Method for comprehensive recovery of valuable elements from high-copper lead-gold concentrate

Abstract

The present application belongs to the technical field of comprehensive recovery of complex polymetallic gold-silver concentrate, and relates to a method for comprehensively recovering valuable elements from high-copper-lead-gold concentrate, comprising the following steps: (1) first-stage sulfur-inhibiting flotation; (2) second-stage copper-lead bulk flotation gold concentrate separation flotation; (3) third-stage bulk flotation tailing activation flotation; and (4) fourth-stage sulfur concentrate gold extraction reduction roasting. The whole process is simple and smooth, and the comprehensive recovery rate of the high-copper-lead-gold concentrate is high, with the recovery rates of gold and silver reaching more than 95% and 90% respectively, which is 8-10% higher than that of the conventional process, thereby realizing efficient recovery of valuable elements from the high-copper-lead-gold concentrate and comprehensive utilization of resources, and greatly improving the economic benefits of enterprises.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive recovery technology of complex polymetallic gold and silver concentrates, and relates to a method for comprehensive recovery of valuable elements from high copper-lead-gold concentrates. Background Technology

[0002] With the deepening of gold mining, processed gold ore resources are becoming increasingly scarce, making the utilization of refractory gold ore increasingly important. Statistics show that approximately one-third of the world's total gold production currently comes from refractory gold mines, and refractory gold ore reserves account for 60% of the world's total gold reserves. In my country, 30% of the proven gold reserves are from refractory gold mines. Therefore, the processing technology for refractory gold ore has become a key issue in the current gold industry for gold extraction.

[0003] Refractory gold ores, also known as difficult-to-leach gold ores, difficult-to-process gold ores, or stubborn gold ores, are often rich in impurities such as sulfur, arsenic, carbon, and high copper and lead content. The direct leaching rate of gold in typical refractory ores is only 10% to 30%. The main reasons why refractory gold ores are difficult to leach are: (1) physical mechanical encapsulation, chemical crystalline solid solutions, and chemical coatings, which prevent cyanide from contacting gold minerals; (2) the presence of cyanide- and oxygen-consuming substances, such as arsenic, copper, antimony, iron, manganese, nickel, and cobalt sulfides and oxides, which have high solubility in solution and consume large amounts of cyanide and dissolved oxygen in solution; (3) the presence of gold-depleting substances, such as carbonaceous substances and clay, which can adsorb gold complexes during leaching, thus "hijacking" the gold; (4) the presence of conductive minerals, such as certain compounds formed by gold with conductive minerals like tellurium, bismuth, and antimony, which passivate the cathodic dissolution of gold.

[0004] High-copper-lead-gold concentrate is a difficult-to-process gold concentrate. Conventional cyanidation leaching is effective, so enhanced cyanidation, oxidative roasting leaching, pressure oxidative leaching, and bacterial oxidative leaching are frequently used to improve gold recovery rates. However, this process often results in the ineffective recovery of associated valuable elements such as copper and lead, leading to resource waste. Comprehensive and efficient recovery and utilization of high-copper-lead-gold concentrate has become an important technological direction for the sustainable development of smelting enterprises. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method for the comprehensive recovery of valuable elements from high-copper, lead, and gold concentrates. The specific technical solution is as follows:

[0006] A method for the comprehensive recovery of valuable elements from high-copper-lead-gold concentrate includes the following steps:

[0007] (1) First-stage sulfur-suppressing flotation: Adjust the concentration of high copper-lead-gold concentrate pulp to 20-30 wt%, then grind the ore. During the grinding process, add calcium hydroxide to adjust the pH value to 9-10; add sodium sulfite and stir; then add collector ethyl xanthate and frother No. 2 oil. Use a flotation process of one roughing, two scavenging and two cleaning to obtain copper-lead mixed gold concentrate and gold-bearing mixed tailings.

[0008] (2) Secondary copper-lead mixed gold concentrate separation flotation: Adjust the pulp concentration of copper-lead mixed gold concentrate to 50-60 wt%, add soda ash and sodium cyanide; after grinding for 20-30 min, adjust the pulp concentration to 20-30 wt%, control the sodium cyanide concentration to 0.50-0.70 wt%, and leaching time to 2-4 h; use ethyl thiocyanate as collector, carry out a process of one roughing, two scavenging and two cleaning to obtain lead concentrate and copper concentrate;

[0009] (3) Three-stage mixed tailings activation flotation: The gold-bearing mixed tailings are slurry concentrated to 50-60 wt%, and the pH is adjusted to 4-5 for grinding. Copper sulfate is added during the grinding process. Then, butyl xanthate is used as the collector and No. 2 oil is used as the frother. A flotation process of one roughing, two scavenging and two cleaning is adopted to obtain low gold and sulfur concentrate and flotation tailings.

[0010] (4) Gold extraction from fourth-grade sulfur concentrate by reduction roasting: The slurry concentration of the low-gold sulfur concentrate is adjusted to 35-40 wt%, sodium hydroxide is added to adjust the pH value to 8-9, and ammonia and sodium cyanide are added for cyanidation to obtain leaching solution and leaching tailings; the leaching tailings are subjected to high-temperature boiling reduction roasting to obtain industrial sulfuric acid and roasted sulfuric acid residue. The roasting temperature is 850-900℃ and the roasting time is 1-3 hours. The roasted sulfuric acid residue is iron concentrate.

[0011] The main components of the high-copper lead-gold concentrate described in this invention are: Au 10-30 g / t, Ag 100-300 g / t, Cu 4.0-6.0 wt%, Pb 3.0-5.0 wt%, sulfur 35-40 wt%, and As 0.20-0.40 wt%. Step (1) yields a copper-lead mixed gold concentrate containing 8-12 wt% copper, 6.0-10 wt% lead, 200-600 g / t silver, and 20-60 g / t gold, and a gold mixed tailings containing 0.10-0.12 wt% copper, 0.20-0.30 wt% lead, 20-40 g / t silver, and 2-4.0 g / t gold; Step (2) yields a lead concentrate containing 40-50 wt% lead, 0.5-1.0 wt% copper, 1000-2000 g / t silver, and 1-3 g / t gold, and a gold mixed tailings containing... The copper concentrate contains 18-22 wt% copper, 1-1.5 wt% lead, 200-400 g / t silver, and 3-5.0 g / t gold. Step (3) yields a low-gold-sulfur concentrate containing 3-5.0 g / t gold and 46.50-48.50 wt% sulfur, as well as flotation tailings containing 0.2-0.40 g / t gold and 0.4-0.6 wt% sulfur. The flotation tailings can be used as building material raw materials. The iron concentrate obtained by high-temperature boiling reduction roasting of the leaching tailings in step (4) can reach 63.0-65.0 wt% iron.

[0012] This invention provides a method for the comprehensive recovery of valuable elements from high-copper, lead, and gold concentrates. It integrates a sulfur-suppressed flotation method for copper-lead mixed gold concentrate, a copper-lead mixed gold concentrate separation flotation method for lead concentrate, and a copper concentrate-mixed tailings activation flotation method for sulfur concentrate, followed by sulfur concentrate gold extraction, reduction, and roasting to produce iron concentrate. This method achieves efficient recovery of valuable elements from high-copper, lead, and gold concentrates and comprehensive utilization of resources, greatly improving the economic benefits of enterprises.

[0013] Furthermore, in step (1), the amount of sodium sulfite added is 1-3 kg / t, the amount of ethyl xanthate collector added is 20-60 g / t, and the amount of foaming agent No. 2 oil added is 20-40 g / t.

[0014] Furthermore, in step (1), the grinding fineness of -0.074mm accounts for 75-85%, the stirring speed after adding sodium sulfite is 200-400r / min, and the stirring time is 2-4h.

[0015] Furthermore, in step (2), the amount of soda ash added is 5.0-7.0 kg / t, the amount of sodium cyanide added is 5.0-7.0 kg / t, and the amount of ethyl thiocyanate added is 50-100 g / t.

[0016] Furthermore, in step (2), the flotation system liquid is separated, and gold and silver are recovered using a zinc powder replacement-smelting process to produce gold ingots and silver ingots.

[0017] Furthermore, in step (3), the amount of copper sulfate used is 500-700 g / t, the amount of butyl xanthate used is 800-1000 g / t, and the amount of No. 2 oil used is 50-100 g / t.

[0018] Furthermore, in step (3), the grinding fineness of -0.037 mm accounts for 90-93%.

[0019] Furthermore, in step (4), the amount of ammonia water added is 1-3 kg / t, the sodium cyanide concentration is controlled at 0.15-0.20 wt%, and the cyanidation time is 24-36 h.

[0020] Furthermore, in step (4), the leaching solution is used to recover gold and silver using a zinc powder replacement-smelting process.

[0021] The beneficial effects of this invention are as follows:

[0022] This invention employs a sulfur-suppressing flotation process to effectively recover associated valuable metals such as copper and lead minerals. This eliminates the problems of low copper and lead recovery rates in traditional cyanidation processes due to excessively fine grinding, muddy formation of antimony minerals, and increased oxidation. Through a copper-lead mixed flotation process separating gold concentrate from the copper-lead concentrate, gold, silver, copper, and lead are recovered. By controlling grinding fineness, inhibitor action time, and collector selection, the recovery rates of gold, silver, copper, and lead are improved, as is the antimony flotation recovery rate. The activation flotation of sulfur concentrate from the mixed tailings eliminates the critical problem of secondary gold encapsulation during roasting of copper and lead minerals, which reduces subsequent cyanidation recovery rates. Finally, an integrated technology is used to produce industrial sulfuric acid and iron concentrate through a gold extraction followed by pyrite reduction roasting, achieving comprehensive recovery of sulfur and iron.

[0023] The entire process of this invention is simple and smooth, with a high comprehensive recovery rate of high copper-lead-gold concentrate. The recovery rates of gold and silver reach 95% and 90% or more, respectively, which are 8-10% higher than conventional processes. This achieves efficient recovery of valuable elements and comprehensive utilization of resources in high copper-lead-gold concentrate, greatly improving the economic benefits of enterprises. Detailed Implementation

[0024] The principles and features of the present invention are described below with reference to embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0025] Example 1:

[0026] A method for the comprehensive recovery of valuable elements from high-copper-lead-gold concentrate includes the following steps:

[0027] (1) Primary sulfur-suppressing flotation: The main components of the high-copper-lead-gold concentrate are: Au 10g / t, Ag 100g / t, Cu 4.0wt%, Pb 3.0wt%, sulfur 35wt%, and As 0.20wt%. The concentration of the high-copper-lead-gold concentrate slurry is adjusted to 20wt%, and then ground. During the grinding process, 5kg / t of calcium hydroxide is added, and the pH value is adjusted to 9. Then, 1kg / t of sodium sulfite is added, and the grinding fineness is -0.074mm, accounting for 8%. 0%, stirring speed 200r / min, stirring for 2h; then add 20g / t of collector ethyl xanthate and 20g / t of frother 2# oil, and adopt a flotation process of one roughing, two scavenging and two cleaning to obtain copper-lead mixed gold concentrate containing 8wt% copper, 6.0wt% lead, 200g / t silver and 20g / t gold, and gold mixed tailings containing 0.10wt% copper, 0.20wt% lead, 20g / t silver and 2g / t gold.

[0028] (2) Secondary copper-lead mixed gold concentrate separation flotation to produce lead concentrate and copper concentrate: The pulp concentration of the copper-lead mixed gold concentrate was adjusted to 50wt%, and soda ash and sodium cyanide were added. The amount of soda ash added was 5.0kg / t, and the amount of sodium cyanide added was 5.0kg / t. The mixture was fed into a grinding mill and the grinding time was 20min. After grinding, the pulp concentration was adjusted to 20wt%, and the sodium cyanide concentration was controlled at 0.50wt%. The leaching time was 2h. Ethylene nitrogen was used as the collector and the amount of ethylene nitrogen added was 50g / t. A roughing, scavenging and cleaning process was carried out to obtain lead concentrate containing 40wt% lead, 0.5wt% copper, 1000g / t silver and 1g / t gold, and copper concentrate containing 18wt% copper, 1wt% lead, 200g / t silver and 3g / t gold. The separation flotation system liquid was treated with zinc powder replacement-smelting process to recover gold and silver, and gold ingots and silver ingots were produced.

[0029] (3) Three-stage mixed flotation tailings activation flotation sulfur concentrate: The gold-bearing mixed flotation tailings were slurryed to a ore concentration of 50 wt%, and the pH was adjusted to 4 by roasting and purifying waste acid. Copper sulfate was added during the grinding process at a dosage of 500 g / t. The grinding fineness was -0.037 mm, accounting for 90%. Butyl xanthate was used as the collector at a dosage of 800 g / t, and No. 2 oil was used as the frother at a dosage of 50 g / t. A flotation process of one roughing, two scavenging, and two cleaning was adopted to obtain a low-gold-sulfur concentrate containing 3 g / t of gold and 46.50 wt% sulfur, as well as flotation tailings containing 0.2 g / t of gold and 0.4 wt% sulfur. The flotation tailings were utilized as building material raw materials.

[0030] (4) Gold extraction from grade IV sulfur concentrate by reduction roasting to produce iron concentrate: The slurry concentration of low gold and sulfur concentrate is adjusted to 35wt%, sodium hydroxide is added to adjust the pH value to 8, 1kg / t of ammonia is added, the sodium cyanide concentration is controlled at 0.15wt%, the cyanidation time is 24h, and the leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver; the leaching tailings are treated with high-temperature boiling reduction roasting at 850℃ for 3 hours to produce industrial sulfuric acid and roasted sulfuric acid residue. The roasted sulfuric acid residue is the iron concentrate with an iron content of 63.0wt%.

[0031] Example 2:

[0032] A method for the comprehensive recovery of valuable elements from high-copper-lead-gold concentrate includes the following steps:

[0033] (1) Primary sulfur suppression flotation: The main components of the high copper-lead-gold concentrate are: Au 20g / t, Ag 200g / t, Cu 5.0wt%, Pb 4.0wt%, sulfur 37.5wt%, and As 0.30wt%. The concentration of the high copper-lead-gold concentrate pulp was adjusted to 25wt%, and then the concentrate was ground. During the grinding process, 5.5kg / t of calcium hydroxide was added, and the pH value was adjusted to 9.5. Then, 2kg / t of sodium sulfite was added, and the grinding fineness was -0.074mm. The mixture was 80% stirred at 300 r / min for 3 hours; then 40 g / t of ethyl xanthate collector and 30 g / t of frother 2# oil were added. A flotation process of one roughing, two scavenging, and two cleaning was adopted to obtain a copper-lead mixed gold concentrate containing 10 wt% copper, 8.0 wt% lead, 400 g / t silver, and 40 g / t gold, and a gold mixed tailings containing 0.11 wt% copper, 0.25 wt% lead, 30 g / t silver, and 3.0 g / t gold.

[0034] (2) Secondary copper-lead mixed gold concentrate separation flotation to produce lead concentrate and copper concentrate: The pulp concentration of the copper-lead mixed gold concentrate was adjusted to 55wt%, and soda ash and sodium cyanide were added. The amount of soda ash added was 6.0kg / t, and the amount of sodium cyanide added was 6.0kg / t. The concentrate was fed into a grinding mill and the grinding time was 25min. After grinding, the pulp concentration was adjusted to 25wt%, and the sodium cyanide concentration was controlled at 0.60wt%. The leaching time was 3h. Ethylene nitrogen was used as the collector and the amount of ethylene nitrogen added was 75g / t. A roughing, scavenging and cleaning process was carried out to obtain lead concentrate containing 45wt% lead, 0.75wt% copper, 1500g / t silver and 2g / t gold, and copper concentrate containing 20wt% copper, 1.25wt% lead, 300g / t silver and 4.0g / t gold. The separation flotation system liquid was treated with zinc powder replacement-smelting process to recover gold and silver, and produce gold ingots and silver ingots.

[0035] (3) Three-stage mixed flotation tailings activation flotation sulfur concentrate: The gold-bearing mixed flotation tailings were slurryed to a ore concentration of 55wt%, and the pH was adjusted to 4.5 by roasting and purifying waste acid. The ore was then ground, and copper sulfate was added during the grinding process at a dosage of 600g / t. The grinding fineness was -0.037mm, accounting for 91.5%. Butyl xanthate was used as the collector at a dosage of 900g / t, and No. 2 oil was used as the frother at a dosage of 75g / t. A flotation process of one roughing, two scavenging, and two cleaning was adopted to obtain a low-gold-sulfur concentrate containing 4.0g / t of gold and 47.50wt% of sulfur, as well as flotation tailings containing 0.30g / t of gold and 0.5wt% of sulfur. The flotation tailings were utilized as building material raw materials.

[0036] (4) Gold extraction from grade IV sulfur concentrate by reduction roasting to produce iron concentrate: The slurry concentration of low gold and sulfur concentrate is adjusted to 37.5wt%, sodium hydroxide is added to adjust the pH value to 8, 2kg / t of ammonia water is added, the sodium cyanide concentration is controlled at 0.18wt%, the cyanidation time is 30h, and the leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver; the leaching tailings are treated with high-temperature boiling reduction roasting at 900℃ for 2 hours to produce industrial sulfuric acid and roasted sulfuric acid residue. The roasted sulfuric acid residue is the iron concentrate with an iron content of 64.0wt%.

[0037] Example 3:

[0038] A method for the comprehensive recovery of valuable elements from high-copper-lead-gold concentrate includes the following steps:

[0039] (1) Primary sulfur-suppressing flotation: The main components of the high-copper-lead-gold concentrate are: Au 30g / t, Ag 300g / t, Cu 6.0wt%, Pb 5.0wt%, sulfur 40wt%, and As 0.40wt%. The concentration of the high-copper-lead-gold concentrate slurry is adjusted to 30wt%, and then ground. During the grinding process, 6kg / t of calcium hydroxide is added, and the pH value is adjusted to 10. Then, 3kg / t of sodium sulfite is added, and the grinding fineness is -0.074mm, accounting for 8%. 0%, stirring speed 400r / min, stirring for 4h; then add 60g / t of collector ethyl xanthate and 40g / t of frother 2# oil, and adopt a flotation process of one roughing, two scavenging and two cleaning to obtain copper-lead mixed gold concentrate containing 12wt% copper, 10wt% lead, 600g / t silver and 60g / t gold, and gold mixed tailings containing 0.12wt% copper, 0.30wt% lead, 40g / t silver and 4.0g / t gold.

[0040] (2) Secondary copper-lead mixed gold concentrate separation flotation to produce lead concentrate and copper concentrate: The pulp concentration of the copper-lead mixed gold concentrate was adjusted to 60wt%, and soda ash and sodium cyanide were added. The amount of soda ash added was 7.0kg / t, and the amount of sodium cyanide added was 7.0kg / t. The concentrate was fed into a grinding mill and the grinding time was 30min. After grinding, the pulp concentration was adjusted to 30wt%, and the sodium cyanide concentration was controlled at 0.70wt%. The leaching time was 4h. Ethylene nitrogen was used as the collector and the amount of ethylene nitrogen added was 100g / t. A roughing, scavenging and cleaning process was carried out to obtain lead concentrate containing 50wt% lead, 1.0wt% copper, 2000g / t silver and 3g / t gold, and copper concentrate containing 22wt% copper, 1.5wt% lead, 400g / t silver and 5.0g / t gold. The separation flotation system liquid was treated with zinc powder replacement-smelting process to recover gold and silver, and produce gold ingots and silver ingots.

[0041] (3) Three-stage mixed flotation tailings activation flotation sulfur concentrate: The gold-bearing mixed flotation tailings were slurryed to a ore concentration of 60 wt%, and the pH was adjusted to 5 by roasting and purifying waste acid. Copper sulfate was added during the grinding process at a dosage of 700 g / t, and the grinding fineness was -0.037 mm, accounting for 93%. Butyl xanthate was used as the collector at a dosage of 1000 g / t, and No. 2 oil was used as the frother at a dosage of 100 g / t. A flotation process of one roughing, two scavenging, and two cleaning was adopted to obtain a low-gold-sulfur concentrate containing 5.0 g / t of gold and 48.50 wt% sulfur, and flotation tailings containing 0.40 g / t of gold and 0.6 wt% sulfur. The flotation tailings were utilized as building material raw materials.

[0042] (4) Gold extraction from grade IV sulfur concentrate by reduction roasting to produce iron concentrate: The slurry concentration of low gold and sulfur concentrate is adjusted to 40wt%, sodium hydroxide is added to adjust the pH value to 8, 3kg / t of ammonia water is added, the sodium cyanide concentration is controlled at 0.20wt%, the cyanidation time is 36h, and the leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver; the leaching tailings are treated with high-temperature boiling reduction roasting at 900℃ for 2 hours to produce industrial sulfuric acid and roasted sulfuric acid residue. The roasted sulfuric acid residue is the iron concentrate with an iron content of 65.0wt%.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the comprehensive recovery of valuable elements from high-copper, lead, and gold concentrates, characterized in that, Includes the following steps: (1) First-stage sulfur-suppressing flotation: Adjust the concentration of high copper-lead-gold concentrate pulp to 20~30wt%, then grind, add calcium hydroxide during grinding to adjust the pH to 9~10; add sodium sulfite and stir; then add collector ethyl xanthate and frother 2# oil, adopt a flotation process of one roughing, two scavenging and two cleaning to obtain copper-lead mixed gold concentrate and gold-bearing mixed tailings, the grinding fineness of -0.074mm accounts for 75~85%, the stirring speed after adding sodium sulfite is 200~400r / min, the stirring time is 2~4h; the amount of sodium sulfite added is 1~3kg / t, the amount of collector ethyl xanthate added is 20~60g / t, and the amount of frother 2# oil added is 20~40g / t; (2) Secondary copper-lead mixed gold concentrate separation flotation: Adjust the pulp concentration of copper-lead mixed gold concentrate to 50~60wt%, add soda ash and sodium cyanide; after grinding for 20~30min, adjust the pulp concentration to 20~30wt%, control the sodium cyanide concentration to 0.50~0.70wt%, and the leaching time to 2~4h; use ethyl thiocyanate as collector, carry out a roughing, scavenging and cleaning process to obtain lead concentrate and copper concentrate, separate the flotation system liquid, and use zinc powder replacement-smelting process to recover gold and silver, and produce gold ingots and silver ingots; the amount of soda ash added is 5.0~7.0kg / t, the amount of sodium cyanide added is 5.0~7.0kg / t, and the amount of ethyl thiocyanate added is 50~100g / t; (3) Three-stage mixed tailings activation flotation: The gold-bearing mixed tailings are slurry concentrated to 50-60 wt%, and the pH is adjusted to 4-5 for grinding. The grinding fineness is -0.037 mm, accounting for 90-93%. Copper sulfate is added during the grinding process. Butyl xanthate is used as the collector and No. 2 oil is used as the frother. The flotation process of one roughing, two scavenging, and two cleaning is adopted to obtain low gold and sulfur concentrate and flotation tailings. The amount of copper sulfate is 500-700 g / t, the amount of butyl xanthate is 800-1000 g / t, and the amount of No. 2 oil is 50-100 g / t. (4) Gold extraction from fourth-grade sulfur concentrate by reduction roasting: The slurry concentration of the low-gold sulfur concentrate is adjusted to 35-40 wt%, sodium hydroxide is added to adjust the pH value to 8-9, and ammonia and sodium cyanide are added for cyanidation to obtain leachate and leaching tailings. The amount of ammonia added is 1-3 kg / t, the concentration of sodium cyanide is controlled at 0.15-0.20 wt%, and the cyanidation time is 24-36 h. The leaching tailings are subjected to high-temperature boiling reduction roasting to obtain industrial sulfuric acid and roasted sulfuric acid residue. The roasting temperature is 850-900℃ and the roasting time is 1-3 hours. The roasted sulfuric acid residue is iron concentrate. The leachate is subjected to zinc powder replacement-smelting process to recover gold and silver.