Method for comprehensive recovery of valuable metals in roasting cyanide tailings

Abstract

This invention belongs to the field of metallurgical technology, specifically relating to a method for the comprehensive recovery of valuable metals from roasted cyanide tailings, comprising the following steps: S1, mixing roasted cyanide tailings with a binder; S2, pelletizing using a granulation device; S3, drying the pellets; S4, high-temperature reduction smelting; and S5, flotation of the smelting slag to obtain gold and silver enriched concentrates. This invention achieves efficient and comprehensive recovery of gold, silver, copper, lead, zinc, and iron from roasted cyanide tailings, improving resource utilization. The gold, silver, copper, and iron enriched products and the lead and zinc enriched products obtained by this invention are all high-value products that can be directly used as raw materials for copper and lead smelting, realizing the high-value utilization of roasted cyanide tailings. This invention is mainly applicable to industrial scenarios such as roasted cyanide tailings treatment, non-ferrous metal smelting, and iron concentrate production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metallurgy, and particularly relates to a method for comprehensively recovering valuable metals from roasting cyanidation tailings. BACKGROUND

[0002] Roasting cyanidation tailings are by-products in the production process of gold concentrate roasting cyanidation technology, and usually contain valuable metals such as gold, silver, copper, lead and zinc. However, due to the low content and high impurities, traditional treatment methods are difficult to achieve high-value utilization. At present, the treatment methods of roasting cyanidation tailings mainly include direct stacking, landfill or simple beneficiation, but these methods not only waste resources, but also may cause environmental pollution. In recent years, with the shortage of resources and the improvement of environmental protection requirements, the development of efficient and environmentally friendly roasting cyanidation tailings treatment technology has become a research hotspot.

[0003] In the prior art, the treatment methods of roasting cyanidation tailings mainly include wet leaching, pyrometallurgical smelting and beneficiation. Wet leaching extracts valuable metals through acid or alkali solution, but has problems such as large reagent consumption, difficult wastewater treatment, serious environmental pollution, etc.; pyrometallurgical smelting has high energy consumption, and the effect on low-grade roasting slag is poor and the adaptability is poor; although the beneficiation method can improve the iron grade, the recovery rate of precious metals such as gold and silver is low. In addition, part of the technology attempts to extract valuable metals by chlorination volatilization, but does not solve the optimization problem of roasting slag granulation and drying process, resulting in low volatilization efficiency. SUMMARY

[0004] The present application aims at the technical problems of low gold and silver content, high impurity content of copper, lead and zinc, and low iron grade in roasting cyanidation tailings, which are difficult to achieve high-value utilization of roasting cyanidation tailings, and provides a method for comprehensively recovering valuable metals from roasting cyanidation tailings.

[0005] The specific technical scheme is as follows: A method for comprehensively recovering valuable metals from roasting cyanidation tailings, comprising the following steps: S1, mixing roasting cyanidation tailings with a binder: uniformly mixing the roasting cyanidation tailings with the binder to obtain a mixture, and the mixture enters the next step; S2, pelletizing equipment produces pellets: the mixture is transported to the pelletizing equipment to produce pellets, and the pellets enter the next step; S3, drying of pellet material: the pellets with water content greater than 10wt% are dried to a water content less than 10wt%, and the dried pellets enter the next step; S4, high-temperature reduction smelting: the dried pellets, coke, lime and fluorite are sent into a direct current arc smelting furnace for high-temperature reduction smelting; the furnace gas is sent to a dust extraction and removal device to collect volatile products to obtain a lead-zinc enriched product, a gold-silver-copper-iron enriched product is produced at the bottom of the direct current arc smelting furnace, and a smelting furnace slag is produced at the top of the smelting furnace; the smelting furnace slag enters the next step; S5. Gold and silver enriched concentrate from flotation of smelting slag: Smelting slag enters the secondary grinding system for grinding. After grinding, the slurry concentration is adjusted. After one roughing and two cleaning processes, gold and silver enriched concentrate and flotation tailings are produced. The gold and silver enriched concentrate is returned to step S1, and the flotation tailings are used as raw materials for building materials or cement concrete production.

[0006] Furthermore, in step S1, the main components of the roasted cyanide tailings include: gold 3~8g / t, silver 10~30g / t, copper 0.4~0.80wt%, lead 0.50~1.50wt%, zinc 0.50~1.00wt%, and iron 25~45wt%.

[0007] Furthermore, in step S1, the binder is one or more of cellulose, bentonite, and water glass, and the amount of binder used is 2 to 6 wt% of the roasted cyanide tailings.

[0008] Furthermore, in step S2, pellets of 20-40mm are produced.

[0009] Furthermore, in step S3, the drying temperature is 350~450℃ and the drying time is 120~240min.

[0010] Furthermore, in step S4, the amount of coke used is 60~120kg / t, the amount of lime used is 100~200kg / t, and the amount of fluorite used is 60~100kg / t.

[0011] Furthermore, in step S4, the melting temperature is 1300~1500℃ and the melting time is 120~240min.

[0012] Furthermore, in step S4, the lead-zinc enriched product contains 30-40 wt% lead and 30-40 wt% zinc; the gold-silver-copper-iron enriched product contains 20-60 g / t gold, 50-150 g / t silver, 2.0-4.0 wt% copper, 0.02-0.04 wt% lead, 0.02-0.04 wt% zinc, and 85-95 wt% iron; the smelting slag contains 0.30-0.50 g / t gold, 3-5.0 g / t silver, 0.02-0.04 wt% copper, 0.01-0.02 wt% lead, 0.01-0.02 wt% zinc, and 5-10 wt% iron.

[0013] Furthermore, in step S5, the grinding concentration is controlled at 50-60 wt%, and the grinding fineness is -0.074 mm, accounting for 80-90 wt%.

[0014] Furthermore, in step S5, the pulp concentration is adjusted to 30-40 wt% after grinding.

[0015] Furthermore, in step S5, during the flotation process, the amount of water glass used is 1000~2000g / t, the amount of butyl xanthate used is 600~1000g / t, the amount of 25# black powder used is 100~200g / t, and the amount of 2# oil used is 50~100g / t.

[0016] Furthermore, in step S5, the gold-silver enriched concentrate contains 6-8 g / t of gold and 10-60 g / t of silver; the flotation tailings contain 0.10-0.15 g / t of gold and 1.0-1.5 g / t of silver.

[0017] Further, in step S1, a roller mill is used to mix the materials evenly; in step S2, the granulation equipment for pellet preparation is an HX400-4 briquetting machine or granulator, which mixes the roasted cyanide tailings with the binder to form pellets; in step S3, the drying equipment is a rotary kiln or fluidized bed dryer, used to dry the pelletized material to a moisture content of less than 10%, and microwave drying can also be used to improve drying efficiency and reduce energy consumption; in step S4, a DC arc furnace is used for high-temperature reduction smelting to produce high-value gold, silver, copper, and iron concentrates, enriched lead and zinc dust and smelting slag; in step S5, the grinding equipment is a ball mill or vertical mill, used to grind the smelting slag; in the primary roughing and secondary cleaning processes, a flotation system is used to recover gold and silver; and a DC arc furnace in the pyrometallurgical smelting system is used to comprehensively recover the minerals after gold and silver extraction.

[0018] This invention addresses the technical challenge of high-value utilization of roasted cyanide tailings due to their low gold and silver content, high copper, lead, and zinc content, and low iron grade. The invention involves adding a binder to the roasted cyanide tailings, mixing them in a roller mill, and then forming pellets on a briquetting machine. The pellets are then dried to less than 10% moisture content, mixed with coke, lime, and fluorite, and fed into a DC electric arc furnace for high-temperature reduction smelting. This produces enriched gold, silver, copper, and iron products, enriched lead and zinc products, and smelting slag. The smelting slag is then used for grinding and flotation to recover gold and silver, yielding a gold and silver enriched concentrate. This concentrate is returned to the smelting process, while the flotation tailings are used for building materials or as raw materials for cement and concrete production. This invention achieves comprehensive recovery of gold, silver, copper, zinc, lead, and iron from roasted cyanide tailings.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention achieves efficient and comprehensive recovery of gold, silver, copper, lead, zinc and iron from roasted cyanide tailings, thereby improving resource utilization. (2) The present invention significantly improves the recovery rate and enrichment of valuable metals through high-temperature reduction smelting process; (3) The gold, silver, copper and iron enriched products and lead and zinc enriched products obtained by this invention are all high-value products that can be directly used as raw materials for copper smelting and lead smelting, realizing the high-value utilization of roasted cyanide tailings. (4) The present invention optimizes the preparation and drying processes of pellets, improves the efficiency of high-temperature reduction smelting, and reduces energy consumption and production costs; (5) This invention is mainly applicable to industrial scenarios such as roasting cyanide tailings treatment, non-ferrous metal smelting, and iron concentrate production. Detailed Implementation

[0020] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0021] Example 1 A method for comprehensive recovery of valuable metals from roasted cyanide tailings includes the following steps: S1. Mixing roasted cyanide tailings and binder in proportion: Mix roasted cyanide tailings and binder. The main components of roasted cyanide tailings include: gold 3g / t, silver 10g / t, copper 0.4wt%, lead 0.50wt%, zinc 0.50wt%, and iron 25wt%. Use cellulose as binder, with the amount of binder being 2wt% of the roasted cyanide tailings. Use a roller mill to mix the materials evenly to obtain a mixture, which will then proceed to the next step. S2, Pelletizing: The mixture is transported to the HX400-4 briquetting machine to produce 20mm pellets, which then proceed to the next step; S3. Drying the pellet material to a moisture content of less than 10 wt%: The pellets with a moisture content of more than 10 wt% are transported to a drying rotary kiln, where the drying temperature is 350℃ and the drying time is 120 min. The dried pellets then proceed to the next step. S4. High-temperature reduction smelting: The dried pellets, coke, lime, and fluorite are fed into a DC electric arc furnace. The coke dosage is 60 kg / t, the lime dosage is 100 kg / t, and the fluorite dosage is 60 kg / t. The smelting temperature is 1300℃ and the time is 120 min. The produced furnace gas enters the dust extraction and dust removal device to collect the volatile products and obtain lead-zinc enriched products. The bottom layer of the DC electric arc furnace produces gold, silver, copper, and iron enriched products, and the top layer of the furnace produces smelting slag. The lead-zinc enriched product contains 30 wt% lead and 30 wt% zinc; the gold-silver-copper-iron enriched product contains 20 g / t gold, 50 g / t silver, 2.0 wt% copper, 0.02 wt% lead, 0.02 wt% zinc, and 85 wt% iron; the smelting slag contains 0.30 g / t gold, 3 g / t silver, 0.02 wt% copper, 0.01 wt% lead, 0.01 wt% zinc, and 5 wt% iron. The smelting slag will proceed to the next step. S5. Gold and silver enriched concentrate from smelting slag flotation: Smelting slag enters the secondary grinding system, with the grinding concentration controlled at 50 wt% and the grinding fineness at -0.074 mm accounting for 80 wt%. After grinding, the pulp concentration is adjusted to 30 wt% for flotation. The dosage of water glass is 1000 g / t, butyl xanthate is 600 g / t, No. 25 black reagent is 100 g / t, and No. 2 oil is 50 g / t. After one roughing and two cleaning processes, gold and silver enriched concentrate and flotation tailings are produced. The gold and silver enriched concentrate contains 6 g / t of gold and 10 g / t of silver, and returns to step S1. The flotation tailings contain 0.10 g / t of gold and 1.0 g / t of silver, which can be used as raw materials for building materials or cement concrete production.

[0022] Example 2 A method for comprehensive recovery of valuable metals from roasted cyanide tailings includes the following steps: S1. Mixing roasted cyanide tailings and binder in proportion: Mix roasted cyanide tailings and binder. The main components of roasted cyanide tailings include: gold 5.5g / t, silver 20g / t, copper 0.60wt%, lead 1.00wt%, zinc 0.75wt%, and iron 35wt%. Bentonite is used as binder, and the amount of binder is 4wt% of roasted cyanide tailings. The materials are mixed evenly using a roller mill to obtain a mixture, which proceeds to the next step. S2, Pelletizing: The mixture is transported to the HX400-4 briquetting machine to produce 30mm pellets, which then proceed to the next step; S3. Drying the pellet material to a moisture content of less than 10 wt%: The pellets with a moisture content of more than 10 wt% are transported to a drying rotary kiln, where the drying temperature is 400℃ and the drying time is 180 min. The dried pellets then proceed to the next step. S4. High-Temperature Reduction Smelting: Dry pellets, coke, lime, and fluorite are fed into a DC electric arc furnace. The coke dosage is 90 kg / t, lime dosage is 150 kg / t, and fluorite dosage is 80 kg / t. The smelting temperature is 1400℃, and the time is 180 min. The produced furnace gas enters a dust extraction and removal device to collect volatile products, obtaining lead-zinc enriched products. Gold, silver, copper, and iron enriched products are produced at the bottom of the DC electric arc furnace, while smelting slag is produced at the top. Lead-zinc enrichment... The product contains 35wt% lead and 35wt% zinc; the gold, silver, copper, and iron enriched product contains 40g / t gold, 100g / t silver, 3.0wt% copper, 0.03wt% lead, 0.03wt% zinc, and 90wt% iron; the smelting slag contains 0.40g / t gold, 4.0g / t silver, 0.03wt% copper, 0.015wt% lead, 0.015wt% zinc, and 7.5wt% iron. The smelting slag will proceed to the next step. S5. Gold and silver enriched concentrate from smelting slag flotation: Smelting slag enters the secondary grinding system, with the grinding concentration controlled at 55 wt% and the grinding fineness at -0.074 mm accounting for 85 wt%. After grinding, the pulp concentration is adjusted to 35 wt% for flotation. The dosage of water glass is 1500 g / t, butyl xanthate is 800 g / t, No. 25 black reagent is 150 g / t, and No. 2 oil is 75 g / t. After one roughing and two cleaning processes, gold and silver enriched concentrate and flotation tailings are produced. The gold and silver enriched concentrate contains 7 g / t of gold and 35 g / t of silver, and returns to step S1. The flotation tailings contain 0.12 g / t of gold and 1.2 g / t of silver, which can be used as raw materials for building materials or cement concrete production.

[0023] Example 3 A method for comprehensive recovery of valuable metals from roasted cyanide tailings includes the following steps: S1. Mixing roasted cyanide tailings and binder in proportion: Mix roasted cyanide tailings and binder. The main components of roasted cyanide tailings include: gold 8g / t, silver 30g / t, copper 0.80wt%, lead 1.50wt%, zinc 1.00wt%, and iron 45wt%. Water glass is used as binder, and the amount of binder is 6wt% of the roasted cyanide tailings. The materials are mixed evenly using a roller mill to obtain a mixture, which proceeds to the next step. S2, Pelletizing: The mixture is transported to the HX400-4 briquetting machine to produce 40mm pellets, which then proceed to the next step; S3. Dry the pellet material to a moisture content of less than 10 wt%: The pellets with a moisture content of more than 10 wt% are transported to a drying rotary kiln, dried at a temperature of 450℃ for 240 minutes. The dried pellets then proceed to the next step.

[0024] S4. High-Temperature Reduction Smelting: Dry pellets, coke, lime, and fluorite are fed into a DC electric arc furnace. The coke dosage is 120 kg / t, the lime dosage is 200 kg / t, and the fluorite dosage is 100 kg / t. The smelting temperature is 1500℃, and the time is 240 min. The produced furnace gas enters a dust extraction and removal device to collect volatile products, obtaining lead-zinc enriched products. The bottom layer of the DC electric arc furnace produces gold, silver, copper, and iron enriched products, while the top layer produces smelting slag. The zinc-enriched product contains 40 wt% lead and 40 wt% zinc; the gold, silver, copper, and iron-enriched product contains 60 g / t gold, 150 g / t silver, 4.0 wt% copper, 0.04 wt% lead, 0.04 wt% zinc, and 95 wt% iron; the smelting slag contains 0.50 g / t gold, 5.0 g / t silver, 0.04 wt% copper, 0.02 wt% lead, 0.02 wt% zinc, and 10 wt% iron. The smelting slag will proceed to the next step. S5. Gold and silver enriched concentrate from smelting slag flotation: Smelting slag enters the secondary grinding system, with the grinding concentration controlled at 60 wt% and the grinding fineness (-0.074 mm) accounting for 90 wt%. After grinding, the pulp concentration is adjusted to 40 wt% for flotation. The dosage of water glass is 2000 g / t, butyl xanthate is 1000 g / t, No. 25 black reagent is 200 g / t, and No. 2 oil is 100 g / t. After one roughing and two cleaning processes, gold and silver enriched concentrate and flotation tailings are produced. The gold and silver enriched concentrate contains 8 g / t of gold and 60 g / t of silver, and returns to step S1. The flotation tailings contain 0.15 g / t of gold and 1.5 g / t of silver, which can be used as raw materials for building materials or cement concrete production.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for comprehensive recovery of valuable metals from roasted cyanide tailings, characterized in that, Includes the following steps: S1. Mixing roasted cyanide tailings with binder: Mix roasted cyanide tailings with binder evenly to obtain a mixture; S2. Pelletizing equipment: The mixture is transported to the pelletizing equipment to produce pellets; S3. Pellet drying: Dry the produced pellets with a moisture content greater than 10 wt% to a moisture content less than 10 wt%. S4. High-temperature reduction smelting: The dried pellets, coke, lime and fluorite are fed into a DC electric arc melting furnace for high-temperature reduction smelting. The produced furnace gas enters the dust extraction and dust removal device to collect the volatile products and obtain lead-zinc enriched products. The bottom layer of the DC electric arc melting furnace produces gold, silver, copper and iron enriched products, and the top layer of the melting furnace produces melting furnace slag. S5. Gold and silver enriched concentrate from flotation of smelting slag: Smelting slag enters the secondary grinding system for grinding. After grinding, the pulp concentration is adjusted. After one roughing and two cleaning processes, gold and silver enriched concentrate and flotation tailings are produced. The gold and silver enriched concentrate is returned to step S1.

2. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S1, the binder is one or more of cellulose, bentonite, and water glass, and the amount of binder used is 2 to 6 wt% of the calcined cyanide tailings.

3. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S3, the drying temperature is 350~450℃ and the drying time is 120~240min.

4. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S4, the amount of coke used is 60~120kg / t, the amount of lime used is 100~200kg / t, and the amount of fluorite used is 60~100kg / t.

5. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S4, the melting temperature is 1300~1500℃ and the melting time is 120~240min.

6. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S4, the lead-zinc enriched product contains 30-40 wt% lead and 30-40 wt% zinc; the gold-silver-copper-iron enriched product contains 20-60 g / t gold, 50-150 g / t silver, 2.0-4.0 wt% copper, 0.02-0.04 wt% lead, 0.02-0.04 wt% zinc, and 85-95 wt% iron; the smelting slag contains 0.30-0.50 g / t gold, 3-5.0 g / t silver, 0.02-0.04 wt% copper, 0.01-0.02 wt% lead, 0.01-0.02 wt% zinc, and 5-10 wt% iron.

7. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S5, the grinding concentration is controlled at 50-60 wt%, and the grinding fineness is -0.074 mm, accounting for 80-90 wt%.

8. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 7, characterized in that, In step S5, the pulp concentration is adjusted to 30-40 wt% after grinding.

9. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S5, during the flotation process, the amount of water glass used is 1000~2000g / t, the amount of butyl xanthate used is 600~1000g / t, the amount of No. 25 black powder used is 100~200g / t, and the amount of No. 2 oil used is 50~100g / t.

10. The method for comprehensive recovery of valuable metals from roasted cyanide tailings according to claim 1, characterized in that, In step S5, the gold-silver enriched concentrate contains 6-8 g / t of gold and 10-60 g / t of silver; the flotation tailings contain 0.10-0.15 g / t of gold and 1.0-1.5 g / t of silver.