Waste acid treatment system for oxidizing roasting pretreatment of gold-containing polymetallic sulfur concentrate

Abstract

The utility model relates to a gold-bearing polymetallic sulfur concentrate oxidizing roasting pretreatment waste acid treatment system which comprises a waste acid storage tank and a 1 # neutralization reaction tank connected with the waste acid storage tank, and a discharge port of the 1 # neutralization reaction tank is sequentially connected with a sedimentation tank, a 1 # filter press, a 1 # vulcanization reaction tank and a 2 # vulcanization reaction tank; a discharge port of the 1 # vulcanization reaction tank is sequentially connected with a 1 # thickener and a 2 # filter press, and an overflow port of the 1 # thickener and a filtrate port of the 2 # filter press are both connected to a feed port of the 2 # vulcanization reaction tank; a discharge port of the 2 # vulcanization reaction tank is sequentially connected with a 2 # thickener and a 3 # filter press, and an overflow port of the 2 # thickener and a filtrate port of the 3 # filter press are both connected to a feed port of the gypsum reaction tank; and a discharge hole of the gypsum reaction tank is connected with a fourth filter press, a second neutralization reaction tank and a fifth filter press. The system adopts a distributed vulcanization treatment process to separate copper and arsenic, the separation effect is stable, the removal rate is high, and the wastewater index can be effectively ensured to stably reach the standard.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrometallurgical flue gas waste acid treatment, in particular to a gold-containing polymetallic sulfur concentrate oxidation roasting pretreatment waste acid treatment system. Background Art

[0002] The waste acid after oxidation roasting pretreatment of polymetallic sulfur concentrate containing gold, silver, copper, sulfur, arsenic, fluorine, etc. will contain a large amount of copper, arsenic, iron and other metal elements, which need to be treated and discharged only after the indicators meet the requirements. Figure 2 As shown, waste acid can remove some heavy metal elements such as copper and arsenic after neutralization and sulfidation reactions, but the treatment effect on high-arsenic wastewater is poor, which can easily lead to unstable wastewater indicators and environmental risks. At the same time, valuable metals such as copper enter the arsenic slag and cannot be recovered, resulting in waste of resources. Utility Model Content

[0003] In view of the above problems, the utility model provides a waste acid treatment system for oxidation roasting pretreatment of gold-containing polymetallic sulphur concentrate.

[0004] The specific technical solution of the utility model is:

[0005] A system for treating waste acid from oxidation roasting pretreatment of gold-containing polymetallic sulfur concentrate, comprising a waste acid storage tank and a 1# neutralization reaction tank connected thereto, wherein the discharge port of the 1# neutralization reaction tank is sequentially connected to a sedimentation tank, a 1# filter press, a 1# sulfidation reaction tank, and a 2# sulfidation reaction tank;

[0006] The discharge port of the 1# vulcanization reaction tank is connected to the 1# thickener and the 2# filter press in sequence, the underflow port of the 1# thickener is connected to the feed port of the 2# filter press, and the overflow port of the 1# thickener and the filtrate port of the 2# filter press are both connected to the feed port of the 2# vulcanization reaction tank;

[0007] The discharge port of the 2# vulcanization reaction tank is connected to the 2# thickener and the 3# filter press in sequence, the underflow port of the 2# thickener is connected to the feed port of the 3# filter press, and the overflow port of the 2# thickener and the filtrate port of the 3# filter press are both connected to the feed port of the gypsum reaction tank;

[0008] The discharge port of the gypsum reaction tank is connected to a 4# filter press, the filtrate port of the 4# filter press is connected to a 2# neutralization reaction tank, and the discharge port of the 2# neutralization reaction tank is connected to a 5# filter press.

[0009] Furthermore, preferably, the feed ports of the 1# sulfidation reaction tank and the 2# sulfidation reaction tank are both connected to the discharge port of the sodium sulfide modulation tank.

[0010] Furthermore, preferably, the exhaust ports of the 1# neutralization reaction tank, the 1# sulfidation reaction tank and the 2# sulfidation reaction tank are all connected to the air inlet of the hydrogen sulfide absorption tower, and the air outlet of the hydrogen sulfide absorption tower is also connected to a pest removal tower.

[0011] The beneficial effects of the present utility model are as follows: the waste acid treatment system adopts a distributed sulfidation treatment process, utilizing the different chemical affinities between copper, arsenic and sulfur, and controlling the sulfidation reaction by adjusting parameters such as pH value, redox potential, and amount of sodium sulfide added, selectively sulfiding copper and arsenic, preferentially settling copper and then settling arsenic, and obtaining a filter cake mainly composed of copper sulfide. The separation effect is stable, the removal rate is high, and it can effectively ensure that the wastewater indicators are stable and meet the standards. Moreover, the separated copper and arsenic can effectively achieve resource recovery. At the same time, the addition of gypsum reaction and neutralization reaction after the sulfidation reaction can effectively filter the gypsum and neutralization residue in the waste acid, further purify the waste acid, and ensure that the effluent can be recycled. In addition, the system also adds a hydrogen sulfide absorption tower and a harm removal tower in the process to treat the hydrogen sulfide gas in the reaction process, effectively avoiding the occurrence of safety accidents caused by the leakage of toxic gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an equipment association diagram of a waste acid treatment system for oxidation roasting pretreatment of gold-containing polymetallic sulphur concentrate in the utility model;

[0013] Figure 2 This is the equipment association diagram of the traditional sulfidation waste acid treatment system;

[0014] In the figure: 1-waste acid storage tank, 2-1# neutralization reaction tank, 3-sedimentation tank, 4-1# filter press, 5-1# sulfidation reaction tank, 6-2# sulfidation reaction tank, 7-1# thickener, 8-2# filter press, 9-2# thickener, 10-3# filter press, 11-gypsum reaction tank, 12-4# filter press, 13-2# neutralization reaction tank, 14-5# filter press, 15-sodium sulfide preparation tank, 16-hydrogen sulfide absorption tower, 17-pest control tower. DETAILED DESCRIPTION

[0015] 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.

[0016] 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" and "outside" indicate orientations or positional relationships based on the orientations or positional relationships 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, and therefore should not be understood as a limitation on the present invention.

[0017] 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 can refer to fixed connections, detachable connections, or integrated connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication 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.

[0018] like Figure 1 As shown, a waste acid treatment system for oxidation roasting pretreatment of gold-containing polymetallic sulfur concentrate includes a waste acid storage tank 1 and a 1# neutralization reaction tank 2 connected thereto, wherein the discharge port of the 1# neutralization reaction tank 2 is sequentially connected to a sedimentation tank 3, a 1# filter press 4, a 1# sulfidation reaction tank 5 and a 2# sulfidation reaction tank 6;

[0019] The discharge port of the 1# vulcanization reaction tank 5 is connected to the 1# thickener 7 and the 2# filter press 8 in sequence, the underflow port of the 1# thickener 7 is connected to the feed port of the 2# filter press 8, and the overflow port of the 1# thickener 7 and the filtrate port of the 2# filter press 8 are both connected to the feed port of the 2# vulcanization reaction tank 6;

[0020] The discharge port of the 2# sulfidation reaction tank 6 is connected to the 2# thickener 9 and the 3# filter press 10 in sequence, the underflow port of the 2# thickener 9 is connected to the feed port of the 3# filter press 10, and the overflow port of the 2# thickener 9 and the filtrate port of the 3# filter press 10 are both connected to the feed port of the gypsum reaction tank 11;

[0021] The discharge port of the gypsum reaction tank 11 is connected to the 4# filter press 12 , the filtrate port of the 4# filter press 12 is connected to the 2# neutralization reaction tank 13 , and the discharge port of the 2# neutralization reaction tank 13 is connected to the 5# filter press 14 .

[0022] Working Principle: The waste acid generated by the oxidation roasting pretreatment of gold-containing polymetallic sulfur concentrate is collected in the waste acid storage tank 1. During treatment, it is transported to the 1# neutralization reaction tank 2 for neutralization reaction. It reacts with the added lime milk to neutralize the sulfuric acid in the waste acid and adjust the concentration of the waste acid to 5%. The specific reaction formula is:

[0023] Ca(OH)2+H2SO4→CaSO4+H2O

[0024] After the reaction is completed, it is transferred to the sedimentation tank 3 for precipitation, and then filtered through the 1# filter press 4. The filter residue is lime slag, and the filtrate enters the 1# sulfidation reaction tank 5 for primary sulfidation reaction, reacting with the added sodium sulfide solution to remove copper and precipitate some arsenic at the same time. The main reaction formula is:

[0025] Na2S+H2SO4→H2S↑+Na2SO4

[0026] Na2S+CuSO4→CuS↓+Na2SO4

[0027] HAsO2+Na2S+H2SO4→As2S3↓+Na2SO4+H2O

[0028] CuSO4+As2S3+H2O→CuS↓+H2SO4+HAsO2

[0029] The addition of sodium sulfide produces CuS and As2S3 precipitates. Subsequently, divalent copper undergoes a replacement reaction with As2S3. By adding an appropriate amount of sodium sulfide, copper is preferentially precipitated, achieving copper-arsenic separation. During the reaction, the primary sulfidation reaction temperature is controlled at around 50°C for 80 minutes, with waste heat steam providing heat. The amount of sodium sulfide added must be controlled, and the PRP (redox potential) of the primary sulfidation reaction liquid is tested to assess the effectiveness of copper and arsenic ion removal, allowing adjustments to be made to the sodium sulfide dosage. Simultaneously, the original waste acid solution is monitored, and sulfidation parameters are adjusted promptly if indicators change.

[0030] After the primary sulfidation reaction, the copper-rich slag is concentrated and filtered through the No. 1 thickener 7 and the No. 2 filter press 8 (the copper-rich slag can be transported to the smelting system for copper smelting). The overflow liquid of the No. 1 thickener 7 and the filtrate of the No. 2 filter press 8 enter the No. 2 sulfidation reaction tank 6 for secondary sulfidation reaction, reacting with the added excess sodium sulfide solution to remove arsenic. After the reaction, the arsenic-rich slag is concentrated and filtered through the 2# thickener 9 and the 3# filter press 10 (As2S3 arsenic trioxide product is produced after refining), and the overflow liquid of the 2# thickener 9 and the filtrate of the 3# filter press 10 enter the gypsum reaction tank 11 to react with the added lime milk to produce gypsum. After the reaction, the 4# filter press 12 is filtered to obtain gypsum (which can be sold to the outside), and the filtrate continues to enter the 2# neutralization reaction tank 13 to neutralize the added lime milk again. After the reaction, it is filtered through the 5# filter press to obtain neutralized slag (containing iron elements, which can be returned to the roasting system for recovery). The filtrate is the desalted water (which can be recycled after entering the desalination system for treatment).

[0031] Preferably, in order to facilitate the addition of appropriate sodium sulfide solution, the feed ports of the 1# sulfide reaction tank 5 and the 2# sulfide reaction tank 6 are both connected to the discharge port of the sodium sulfide modulation tank 15. The sodium sulfide solution can be prepared in the sodium sulfide modulation tank 15 and directly supplied to the two reaction tanks for use, and the amount of sodium sulfide added can be controlled in conjunction with a dosing metering pump.

[0032] Preferably, the exhaust ports of the 1# neutralization reaction tank 2, the 1# sulfidation reaction tank 5, and the 2# sulfidation reaction tank 6 are all connected to the air inlet of the hydrogen sulfide absorption tower 16, and the air outlet of the hydrogen sulfide absorption tower 16 is further connected to the harm removal tower 17. The hydrogen sulfide absorption tower 16 and the harm removal tower 17 can remove the hydrogen sulfide gas generated during the waste acid neutralization reaction and the sulfidation reaction, effectively preventing the occurrence of safety accidents caused by the leakage of toxic gases.

[0033] In summary, the waste acid treatment system adopts a distributed sulfidation process, taking advantage of the different chemical affinities between copper, arsenic, and sulfur. The sulfidation reaction is controlled by adjusting parameters such as pH value, redox potential, and the amount of sodium sulfide added. Copper and arsenic are selectively sulfided, with copper being preferentially precipitated before arsenic, resulting in a filter cake composed mainly of copper sulfide. The separation effect is stable and the removal rate is high, which can effectively ensure that wastewater indicators are consistently met. Moreover, the separated copper and arsenic can be effectively recycled. At the same time, the addition of gypsum reaction and neutralization reaction after the sulfidation reaction can effectively filter out gypsum and neutralization residue in the waste acid, further purify the waste acid, and ensure that the effluent can be recycled. In addition, the system also adds a hydrogen sulfide absorption tower and a harm removal tower to the process to treat the hydrogen sulfide gas during the reaction, effectively avoiding safety accidents caused by toxic gas leakage.

[0034] 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 waste acid treatment system for oxidation roasting pretreatment of gold-containing polymetallic sulphide concentrate, comprising a waste acid storage tank (1) and a 1# neutralization reaction tank (2) connected thereto, characterized in that: The discharge port of the 1# neutralization reaction tank (2) is sequentially connected to a sedimentation tank (3), a 1# filter press (4), a 1# sulfidation reaction tank (5) and a 2# sulfidation reaction tank (6); The discharge port of the 1# sulfidation reaction tank (5) is connected to the 1# thickener (7) and the 2# filter press (8) in sequence, the bottom flow port of the 1# thickener (7) is connected to the feed port of the 2# filter press (8), and the overflow port of the 1# thickener (7) and the filtrate port of the 2# filter press (8) are both connected to the feed port of the 2# sulfidation reaction tank (6); The discharge port of the 2# sulfidation reaction tank (6) is connected to the 2# thickener (9) and the 3# filter press (10) in sequence, the bottom flow port of the 2# thickener (9) is connected to the feed port of the 3# filter press (10), and the overflow port of the 2# thickener (9) and the filtrate port of the 3# filter press (10) are both connected to the feed port of the gypsum reaction tank (11); The discharge port of the gypsum reaction tank (11) is connected to a 4# filter press (12), the filtrate port of the 4# filter press (12) is connected to a 2# neutralization reaction tank (13), and the discharge port of the 2# neutralization reaction tank (13) is connected to a 5# filter press (14).

2. The system for treating waste acid from oxidation roasting pretreatment of gold-containing polymetallic sulphide concentrate according to claim 1, characterized in that: The feed ports of the 1# sulfidation reaction tank (5) and the 2# sulfidation reaction tank (6) are both connected to the discharge port of the sodium sulfide modulation tank (15).

3. The system for treating waste acid from oxidation roasting pretreatment of gold-containing polymetallic sulphide concentrate according to claim 1, characterized in that: The exhaust ports of the 1# neutralization reaction tank (2), the 1# sulfidation reaction tank (5) and the 2# sulfidation reaction tank (6) are all connected to the air inlet of the hydrogen sulfide absorption tower (16), and the air outlet of the hydrogen sulfide absorption tower (16) is also connected to the pest removal tower (17).

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