High-efficiency beneficiation method for arsenic-containing low-grade fine-grained disseminated gold ore

Abstract

The application discloses a high-efficiency beneficiation method for low-grade arsenic-containing fine-grained disseminated gold ore, and relates to the technical field of ore dressing, and in particular to a method for controlling the pulp potential by using lime slurry, without adding any activator, and realizing high-efficiency recovery of low-grade fine-grained gold ore by using a one-stage coarse grinding + middlings regrinding and reselection process.The method comprises the following steps: grinding the raw ore, controlling the grinding fineness, and using lime slurry to control the pulp potential in a certain range without any activator, and then performing roughing by using isobutyl xanthate + butyl ammonium black drug combination or isobutyl xanthate + MC combination as a collector and 2# oil as a foaming agent, performing cleaning on the roughing foam to obtain gold concentrate 1, adding isobutyl xanthate + amyl xanthate + butyl ammonium black drug combination or isobutyl xanthate + MC combination as a collector and 2# oil as a foaming agent to the roughing tailings after roughing to perform three times of intensified scavenging, and obtaining scavenging concentrate, and combining the cleaning middlings and the scavenging concentrate to perform regrinding and reselection, wherein the regrinding equipment is a Aixing mill, the grinding fineness is controlled, and after the regrinding and reselection, gold concentrate 2 can be obtained, and the gold concentrate 1 and the gold concentrate 2 are used as final concentrates, and the method has the advantages of improving the efficiency, reducing the energy consumption and reagent cost, and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gold ore dressing, and particularly relates to a high-efficiency dressing method for a low-grade micro-fine disseminated gold ore containing arsenic. BACKGROUND

[0002] The micro-fine disseminated gold ore is a common type of gold ore and belongs to refractory ore. Many micro-fine disseminated gold ores are found in two gold triangles of Yunnan-Guizhou-Guangxi and Sichuan-Shaanxi-Gansu in China, such as Shuiyindong gold mine, Lannigou gold mine and Yata gold mine in Guizhou, Dongbeizhai gold mine in Sichuan, etc. The micro-fine disseminated gold ore containing arsenic has pyrite and arsenopyrite as main gold-bearing minerals, and has calcite, dolomite and sericite as main gangue minerals. Since the gangue minerals such as carbonate and clay are easily overground to produce mudification during fine grinding, the flotation is deteriorated, the overground mudification is caused, and the dressing index is poor. Therefore, the gold ore is difficult to be selected and smelted.

[0003] To solve the above problems, Chinese scientists have carried out a lot of research and developed a series of fine particle leaching type gold ore dressing process, which realizes the recovery of fine particle gold ore. Such as Huang Renzhi [Guangxi University 2015 master thesis] for Guizhou Nibao high carbon content, high arsenic refractory gold ore, in the process of flotation, easy to float with sulfide, the recovery of gold is not conducive to the characteristics, using a stage of fine grinding, grinding fineness control-0.074 mm accounted for 95%, using water glass as dispersant, copper sulfate as activator, a rough four fine three closed circuit process, can obtain gold concentrate grade 13.71g / t, gold recovery rate of 78.24% of the better ore dressing index; Yao Jin et al [Metal Mine, 2016(2):77-81] for Guizhou some sulfur containing micro fine disseminated type gold ore, the gangue mineral is mainly carbonates and clay minerals, which are easy to be slimed, fine grinding will produce a lot of slime, reduce the flotation index characteristics, using two stage grinding-stage flotation process for dressing test, the results show that: in the first stage of grinding fineness of-0.074 mm accounted for 80%, with (NH4)2SO4+CuSO4 as activator, butyl xanthate + butyl ammonium black medicine as collector, 2 number oil as foaming agent, through 1 rough 1 fine one stage flotation, the tailings of one stage flotation is ground to-0.074 mm accounted for 95%, through 1 rough 3 fine 3 sweep two stage flotation, the mixed concentrate gold grade is 50.79g / t, the recovery rate is 88.31%, which realizes the effective recovery of the micro fine disseminated type gold ore; Xing Qingqing et al [Gold, 2016(11):46-50] for the characteristics of high content of easy sliming mineral (up to 37.07%) in a low grade micro fine disseminated type easy sliming refractory gold ore in Qinghai, using a stage of fine grinding, grinding fineness of-0.074 mm accounted for 85%, slime dispersion + enhanced flotation process, obtained good test index: closed circuit flotation gold concentrate gold grade 37.56g / t, gold recovery rate 85.57%, get good separation effect; Luo Xing [Metal Mine, 2019(11):94-97] for the characteristics of a micro fine disseminated type primary gold ore in Guangxi with high arsenic and high organic carbon, mainly fine particle inclusions gold, using a stage of fine grinding, grinding fineness of-0.074 mm accounted for 85%, using copper sulfate as the activator of the main gold bearing mineral pyrite, butyl xanthate + butyl amine black medicine combination as the collector of gold mineral and gold bearing mineral, through 1 rough 2 fine 3 sweep closed circuit flotation process, can obtain gold grade of 31.50g / t, gold recovery rate of 86.57% of gold concentrate, and good beneficiation results are obtained. The above research shows that fine grinding + slurry dispersion + enhanced activation flotation combined process is often used to obtain good beneficiation results for fine-grained disseminated gold ore. Because fine grinding process is used in mineral processing, 70% of energy consumption is in grinding. At the same time, fine grinding often leads to over-grinding and slurry phenomenon, which requires the addition of dispersing agent to improve the influence of slurry on beneficiation index, and is not conducive to tailings settling. In order to strengthen the floatability of gold-bearing minerals such as pyrite and arsenopyrite, copper sulfate (high cost of reagent) is added as an activator, so there are disadvantages such as low efficiency, high energy consumption and high cost of reagent, especially for low-grade arsenic-containing fine-grained disseminated gold ore with less than 20g gold / T ore, which is abandoned due to high cost and low benefit, resulting in the idle of such low-grade gold ore.

[0004] The same patent technology of the research group is as follows: (1) No same patent of beneficiation method for arsenic-containing fine-grained disseminated gold ore is found, only two related patents of a comprehensive recovery method for arsenopyrite-bearing fine-grained disseminated gold ore [CN201911135704.9] and a flotation reagent for arsenic-containing disseminated gold ore, preparation method and use method [CN114682388A] are found. The former adopts gravity separation + flash flotation + cyanide combined process to realize high-efficiency recovery of arsenopyrite-bearing fine-grained disseminated gold ore, but due to the use of cyanide process, sodium cyanide is a toxic reagent, and cyanide process has been listed as forbidden process in many environmentally sensitive areas in China, while the research group aims at gold-bearing minerals of pyrite and arsenopyrite, and the beneficiation process is different; the latter is about the preparation method and use method of flotation reagent for arsenic-containing disseminated gold ore, not a beneficiation method; (2) No same patent of potential control flotation of gold-bearing pyrite and arsenopyrite is found, only related patents of potential control flotation of lead-zinc sulfide ore, copper-molybdenum ore and copper sulfide ore are found; (3) Only one related patent of gold ore regrinding and reselection is found, namely a gold ore selection method [CN201911166006.5], but the gold ore properties involved are different from the research group, the object is quartz vein type gold ore, that is, there are natural gold, unevenly distributed gold, and the main gangue mineral is quartz), and only regrinding and reselection process is used and no equipment is described, the research group is fine-grained disseminated ore, that is, gold is finely dispersed in pyrite and arsenopyrite; (4) No same patent of ai sand mill used in gold ore regrinding and reselection process is found.

[0005] Therefore, it is of great significance to develop a low-cost, environmentally friendly and efficient beneficiation method for low-grade arsenic-containing fine-grained disseminated gold ore. SUMMARY

[0006] The present application aims to overcome the deficiencies of the prior art and provide a high-efficiency beneficiation method for arsenic-containing low-grade fine-grained disseminated gold ore, which can improve efficiency and reduce energy consumption and reagent cost.

[0007] The present application is accomplished by the following technical solutions:

[0008] The high-efficiency beneficiation method for arsenic-containing low-grade fine-grained disseminated gold ore uses lime to control the potential of the ore slurry without adding any activator, and uses a one-stage coarse grinding + middlings regrinding and reselection process to achieve high-efficiency recovery of low-grade fine-grained gold ore, and specifically includes the following process steps and conditions:

[0009] (1) Grinding, the raw ore is ground, the grinding fineness is controlled to be 70-75% of-0.074 mm, lime is used for slurry conditioning, the potential of the ore slurry is controlled to be 200-250 mV, the corresponding pH value is 7.5-8.5, and no activator is added, and isobutyl xanthate + butyl ammonium black drug combination or isobutyl xanthate + MC combination is used as the collector, 2# oil is used as the frother for roughing, the roughing froth is subjected to cleaning, and cleaned middlings and gold concentrate 1 are obtained;

[0010] (2) Intensified scavenging, isobutyl xanthate + amyl xanthate + butyl ammonium black drug combination or isobutyl xanthate + MC combination is added to the roughing tailings after roughing as the collector, 2# oil is used as the frother for 3 times of intensified scavenging, and scavenging concentrate is obtained;

[0011] (3) Re-grinding and re-selection, the cleaned middlings and the scavenging concentrate are combined for re-grinding and re-selection, the re-grinding equipment is a Aixing mill, a narrow particle size ultra-fine grinding equipment without a classification equipment is configured, the grinding fineness is controlled to be 85-90% of-0.038 mm, and after the re-grinding and re-selection, gold concentrate 2 and its tailings 2, and the combination of the gold concentrate 1 and the gold concentrate 2 are obtained as the final concentrate.

[0012] Compared with the prior art, the present application has the following advantages or effects:

[0013] (1) The reagent cost is saved, and the reagent cost can be reduced by 20-30% compared with the traditional process.

[0014] (2) The amount of ore that needs to be finely ground is small, the energy consumption per ton of ore is low, and the energy consumption is reduced by 15-20%.

[0015] (3) Narrow particle size grinding is achieved, the over-grinding and mudification phenomenon is reduced, which is conducive to improving the gold recovery index, and the gold recovery rate is increased by 3-4% compared with the original process; no mud dispersant needs to be added, which is conducive to the settlement of tailings and dam construction.

[0016] (4) Non-toxic reagents are used to achieve clean production.

[0017] In summary, this invention uses lime as a pulp conditioner to precisely adjust the pulp potential, enabling the flotation of gold-loaded sulfides without activators, thus significantly reducing reagent costs; employs a single-stage coarse grinding + middlings regrinding and re-selection process, effectively reducing energy consumption; uses an abrasive mill to achieve narrow-particle grinding, reducing over-grinding and mud formation, which is beneficial for improving gold beneficiation indicators; and does not add any slime dispersant, which is beneficial for tailings settling in the tailings dam.

[0018] The percentages mentioned in the application documents refer to mass percentages, and MC is the code for several xanthate compound collectors produced and sold by domestic pharmaceutical companies. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of an efficient beneficiation method for low-grade, fine-grained disseminated gold ore containing arsenic, based on the present invention.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. Detailed Implementation

[0021] like Figure 1 As shown, an efficient beneficiation method for low-grade, fine-grained disseminated gold deposits containing arsenic addresses the issue that the gold-bearing minerals in these deposits are pyrite and arsenopyrite. Lime is used to control the slurry potential, without adding any activators. A single-stage coarse grinding followed by regrinding and beneficiation is employed to achieve efficient recovery of low-grade, fine-grained gold ore. The specific process steps and conditions include:

[0022] (1) Grinding: Grind the raw ore to control the grinding fineness to 70-75% of -0.074mm. Use lime to adjust the slurry to control the slurry potential at 200-250mV, corresponding to a pH of 7.5-8.5. Do not add any activator. Use isobutyl xanthate + butylammonium black powder combination or isobutyl xanthate + MC combination as collector and No. 2 oil as frother for roughing. Use the roughing foam for cleaning to obtain cleaned middlings and gold concentrate 1.

[0023] (2) Enhanced scavenging: Add isobutyl xanthate + pentyl xanthate + butylammonium black powder combination or isobutyl xanthate + MC combination as collector and No. 2 oil as frother to the roughing tailings after roughing to carry out three enhanced scavenging processes to obtain scavenging concentrate.

[0024] (3) Regrinding and re-selection: The middlings and scavenging concentrate are combined for regrinding and re-selection. The regrinding equipment is an abrasive mill. The narrow-particle ultrafine mill does not require the configuration of a grading device. The grinding fineness is controlled to be -0.038mm, accounting for 85-90%. After regrinding and re-selection, gold concentrate 2 and its tailings 2 can be obtained. Gold concentrate 1 and gold concentrate 2 are combined as the final concentrate.

[0025] The process of the present invention can be further described as follows:

[0026] The step (1) grinding, slurry adjustment, roughing and cleaning can make the dissociation degree of gold-bearing sulfides such as pyrite and arsenopyrite reach 75-80%.

[0027] The step (1) grinding can improve the floatability of pyrite and arsenopyrite by using lime to adjust the potential of the ore slurry.

[0028] The step (2) intensive scavenging, before scavenging, the collecting agent is a combination of isobutyl xanthate + amyl xanthate + butyl ammonium black drug or a combination of isobutyl xanthate + MC, and the frother is 2# oil, the above combination of reagents has strong collecting ability, and can strengthen the recovery of sulfide intergrowth such as pyrite and arsenopyrite.

[0029] The step (3) regrinding and reselection, the regrinding equipment is selected as the Aixi mill, and no any slime dispersant is added, so that narrow particle size grinding can be realized, the overground and sliming phenomenon is reduced, the influence of overground and sliming on the flotation index is reduced, the beneficiation index is effectively improved, and the settlement of fine tailings particles is facilitated.

[0030] The step (3) regrinding and reselection, the roughing collecting agent is a combination of isobutyl xanthate + butyl ammonium black drug or a combination of isobutyl xanthate + MC, and the frother is 2# oil; the scavenging collecting agent is a combination of isobutyl xanthate + amyl xanthate + butyl ammonium black drug or a combination of isobutyl xanthate + MC, and the frother is 2# oil.

[0031] The step (1) grinding is followed by the flotation process of the open circuit process of 'one roughing + one cleaning + three scavenging', and the middlings in cleaning and the scavenging concentrates are combined to enter the Aixi mill for regrinding.

[0032] The step (3) regrinding and reselection is followed by the flotation process of the closed circuit process of 'one roughing + two cleanings + three scavenging', and the middlings in cleaning and the scavenging concentrates are sequentially returned.

[0033] Example 1

[0034] The method is used for beneficiation of a certain arsenic-containing low-grade fine-grained disseminated gold ore in Gansu, and the element analysis of the raw ore is shown in Table 1.

[0035] Table 1: Element analysis results of the raw ore

[0036]

[0037] *g / t

[0038] From the data in Table 1, the main metal elements that can be recovered from the ore are Au, and according to the properties of the raw ore, the process of the application is adopted, and the specific process steps are as follows:

[0039] (1) grinding, slurry adjustment is performed by using lime, roughing is performed, and cleaning is performed on the froth of roughing to obtain gold concentrate 1;

[0040] (2) intensive scavenging, three times of intensive scavenging are performed on the tailings of roughing;

[0041] (3) Regrinding and re-selection: The middlings and scavenged concentrate are combined for regrinding and re-selection. The regrinding equipment is an abrasive mill. After regrinding and re-selection, gold concentrate 2 can be obtained. Gold concentrate 1 and gold concentrate 2 are combined as the final gold concentrate.

[0042] As attached Figure 1 As shown, the ore is first subjected to a grinding process, with the grinding fineness controlled to -0.074mm accounting for 73.75%. Then, flotation is carried out. In the roughing process, lime is added to adjust the pulp potential to 220-240mV (corresponding to pH 8), and isobutyl xanthate / butylammonium black powder is added as a combined collector at a dosage of 40 / 20g / t, and No. 2 oil is added at 10g / t. The rough concentrate is then subjected to one cleaning process without the addition of any reagents. The tailings from the roughing process are then subjected to three scavenging processes, with different amounts of collector added for each scavenging process: 30 / 10 / 10g / t, 24 / 8 / 8g / t, and 18 / 6 / 6g / t of the isobutyl xanthate / pentyl xanthate / butylammonium black powder combined collector, respectively. No. 2 oil is added as a frother at 5g / t, 4g / t, and 3g / t, respectively.

[0043] The middlings and scavenging concentrate were combined and refracted through an isobutyl xanthate mill. The grinding fineness was controlled to be -0.038mm, accounting for 89.46%. The roughing was carried out with a combination collector of isobutyl xanthate / ammonium phosphate (ABMP) at 10 / 2.5g / t and No. 2 oil at 2.5g / t. The rough concentrate was cleaned twice without any reagents. The tailings from the roughing were scavenged three times, with different amounts of collector added each time: 10 / 3 / 3g / t, 9 / 3 / 3g / t, and 6 / 2 / 2g / t of the combination collector of isobutyl xanthate / ammonium phosphate (ABMP), and No. 2 oil was added as a frother at 2.5g / t, 2g / t, and 2g / t, respectively.

[0044] The experimental results are shown in Table 2. As can be seen from Table 2, after a process of roughing, cleaning, and scavenging followed by middlings regrinding and re-concentration, a gold concentrate containing 22.65 g / t of gold and 2.75% of arsenic can be obtained, with a gold recovery rate of 85.77%. This demonstrates that the process of this invention can efficiently recover gold. Compared with the original process, the gold recovery rate is increased by 3.29%, energy consumption per ton of ore is reduced by approximately 17%, and reagent costs are saved by approximately 28%.

[0045] Table 2. Experimental Results of Example 1

[0046]

[0047] *g / t

[0048] Example 2

[0049] The copper-zinc separation of the above-mentioned ore using the method of the present invention with isobutyl xanthate / MC combined collector is as follows:

[0050] The ore is first ground, and the grinding fineness is controlled to be 73.75% of -0.074 mm, then flotation is carried out, lime is added to adjust the ore pulp potential to 200-220 mV (corresponding to pH 8), isobutyl xanthate / MC is used as a combined collector, the dosage is 45 / 15 g / t, and 2# oil is added at 15 g / t; the rough concentrate is subjected to one-time cleaning, and no any reagent is added; the cleaning is strengthened, and the roughing tailings are subjected to three times of scavenging, different dosages of the collector are added each time, which are 30 / 10 g / t, 24 / 8 g / t and 18 / 6 g / t of isobutyl xanthate / MC combined collector respectively, and 2# oil is added as a foaming agent, which is 7.5 g / t, 5 g / t and 3 g / t respectively.

[0051] The middlings in the cleaning and the scavenging concentrate are combined, ground again by the Aishajia sand, and then reselected, the grinding fineness is controlled to be 89.46% of -0.038 mm, in the reselection step, isobutyl xanthate / MC combined collector is added in roughing, which is 10 / 2.5 g / t, 2# oil is added at 3 g / t; the rough concentrate is subjected to two-time cleaning, and no any reagent is added; the roughing tailings are subjected to three times of scavenging, different dosages of the collector are added each time, which are 10 / 3 g / t, 9 / 3 g / t and 6 / 2 g / t of isobutyl xanthate / MC combined collector respectively, and 2# oil is added as a foaming agent, which is 3 g / t, 2 g / t and 2 g / t respectively.

[0052] The test results are shown in Table 3, and it can be known from the test results in Table 3 that, after the middlings are ground again and reselected by the one roughing+one cleaning+three scavenging process, a gold concentrate containing 22.34 g / t of gold and 2.69% of arsenic can be obtained, the gold recovery rate is 86.43%, and thus gold can be efficiently recovered, and compared with the original process, the gold recovery rate is increased by 3.95%, the energy consumption per ton of ore is reduced by about 17%, and the reagent cost is saved by about 21%.

[0053] Table 3 Test results of Example 2

[0054]

[0055] *g / t

[0056] As described above, the present application can be better realized. The above examples are only the best mode of the present application, but the embodiments of the present application are not limited by the above examples, and other changes, modifications, replacements, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement modes, and all are included in the protection scope of the present application.

Claims

1. A high-efficiency beneficiation method for arsenic-containing low-grade fine-grained disseminated gold ore, characterized in that The lime is used to control the ore slurry potential, no activator is added, the one-stage coarse grinding + middling regrinding and reselection process is used to realize the efficient recovery of low-grade fine gold ore, and the process steps and conditions are as follows: (1) grinding, the ore is ground, the grinding fineness is controlled to be 70-75% of-0.074 mm, the lime is used for slurry conditioning, the ore slurry potential is controlled to be 200-250 mV, the corresponding pH value is 7.5-8.5, no activator is added, the isobutyl xanthate + butylamine black medicine combination or the isobutyl xanthate + MC combination is used as the collector, the 2# oil is used as the frother for roughing, the roughing froth is subjected to cleaning, the cleaning middling and the gold concentrate I are obtained; (2) the intensified scavenging, the isobutyl xanthate + amyl xanthate + butylamine black medicine combination or the isobutyl xanthate + MC combination is added as the collector, the 2# oil is used as the frother for 3 times of intensified scavenging, the scavenging concentrate and the tailings are obtained; (3) regrinding and reselection, the cleaning middling and the scavenging concentrate are combined to be subjected to regrinding and reselection, the Ei sand mill is used as the regrinding equipment, the narrow particle size ultrafine grinding equipment without the classification equipment is configured, the grinding fineness is controlled to be 85-90% of-0.038 mm, the gold concentrate II is obtained after the regrinding and reselection, and the gold concentrate I and the gold concentrate II are combined as the final concentrate.

2. The method of claim 1, wherein In the step (2), the isobutyl xanthate + amyl xanthate + butylamine black medicine combination or the isobutyl xanthate + MC combination is added as the collector before the scavenging, and the 2# oil is used as the frother.

3. The method of claim 1, wherein In the step (3), the Ei sand mill is selected as the regrinding equipment, no sludge dispersant is added, the narrow particle size grinding can be realized, the overground sludge phenomenon is reduced, the influence of the overground sludge on the flotation index is reduced, the beneficiation index is effectively improved, and the fine tailings particles are beneficial to the settlement.

4. The method of claim 1, wherein In the step (1), the flotation process after the grinding is the "one roughing + one cleaning + three scavenging" open circuit process, and the cleaning middling and the scavenging concentrate are combined to enter the Ei sand mill for regrinding.

5. The method of claim 1 or 3 or 4, characterized in that In the step (3), the flotation process after the regrinding is the "one roughing + two cleanings + three scavengings" closed circuit process, and the cleaning middling and the scavenging concentrate are sequentially returned.

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