with calcium sulfate. The reaction principle with calcium hydroxide is the same.

[0048] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to a circulating desorption column and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to acid washing and decalcification. In this process, the desorbent is a mixture of 2% to 3% sodium carbonate, 1% to 1.5% sodium hydroxide and 0.3% sodium cyanide, the desorption temperature is 140°C to 165°C, and the desorption time is 16 to 18 hours. Adding sodium hydroxide has the effect of increasing the pH value and desorption, because at a low pH value, sodium cyanide will turn into hydrogen cyanide gas, overflow from the solution, and lose its effect; adding sodium hydroxide and sodium cyanide at the same time has a strong ability to desorb gold from the activated carbon. The purpose of adding sodium carbonate is to increase the carbonate concentration in the desorption solution and reduce the solubility of calcium carbonate, thereby reducing the calcium ion concentration and avoiding excessive calcium ion concentration, which will lead to scaling on the walls of pipelines or gate valves and affect continued production.

[0049] Embodiment 1:

[0050] The chemical composition of an activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching is shown in Table 1-1. It can be seen from the table that the gold content of the gold-loaded activated carbon is 428g / t, the silver content is 955g / t, the sulfur content is 9500g / t, and the calcium content is relatively high, which is 65000g / t.

[0051] Table 1-1 Chemical composition of activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching

[0052]

[0053] Experiment 1

[0054] The present invention is used to implement the gold-containing sulfide ore carbon leaching method for extracting gold activated carbon, and the specific steps are:

[0055] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0056] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2% sodium carbonate and 1% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 6:1, and the conversion treatment time is 3 hours;

[0057] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixed solution with a mass concentration of 2% sodium carbonate, 1% sodium hydroxide and 0.3% sodium cyanide, the desorption temperature is 165°C, and the desorption time is 18 hours.

[0058] The final test results obtained by using the invention are: the desorbed lean activated carbon contains 23.54g / t of gold and 66.48g / t of silver, the gold desorption rate is 95.50%, and the silver desorption rate is 93.00%. There is basically no blockage, and continuous production can be achieved for at least 100 days.

[0059] Comparative experiment 1.1 (Zadra desorption method—no sodium hydroxide and sodium carbonate are added in step (2) and no sodium carbonate is added in step (3):

[0060] The Zadra desorption method is used to extract gold from the gold-containing sulfide ore by carbon leaching activated carbon, and the specific steps are as follows:

[0061] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0062] (2) Add 1.0% sodium hydroxide to 0.3% sodium cyanide and heat the mixture to 165°C. The desorption time is 18 hours.

[0063] The final test results are: the desorbed lean activated carbon contains 128g / t gold and 310g / t silver, with a gold desorption rate of 70.50% and a silver desorption rate of 67.50%.

[0064] Comparative experiment 1.2: sodium hydroxide and sodium carbonate were added in step (2); sodium carbonate was not added in step (3);

[0065] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0066] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2% sodium carbonate and 1% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 6:1, and the conversion treatment time is 3 hours;

[0067] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixture of 1% sodium hydroxide and 0.3% sodium cyanide by mass concentration, the desorption temperature is 165°C, and the desorption time is 18 hours.

[0068] The final test results are: the lean activated carbon contains 25.56k / t gold, 95.62g / t silver, 94.67% gold desorption rate, and 90.35% silver desorption rate. 30 days of plugging.

[0069] Table 1-2 Comparison of test results

[0070]

[0071] Embodiment 2:

[0072] The chemical composition of a kind of activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching is shown in Table 2-1. From the table, it can be seen that the gold content of the gold-loaded activated carbon is 768g / t, the silver content is 3452g / t, the sulfur content is 9300g / t, and the calcium content is relatively high, which is 51100g / t.

[0073] Table 2-1 Chemical composition of activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching

[0074]

[0075] Experiment 2

[0076] The present invention is used to implement the gold-containing sulfide ore carbon leaching method for extracting gold activated carbon, and the specific steps are:

[0077] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0078] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 3% sodium carbonate and 1.5% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 5:1, and the conversion treatment time is 1 hour;

[0079] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixture of 3% sodium carbonate, 1.5% sodium hydroxide and 0.3% sodium cyanide by mass concentration, the desorption temperature is 140°C, and the desorption time is 16 hours.

[0080] The final test results obtained by using the invention are: the desorbed lean activated carbon contains 26.11g / t of gold and 157.07g / t of silver, the gold desorption rate is 96.60%, and the silver desorption rate is 95.45%. There is basically no blockage, and continuous production can be achieved for at least 100 days.

[0081] Comparative experiment 2.1 (Zadra desorption method—no sodium hydroxide and sodium carbonate are added in step (2) and no sodium carbonate is added in step (3):

[0082] The Zadra desorption method is used to extract gold from the gold-containing sulfide ore by carbon leaching activated carbon, and the specific steps are as follows:

[0083] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0084] (2) Add 1.5% sodium hydroxide to 0.3% sodium cyanide and heat the mixture to 140°C. The desorption time is 16 hours.

[0085] The final test results are: the desorbed lean activated carbon contains 185g / t gold and 839g / t silver, with a gold desorption rate of 70.72% and a silver desorption rate of 67.35%. 5 days of blockage.

[0086] Comparative experiment 2.2: sodium hydroxide and sodium carbonate were added in step (2); sodium carbonate was not added in step (3);

[0087] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0088] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2-, to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 3% sodium carbonate and 1.5% sodium hydroxide, the volume ratio of the conversion agent to the activated carbon is 5:1, and the conversion treatment time is 1 hour;

[0089] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixture of 1.5% sodium hydroxide and 0.3% sodium cyanide by mass concentration, the desorption temperature is 140°C, and the desorption time is 16 hours.

[0090] The final test results were: the lean activated carbon contained 27.38k / t gold, 291.76g / t silver, 94.12% gold desorption rate, and 90.69% silver desorption rate. 32 days of blockage.

[0091] Table 2-2 Comparison of test results

[0092]

[0093] Embodiment three:

[0094] Experiment 3

[0095] The chemical composition of an activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching is shown in Table 3-1. From the table, it can be seen that the gold content of the gold-loaded activated carbon is 831g / t, the silver content is 2350g / t, the sulfur content is 9800g / t, and the calcium content is relatively high, which is 44100g / t.

[0096] Table 3-1 Chemical composition of activated carbon for gold extraction from gold-containing sulfide ore by carbon leaching

[0097]

[0098] The present invention is used to implement the gold-containing sulfide ore carbon leaching method for extracting gold activated carbon, and the specific steps are:

[0099] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0100] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2-, to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2.5% sodium carbonate and 1.5% sodium hydroxide by mass concentration, the volume ratio of the conversion agent to the activated carbon is 5:1, and the conversion treatment time is 2 hours;

[0101] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixture of 2.5% sodium carbonate, 1.5% sodium hydroxide and 0.3% sodium cyanide by mass concentration, the desorption temperature is 160°C, and the desorption time is 17 hours.

[0102] The final test results obtained by using the invention are: the desorbed lean activated carbon contains 31.16g / t of gold and 149.23g / t of silver, the gold desorption rate is 96.25%, and the silver desorption rate is 93.65%. There is basically no blockage, and continuous production can be achieved for at least 100 days.

[0103] Comparative experiment 3.1 (Zadra desorption method—no sodium hydroxide and sodium carbonate are added in step (2) and no sodium carbonate is added in step (3):

[0104] The Zadra desorption method is used to extract gold from the gold-containing sulfide ore by carbon leaching activated carbon, and the specific steps are as follows:

[0105] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0106] (2) Add 1.5% sodium hydroxide to 0.3% sodium cyanide and heat the mixture to 160°C. The desorption time is 17 hours.

[0107] The final test results were: the desorbed lean activated carbon contained 168g / t gold and 625g / t silver, with a gold desorption rate of 71.34% and a silver desorption rate of 68.42%. 5 days of blockage.

[0108] Comparative experiment 3.2: sodium hydroxide and sodium carbonate were added in step (2); sodium carbonate was not added in step (3);

[0109] (1) Peat separation (de-sludge): The gold-loaded activated carbon obtained in the carbon leaching process is transported to a mixing tank for dispersion and de-sludge, and then the gold-loaded activated carbon is separated from the mud water through a vibrating screen;

[0110] (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a circulating replacement conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, thereby removing sulfate SO4 2- , to obtain gold-loaded activated carbon containing calcium carbonate. In this process, the conversion agent is: a mixture of 2.5% sodium carbonate and 1.5% sodium hydroxide by mass concentration, the volume ratio of the conversion agent to the activated carbon is 5:1, and the conversion treatment time is 2 hours;

[0111] (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to the desorption column of the circulating desorption system, and treated with a desorption liquid mixture to desorb gold from the gold-loaded activated carbon into the solution. The obtained gold-containing precious liquid is transported to the electrolysis system, and the lean activated carbon is transported to the acid washing and decalcification system. In this process, the desorbent is a mixture of 1.5% sodium hydroxide and 0.3% sodium cyanide by mass concentration, the desorption temperature is 160°C, and the desorption time is 17 hours.

[0112] The final test results are: the lean activated carbon contains 35.85k / t gold, 196.84g / t silver, 93.87% gold desorption rate, and 89.06% silver desorption rate. 35 days of blockage.

[0113] Table 3-2 Comparison of test results

[0114]

[0115] The above cases illustrate that after adding the conversion step (adding sodium carbonate and sodium hydroxide), the desorption rate of gold and silver has been significantly improved, scale is not easily formed, and the operation time is significantly extended; adding sodium carbonate in the desorption step further improves the desorption rate of gold and silver, which can effectively prevent the formation of scale and can be continuously produced, effectively solving the problem that the analytical method cannot desorb gold-loaded activated carbon outside the gold-containing sulfide ore. The invention can obtain stable and reliable gold desorption indicators, and has good adaptability to the desorption of different gold-loaded activated carbons.

Claims

1. A method for extracting gold from gold-containing sulfide ore by carbon leaching and high-efficiency desorption of gold-loaded carbon, characterized in that: The specific steps are as follows: (1) Peat separation: The gold-loaded activated carbon obtained in the carbon leaching process is dispersed and desludged, and the gold-loaded activated carbon is separated from the mud water by a vibrating screen; (2) Phase conversion: The clean activated carbon obtained in step (1) is transported to a circulating conversion column and treated with a conversion agent to convert the gold-loaded activated carbon containing calcium sulfate into the gold-loaded activated carbon containing calcium carbonate, removing sulfate SO4 2- , obtaining calcium carbonate-containing gold-loaded activated carbon, wherein the conversion agent is a mixed solution of sodium carbonate and sodium hydroxide, and the conversion treatment time is 1 to 3 hours; (3) Gold desorption from gold-loaded activated carbon: The gold-loaded activated carbon containing calcium carbonate obtained in step (2) above is transported to a circulating desorption column and treated with a desorption liquid to desorb gold from the gold-loaded activated carbon into a solution. The obtained gold-containing precious liquid is transported to an electrolysis system, and the lean activated carbon is transported to a pickling and decalcification system. The desorbent is a mixed solution of sodium carbonate, sodium hydroxide and sodium cyanide. The desorption temperature is 140°C to 165°C and the desorption time is 16 to 18 hours.

2. The efficient desorption method according to claim 1, characterized in that: The conversion agent is a mixed solution of 2% to 3% sodium carbonate and 1% to 1.5% sodium hydroxide in a mass concentration, and the volume ratio of the conversion agent to the activated carbon is 5:1 to 6:

1.

3. The efficient desorption method according to claim 2, characterized in that: The desorbent is a mixed solution of 2% to 3% sodium carbonate, 1% to 1.5% sodium hydroxide and 0.3% sodium cyanide by mass concentration.

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