A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings

Abstract

This invention belongs to the field of gold beneficiation and smelting technology, and relates to a method for the comprehensive recovery of arsenic- and carbon-containing refractory gold concentrate from roasting cyanide tailings through co-processing. The method includes the following steps: S1 pre-acidification and fine grinding; S2 acidolysis treatment; S3 flotation recovery of gold concentrate; S4 two-stage roasting for decarburization, desulfurization, and arsenic removal; S5 acid leaching and flotation; S6 high-cyanide leaching; and S7 low-cyanide leaching. This invention effectively combines flotation with smelting processes, which is beneficial for the high-value recovery of high-arsenic- and carbon-containing gold concentrate. It optimizes the process technology by specifically addressing the low-temperature arsenic removal in rotary kilns, the desulfurization, arsenic removal, and decarburization in fluidized bed roasting, acid leaching, and flotation. The controlled sodium cyanide concentration at different stages improves the gold leaching rate, reduces sodium cyanide consumption, and lowers energy consumption, resulting in significant economic benefits. The process is simple, easy to operate, and environmentally friendly, achieving comprehensive recovery of valuable metals. The entire process is clean production, generating no waste gas or wastewater, and has good environmental benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of gold dressing and smelting, and in particular relates to a method for comprehensive recovery of roasting cyanidation tailings by co-processing arsenic-carbon-containing difficult-to-treat gold concentrate. Background Art

[0002] With the large-scale exploitation of mineral resources in the world, the easy-to-process gold resources are constantly decreasing, and the hard-to-process gold has become an important raw material for gold extraction in various countries around the world. The reasonable and efficient development and utilization technology of hard-to-process gold has become a hot topic of research in gold-producing countries around the world. my country's gold resources are relatively rich, but the proportion of hard-to-process gold resources has increased year by year. Among the proven geological reserves, the hard-to-process gold reserves exceed 3,000 tons, accounting for more than 1 / 3 of the total proven reserves.

[0003] Carbon-containing refractory gold concentrate is a complex gold concentrate that is difficult to smelt. This type of gold concentrate is characterized by containing carbon, arsenic, antimony and other elements. Gold and silver are mainly wrapped in arsenopyrite. The recovery rate of gold and silver using conventional processes is extremely low. For example, when a two-stage roasting system is used to process carbon-containing arsenic gold concentrate, although the temperature in the furnace meets the conditions for carbon combustion, the carbonaceous minerals are relatively light in texture and are affected by the bottom blast and system negative pressure. The residence time in the furnace is too short and it is very easy to be blown out of the furnace with smoke and dust. Therefore, the decarbonization rate of the two-stage roasting system is not ideal. Because unburned carbon has adsorption properties, it will form a large amount of adsorption on gold after entering the cyanidation system during cyanidation gold extraction, thus affecting the gold recovery rate of the cyanidation process; the production process produces a large amount of cyanidation tailings and arsenic-containing gypsum slag hazardous waste, which does not comply with the current national environmental protection policy; if the pyrometallurgical copper smelting process is adopted, the recovery rate of gold and silver is relatively high, but a large amount of copper-containing materials are required for ore blending, and there are strict requirements for the arsenic content after ore blending. Once arsenic exceeds the standard, it will seriously affect the quality of copper products and produce a large amount of arsenic-containing hazardous waste, which is difficult to handle. At present, the conventional method for treating carbon-arsenic gold concentrate can only be through a two-stage roasting cyanidation process or a small amount of blending into the pyrometallurgical copper smelting system, which is not only costly and time-consuming, but also has complex procedures and high labor intensity. Therefore, it is urgent to develop a new process technology for comprehensive recovery of valuable elements from carbon-arsenic refractory gold concentrates based on technology integration and innovation, and solve a series of key technical problems such as the low comprehensive utilization rate of valuable elements in carbon-arsenic gold concentrates.

[0004] The main mineral phases of arsenic-containing and sulfur-containing gold concentrates, such as pyrite, arsenopyrite and some quartz, produce microscopic inclusions on gold. If the conventional cyanidation method is used to directly leach gold, the leaching rate of gold is generally less than 40%. Therefore, it is usually necessary to perform pretreatment before the gold leaching process. The current main pretreatment method is roasting. The roasting process can remove most of the arsenic and sulfur in the gold concentrate and convert the iron-containing phase therein into porous hematite (Fe 2 O 3), the gold ore roasted sand obtained after roasting can be subjected to the cyanide leaching process to achieve gold extraction. However, in the current roasting process, it is impossible to avoid the occurrence of phenomena such as overburning and agglomeration, so it is impossible to ensure that the iron-containing phase is completely converted into porous hematite. A part of it will be converted into dense hematite, and gold will be secondary coated, which seriously affects the effect of subsequent cyanide leaching. In addition, the roasting process cannot eliminate the coating of gold by quartz and silicate minerals. At the same time, due to the incomplete combustion of carbonaceous minerals that are difficult to handle gold concentrate during the roasting process, there is a situation of carbon adsorption of gold during the cyanidation process, resulting in a high loss of gold content in the roasting cyanide tailings. At present, the Au content in the roasting cyanide tailings is 1.5-15g / t, and resources are seriously wasted.

[0005] Patent CN103014319A discloses a method for strengthening the extraction of gold from roasted sand of iron-gold concentrate containing sulfur and arsenic. This method aims at the problem of iron oxides encapsulating gold in gold ore roasted sand, and proposes a method of "metallization reduction roasting-acid leaching-gold leaching". The iron oxides are first reduced, and then the iron oxides encapsulating gold are opened by acid leaching. However, this method will produce a large amount of iron-containing waste acid liquid, which is difficult to handle. Patent CN101942566A discloses a method for recovering gold and silver from tailings after roasting and cyanidation of gold concentrate. The process mixes the dry tailings with a reducing agent and a desulfurizing agent, reduces them at 900-1200°C for 10-30h, isolates them from air and cools them before discharging them, and magnetically separates them to obtain metallic iron powder containing gold and silver. The metallic iron powder is dissolved in sulfuric acid to form ferrous sulfate, and the acid leaching residue is used to extract gold and silver by cyanidation. However, the process has a high reduction temperature, a long reduction time, and great energy consumption. Patent CN104404261A discloses a method for recovering gold and iron by chlorination roasting and simultaneous reduction of cyanidation tailings of gold concentrate. The method uses reverse flotation to pre-desiliconize and enrich the cyanidation tailings, mixes the dried coarse concentrate with a chlorinating agent, a reducing agent, a dephosphorizing agent, a desulfurizing agent, etc. to form pellets, and the dried pellets are subjected to chlorination volatilization at 1050-1250°C for simultaneous deep reduction and desulfurization of phosphorus. The flue gas is collected to recover gold, and sponge iron is obtained by magnetic separation. The method uses high-temperature chlorination to volatilize gold, and the gold recovery rate is high, but the high-temperature chlorination volatilization process produces a large amount of highly toxic chlorine and hydrogen chloride gases, and the flue gas dust collection and purification process is complicated.

[0006] In summary, the existing treatment methods of gold ore roasted sand or roasting cyanide tailings generally have the disadvantages of being unable to achieve clean production, high energy consumption, and high treatment costs. The high-value recovery of valuable metals in roasting cyanide tailings is of great significance to the roasting pretreatment process of gold mines and the gold smelting industry. Summary of the invention

[0007] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for the comprehensive recovery of roasting cyanide tailings by co-processing arsenic-carbon-containing difficult-to-treat gold concentrate.

[0008] The specific technical solutions of the present invention are as follows:

[0009] A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings, comprising the following steps:

[0010] S1: Pre-acidification and fine grinding: the arsenic-containing carbon gold concentrate is mixed with the roasting cyanide tailings to obtain a mixed slurry, the concentration of the mixed slurry is adjusted with sulfuric acid, the pH value of the mixed slurry is adjusted to 1-2, and the mixed slurry is finely ground to obtain a grinding slurry;

[0011] S2 acid hydrolysis treatment: adding sulfuric acid to the grinding pulp in S1 for acid hydrolysis, and then entering the concentrator after acid hydrolysis to obtain overflow liquid 1 and underflow pulp 1;

[0012] S3 flotation recovery of gold concentrate: the concentration of the bottom flow pulp in S2 is controlled to 30-45wt%, soda ash is added, pH is adjusted to 5-6, and then butyl ammonium black medicine, 25# black medicine, and 2# oil are added, stirred, and floated. A roughing selection, a scavenging selection, and a tertiary flotation selection process are adopted to obtain a carbon tailing and a foam, and the foam is scraped out. The foam is a high-carbon gold concentrate;

[0013] S4 two-stage roasting for decarbonization, desulfurization and dearsenicization: the first stage roasting is high-carbon gold concentrate rotary kiln roasting, the high-carbon gold concentrate enters the rotary kiln for roasting, the roasting process generates flue gas, the flue gas is treated by bag collecting arsenic to obtain primary roasted sand and tail gas; the second stage roasting is primary roasted sand in a fluidized bed roasting furnace, water is added to the primary roasted sand to adjust the slurry to 65-68wt%, and it is transported to the fluidized bed roasting furnace for roasting to obtain secondary roasted sand;

[0014] S5 acid leaching and flotation: add sulfuric acid to the secondary roasted sand in S4 for acid leaching, and the pulp after acid leaching enters the concentrator to obtain overflow liquid 2 and underflow pulp 2, the concentration of the underflow pulp 2 is controlled to be 20-30wt%, add soda ash, adjust the pH to 5-6, then add sodium sulfide, butyl xanthate, 2# oil, stir and float, adopt a roughing selection, a second scavenging selection, and a third concentrating flotation process to obtain carbon tailings 2 and foam 2, scrape out foam 2, the foam 2 is a high-grade gold concentrate, and the carbon tailings 2 is a low-grade acid leaching residue;

[0015] S6 high cyanide leaching: add 30-50kg / t sodium cyanide to the high-grade gold concentrate in S5, adopt three leaching and three washing process to obtain leaching residue one;

[0016] S7 low-cyanide cyanide leaching: add 3-5kg / t of sodium cyanide to the low-grade acid leaching in S5, adopt the secondary leaching and secondary washing process to obtain leaching slag II.

[0017] The invention firstly adopts arsenic-carbon refractory gold concentrate and roasting cyanidation tailings to mix and configure, first-stage pre-acidification and fine grinding, and then second-stage acidolysis to further promote the decomposition and removal of minerals wrapping gold particles, and at the same time, part of soluble gold is adsorbed by carbon minerals in the acidolysis process, and the gold concentrate is recovered by third-stage flotation technology, fourth-stage two-stage roasting decarbonization, desulfurization and arsenic removal technology, fifth-stage roasting ore is acid-leached, and second-stage flotation is performed to select gold after acid leaching to obtain high-grade gold and silver concentrate, sixth-stage high-grade gold concentrate is leached with high cyanide to extract gold and silver, and seventh-stage gold-containing low-grade acid leaching residue is leached with low cyanide to extract gold and silver, and the gold and silver leaching rate is significantly improved and the production cost is greatly reduced by controlling the stepwise sodium cyanide concentration conditions, so as to solve the problem of low gold leaching rate of arsenic-carbon refractory gold concentrate using conventional roasting-cyanidation gold extraction process, and at the same time, the precious metals in the roasting cyanidation tailings can be effectively recovered, and the invention has good economic benefits and wide promotion and application value.

[0018] Furthermore, in S1, the mass ratio of the arsenic-containing carbon gold concentrate to the roasting cyanidation tailings is 1:(1-2); the fineness is -200 mesh 90-92%.

[0019] Furthermore, in S1, after the concentration of the mixed slurry is adjusted with sulfuric acid, the concentration of the mixed slurry is 60-65wt%.

[0020] Furthermore, in S1, the mixed ore pulp is finely ground in a grinding machine with ceramic balls as grinding media at a temperature of 40-50° C. for 20-30 minutes, and the fineness of the grinding ore pulp is -400 mesh 98-99%.

[0021] Further, in S2, the sulfuric acid concentration is 20-30wt%, and the solid-liquid mass ratio is 1:(3-8);

[0022] Furthermore, in S1 and S2, the sulfuric acid is waste sulfuric acid purified from a roasting acid-making system.

[0023] Furthermore, in S2, the acid hydrolysis temperature is 60-90° C., and the acid hydrolysis time is 4-6 hours.

[0024] Furthermore, the overflow liquid 1 in S2 and the overflow liquid 2 in S5 are rendered harmless by sulfidation and neutralization.

[0025] Furthermore, in S3, the dosage of the butyl ammonium black medicine is 100-300 g / t, the dosage of the 25# black medicine is 100-300 g / t, the dosage of the 2# oil is 100-300 g / t, the stirring time is 10-20 minutes, and the flotation time is 5-15 minutes.

[0026] Furthermore, in S3, the carbon-selected tailings are used as raw materials for the production of building materials.

[0027] Furthermore, in S4, the temperature at the kiln head of the rotary kiln is 480-500°C, the temperature in the kiln is 430-480°C, the temperature at the kiln tail is 400-430°C, and the calcination time of the rotary kiln is 2-4 hours.

[0028] Furthermore, in S4, the temperature of the fluidized bed roasting furnace is 630-660°C, and the air volume is controlled to be 8000-10000m 3 / h, and the roasting time is 2-4h.

[0029] Furthermore, in S5, the mass concentration of sulfuric acid is 1-3wt%, and the solid-liquid mass ratio is 1:(2-4); the temperature of the acid leaching is 60-90°C, and the time is 4-6 hours.

[0030] Furthermore, in S5, the amount of the alkali sulfide is 500-1500 g / t, the amount of the butyl xanthate is 300-1000 g / t, the amount of the 2# oil is 100-300 g / t, the stirring time is 10-20 minutes, and the flotation time is 5-15 minutes.

[0031] Furthermore, in S6, the leaching liquid-solid ratio is controlled to be (3-5):1, and the leaching time is 60-80 hours.

[0032] Furthermore, in S6, the leached residue is returned to step S1 as roasting cyanidation tailings for further comprehensive recovery.

[0033] Furthermore, in S7, the leaching liquid-solid ratio is controlled to be (2-3):1, and the leaching time is 30-40 hours.

[0034] Beneficial effects of the present invention:

[0035] (1) The flotation process is effectively combined with the smelting process. The carbon-arsenic gold concentrate and roasting cyanide tailings are finely ground, acidified, and pre-floated to break down the hematite and silicate that encapsulate the gold in the roasting cyanide tailings, so that the gold particles can be fully exposed. In the pre-flotation, the gold can float up into the high-carbon-arsenic gold concentrate, which is conducive to the high-value recovery of the high-arsenic carbon-gold concentrate.

[0036] (2) The high-arsenic-carbon gold concentrate is subjected to low-temperature dearsenicization in a rotary kiln, desulfurization, dearsenicization and decarbonization by a boiling furnace, acid leaching and flotation treatment, which solves the problems of incomplete roasting of arsenic minerals and carbon minerals, and the encapsulation of gold by metal oxides and sulfides in the conventional two-stage roasting process, achieves maximum exposure of gold, and obtains high-grade gold concentrate and low-grade acid leaching residue, so that gold can be significantly graded and separated, which is conducive to the targeted optimization of process technology recovery of high-grade gold concentrate and low-grade acid leaching residue.

[0037] (3) The high-cyanide leaching technology and low-cyanide leaching technology are used for high-grade gold concentrate and low-grade acid leaching residue respectively, so as to improve the leaching rate of gold in the cyanidation process, reduce the consumption of sodium cyanide, and reduce energy consumption, with significant economic benefits.

[0038] (4) The process of the present invention has simple technical conditions, convenient operation, and friendly working environment. It realizes the comprehensive recovery of valuable metals gold, arsenic, and sulfur in arsenic-containing carbon gold concentrate and roasting cyanide tailings. The whole process is a clean production, without the generation of waste gas or wastewater, and has good environmental benefits. DETAILED DESCRIPTION

[0039] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0040] Embodiment 1:

[0041] A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings, comprising the following steps:

[0042] S1: Pre-acidification and fine grinding: the arsenic-containing carbon gold concentrate and the roasting cyanide tailings are mixed in a mass ratio of 1:1 to obtain a mixed slurry with a fineness of -200 mesh 90%, and the waste sulfuric acid produced by the roasting acid system is used to purify the output to adjust the concentration of the mixed slurry to 60wt%, and the pH of the mixed slurry is adjusted to 1. The mixed slurry is finely ground in a grinding machine with ceramic balls as grinding media at a temperature of 40°C for 20 minutes. The grinding slurry has a fineness of -400 mesh 98%, thereby obtaining a grinding slurry;

[0043] S2 acid hydrolysis treatment: the grinding slurry in S1 is pumped into the acid hydrolysis device, and waste sulfuric acid with a concentration of 20wt% purified by the roasting acid system is added for acid hydrolysis, and the solid-liquid mass ratio is controlled to be 1:3. The acid hydrolysis temperature is 60°C and the acid hydrolysis time is 4 hours. After acid hydrolysis, the ore pulp enters the concentrator to obtain overflow liquid 1 and underflow slurry 1. The overflow liquid 1 is harmlessly disposed of by sulfidation and neutralization;

[0044] S3 flotation recovery of gold concentrate: pump the bottom flow pulp in S2 into the pre-flotation reagent mixing tank, control the concentration to 30wt%, add soda ash, adjust the pH to 5, then add 100g / t of butyl ammonium black medicine, 100g / t of 25# black medicine, and 100g / t of 2# oil, stir for 10 minutes, flotation time for 10 minutes, adopt a roughing selection, a scavenging selection, and a three-selection flotation process to obtain a carbon tailing and a foam, scrape out the foam, the foam is a high-carbon gold concentrate, the main components of the high-carbon concentrate are 10wt% carbon, 60g / t gold, 20wt% sulfur, and 10wt% arsenic; the product in the tank is a carbon tailing, containing 0.2g / t gold, 10g / t silver, and 1wt% sulfur, which is used as a raw material for building materials production;

[0045] S4 two-stage roasting for decarbonization, desulfurization and dearsenicization: the first stage of roasting is high-carbon gold concentrate rotary kiln roasting, the high-carbon gold concentrate enters the rotary kiln for roasting, the kiln head temperature is controlled to be 480°C, the kiln temperature is 430°C and the kiln tail temperature is 400°C, the roasting time is controlled to be 2 hours, the roasting process produces flue gas, the flue gas is treated by bag arsenic collection to obtain primary roasted sand and tail gas, the particle size of the primary roasted sand is 10mm, containing 70g / t of gold, 0.30wt% of carbon, 16wt% of sulfur and 0.30wt% of arsenic, and the tail gas is sent to the smelting flue gas acid production system to produce sulfuric acid;

[0046] The second stage roasting is roasting in a fluidized bed roasting furnace. The first roasted sand is slurried to 65wt% by adding water and then transported to the fluidized bed roasting furnace by a slurry delivery pump for roasting. The roasting temperature of the fluidized bed roasting furnace is 630℃ and the air volume is controlled to 8000m 3 / h, the roasting time is 2h, the temperature of the roasting process and the boiling state of the materials in the furnace are adjusted and stabilized to obtain secondary roasted sand, wherein the secondary roasted sand contains 90g / t of gold, 0.08wt% of carbon, 0.5wt% of sulfur, and 0.10wt% of arsenic;

[0047] S5 acid leaching flotation: add waste sulfuric acid with a mass concentration of 1wt% to the secondary roasted sand in S4 for acid leaching, control the solid-liquid mass ratio to 1:2, the acid leaching temperature is 60℃, and the time is 4 hours; after acid leaching, the pulp enters the concentrator to obtain overflow liquid 2 and underflow pulp 2, and the overflow liquid 2 is harmlessly disposed by sulfidation and neutralization; the underflow pulp 2 is pumped into the pre-flotation reagent mixing tank, the concentration is controlled to 20wt%, soda ash is added, the pH is adjusted to 5, and then added Add 500g / t of alkali sulfide, 300g / t of butyl xanthate, and 100g / t of 2# oil, stir for 10 minutes, and flotation for 10 minutes. Use a roughing process, a scavenging process, and a concentrating process to select carbon tailings 2 and foam 2. Scrape out foam 2, which is a high-grade gold concentrate. The main component of the high-grade gold concentrate is 600g / t of gold. The product in the tank is carbon tailings 2, which is a low-grade acid leaching residue with a gold content of 5g / t.

[0048] S6 high cyanide leaching: add 30kg / t of sodium cyanide to the high-grade gold concentrate in S5, control the leaching liquid-solid ratio to 3:1, adopt a three-time leaching and three-time washing process, and leaching time is 72 hours to obtain leaching residue 1, the leaching residue 1 contains 2g / t of gold, and the leaching residue 1 is returned to step S1 as roasting cyanidation tailings for further comprehensive recovery;

[0049] S7 low-cyanide cyanide leaching: add 3kg / t of sodium cyanide to the low-grade acid leaching in S5, control the leaching liquid-solid ratio to 2:1, adopt the secondary leaching and secondary washing process, leaching time is 36 hours, and obtain leaching slag II, which contains 0.5g / t of gold and is used for iron recovery process or cement production raw material.

[0050] Embodiment 2:

[0051] A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings, comprising the following steps:

[0052] S1: Pre-acidification and fine grinding: the arsenic-containing carbon gold concentrate and the roasting cyanide tailings are mixed in a mass ratio of 1:1.5 to obtain a mixed slurry with a fineness of -200 mesh 91%. The waste sulfuric acid produced by the roasting acid system is used to purify the mixed slurry concentration to 63wt%, and the pH of the mixed slurry is adjusted to 1.5. The mixed slurry is finely ground in a grinding machine with ceramic balls as grinding media at a temperature of 45°C for 25 minutes. The grinding slurry fineness is -400 mesh 98.5%, thereby obtaining a grinding slurry;

[0053] S2 acid hydrolysis treatment: the grinding slurry in S1 is pumped into the acid hydrolysis device, and waste sulfuric acid with a concentration of 25wt% purified by the roasting acid system is added for acid hydrolysis, and the solid-liquid mass ratio is controlled to be 1:6. The acid hydrolysis temperature is 75°C and the acid hydrolysis time is 5 hours. After acid hydrolysis, the ore pulp enters the concentrator to obtain overflow liquid 1 and underflow slurry 1. The overflow liquid 1 is harmlessly disposed of by sulfidation and neutralization;

[0054] S3 flotation recovery of gold concentrate: pump the bottom flow pulp in S2 into the pre-flotation reagent mixing tank, control the concentration to 37.5wt%, add soda ash, adjust the pH to 5.5, then add 200g / t of butyl ammonium black medicine, 200g / t of 25# black medicine, and 200g / t of 2# oil, stir for 15 minutes, flotation time for 10 minutes, adopt a roughing selection, a scavenging selection, and a three-selection flotation process to obtain a carbon tailing and a foam, scrape out the foam, the foam is a high-carbon gold concentrate, the main components of the high-carbon concentrate are 15wt% carbon, 70g / t gold, 25wt% sulfur, and 12.5wt% arsenic; the product in the tank is a carbon tailing, containing 0.35g / t gold, 10g / t silver, and 1.5wt% sulfur, which is used as a raw material for building materials production;

[0055] S4 two-stage roasting for decarbonization, desulfurization and dearsenicization: the first stage of roasting is high-carbon gold concentrate rotary kiln roasting, the high-carbon gold concentrate enters the rotary kiln for roasting, the kiln head temperature is controlled to be 490°C, the kiln temperature is 455°C and the kiln tail temperature is 415°C, the roasting time is controlled to be 3 hours, the roasting process produces flue gas, the flue gas is treated by bag arsenic collection to obtain primary roasted sand and tail gas, the particle size of the primary roasted sand is 15mm, containing 80g / t of gold, 0.40wt% of carbon, 21wt% of sulfur and 0.4wt% of arsenic, and the tail gas is sent to the smelting flue gas acid production system to produce sulfuric acid;

[0056] The second stage roasting is roasting in a fluidized bed roasting furnace. The first roasted sand is slurried to 66.5wt% by adding water and then transported to the fluidized bed roasting furnace by a slurry delivery pump for roasting. The roasting temperature of the fluidized bed roasting furnace is 645℃ and the air volume is controlled at 9000m 3 / h, the roasting time is 3h, the temperature of the roasting process and the boiling state of the materials in the furnace are adjusted and stabilized to obtain secondary roasted sand, wherein the secondary roasted sand contains 100g / t of gold, 0.09wt% of carbon, 0.65wt% of sulfur, and 0.12wt% of arsenic;

[0057] S5 acid leaching flotation: add waste sulfuric acid with a mass concentration of 2wt% to the secondary roasted sand in S4 for acid leaching, control the solid-liquid mass ratio to 1:3, the acid leaching temperature is 75℃, and the time is 5 hours; after acid leaching, the pulp enters the concentrator to obtain overflow liquid 2 and underflow pulp 2, and the overflow liquid 2 is harmlessly disposed by sulfidation and neutralization; the underflow pulp 2 is pumped into the pre-flotation reagent mixing tank, the concentration is controlled to 25wt%, soda ash is added, the pH is adjusted to 5.5, and then added Sodium sulfide 1000g / t, butyl xanthate 650g / t, 2# oil 200g / t, after stirring for 15 minutes, flotation time 10 minutes, adopting a roughing selection, a scavenging selection, a concentrating selection and a flotation selection process, carbon tailings 2 and foam 2 are selected, and foam 2 is scraped out. The foam 2 is a high-grade gold concentrate, and the main component of the high-grade gold concentrate is 1300g / t of gold; the product in the tank is carbon tailings 2, and the carbon tailings 2 is a low-grade acid leaching residue, containing 10g / t of gold;

[0058] S6 high cyanide leaching: add 40kg / t of sodium cyanide to the high-grade gold concentrate in S5, control the leaching liquid-solid ratio to 4:1, adopt a three-time leaching and three-time washing process, and leaching time is 72 hours to obtain leaching residue 1, the leaching residue 1 contains 2.5g / t of gold, and the leaching residue 1 is returned to step S1 as roasting cyanidation tailings for further comprehensive recovery;

[0059] S7 low-cyanide cyanide leaching: add 4kg / t of sodium cyanide to the low-grade acid leaching in S5, control the leaching liquid-solid ratio to 2.5:1, adopt the secondary leaching and secondary washing process, leaching time is 36 hours, and obtain leaching slag II, which contains 0.75g / t of gold and is used for iron recovery process or cement production raw material.

[0060] Embodiment 3:

[0061] A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings, comprising the following steps:

[0062] S1: Pre-acidification and fine grinding: the arsenic-containing carbon gold concentrate and the roasting cyanide tailings are mixed in a mass ratio of 1:2 to obtain a mixed slurry with a fineness of -200 mesh 92%. The waste sulfuric acid produced by the roasting acid system is used to purify the mixed slurry concentration to 65wt%, and the pH value of the mixed slurry is adjusted to 2. The mixed slurry is finely ground in a grinding machine with ceramic balls as grinding media at a temperature of 50°C for 30 minutes. The grinding slurry fineness is -400 mesh 99%, thereby obtaining a grinding slurry;

[0063] S2 acid hydrolysis treatment: the grinding slurry in S1 is pumped into the acid hydrolysis device, and waste sulfuric acid with a concentration of 30wt% purified by the roasting acid system is added for acid hydrolysis, and the solid-liquid mass ratio is controlled to be 1:8. The acid hydrolysis temperature is 90°C and the acid hydrolysis time is 6 hours. After acid hydrolysis, the ore pulp enters the concentrator to obtain overflow liquid 1 and underflow slurry 1. The overflow liquid 1 in S2 is harmlessly disposed of by sulfidation and neutralization;

[0064] S3 flotation recovery of gold concentrate: pump the bottom flow pulp in S2 into the pre-flotation reagent mixing tank, control the concentration to 45wt%, add soda ash, adjust the pH to 6, then add 300g / t of butyl ammonium black medicine, 300g / t of 25# black medicine, and 300g / t of 2# oil, stir for 20 minutes, flotation time for 10 minutes, adopt a roughing selection, a scavenging selection, and a three-selection flotation process to obtain a carbon tailing and a foam, scrape out the foam, the foam is a high-carbon gold concentrate, the main components of the high-carbon concentrate are 20wt% carbon, 80g / t gold, 30wt% sulfur, and 15wt% arsenic; the product in the tank is a carbon tailing, containing 0.5g / t gold, 10g / t silver, and 2wt% sulfur, which is used as a raw material for building materials production;

[0065] S4 two-stage roasting for decarbonization, desulfurization and dearsenicization: the first stage of roasting is high-carbon gold concentrate rotary kiln roasting, the high-carbon gold concentrate enters the rotary kiln for roasting, the kiln head temperature is controlled to be 500°C, the kiln temperature is 480°C and the kiln tail temperature is 430°C, the roasting time is controlled to be 4 hours, the roasting process produces flue gas, the flue gas is treated by bag arsenic collection to obtain primary roasted sand and tail gas, the particle size of the primary roasted sand is 20mm, containing 90g / t of gold, 0.50wt% of carbon, 26wt% of sulfur and 0.5wt% of arsenic, and the tail gas is sent to the smelting flue gas acid production system to produce sulfuric acid;

[0066] The second stage roasting is roasting in a fluidized bed roasting furnace. The first stage roasting sand is slurried to 68wt% by adding water and then transported to the fluidized bed roasting furnace by a slurry delivery pump for roasting. The roasting temperature of the fluidized bed roasting furnace is 660℃ and the air volume is controlled to 10000m 3 / h, the roasting time is 4h, the temperature of the roasting process and the boiling state of the materials in the furnace are adjusted and stabilized to obtain secondary roasted sand, wherein the secondary roasted sand contains 110g / t of gold, 0.10wt% of carbon, 0.8wt% of sulfur, and 0.15wt% of arsenic;

[0067] S5 acid leaching flotation: the secondary roasted sand in S4 is added with waste sulfuric acid with a mass concentration of 3wt% for acid leaching, and the solid-liquid mass ratio is controlled to be 1:4. The acid leaching temperature is 90°C and the time is 6 hours. After acid leaching, the pulp enters the concentrator to obtain overflow liquid 2 and underflow pulp 2. The overflow liquid 2 is harmlessly disposed by sulfidation and neutralization. The underflow pulp 2 is pumped into the pre-flotation reagent mixing tank, the concentration is controlled to 30wt%, soda ash is added, the pH is adjusted to 6, and sulfur is added. 1500g / t of caustic soda, 1000g / t of butyl xanthate, 300g / t of 2# oil, after stirring for 20 minutes, the flotation time is 10 minutes, and the process of primary roughing, secondary scavenging and tertiary concentrating flotation is adopted to select carbon tailings 2 and foam 2, and scrape out foam 2, the foam 2 is a high-grade gold concentrate, and the main component of the high-grade gold concentrate is 2000g / t of gold; the product in the tank is carbon tailings 2, and the carbon tailings 2 is a low-grade acid leaching residue with a gold content of 15g / t;

[0068] S6 high cyanide leaching: add 50kg / t of sodium cyanide to the high-grade gold concentrate in S5, control the leaching liquid-solid ratio to 5:1, adopt a three-time leaching and three-time washing process, and leaching time is 72 hours to obtain leaching residue 1, the leaching residue 1 contains 3g / t of gold, and the leaching residue 1 is returned to step S1 as roasting cyanidation tailings for further comprehensive recovery;

[0069] S7 low-cyanide cyanide leaching: add 5kg / t of sodium cyanide to the low-grade acid leaching in S5, control the leaching liquid-solid ratio to 3:1, adopt the secondary leaching and secondary washing process, and the leaching time is 36 hours to obtain the leaching slag II, which contains 1.0g / t of gold and is used for iron recovery process or cement production raw material.

[0070] In summary, the present invention provides a method for comprehensive recovery of arsenic-carbon refractory gold concentrate by co-processing roasting cyanide tailings, which firstly adopts a mixture of arsenic-carbon refractory gold concentrate and roasting cyanide tailings, and pre-acidifies and finely grinds them in a first stage; then, a second stage of acid hydrolysis is performed to further promote the decomposition and removal of minerals wrapping gold particles, and at the same time, part of the soluble gold is adsorbed by carbon minerals during the acid hydrolysis process; and a third stage of flotation is used to recover the gold concentrate, and the main components of the high-carbon gold concentrate in the foam are 10-20wt% carbon and 60-80g / t, containing 20-30wt% sulfur and 10-15wt% arsenic; the first carbon tailing contains 0.2-0.5g / t gold, 10g / t silver and 1-2% sulfur; through the four-stage two-stage roasting decarbonization, desulfurization and arsenic removal technology, the particle size of the first roasted sand is 10-20mm, containing 70-90g / t gold, 0.30-0.50wt% carbon, 16-26wt% sulfur and 0.30-0.5wt% arsenic, and the tail gas is sent to the smelting flue gas acid production system to produce sulfuric acid; the second roasted sand contains Gold 90-110g / t, carbon 0.08-0.10wt%, sulfur 0.5-0.8wt%, arsenic 0.10-0.15wt%; after five-stage roasting, the ore is acid-leached, and then secondary flotation is performed to select gold to obtain high-grade gold and silver concentrate. The main component of the high-grade gold concentrate is 600-2000g / t gold; low-grade acid leaching residue contains 5-15g / t gold; the sixth-grade high-grade gold concentrate is leached with high cyanide cyanide to extract gold and silver, and the seventh-grade gold-containing low-grade acid leaching residue is leached with low cyanide cyanide to extract gold and silver. The leaching residue 1 contains 2-3g / t gold and can be returned to S1 for further comprehensive recovery. The leaching residue 2 contains 0.5-1.0g / t gold and can be used for iron recovery process or cement production raw material. By controlling the stepwise sodium cyanide concentration conditions, the gold and silver leaching rate is significantly improved and the production cost is greatly reduced, so as to solve the problem of low gold leaching rate of arsenic-carbon difficult-to-treat gold concentrate using conventional roasting-cyaniding gold extraction process. At the same time, it can effectively recover precious metals in roasting cyanidation tailings, which has good economic benefits and wide promotion and application value.

[0071] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A method for comprehensive recovery of arsenic-carbon-containing refractory gold concentrate by co-processing roasting cyanide tailings, characterized in that: The steps include: S1: Pre-acidification and fine grinding: the arsenic-containing carbon gold concentrate is mixed with the roasting cyanide tailings to obtain a mixed slurry, the concentration of the mixed slurry is adjusted with sulfuric acid, the pH value of the mixed slurry is adjusted to 1-2, and the mixed slurry is finely ground to obtain a grinding slurry; S2 acid hydrolysis treatment: adding sulfuric acid to the grinding pulp in S1 for acid hydrolysis, and then entering the concentrator after acid hydrolysis to obtain overflow liquid 1 and underflow pulp 1; S3 flotation recovery of gold concentrate: the concentration of the bottom flow pulp in S2 is controlled to 30-45wt%, soda ash is added, pH is adjusted to 5-6, and then butyl ammonium black medicine, 25# black medicine, and 2# oil are added, stirred, and floated. A roughing selection, a scavenging selection, and a tertiary flotation selection process are adopted to obtain a carbon tailing and a foam, and the foam is scraped out. The foam is a high-carbon gold concentrate; S4 two-stage roasting for decarbonization, desulfurization and dearsenicization: the first stage roasting is high-carbon gold concentrate rotary kiln roasting, the high-carbon gold concentrate enters the rotary kiln for roasting, the roasting process generates flue gas, the flue gas is treated by bag collecting arsenic to obtain primary roasted sand and tail gas; the second stage roasting is primary roasted sand in a fluidized bed roasting furnace, water is added to the primary roasted sand to adjust the slurry to 65-68wt%, and it is transported to the fluidized bed roasting furnace for roasting to obtain secondary roasted sand; S5 acid leaching and flotation: add sulfuric acid to the secondary roasted sand in S4 for acid leaching, and the pulp after acid leaching enters the concentrator to obtain overflow liquid 2 and underflow pulp 2, the concentration of the underflow pulp 2 is controlled to be 20-30wt%, add soda ash, adjust the pH to 5-6, then add sodium sulfide, butyl xanthate, 2# oil, stir and float, adopt a roughing selection, a second scavenging selection, and a third concentrating flotation process to obtain carbon tailings 2 and foam 2, scrape out foam 2, the foam 2 is a high-grade gold concentrate, and the carbon tailings 2 is a low-grade acid leaching residue; S6 high cyanide leaching: add 30-50kg / t sodium cyanide to the high-grade gold concentrate in S5, adopt three leaching and three washing process to obtain leaching residue one; S7 low-cyanide cyanide leaching: add 3-5kg / t of sodium cyanide to the low-grade acid leaching in S5, adopt the secondary leaching and secondary washing process to obtain leaching slag II.

2. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S1, the mass ratio of the arsenic-containing carbon gold concentrate to the roasting cyanide tailings is 1:(1-2); the fineness is -200 mesh 90-92%; after adjusting the mixed slurry concentration with sulfuric acid, the mixed slurry concentration is 60-65wt%.

3. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S1, the mixed ore pulp is finely ground in a grinding machine with ceramic balls as grinding media at a temperature of 40-50° C. for 20-30 minutes, and the fineness of the grinding ore pulp is -400 mesh 98-99%.

4. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S2, the sulfuric acid concentration is 20-30wt%, and the solid-liquid mass ratio is 1:(3-8).

5. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 4, characterized in that: In S2, the acid hydrolysis temperature is 60-90° C., and the acid hydrolysis time is 4-6 hours.

6. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S3, the dosage of the butyl ammonium black medicine is 100-300 g / t, the dosage of the 25# black medicine is 100-300 g / t, the dosage of the 2# oil is 100-300 g / t, the stirring time is 10-20 minutes, and the flotation time is 5-15 minutes.

7. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S4, the temperature of the rotary kiln head is 480-500°C, the temperature in the kiln is 430-480°C, the temperature at the kiln tail is 400-430°C, and the roasting time of the rotary kiln is 2-4 hours; the roasting temperature of the fluidized bed roasting furnace is 630-660°C, and the air volume is controlled to 8000-10000m 3 / h, and the roasting time is 2-4h.

8. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S5, the mass concentration of sulfuric acid is 1-3wt%, and the solid-liquid mass ratio is 1:(2-4); the temperature of the acid leaching is 60-90°C, and the time is 4-6 hours.

9. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 8, characterized in that: In S5, the amount of alkali sulfide is 500-1500 g / t, the amount of butyl xanthate is 300-1000 g / t, the amount of 2# oil is 100-300 g / t, the stirring time is 10-20 minutes, and the flotation time is 5-15 minutes.

10. The method for comprehensive recovery of arsenic-containing carbon gold concentrate by coordinated treatment of roasting cyanide tailings according to claim 1, characterized in that: In S6, the leaching liquid-solid ratio is controlled to be (3-5):1, and the leaching time is 60-80 hours; in S7, the leaching liquid-solid ratio is controlled to be (2-3):1, and the leaching time is 30-40 hours.