Comprehensive recovery system for valuable components of arsenic-containing gold pyrite

Abstract

The utility model relates to a comprehensive recovery system for valuable components of arsenic-containing gold pyrite, which comprises an air flow classifier, a fine powder discharge port of the air flow classifier is connected to a 1 # microwave oven, a coarse powder discharge port of the air flow classifier is connected to a 2 # microwave oven, the 1 # microwave oven and the 2 # microwave oven are sequentially connected to a high-temperature oxidation rinsing tank and a 1 # filter, and the 1 # filter is connected to a high-temperature oxidation rinsing tank. A filtrate port of the 1 # filter is connected to the copper recovery system, a filter residue port of the 1 # filter is sequentially connected to the alkaline leaching pretreatment tank and the 2 # filter, a filtrate port of the 2 # filter is connected to the arsenic removal system, and a filter residue port of the 2 # filter is connected to the carbon leaching method gold and silver extraction system. The comprehensive utilization of valuable components of the arsenic-containing gold pyrite can be efficiently realized, high-quality iron ore concentrate can be obtained, the comprehensive recovery processing capacity is strong, the production index is stable, the comprehensive recovery processing device can be widely used for comprehensive recovery processing of ores such as arsenic-containing wrapped pyrite, sulfur concentrate, iron ore concentrate and gold concentrate, and the comprehensive recovery processing device has important industrial popularization and application values.

Description

Technical Field

[0001] The utility model belongs to the technical field of metallurgy, and in particular relates to a comprehensive recovery system for valuable components of arsenic-gold pyrite. Background Art

[0002] As the grade of gold ore in mines continues to decline, low-grade, difficult-to-process gold ores have gradually become a hot topic of research in the gold industry. Encapsulated gold ores are the most common type of difficult-to-process gold ore. In this type of ore, gold is often encapsulated in sulfide minerals as fine impregnations, resulting in low cyanide leaching rates. Furthermore, the ore contains other metals, resulting in an extremely complex distribution pattern, making its comprehensive development and utilization a challenge for the industry. When gold coexists with non-ferrous metals such as copper, leaching significantly increases cyanide consumption, resulting in high production costs and low recovery rates. Furthermore, arsenic in the ore often exists as an isomorphous substance within the pyrite crystal structure, making it difficult to remove. This seriously affects the quality of the subsequent iron ore concentrate and poses safety risks.

[0003] Therefore, in recent years, extensive and in-depth research has been conducted both domestically and internationally on pretreatment technologies for refractory gold ores containing finely encapsulated arsenic. Currently, several pretreatment methods exist, including oxidative roasting, pressure oxidation, and biological oxidation. While these techniques differ, they all aim to break open minerals like pyrite and arsenopyrite, exposing the gold and thereby increasing its leaching rate.

[0004] The biological oxidation method uses certain sulfur-iron oxidizing microorganisms to decompose oxidized minerals, thereby improving the recovery of encapsulated difficult-to-treat minerals. It has the advantages of low equipment cost, no arsenic-containing flue gas and good mineral treatment effect. However, this method has low treatment efficiency, especially for minerals with low arsenic content, the oxidation and decomposition rate is slow, which restricts its further development.

[0005] The pressure oxidation method dissociates sulfide minerals under high temperature and high pressure conditions, exposing the encapsulated gold particles, thereby achieving the purpose of improving gold recovery. It has the advantages of high recovery rate and stable leaching residue. However, this method requires extremely high equipment investment and high production costs, and basic research on pressure oxidation is relatively lacking.

[0006] While the widely used oxidation roasting method boasts mature technology and high throughput, it also suffers from high energy consumption, unstable slag, and susceptibility to sintering. Metal recovery is particularly low for fine-grained ores and those coated with multiple metals. Amidst resource constraints and increasingly challenging environmental conditions, this process has also encountered several urgent challenges with arsenic-gold coated pyrite ores, including the following:

[0007] (1) Fine-grained minerals are easily sintered, resulting in low recovery rates of valuable metals.

[0008] (2) The arsenic in pyrite is partially present in the form of a homogeneous species in the pyrite crystals, and some is present in arsenopyrite. Most of the arsenopyrite exists in the form of a single substance, a small part is associated with or encapsulated by pyrite, and a small part is encapsulated by gangue. During the roasting process, the arsenic originally present in the pyrite crystals is converted into ferric arsenate and encapsulated by the generated iron oxide. The arsenic in the arsenopyrite is partially converted into arsenic trioxide, and some is converted into ferric arsenate and encapsulated by iron oxide and gangue. The encapsulated arsenic is difficult to remove, seriously affecting the quality of the subsequent iron concentrate.

[0009] (3) Poor adaptability, poor processing effect on fine particles and encapsulated ores, seriously affecting the recovery of valuable metals.

[0010] Based on the above problems, the utility model proposes a comprehensive recovery system for valuable components of arsenic-gold pyrite to overcome the current shortcomings and problems, improve the recovery rate of valuable components in difficult-to-treat minerals, realize comprehensive utilization of resources, and enhance the economic and social benefits of the enterprise. Utility Model Content

[0011] In view of the above problems, the utility model provides a comprehensive recovery system for valuable components of arsenic-containing gold pyrite.

[0012] The specific technical solution is: a comprehensive recovery system for valuable components of arsenic-containing gold pyrite, including an air flow classifier, the fine powder discharge outlet of the air flow classifier is connected to a No. 1 microwave oven, the coarse powder discharge outlet of the air flow classifier is connected to a No. 2 microwave oven, the No. 1 microwave oven and the No. 2 microwave oven are connected to a high-temperature oxidation rinsing tank and a No. 1 filter in sequence, the filtrate outlet of the No. 1 filter is connected to a copper recovery system, the filter residue outlet of the No. 1 filter is connected to an alkaline leaching pretreatment tank and a No. 2 filter in sequence, the filtrate outlet of the No. 2 filter is connected to an arsenic removal system, and the filter residue outlet of the No. 2 filter is connected to a carbon-based leaching system for gold and silver extraction.

[0013] The beneficial effects of this utility model are as follows: Based on the differences in the ignition points of pyrites of different particle sizes, this utility model first separates the material into different particle sizes through an airflow classifier and matches the corresponding microwave roasting conditions. This prevents sintering of the fine particles while allowing the sulfur and arsenic with higher dielectric constants to be burned and volatilized first, creating a large number of cavities and cracks. The ore is then rinsed in a high-temperature oxidation rinsing tank to break up and dissociate the ore, fully exposing the encapsulated gold particles, thereby improving the gold recovery rate. Subsequently, valuable components such as copper, gold, and silver are recovered through a copper recovery system, an alkaline leaching pretreatment tank, and a carbon-based leaching system.

[0014] Through application examples, it can be seen that the utility model can efficiently realize the comprehensive utilization of valuable components of arsenic-containing gold pyrite, with the recovery rates of gold, silver and sulfur reaching more than 90%, and the copper recovery rate also reaching 86%. In addition, high-quality iron concentrate can be obtained, with strong comprehensive recovery and processing capabilities and stable production indicators. It can be widely used in the comprehensive recovery and processing of ores such as arsenic-encapsulated pyrite, sulfur concentrate, iron concentrate and gold concentrate, and has important industrial promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the equipment association diagram of the utility model;

[0016] In the figure: 1-air flow classifier, 2-1# microwave oven, 3-2# microwave oven, 4-high temperature oxidation rinsing tank, 5-1# filter, 6-copper recovery system, 7-alkaline leaching pretreatment tank, 8-2# filter, 9-arsenic removal system, 10-carbon leaching gold and silver extraction system. DETAILED DESCRIPTION

[0017] In order to make the technical problems and technical solutions solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0018] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention.

[0019] It should also be noted that, in the description of this utility model, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on the specific circumstances.

[0020] like Figure 1As shown, the present application provides a comprehensive recovery system for valuable components of arsenic-containing gold pyrite, comprising an airflow classifier 1, the fine powder outlet of the airflow classifier 1 being connected to a #1 microwave oven 2, the coarse powder outlet of the airflow classifier 1 being connected to a #2 microwave oven 3, the #1 microwave oven 2 and the #2 microwave oven 3 being sequentially connected to a high-temperature oxidation rinsing tank 4 and a #1 filter 5, the filtrate outlet of the #1 filter 5 being connected to a copper recovery system 6, the residue outlet of the #1 filter 5 being sequentially connected to an alkaline leaching pretreatment tank 7 and a #2 filter 8, the filtrate outlet of the #2 filter 8 being connected to an arsenic removal system 9, and the residue outlet of the #2 filter 8 being connected to a carbon-based leaching gold and silver extraction system 10. These devices are all existing devices, and this application only relates to the use of these existing devices, and does not relate to improvements to these devices.

[0021] Working Principle: Arsenic-gold pyrite is transported to air classifier 1 for classification, separating the ore into particle sizes of -0.074mm to +0.025mm and -0.025mm. The -0.025mm particle size is then transported to microwave oven 1 for roasting, while the -0.074mm to +0.025mm particle size is transported to microwave oven 2 for roasting. The roasting conditions in both microwave ovens are appropriately set based on the particle size to prevent sintering of fine particles. In principle, larger particles are roasted at higher temperatures and for longer times. After roasting, slag and sulfur dioxide flue gas are produced (which can be used to produce sulfuric acid).

[0022] The calcined slag is then transferred to a high-temperature oxidation rinsing tank 4 for rinsing. This rinsing process involves adding a clear liquid to the high-temperature calcined slag (300-400°C), causing it to cool rapidly, generating significant structural stress and breaking it into fine particles. This breaks the slag apart, fully dissociating the sulfide minerals and exposing the encapsulated gold particles. After rinsing, the material is transferred to filter #1 5 for filtration, yielding the rinsing slag and rinsing liquid.

[0023] The rinse liquid is then transported to the copper recovery system 6 to recover copper, and a copper precipitant (sodium hydrosulfide is used, and the amount is added is 1.2 times the theoretically calculated amount). After stirring and slurrying for 30 minutes, it is filtered to obtain a copper product and waste liquid, and the waste liquid is sent to the waste liquid treatment system; the rinse residue is transported to the alkaline leaching pretreatment tank 7 for alkaline leaching pretreatment, and sodium hydroxide and sodium sulfide are added to leach most of the arsenic in the rinse residue. The residue is filtered through the second filter 8 to obtain alkaline leaching residue with extremely low arsenic content and arsenic-containing alkaline leaching liquid. The arsenic-containing alkaline leaching liquid is transported to the arsenic removal system 9 to achieve the purpose of improving the quality of the iron ore concentrate.

[0024] Finally, the obtained alkaline leaching residue is transported to the carbon-based leaching system 10 for gold and silver extraction, where activated carbon and sodium cyanide are added for leaching to obtain gold-loaded activated carbon and high-quality iron ore concentrate.

[0025] Application Example 1

[0026] Raw material 1#: an arsenic-gold pyrite, the valuable elements of which are mainly Au, Ag, Fe, Cu and S, with grades of 2.29g / t, 26.04g / t, 40.35%, 0.11% and 45.25% respectively; the harmful element is mainly arsenic, with a grade of 0.21%; the gold in the pyrite is mainly present in the form of gold inclusions, accounting for 56.6%, of which metal sulfide inclusions account for 51.95% and gangue inclusions account for 4.65%; silver is mainly present in the form of silver inclusions, accounting for 79.80%; iron is mainly present in the form of pyrite and pyrrhotite, accounting for 85.55%, followed by hematite and magnetite; copper is present in the form of chalcopyrite; arsenic is mainly present in pyrite and arsenopyrite; the gangue minerals are mainly quartz and feldspar.

[0027] like Figure 1 As shown, the utility model is used to implement the arsenic-containing gold pyrite, and the specific treatment process is as follows:

[0028] (1) Classification of materials to be processed: The materials to be processed are transported to the air classifier 1 for classification to obtain ore materials with particle sizes of -0.074 mm to +0.025 mm and -0.025 mm;

[0029] (2) Microwave roasting: The -0.025 mm particle size ore obtained in step (1) is transported to microwave oven 1#2 for roasting, and the -0.074 mm to +0.025 mm particle size ore is transported to microwave oven 2#3 for roasting, wherein the roasting temperature of the -0.074 mm to +0.025 mm particle size ore is 550 to 680 ° C, and the roasting time is 2 to 3 h, and the roasting temperature of the -0.025 mm particle size ore is 450 to 500 ° C, and the roasting time is 1 to 2 h. After roasting the two particle size ore materials, roasting slag and sulfur dioxide flue gas (for making sulfuric acid) are obtained;

[0030] (3) High-temperature oxidation rinsing of calcined slag: The calcined slag obtained in step (2) at a temperature of 300-400°C is transported to a high-temperature oxidation rinsing tank 4 for rinsing. During rinsing, the liquid-to-solid ratio is 2.5:1, and the slurry mixing time is 20-30 minutes. During rinsing, 0.8-1 kg / t of manganese dioxide is added to convert the residual iron sulfide and silver sulfide into oxides, and to convert divalent iron into trivalent iron precipitation. After the manganese dioxide reaction, sodium hydroxide is added to adjust the pH value of the rinsing liquid to 3-5.4. Then, the rinsing slag and rinsing liquid are obtained by filtering through the No. 1 filter 5.

[0031] (4) Recovering copper from the rinse liquid: The rinse liquid obtained in step (3) is transported to the copper recovery system 6, and a copper precipitant (sodium hydrosulfide, the amount of which is 1.1 to 1.2 times the theoretical amount) is added. The mixture is stirred and slurried for 30 minutes and then filtered to obtain a copper product and waste liquid, which is then transported to the waste liquid treatment system;

[0032] (5) Alkali leaching pretreatment of rinse residue: The rinse residue obtained in step (3) is transported to an alkaline leaching pretreatment tank 7, 15-20 kg / t of sodium hydroxide and 1-2 kg / t of sodium sulfide are added, the liquid-to-solid ratio is 1.5:1, the temperature is 70°C, the leaching time is 2-3 h, and the alkali leaching residue and arsenic-containing alkaline leaching liquid with extremely low arsenic content are filtered through a No. 2 filter 8, and the arsenic-containing alkaline leaching liquid is transported to an arsenic removal system 9;

[0033] (6) Extracting gold and silver by carbon-based leaching of alkali leaching residue: The alkali leaching residue obtained in step (5) is transported to a carbon-based leaching system 10 for extracting gold and silver. When extracting gold and silver by carbon-based leaching, the liquid-solid ratio is 2:1, the pH value is controlled at 10.5-11.5, the free cyanide concentration in the pulp is adjusted to 0.6‰-1‰ with sodium cyanide, the activated carbon concentration is 15-30 g / L, and the leaching time is 32 h to obtain gold-loaded activated carbon and high-quality iron ore concentrate.

[0034] The above treatment process was applied to raw material 1#, and the test results obtained were: gold recovery rate reached 92.45%, silver recovery rate reached 90.52%, sulfur recovery rate reached 99.2%, and copper recovery rate reached 86.23%; high-quality iron ore was obtained with a grade of 64.23%, arsenic content reduced to 0.018%, and iron recovery rate reached 96.12%.

[0035] Application Example 2

[0036] Raw material 2#: an arsenic-gold pyrite, the valuable elements of which are mainly Au, Ag, Fe, Cu and S, with grades of 2.18g / t, 25.34g / t, 41.05%, 0.12% and 45.15% respectively; the harmful element is mainly arsenic, with a grade of 0.23%; the gold in the pyrite is mainly present in the form of gold inclusions, accounting for 57.5%, of which metal sulfide inclusions account for 52.05% and gangue inclusions account for 5.45%; silver is mainly present in the form of silver inclusions, accounting for 79.76%; iron is mainly present in the form of pyrite and pyrrhotite, accounting for 86.15%, followed by hematite and magnetite; copper is present in the form of chalcopyrite; arsenic is mainly present in pyrite and arsenopyrite; the gangue minerals are mainly quartz and feldspar.

[0037] The treatment process described in Application Example 1 was applied to raw material 2#, and the test results were as follows: gold recovery rate reached 92.13%, silver recovery rate reached 90.24%, sulfur recovery rate reached 99.21%, and copper recovery rate reached 86.31%; high-quality iron ore was obtained with a grade of 64.34%, arsenic content reduced to 0.018%, and iron recovery rate reached 96.51%.

[0038] Application Example 3

[0039] Raw material 3#: an arsenic-gold pyrite, the valuable elements of which are mainly Au, Ag, Fe, Cu and S, with grades of 2.31g / t, 26.24g / t, 40.75%, 0.13% and 45.57% respectively; the harmful element is mainly arsenic, with a grade of 0.22%; gold in pyrite mainly exists in the form of gold inclusions, with a proportion of 56.7%, of which metal sulfide inclusions account for 51.87% and gangue inclusions account for 4.93%; silver mainly exists in the form of silver inclusions, with a proportion of 79.66%; iron mainly exists in the form of pyrite and pyrrhotite, with a proportion of 85.65%, followed by hematite and magnetite; copper exists in the form of chalcopyrite; arsenic mainly exists in pyrite and arsenopyrite; gangue minerals are mainly quartz and feldspar.

[0040] The treatment process described in Application Example 1 was applied to raw material 3#, and the test results were as follows: the gold recovery rate reached 92.46%, the silver recovery rate reached 90.43%, the sulfur recovery rate reached 99.36%, and the copper recovery rate reached 85.97%; high-quality iron ore was obtained with a grade of 64.23%, an arsenic content reduced to 0.019%, and an iron recovery rate of 96.48%.

[0041] Application Example 4

[0042] Raw material 4#: an arsenic-gold pyrite, the valuable elements of which are mainly Au, Ag, Fe, Cu and S, with grades of 2.33g / t, 25.97g / t, 41.05%, 0.11% and 45.47% respectively; the harmful element is mainly arsenic, with a grade of 0.22%; gold in the pyrite mainly exists in the form of gold inclusions, accounting for 57.1%, of which metal sulfide inclusions account for 51.65% and gangue inclusions account for 5.45%; silver mainly exists in the form of silver inclusions, accounting for 79.78%; iron mainly exists in the form of pyrite and pyrrhotite, accounting for 86.25%, followed by hematite and magnetite; copper exists in the form of chalcopyrite; arsenic mainly exists in pyrite and arsenopyrite; gangue minerals are mainly quartz and feldspar.

[0043] The treatment process described in Application Example 1 was applied to raw material 4#, and the test results were as follows: gold recovery rate reached 91.98%, silver recovery rate reached 90.54%, sulfur recovery rate reached 99.45%, and copper recovery rate reached 86.78%; high-quality iron ore was obtained with a grade of 64.35%, arsenic content reduced to 0.018%, and iron recovery rate reached 96.46%.

[0044] In summary, the system used to treat this type of arsenic-encapsulated gold-pyrite ore achieved gold recovery rates of 92%, silver recovery rates of 90%, sulfur recovery rates of 99%, and copper recovery rates of 86%. High-quality iron concentrate was obtained, with a grade of 64%, an arsenic content reduced to 0.019%, and an iron recovery rate of 96%. This system demonstrates its strong applicability and stable production performance, enabling efficient and comprehensive utilization of arsenic-encapsulated gold-pyrite ore. It can also be used for the comprehensive recovery and treatment of arsenic-encapsulated sulfur concentrate, iron concentrate, and gold concentrate, possessing significant industrial application value.

[0045] The present invention is described in detail above through specific and preferred embodiments, but those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A comprehensive recovery system for valuable components of arsenic-containing gold pyrite, characterized in that: The invention comprises an airflow classifier (1), wherein the fine powder discharge port of the airflow classifier (1) is connected to a No. 1 microwave oven (2), the coarse powder discharge port of the airflow classifier (1) is connected to a No. 2 microwave oven (3), the No. 1 microwave oven (2) and the No. 2 microwave oven (3) are connected in sequence to a high-temperature oxidation rinsing tank (4) and a No. 1 filter (5), the filtrate port of the No. 1 filter (5) is connected to a copper recovery system (6), the filter residue port of the No. 1 filter (5) is connected in sequence to an alkaline leaching pretreatment tank (7) and a No. 2 filter (8), the filtrate port of the No. 2 filter (8) is connected to an arsenic removal system (9), and the filter residue port of the No. 2 filter (8) is connected to a carbon-based leaching gold and silver extraction system (10).

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