Method for gold-sulfur flotation separation of sulfur-containing gold ore

Abstract

The present invention provides a method for gold-sulfur flotation separation of sulfur-containing gold ore. The method includes a gold-sulfur bulk flotation process, regrinding of the gold-sulfur bulk concentrate, and a gold-sulfur flotation separation process. Under the synergistic action of specially formulated reagents, gold and pyrite in the gold-sulfur bulk concentrate refined to the target particle size are effectively separated, thereby significantly improving the recovery rate of gold. In the gold-sulfur flotation separation process, a highly efficient inhibitor CD-6 with strong selectivity for pyrite and a highly efficient gold collector B7 with strong selectivity for gold are used. While reducing the activity of pyrite in the pulp system, the floatability of gold is improved, significantly increasing the recovery rate of gold and creating favorable conditions for the recovery of gold. This effectively solves the problem that it is difficult to recover pyrite resources in sulfur-containing gold ore and provides a new effective method for the development and utilization of similar sulfur-containing gold ore resources.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and particularly to a method for gold-sulfur flotation separation of sulfur-containing gold ores. Background Art

[0002] Currently, the gold ore resources in China are mostly placer gold, lode gold and associated gold, and their overall distribution is uneven. More gold deposits have been discovered in the central and eastern regions than in the western regions. Among them, Shandong, Jiangxi, Henan, Yunnan and Inner Mongolia are important regions for gold production in China.

[0003] In China, the proportion of associated gold is large, and there are many gold-bearing ore types and deposit types. Due to the affinity of gold, it often coexists with sulfides. Most of the associated gold is found in sulfide ores such as chalcopyrite, bornite and arsenopyrite. Gold mostly exists in the form of fine grains and is wrapped in gangue minerals and other minerals in the form of micro-fine grains. The gold content in most gold ores is below 20 g / t, and it is necessary to concentrate the gold content to a certain grade through mineral processing methods for smelting in downstream industries; for micro-fine gold ores, the flotation method is the most stable and effective mineral processing method. Gold mostly exists in the form of being wrapped in pyrite. During the mineral processing process, both gold and pyrite are concentrated in the concentrate product. Because the value of gold is much greater than that of pyrite and the separation of gold and pyrite is relatively difficult, mineral processing researchers often ignore the value of pyrite.

[0004] In view of this, it is necessary to design a method for gold-sulfur flotation separation of sulfur-containing gold ores to solve the above problems. Summary of the Invention

[0005] Aiming at the defects of the above-mentioned prior art, the purpose of the present invention is to provide a method for gold-sulfur flotation separation of sulfur-containing gold ores for efficiently recovering gold.

[0006] To achieve the above purpose, the present invention provides a method for gold-sulfur flotation separation of sulfur-containing gold ores, including the following steps:

[0007] S1. Crushing and ball-milling the target raw ore to a predetermined fineness, and then making a raw ore pulp with a predetermined concentration;

[0008] S2. Conducting gold-sulfur bulk flotation on the raw ore pulp according to a preset reagent regime to obtain a gold-sulfur bulk flotation concentrate and a gold-sulfur bulk flotation tailing;

[0009] S3. Adding a predetermined amount of inhibitor CD-6 to the gold-sulfur bulk flotation concentrate obtained in step S2, and then grinding it to a predetermined fineness to obtain a re-ground gold-sulfur bulk flotation concentrate;

[0010] S4. Make the re-ground gold-sulfur bulk flotation concentrate obtained in step S3 into a re-ground gold-sulfur bulk flotation concentrate pulp with a predetermined concentration. After adjusting the pH, add gold collector B7 and conduct gold-sulfur separation flotation to obtain gold concentrate and sulfur concentrate.

[0011] Further, the gold-sulfur bulk flotation in step S2 includes one roughing, two scavengings, and two cleanings, and specifically includes the following steps:

[0012] (a) Add a predetermined amount of a first inhibitor and an activator to the original pulp in sequence. After sufficient stirring, add a predetermined amount of a first collector and a foaming agent, and conduct the first roughing of gold-sulfur bulk flotation after stirring to obtain gold-sulfur bulk flotation rough concentrate I and gold-sulfur bulk flotation roughing tailings I;

[0013] (b) Add a predetermined amount of a second collector to the gold-sulfur bulk flotation roughing tailings I. After sufficient stirring, conduct the first scavenging of gold-sulfur bulk flotation to obtain gold-sulfur bulk flotation scavenging concentrate I and gold-sulfur bulk flotation scavenging tailings I; and return the obtained gold-sulfur bulk flotation scavenging concentrate I to the first roughing process of gold-sulfur bulk flotation;

[0014] (c) Add a predetermined amount of a third collector to the gold-sulfur bulk flotation scavenging tailings I. After sufficient stirring, conduct the second scavenging of gold-sulfur bulk flotation to obtain gold-sulfur bulk flotation scavenging concentrate II and gold-sulfur bulk flotation scavenging tailings II; and return the obtained gold-sulfur bulk flotation scavenging concentrate II to the first scavenging process of gold-sulfur bulk flotation;

[0015] (d) Add a predetermined amount of a second inhibitor to the gold-sulfur bulk flotation rough concentrate I in step (a). After sufficient stirring, conduct the first cleaning of gold-sulfur bulk flotation to obtain gold-sulfur bulk flotation cleaning concentrate I and gold-sulfur bulk flotation cleaning tailings I; and return the obtained gold-sulfur bulk flotation cleaning tailings I to the first roughing process of gold-sulfur bulk flotation;

[0016] (e) Add a predetermined amount of a third inhibitor to the gold-sulfur bulk flotation cleaning concentrate I in step (d). After sufficient stirring, conduct the second cleaning of gold-sulfur bulk flotation to obtain gold-sulfur bulk flotation cleaning concentrate II and gold-sulfur bulk flotation cleaning tailings II; and return the obtained gold-sulfur bulk flotation cleaning tailings II to the first cleaning process of gold-sulfur bulk flotation.

[0017] Further, the gold-sulfur separation flotation in step S4 includes one gold roughing, two gold scavengings, and two gold cleanings, and specifically includes the following steps:

[0018] (f) Add a predetermined amount of the gold collector B7 to the re-ground gold-sulfur bulk flotation concentrate pulp adjusted to a predetermined pH value. After sufficient stirring, conduct the first gold-sulfur flotation separation for rougher gold concentration, i.e., obtain the rougher gold concentration concentrate I and the rougher gold concentration tailings I;

[0019] (g) Add a predetermined amount of the gold collector B7 to the rougher gold concentration tailings I. After sufficient stirring, conduct the first gold-sulfur flotation separation for scavenger gold concentration, i.e., obtain the scavenger gold concentration concentrate I and the scavenger gold concentration tailings I; and return the scavenger gold concentration concentrate I to the first gold-sulfur flotation separation for rougher gold concentration process;

[0020] (h) Add a predetermined amount of the gold collector B7 to the scavenger gold concentration tailings I. After sufficient stirring, conduct the second gold-sulfur flotation separation for scavenger gold concentration, i.e., obtain the scavenger gold concentration concentrate II and the scavenger gold concentration tailings II; and return the scavenger gold concentration concentrate II to the first gold-sulfur flotation separation for scavenger gold concentration, and the scavenger gold concentration tailings II is the sulfur concentrate;

[0021] (i) Add a predetermined amount of the inhibitor CD-6 to the rougher gold concentration concentrate I in step (f). After sufficient stirring, conduct the first gold-sulfur flotation separation for cleaner gold concentration, i.e., obtain the cleaner gold concentration concentrate I and the cleaner gold concentration tailings I; and return the cleaner gold concentration tailings I to the first gold-sulfur flotation separation for rougher gold concentration process;

[0022] (j) Add a predetermined amount of the inhibitor CD-6 to the cleaner gold concentration concentrate I. After sufficient stirring, conduct the second gold-sulfur flotation separation for cleaner gold concentration, i.e., obtain the cleaner gold concentration concentrate II and the cleaner gold concentration tailings II; and return the cleaner gold concentration tailings II to the first gold-sulfur flotation separation for cleaner gold concentration process.

[0023] Further, the gold-sulfur separation flotation in step S4 further includes the third gold cleaning concentration, specifically including the following steps:

[0024] (k) Add a predetermined amount of the inhibitor CD-6 to the cleaner gold concentration concentrate II. After sufficient stirring, conduct the third gold-sulfur flotation separation for cleaner gold concentration, i.e., obtain the cleaner gold concentration concentrate III and the cleaner gold concentration tailings III; and return the cleaner gold concentration tailings III to the second gold-sulfur flotation separation for cleaner gold concentration step.

[0025] Further, the inhibitor CD-6 is one or more of lime, sodium hydroxide, sodium sulfide, sodium humate, and sodium carbonate; the gold collector B7 is one or more of MB xanthate, Y89 xanthate, Z-200, ethyl xanthate, propionitrile alkyl xanthate, and ammonium dibutyl dithiophosphate.

[0026] Further, the mass ratio of the inhibitor CD-6 is: sodium hydroxide:sodium carbonate:sodium humate:water = 29:10:1:200; the mass ratio of the gold collector B7 is: Y89:ethyl xanthate:propyl alkyl xanthate:cosolvent = 3:4:1:2; the cosolvent is an alcohol with more than ten carbon atoms.

[0027] Further, the predetermined fineness of the re-ground gold-sulfur mixed flotation concentrate in step S3 is: the particle size less than 0.038 mm accounts for 50-100%.

[0028] Further, the first inhibitor, the second inhibitor, and the third inhibitor are each one or more of sodium carbonate, water glass, citric acid, and oxalic acid; the activator is copper sulfate; the first collector, the second collector, and the third collector are each one or more of butyl xanthate, amyl xanthate, Y89 xanthate, MB xanthate, and ammonium butyl dithiophosphate.

[0029] Further, the predetermined concentration of the original ore pulp in step S1 is 28-38%; the predetermined fineness of the original ore ball milling is: the particle size less than 0.074 mm accounts for 50-95%;

[0030] In step (a) of step S2, the predetermined amount of the first inhibitor is 500-2000 g / t, the predetermined amount of copper sulfate is 0-200 g / t, the predetermined amount of the first collector is 100-200 g / t, and the predetermined amount of the foaming agent is 10-50 g / t;

[0031] In step (b) of step S2, the predetermined amount of the second collector is 10-50 g / t;

[0032] In step (c) of step S2, the predetermined amount of the third collector is 5-30 g / t;

[0033] In step (d) of step S2, the predetermined amount of the second inhibitor is 50-500 g / t;

[0034] In step (e) of step S2, the predetermined amount of the third inhibitor is 0-200 g / t.

[0035] Further, the predetermined concentration of the re-ground gold-sulfur mixed flotation concentrate pulp in step S4 is 5-20%;

[0036] In step (f) of step S4, the predetermined pH value is greater than 12, and the predetermined amount of the gold collector B7 is 0-50 g / t;

[0037] In step S3, the predetermined amount of the inhibitor CD-6 is 500-3000 g / t;

[0038] In step (g) of step S4, the predetermined amount of the gold collector B7 is 10-40 g / t;

[0039] The predetermined amount of gold collector B7 described in step (h) is 5-20 g / t;

[0040] The predetermined amount of inhibitor CD-6 described in step (i) is 100-500 g / t;

[0041] The predetermined amount of inhibitor CD-6 described in step (j) is 100-300 g / t;

[0042] The predetermined amount of inhibitor CD-6 described in step (k) is 50-200 g / t.

[0043] The beneficial effects of the present invention are as follows:

[0044] 1. A method for gold-sulfur flotation separation of sulfur-containing gold ore provided by the present invention effectively separates gold and pyrite in the gold-sulfur mixed concentrate refined to the target particle size through the processes of gold-sulfur bulk flotation, regrinding of the gold-sulfur mixed concentrate, and gold-sulfur flotation separation, under the synergistic action of specially formulated agents, thereby significantly improving the gold recovery rate. In this way, the problem that it is difficult to recover pyrite resources in sulfur-containing gold ore is effectively solved, providing a new and effective method for the development and utilization of similar sulfur-containing gold ore resources.

[0045] 2. A method for gold-sulfur flotation separation of sulfur-containing gold ore provided by the present invention uses inhibitor CD-6 with strong selectivity for pyrite and gold collector B7 with strong selectivity for gold. While reducing the activity of pyrite in the pulp system, it improves the floatability of gold, significantly increasing the gold recovery rate and creating favorable conditions for gold recovery. Brief Description of the Drawings

[0046] Figure 1 It is a flow chart of a method for gold-sulfur flotation separation of sulfur-containing gold ore provided in Example 1 of the present invention.

[0047] Figure 2 It is a flow chart in a method for gold-sulfur flotation separation of sulfur-containing gold ore provided in Comparative Examples 1-4 of the present invention.

[0048] Figure 3 It is a flow chart in a method for gold-sulfur flotation separation of sulfur-containing gold ore provided in Comparative Examples 5-7 of the present invention. Detailed Embodiments

[0049] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail below with reference to the drawings and specific embodiments.

[0050] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0051] In addition, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0052] A method for gold-sulfur flotation separation of sulfur-containing gold ore comprises the following steps:

[0053] S1. Crushing and ball-milling the target ore to a particle size of less than 0.074 mm, accounting for 50-95% of the fineness, to prepare a slurry with a concentration of 28-38%;

[0054] S2. performing gold-sulfur mixed flotation on the raw ore pulp according to a preset reagent system to obtain a gold-sulfur mixed flotation concentrate and a gold-sulfur mixed flotation tailings;

[0055] S3, adding 500-3000 g / t of inhibitor CD-6 to the gold-sulfur mixed flotation concentrate obtained in step S2, and then grinding it to a particle size of less than 0.038 mm accounting for 50-100% of the fineness, to obtain a reground gold-sulfur mixed flotation concentrate;

[0056] S4, preparing the reground gold-sulfur mixed flotation concentrate obtained in step S3 into a reground gold-sulfur mixed flotation concentrate slurry with a concentration of 5-20%, adjusting the pH and then adding a gold collector B7 to perform gold-sulfur separation flotation to obtain a gold concentrate and a sulfur concentrate.

[0057] Specifically, in some embodiments of the present invention, the gold-sulfur mixed flotation in step S2 includes one roughing selection, two scavenging selections, and two cleaning selections, specifically including the following steps:

[0058] (a) adding 500-2000 g / t of a first inhibitor and 0-200 g / t of an activator copper sulfate to the raw ore pulp in sequence, stirring them fully, adding 100-200 g / t of a first collector and 10-50 g / t of a frother, stirring them, and performing a first gold-sulfur mixed flotation roughing, thereby obtaining a gold-sulfur mixed flotation rough concentrate I and a gold-sulfur mixed flotation roughing tailing I;

[0059] (b) Add 10 - 50 g / t of the second collector to the rougher tailings Ⅰ of the gold-sulfur bulk flotation, fully stir, and then conduct the first scavenging of the gold-sulfur bulk flotation to obtain the scavenger concentrate Ⅰ of the gold-sulfur bulk flotation and the scavenger tailings Ⅰ of the gold-sulfur bulk flotation; and return the obtained scavenger concentrate Ⅰ of the gold-sulfur bulk flotation to the rougher process of the first gold-sulfur bulk flotation;

[0060] (c) Add 5 - 30 g / t of the third collector to the scavenger tailings Ⅰ of the gold-sulfur bulk flotation, fully stir, and then conduct the second scavenging of the gold-sulfur bulk flotation to obtain the scavenger concentrate Ⅱ of the gold-sulfur bulk flotation and the scavenger tailings Ⅱ of the gold-sulfur bulk flotation; and return the obtained scavenger concentrate Ⅱ of the gold-sulfur bulk flotation to the scavenging process of the first gold-sulfur bulk flotation;

[0061] (d) Add 50 - 500 g / t of the second depressant to the rougher concentrate Ⅰ of the gold-sulfur bulk flotation in step (a), fully stir, and then conduct the first cleaning of the gold-sulfur bulk flotation to obtain the cleaning concentrate Ⅰ of the gold-sulfur bulk flotation and the cleaning tailings Ⅰ of the gold-sulfur bulk flotation; and return the obtained cleaning tailings Ⅰ of the gold-sulfur bulk flotation to the rougher process of the first gold-sulfur bulk flotation;

[0062] (e) Add 0 - 200 g / t of the third depressant to the cleaning concentrate Ⅰ of the gold-sulfur bulk flotation in step (d), fully stir, and then conduct the second cleaning of the gold-sulfur bulk flotation to obtain the cleaning concentrate Ⅱ of the gold-sulfur bulk flotation and the cleaning tailings Ⅱ of the gold-sulfur bulk flotation; and return the obtained cleaning tailings Ⅱ of the gold-sulfur bulk flotation to the cleaning process of the first gold-sulfur bulk flotation.

[0063] Specifically, in some embodiments of the present invention, the gold-sulfur separation flotation in step S4 includes one roughing of the gold concentrate, two scavengings of the gold concentrate, and two cleanings of the gold concentrate, and specifically includes the following steps:

[0064] (f) Add 0 - 50 g / t of the gold collector B7 to the re-ground gold-sulfur bulk flotation concentrate pulp adjusted to a pH value greater than 12, fully stir, and then conduct the first roughing of the gold-sulfur flotation separation to obtain the roughing concentrate Ⅰ of the gold concentrate and the roughing tailings Ⅰ of the gold concentrate;

[0065] (g) Add 10 - 40 g / t of the gold collector B7 to the roughing tailings Ⅰ of the gold concentrate, fully stir, and then conduct the first scavenging of the gold-sulfur flotation separation to obtain the scavenging concentrate Ⅰ of the gold concentrate and the scavenging tailings Ⅰ of the gold concentrate; and return the scavenging concentrate Ⅰ of the gold concentrate to the roughing process of the first gold-sulfur flotation separation;

[0066] (h) Add 5 - 20 g / t of the gold collector B7 to the first gold scavenging tailings I. After sufficient stirring, conduct the second gold-sulfur flotation separation for gold scavenging, namely obtaining the second gold scavenging concentrate and the second gold scavenging tailings; and return the second gold scavenging concentrate to the first gold-sulfur flotation separation for gold scavenging, and the second gold scavenging tailings is the sulfur concentrate;

[0067] (i) Add 100 - 500 g / t of the inhibitor CD-6 to the first gold roughing concentrate I in step (f). After sufficient stirring, conduct the first gold-sulfur flotation separation for gold cleaning, namely obtaining the first gold cleaning concentrate and the first gold cleaning tailings; and return the first gold cleaning tailings to the first gold-sulfur flotation separation for gold roughing process;

[0068] (j) Add 100 - 300 g / t of the inhibitor CD-6 to the first gold cleaning concentrate I. After sufficient stirring, conduct the second gold-sulfur flotation separation for gold cleaning, namely obtaining the second gold cleaning concentrate and the second gold cleaning tailings; and return the second gold cleaning tailings to the first gold-sulfur flotation separation for gold cleaning process.

[0069] Specifically, in some embodiments of the present invention, the gold-sulfur separation flotation in step S4 further includes the third gold cleaning, which specifically includes the following steps:

[0070] (k) Add 50 - 200 g / t of the inhibitor CD-6 to the second gold cleaning concentrate II. After sufficient stirring, conduct the third gold-sulfur flotation separation for gold cleaning, namely obtaining the third gold cleaning concentrate and the third gold cleaning tailings; and return the third gold cleaning tailings to the second gold-sulfur flotation separation for gold cleaning step.

[0071] With such settings, under the synergistic effect of the specially formulated agents, the gold and pyrite in the gold-sulfur mixed concentrate refined to the target particle size are effectively separated, thus ensuring a high gold recovery rate.

[0072] Specifically, in some embodiments of the present invention, the inhibitor CD-6 is one or more of lime, sodium hydroxide, sodium sulfide, sodium humate, and sodium carbonate; the gold collector B7 is one or more of MB xanthate, Y89 xanthate, Z-200, ethyl xanthate, propionitrile alkyl xanthate, and ammonium dibutyl dithiophosphate.

[0073] Specifically, in some embodiments of the present invention, the mass ratio of the inhibitor CD-6 is: sodium hydroxide:sodium carbonate:sodium humate:water = 29:10:1:200; the mass ratio of the gold collector B7 is: Y89:ethyl xanthate:propionitrile alkyl xanthate:cosolvent = 3:4:1:2; the cosolvent is an alcohol with more than ten carbon atoms.

[0074] With such settings, by using inhibitor CD-6 with strong selectivity for pyrite and collector B7 with strong selectivity for gold, while reducing the activity of pyrite in the pulp system, the floatability of gold is improved, creating favorable conditions for the recovery of gold.

[0075] Specifically, in some embodiments of the present invention, the first inhibitor, the second inhibitor, and the third inhibitor are each one or more of sodium carbonate, water glass, citric acid, and oxalic acid; the activator is copper sulfate; the first collector, the second collector, and the third collector are each one or more of butyl xanthate, amyl xanthate, Y89 xanthate, MB xanthate, and ammonium butyl dithiophosphate.

[0076] The following specifically describes the gold-sulfur flotation separation method for sulfur-containing gold ore provided by the present invention in conjunction with embodiments:

[0077] Example 1

[0078] This example provides a gold-sulfur flotation separation method for sulfur-containing gold ore, which specifically includes the following steps:

[0079] Preliminary preparation:

[0080] The selected raw ore in this example contains 3.01 g / t of gold and 4.09% of sulfur. The main gangue minerals are potassium feldspar, quartz, albite, calcic albite, and mica, etc.

[0081] In this example, inhibitor CD-6 is compounded from sodium hydroxide, sodium carbonate, sodium humate, and water in a mass ratio of 29:10:1:200; gold collector B7 is compounded from Y89, ethyl xanthate, propyl cyanoalkyl xanthate, and co-solvent C12 alcohol in a mass ratio of 3:4:1:2.

[0082] S1. After crushing and grinding the target raw ore to a fineness where the particle size less than 0.074 mm accounts for 60%, water is added to make a raw ore pulp with a concentration of 32%.

[0083] S2. According to the preset reagent regime, gold-sulfur bulk flotation is carried out on the raw ore pulp to obtain gold-sulfur bulk flotation concentrate and gold-sulfur bulk flotation tailings. The specific steps are as follows:

[0084] (a) 1000 g / t of the first inhibitor (500 g / t of water glass and 500 g / t of sodium carbonate) is added to the raw ore pulp in sequence. After fully stirring for 2 min, 150 g / t of the first collector (120 g / t of butyl xanthate and 30 g / t of ammonium butyl dithiophosphate) and 20 g / t of frother No. 2 oil are added. After stirring for 3 min, the first roughing of gold-sulfur bulk flotation is carried out for 3 min, obtaining gold-sulfur bulk flotation rough concentrate I and gold-sulfur bulk flotation roughing tailings I;

[0085] (b) Add 45 g / t of the second collector (30 g / t of xanthate + 15 g / t of butylammonium black collector) to the rougher tailings Ⅰ of the gold-sulfur bulk flotation, stir well for 3 min, and then conduct the first scavenging of the gold-sulfur bulk flotation for 2 min to obtain the scavenger concentrate Ⅰ of the gold-sulfur bulk flotation and the scavenger tailings Ⅰ of the gold-sulfur bulk flotation; and return the obtained scavenger concentrate Ⅰ of the gold-sulfur bulk flotation to the rougher process of the first gold-sulfur bulk flotation;

[0086] (c) Add 20 g / t of the third collector (15 g / t of xanthate + 5 g / t of butylammonium black collector) to the scavenger tailings Ⅰ of the gold-sulfur bulk flotation, stir well for 2 min, and then conduct the second scavenging of the gold-sulfur bulk flotation for 2 min to obtain the scavenger concentrate Ⅱ of the gold-sulfur bulk flotation and the scavenger tailings Ⅱ of the gold-sulfur bulk flotation; and return the obtained scavenger concentrate Ⅱ of the gold-sulfur bulk flotation to the scavenging process of the first gold-sulfur bulk flotation;

[0087] (d) Add 50 g / t of the depressant (50 g / t of water glass) to the rougher concentrate Ⅰ of the gold-sulfur bulk flotation in step (a), stir well for 1 min, and then conduct the first cleaning of the gold-sulfur bulk flotation for 2.30 min to obtain the cleaning concentrate Ⅰ of the gold-sulfur bulk flotation and the cleaning tailings Ⅰ of the gold-sulfur bulk flotation; and return the obtained cleaning tailings Ⅰ of the gold-sulfur bulk flotation to the rougher process of the first gold-sulfur bulk flotation;

[0088] (e) Stir the cleaning concentrate Ⅰ of the gold-sulfur bulk flotation in step (d) well for 1 min, and then conduct the second cleaning of the gold-sulfur bulk flotation for 2 min to obtain the cleaning concentrate Ⅱ of the gold-sulfur bulk flotation and the cleaning tailings Ⅱ of the gold-sulfur bulk flotation; and return the obtained cleaning tailings Ⅱ of the gold-sulfur bulk flotation to the cleaning process of the first gold-sulfur bulk flotation.

[0089] S3. After adding 2000 g / t of the depressant CD-6 to the gold-sulfur bulk flotation concentrate obtained in step S2, grind it to a fineness where the particle size less than 0.038 mm accounts for 95% to obtain the re-ground gold-sulfur bulk flotation concentrate;

[0090] S4. Make the re-ground gold-sulfur bulk flotation concentrate obtained in step S3 into a pulp with a concentration of 10%, adjust the pH, and then add the gold collector B7 to conduct the gold-sulfur separation flotation to obtain the gold concentrate and the sulfur concentrate. The specific steps are as follows:

[0091] (f) Add 20 g / t of the gold collector B7 to the pulp of the re-ground cleaning concentrate Ⅱ of the gold-sulfur bulk flotation adjusted to a pH value of 13, stir well for 2 min, and then conduct the first roughing of the gold-sulfur flotation separation for 3.5 min to obtain the roughing concentrate Ⅰ of the gold concentrate and the roughing tailings Ⅰ of the gold concentrate;

[0092] (g) Add 20 g / t of gold collector B7 to the rough gold concentrate tailings I, stir well for 2 min, and then conduct the first gold-sulfur flotation separation gold scavenging for 2 min to obtain the gold scavenging concentrate I and the gold scavenging tailings I; and return the gold scavenging concentrate I to the first gold-sulfur flotation separation rough gold concentration process;

[0093] (h) Add 10 g / t of gold collector B7 to the gold scavenging tailings I, stir well for 2 min, and then conduct the second gold-sulfur flotation separation gold scavenging for 2 min to obtain the gold scavenging concentrate II and the gold scavenging tailings II; and return the gold scavenging concentrate II to the first gold-sulfur flotation separation gold scavenging, and the gold scavenging tailings II are the sulfur concentrate;

[0094] (i) Add 500 g / t of inhibitor CD-6 to the rough gold concentrate I in step (f), stir well for 2 min, and then conduct the first gold-sulfur flotation separation gold cleaning for 2.5 min to obtain the gold cleaning concentrate I and the gold cleaning tailings I; and return the gold cleaning tailings I to the first gold-sulfur flotation separation rough gold concentration process;

[0095] (j) Add 300 g / t of inhibitor CD-6 to the gold cleaning concentrate I, stir well for 2 min, and then conduct the second gold-sulfur flotation separation gold cleaning for 2 min to obtain the gold cleaning concentrate II and the gold cleaning tailings II; and return the gold cleaning tailings II to the first gold-sulfur flotation separation gold cleaning process.

[0096] The test results are shown in Table 1. It can be seen that finally, gold concentrate with an Au grade of 88.72 g / t and an Au recovery rate of 87.85% is obtained; qualified sulfur concentrate with an S grade of 42.27% and an S recovery rate of 61.61% is obtained, the gold content in the sulfur concentrate is 4.61 g / t, and the recovery rate is 9.13%; the comprehensive Au recovery rate reaches 96.98%.

[0097] Table 1 Results of the full-process closed-circuit test

[0098]

[0099] Comparative Examples 1-4

[0100] Comparative Examples 1-4 provide a gold-sulfur flotation separation method for sulfur-containing gold ore. Compared with Example 1, the difference is that different types of inhibitors are used in the gold-sulfur flotation separation process in step (2). The inhibitors added in Comparative Examples 1-4 are lime, sodium hydroxide, sodium carbonate, and sodium humate respectively, and the process flow is as Figure 2 shown. Other experimental steps are the same as those in Example 1 and will not be elaborated here.

[0101] The experimental results are shown in Table 2. It can be seen that the conventional pyrite inhibitor lime has a strong inhibitory effect on gold, which is not conducive to the recovery of gold. The inhibitory effect of inhibitor CD-6 is significantly better than that of single sodium hydroxide, sodium carbonate and sodium humate, which is beneficial to promoting the separation of gold and pyrite in sulfur-bearing gold ore and is more conducive to the recovery of gold.

[0102] Table 2 Test results of different inhibitors

[0103]

[0104] Comparative Examples 5-7

[0105] Comparative Examples 5-7 provide a method for gold-sulfur flotation separation of sulfur-bearing gold ore. Compared with Example 1, the difference is that different types of gold collectors are used in the gold-sulfur flotation separation process in step (2). The inhibitors added in Comparative Examples 5-7 are butyl xanthate, ethyl xanthate, and Y89 respectively. The process flow is as Figure 3 shown. Other experimental steps are the same as those in Example 1 and will not be elaborated here.

[0106] The test results are shown in Table 3. It can be seen that when the collector butyl xanthate is used to collect gold, it also has a strong collecting ability for pyrite, which is not conducive to the separation of gold and pyrite in sulfur-bearing gold ore. Therefore, the obtained sulfur concentrate is unqualified. The collector ethyl xanthate has good selectivity for Au, but its collecting ability is weak. The collecting effect of the combined collector B7 is significantly better than that of single ethyl xanthate and Y89 xanthate.

[0107] Table 3 Test results of different collectors

[0108]

[0109]

[0110] Example 2

[0111] This example provides a method for gold-sulfur flotation separation of sulfur-bearing gold ore. Compared with Example 1, the difference is that on the basis of step (j) in step S4, a third gold concentrate cleaning is added, that is: (k) Add 200 g / t of inhibitor CD-6 to the gold concentrate cleaning concentrate II obtained in step (j), stir well for 2 min, and then perform the third gold-sulfur flotation separation gold concentrate cleaning for 2 min to obtain the gold concentrate cleaning concentrate III and the gold concentrate cleaning tailings III; and return the gold concentrate cleaning tailings III to the second gold-sulfur flotation separation gold concentrate cleaning step. Other experimental steps are the same as those in Example 1 and will not be elaborated here.

[0112] The test results are shown in Table 4. It can be seen that finally, gold concentrate with a Au grade of 113.40 g / t and a Au recovery rate of 86.71% is obtained; qualified sulfur concentrate with an S grade of 42.78% and an S recovery rate of 69.46% is obtained. The Au content in the sulfur concentrate is 4.65 g / t, the Au recovery rate is 10.26%, and the comprehensive Au recovery rate reaches 96.97%. Compared with Example 1, in this example, the Au grade in the gold concentrate increases by 24.68 g / t, and the S recovery rate in the sulfur concentrate increases by 7.85 percentage points. It shows that multiple gold concentrate selections for the gold-sulfur mixed concentrate in the gold-sulfur flotation separation process are also beneficial to the separation of gold and pyrite in sulfur-containing gold ore.

[0113] Table 4 Results of the full-process closed-circuit test

[0114]

[0115] Example 3

[0116] This example provides a method for gold-sulfur flotation separation of sulfur-containing gold ore. Compared with Example 1, the difference lies in that in step (2) of the gold-sulfur flotation separation process, the fineness of grinding the gold-sulfur mixed flotation concentrate II added with CD-6 in step (g) is different. In Example 3, the gold-sulfur mixed flotation concentrate II added with CD-6 is ground to a particle size less than 0.023 mm, and the proportion is 95% (this fineness is the maximum fineness that can be achieved in the current actual process production). Other experimental steps are the same as those in Example 1 and will not be elaborated here.

[0117] The test results are shown in Table 5. It can be seen that finally, gold concentrate with a Au grade of 147.93 g / t and a Au recovery rate of 89.85% is obtained; qualified sulfur concentrate with an S grade of 43.06% and an S recovery rate of 74.86% is obtained. The Au content in the sulfur concentrate is 3.02 g / t, the Au recovery rate is 7.13%, and the comprehensive Au recovery rate reaches 96.97%. Compared with Example 1, in this example, the Au grade in the gold concentrate increases by 59.21 g / t, the Au recovery rate increases by 2 percentage points, the S grade in the sulfur concentrate increases by 0.79 percentage points, and the S recovery rate increases by 13.25 percentage points. It shows that further grinding of the particle size of the gold-sulfur mixed concentrate in the gold-sulfur flotation separation process is also beneficial to the separation of gold and pyrite in sulfur-containing gold ore.

[0118] Table 5 Results of the full-process closed-circuit test

[0119]

[0120] In summary, the present invention provides a method for gold-sulfur flotation separation of sulfur-bearing gold ore, which includes a gold-sulfur bulk flotation process, regrinding of the gold-sulfur bulk concentrate, and a gold-sulfur flotation separation process. Under the synergistic action of specially formulated reagents, gold and pyrite in the gold-sulfur bulk concentrate refined to the target particle size are effectively separated, thus significantly improving the gold recovery rate. This effectively solves the problem that it is difficult to recover pyrite resources in sulfur-bearing gold ore and provides a new effective method for the development and utilization of similar sulfur-bearing gold ore resources. In the gold-sulfur flotation separation process, a highly efficient inhibitor CD-6 with strong selectivity for pyrite (sodium hydroxide: sodium carbonate: sodium humate: water = 29:10:1:200) and a highly efficient gold collector B7 with strong selectivity for gold (Y89: ethyl xanthate: propyl alkyl xanthogen cyanide: cosolvent = 3:4:1:2) are used. While reducing the activity of pyrite in the pulp system, the floatability of gold is improved, significantly increasing the gold recovery rate and creating favorable conditions for gold recovery.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for gold-sulfur flotation separation of sulfur-containing gold ore, characterized in that, It includes the following steps: S1. After crushing and ball milling the target raw ore to a predetermined fineness, prepare a raw ore pulp with a predetermined concentration; S2. Conduct gold-sulfur bulk flotation on the raw ore pulp according to a preset reagent regime to obtain a gold-sulfur bulk flotation concentrate and a gold-sulfur bulk flotation tailing; S3. Add a predetermined amount of inhibitor CD-6 to the gold-sulfur bulk flotation concentrate obtained in step S2, and then grind it to a predetermined fineness to obtain a re-ground gold-sulfur bulk flotation concentrate; The mass ratio of the inhibitor CD-6 is sodium hydroxide:sodium carbonate:sodium humate:water = 29:10:1:200; S4. Prepare the re-ground gold-sulfur bulk flotation concentrate obtained in step S3 into a re-ground gold-sulfur bulk flotation concentrate pulp, adjust the pH, and then add a gold collector B7 to conduct gold-sulfur separation flotation to obtain a gold concentrate and a sulfur concentrate; The mass ratio of the gold collector B7 is Y89 xanthate:ethyl xanthate:propyl alkyl xanthogen cyanide:cosolvent = 3:4:1:2; the cosolvent is an alcohol with more than ten carbon atoms.

2. The method for gold-sulfur flotation separation of sulfur-containing gold ore according to claim 1, characterized in that: The gold-sulfur bulk flotation in step S2 includes one roughing, two scavengings, and two cleanings, and specifically includes the following steps: (a) Sequentially add a predetermined amount of a first inhibitor and an activator to the raw ore pulp, fully stir, then add a predetermined amount of a first collector and a frother, and stir and conduct the first roughing of gold-sulfur bulk flotation to obtain a gold-sulfur bulk flotation rough concentrate I and a gold-sulfur bulk flotation roughing tailing I; (b) Add a predetermined amount of a second collector to the gold-sulfur bulk flotation roughing tailing I, fully stir, and conduct the first scavenging of gold-sulfur bulk flotation to obtain a gold-sulfur bulk flotation scavenging concentrate I and a gold-sulfur bulk flotation scavenging tailing I; and return the obtained gold-sulfur bulk flotation scavenging concentrate I to the first roughing process of gold-sulfur bulk flotation; (c) Add a predetermined amount of a third collector to the gold-sulfur bulk flotation scavenging tailing I, fully stir, and conduct the second scavenging of gold-sulfur bulk flotation to obtain a gold-sulfur bulk flotation scavenging concentrate II and a gold-sulfur bulk flotation scavenging tailing II; and return the obtained gold-sulfur bulk flotation scavenging concentrate II to the first scavenging process of gold-sulfur bulk flotation; (d) Add a predetermined amount of a second inhibitor to the gold-sulfur bulk flotation rough concentrate I in step (a), fully stir, and conduct the first cleaning of gold-sulfur bulk flotation to obtain a gold-sulfur bulk flotation cleaning concentrate I and a gold-sulfur bulk flotation cleaning tailing I; and return the obtained gold-sulfur bulk flotation cleaning tailing I to the first roughing process of gold-sulfur bulk flotation; (e) Add a predetermined amount of a third inhibitor to the gold-sulfur bulk flotation cleaning concentrate I in step (d), fully stir, and conduct the second cleaning of gold-sulfur bulk flotation to obtain a gold-sulfur bulk flotation cleaning concentrate II and a gold-sulfur bulk flotation cleaning tailing II; and return the obtained gold-sulfur bulk flotation cleaning tailing II to the first cleaning process of gold-sulfur bulk flotation.

3. The gold-sulfur flotation separation method for sulfur-containing gold ore according to claim 1, characterized in that: The gold-sulfur separation flotation in step S4 includes one roughing of gold concentrate, two scavengings of gold concentrate, and two cleanings of gold concentrate, and specifically includes the following steps: (f) Add a predetermined amount of the gold collector B7 to the regrinded gold-sulfur bulk flotation concentrate pulp adjusted to a predetermined pH value. After sufficient stirring, conduct the first gold-sulfur flotation separation for roughing of gold concentrate, i.e., obtain the roughing gold concentrate I and the roughing tailings I of gold concentrate; (g) Add a predetermined amount of the gold collector B7 to the roughing tailings I of gold concentrate. After sufficient stirring, conduct the first gold-sulfur flotation separation for scavenging of gold concentrate, i.e., obtain the scavenging gold concentrate I and the scavenging tailings I of gold concentrate; and return the scavenging gold concentrate I to the first gold-sulfur flotation separation process for roughing of gold concentrate; (h) Add a predetermined amount of the gold collector B7 to the scavenging tailings I of gold concentrate. After sufficient stirring, conduct the second gold-sulfur flotation separation for scavenging of gold concentrate, i.e., obtain the scavenging gold concentrate II and the scavenging tailings II of gold concentrate; and return the scavenging gold concentrate II to the first gold-sulfur flotation separation for scavenging of gold concentrate, and the scavenging tailings II of gold concentrate is the sulfur concentrate; (i) Add a predetermined amount of the inhibitor CD-6 to the roughing gold concentrate I in step (f). After sufficient stirring, conduct the first gold-sulfur flotation separation for cleaning of gold concentrate, i.e., obtain the cleaning gold concentrate I and the cleaning tailings I of gold concentrate; and return the cleaning tailings I of gold concentrate to the first gold-sulfur flotation separation process for roughing of gold concentrate; (j) Add a predetermined amount of the inhibitor CD-6 to the cleaning gold concentrate I. After sufficient stirring, conduct the second gold-sulfur flotation separation for cleaning of gold concentrate, i.e., obtain the cleaning gold concentrate II and the cleaning tailings II of gold concentrate; and return the cleaning tailings II of gold concentrate to the first gold-sulfur flotation separation process for cleaning of gold concentrate.

4. The method for gold-sulfur flotation separation of sulfur-containing gold ore according to claim 3, characterized in that: The gold-sulfur separation flotation in step S4 further includes the third cleaning of gold concentrate, which specifically includes the following steps: (k) Add a predetermined amount of the inhibitor CD-6 to the cleaning gold concentrate II. After sufficient stirring, conduct the third gold-sulfur flotation separation for cleaning of gold concentrate, i.e., obtain the cleaning gold concentrate III and the cleaning tailings III of gold concentrate; and return the cleaning tailings III of gold concentrate to the second gold-sulfur flotation separation step for cleaning of gold concentrate.

5. The method for gold-sulfur flotation separation of sulfur-containing gold ore according to claim 1, wherein: The predetermined fineness of the regrinded gold-sulfur bulk flotation concentrate in step S3 is: the particle size less than 0.038 mm accounts for 50 - 100%.

6. The method for gold-sulfur flotation separation of sulfur-containing gold ore according to claim 2, characterized in that: The first inhibitor, the second inhibitor, and the third inhibitor are each one or more of sodium carbonate, water glass, citric acid, and oxalic acid; the activator is copper sulfate; the first collector, the second collector, and the third collector are each one or more of butyl xanthate, amyl xanthate, Y89 xanthate, MB xanthate, and ammonium butyl dithiophosphate.

7. The gold-sulfur flotation separation method for sulfur-containing gold ore according to claim 6, wherein: The predetermined concentration of the raw ore pulp in step S1 is 28 - 38%; the predetermined fineness of the raw ore ball milling is: the particle size less than 0.074 mm accounts for 50 - 95%; In step (a) of step S2, the predetermined amount of the first inhibitor is 500 - 2000 g / t, the predetermined amount of the copper sulfate is 0 - 200 g / t, the predetermined amount of the first collector is 100 - 200 g / t, and the predetermined amount of the frother is 10 - 50 g / t; The predetermined amount of the second collector described in step (b) is 10 - 50 g / t; The predetermined amount of the third collector described in step (c) is 5 - 30 g / t; The predetermined amount of the second inhibitor described in step (d) is 50 - 500 g / t; The predetermined amount of the third inhibitor described in step (e) is 0 - 200 g / t.

8. The method for gold-sulfur flotation separation of sulfur-containing gold ore according to claim 4, characterized in that: The predetermined concentration of the re-ground gold-sulfur bulk flotation concentrate pulp described in step S4 is 5 - 20%; In step (f) of step S4, the predetermined pH value is greater than 12, and the predetermined amount of the gold collector B7 is 0 - 50 g / t; The predetermined amount of the inhibitor CD-6 described in step S3 is 500 - 3000 g / t; In step (g) of step S4, the predetermined amount of the gold collector B7 is 10 - 40 g / t; The predetermined amount of the gold collector B7 described in step (h) is 5 - 20 g / t; The predetermined amount of the inhibitor CD-6 described in step (i) is 100 - 500 g / t; The predetermined amount of the inhibitor CD-6 described in step (j) is 100 - 300 g / t; The predetermined amount of the inhibitor CD-6 described in step (k) is 50 - 200 g / t.

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