Large-scale industrial development method for low-grade complex secondary copper sulfide ore

Abstract

The invention relates to a large-scale industrial development method for low-grade complex secondary copper sulfide ore, and belongs to the field of mineral engineering. According to the method, ores with different clay contents are classified, raw ores of high-clay ores are directly heaped, the permeability of ore heaps is improved, low-clay ores are crushed and heaped, and the ore leaching rate is increased; aiming at the problem of high pyrite content, pile sealing is performed in advance to control pyrite oxidation, biological population regulation and control are performed to inhibit pyrite oxidation, a solution is reasonably dispatched to reduce acid, copper rainwater is discharged to the bottom of a mining pit to be stored, and after rainwater in the pit is diluted, the pH is increased, and Fe < 3 + > generates precipitate to settle at the bottom of the pit, so that the iron and acid reducing effect is achieved, and environmental protection accidents are reduced.

Description

Technical Field

[0001] The invention belongs to the field of mining engineering, and in particular relates to a large-scale industrial development method of secondary copper sulfide ore. Background Art

[0002] Secondary copper sulfide minerals include: chalcocite, blue chalcocite, covellite, bornite, etc. This type of copper mineral is often associated with a large amount of pyrite, and its treatment methods mainly include flotation and bio-heap leaching. For the flotation treatment method, the pyrite content and copper grade in the ore are key indicators. Generally, the process scheme of sulfur-suppressing copper flotation is adopted, among which the main factors affecting the copper-sulfur separation indicators are: pyrite content, mineral type and floatability. When the pyrite content is high, the secondary copper sulfide minerals are easily oxidized and dissolved, resulting in a large amount of copper ions in the slurry. The copper ions will activate pyrite, thereby deteriorating the copper-sulfur separation during the selection process, affecting the concentrate grade and copper recovery rate. When the copper grade is low, the economic indicators deteriorate, bringing greater challenges to the operation. For the bio-heap leaching method, the pyrite content and clay content in the ore are key indicators. During the ore heap leaching process, pyrite undergoes oxidation reaction to generate trivalent iron and sulfuric acid. The heat released by oxidation and the trivalent iron produced promote the leaching of secondary copper sulfide ore. However, if there is more pyrite in the ore and less acid-consuming gangue, as the solution circulates continuously in the system, the oxidation of pyrite will lead to excess accumulation of acid iron in the system. Factors such as acid return from extraction and acid production from alum precipitation will also aggravate the excess acid in the system, thereby reducing the extraction efficiency, reducing the amount of copper transfer, affecting the current efficiency, and ultimately limiting the cathode copper production and increasing production costs. Too high a clay content in the ore is not conducive to the permeability of the ore pile, affecting the leaching rate of the copper ore, and is not conducive to the efficient use of resources. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] The technical problem to be solved by the present invention is how to provide a large-scale industrial development method for low-grade complex secondary copper sulfide ore to alleviate the problem of reduced product output and quality caused by excessively high pyrite content and improve the utilization rate of copper resources.

[0005] (II) Technical solution

[0006] In order to solve the above technical problems, the present invention proposes a large-scale industrial development method for low-grade complex secondary copper sulfide ore, comprising the following steps:

[0007] Step 1: After drilling the ore body, the drilled powder is tested to determine the type of ore and classify the ore body into low-clay ore and high-clay ore;

[0008] Step 2: Mining different types of ores and transporting them to their respective stockpiles. The upper stockpile solution of each stockpile is divided into: raffinate and intermediate solution, and the lower stockpile solution is divided into: intermediate solution and qualified solution; and the stockpile is divided into old stockpile area and new stockpile area according to the ore leaching time. The intermediate solutions of different stockpiles are circulated with each other to regulate the leaching environment and equilibrium liquid level of the stockpile ore;

[0009] Step 3: Equip at least two extraction electrowinning workshops and one independent electrowinning workshop. Each of the extraction electrowinning workshops receives qualified liquid from different stockpiles, and transports its own raffinate to the old stockpiles in different stockpiles. The rich liquid produced by each extraction electrowinning workshop flows to the independent electrowinning workshop, and the lean liquid produced by the independent electrowinning workshop is mixed with the lean liquid produced by any extraction electrowinning workshop and flows to the stripping section.

[0010] In the step 1, the high-clay ore and the low-clay ore are classified into ore types according to the different clay contents in the ore. The high-clay ore is transported to the 2# yard and directly piled, and the low-clay ore is crushed to P80=70mm and then transported to the 1# yard by a belt conveyor and piled by a placing machine.

[0011] Among them, the raffinate generated in the extraction electrowinning workshop in step 3 is piled up in the old pile area for acid reduction once, and the intermediate liquid of the lower pile solution is piled up in the old pile area or the new pile area separately or simultaneously for acid reduction again, thereby reducing the acidity of the qualified liquid and increasing the copper ion concentration.

[0012] In the heap leaching process of step 2, during the rainy season, the copper-containing rainwater in each stockpile is discharged to the bottom of the mining pit for storage. During the dry season, the low-acid and low-iron solution on the surface of the bottom of the mining pit is returned to the intermediate solution of the stockpile to compensate for evaporation and reduce the acid and iron concentrations in the heap leaching solution system.

[0013] Wherein, in step 2, when the average total iron concentration of each stockpile exceeds 45 g / L and the acidity exceeds 14 g / L, a ferrous oxide microbial activity inhibitor is added to regulate the ferrous oxide microbial activity and reduce the pyrite oxidation rate.

[0014] Among them, benign waste rock is used to seal the stockpile that has reached the designed height to isolate the leached slag from the external environment.

[0015] Among them, the configuration of each workshop in step 3 is set as follows: 1# storage yard is equipped with 1# extraction electrowinning system, 2# storage yard is equipped with 2# extraction electrowinning system, and a set of 3# electrowinning system is independently set up.

[0016] Among them, the 1# stockpile qualified liquid and the 2# stockpile qualified liquid are both supplied to the 1# extraction electrowinning system and the 2# extraction electrowinning system.

[0017] The raffinate of the 1# extraction and electrowinning system is supplied to the old stockpile areas of the 1# and 2# stockpile yards, and the raffinate of the 2# extraction and electrowinning system is supplied to the upper stockpile solution of the old stockpile areas of the 1# and 2# stockpile yards.

[0018] The rich solution from the 1# and 2# extraction electrowinning systems is supplied to the 3# electrowinning system, and the lean solution from the 3# electrowinning system is supplied to the stripping sections of the 1# and 2# extraction electrowinning systems.

[0019] (III) Beneficial effects

[0020] The invention provides a large-scale industrial development method for secondary copper sulfide ore, which can effectively reduce the acid iron concentration of the heap leaching solution system, improve the utilization rate of copper resources, ensure the output and quality of cathode copper, and reduce the environmental protection risks in the mining area. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0023] This embodiment provides a large-scale industrial development method for low-grade complex secondary copper sulfide ore, comprising the following steps:

[0024] Step 1: After drilling the ore body, the drilled powder is tested to determine the type of ore and classify the ore body into low-clay ore and high-clay ore;

[0025] Step 2: Mining different types of ores and transporting them to their respective stockpiles. The upper stockpile solution of each stockpile is divided into: raffinate and intermediate solution, and the lower stockpile solution is divided into: intermediate solution and qualified solution; and the stockpile is divided into old stockpile area and new stockpile area according to the ore leaching time. The intermediate solutions of different stockpiles are circulated with each other to regulate the leaching environment and equilibrium liquid level of the stockpile ore;

[0026] Step 3: Equip at least two extraction electrowinning workshops and one independent electrowinning workshop. Each of the extraction electrowinning workshops receives qualified liquid from different stockpiles, and transports its own raffinate to the old stockpiles in different stockpiles. The rich liquid produced by each extraction electrowinning workshop flows to the independent electrowinning workshop, and the lean liquid produced by the independent electrowinning workshop is mixed with the lean liquid produced by any extraction electrowinning workshop and flows to the stripping section.

[0027] In the step 1, the high-clay ore and the low-clay ore are classified into ore types according to the different clay contents in the ore. The high-clay ore is transported to the 2# yard and directly piled, and the low-clay ore is crushed to P80=70mm and then transported to the 1# yard by a belt conveyor and piled by a placing machine.

[0028] Among them, the raffinate generated in the extraction electrowinning workshop in step 3 is piled up in the old pile area for acid reduction once, and the intermediate liquid of the lower pile solution is piled up in the old pile area or the new pile area separately or simultaneously for acid reduction again, thereby reducing the acidity of the qualified liquid and increasing the copper ion concentration.

[0029] In the heap leaching process of step 2, during the rainy season, the copper-containing rainwater in each stockpile is discharged to the bottom of the mining pit for storage. During the dry season, the low-acid and low-iron solution on the surface of the bottom of the mining pit is returned to the intermediate solution of the stockpile to compensate for evaporation and reduce the acid and iron concentrations in the heap leaching solution system.

[0030] Wherein, in step 2, when the average total iron concentration of each stockpile exceeds 45 g / L and the acidity exceeds 14 g / L, a ferrous oxide microbial activity inhibitor is added to regulate the ferrous oxide microbial activity and reduce the pyrite oxidation rate.

[0031] Among them, benign waste rock is used to seal the stockpile that has reached the designed height to isolate the leached slag from the external environment.

[0032] Among them, the configuration of each workshop in step 3 is set as follows: 1# storage yard is equipped with 1# extraction electrowinning system, 2# storage yard is equipped with 2# extraction electrowinning system, and a set of 3# electrowinning system is independently set up.

[0033] Among them, the 1# stockpile qualified liquid and the 2# stockpile qualified liquid are both supplied to the 1# extraction electrowinning system and the 2# extraction electrowinning system.

[0034] The raffinate of the 1# extraction and electrowinning system is supplied to the old stockpile areas of the 1# and 2# stockpile yards, and the raffinate of the 2# extraction and electrowinning system is supplied to the upper stockpile solution of the old stockpile areas of the 1# and 2# stockpile yards.

[0035] The rich solution from the 1# and 2# extraction electrowinning systems is supplied to the 3# electrowinning system, and the lean solution from the 3# electrowinning system is supplied to the stripping sections of the 1# and 2# extraction electrowinning systems.

[0036] Embodiment 1:

[0037] (1) "Geology-mining linkage open-pit mining". After drilling the ore body, the geology department will test the drilled powder. By testing the grade, liquid limit and plasticity index of the drilled ore powder, the type of ore is determined, and then the ore body is divided into easy-to-leach ores and difficult-to-leach ores. The mining department will design and produce mining production according to the ore body model.

[0038] (2) "Mining-ore dressing linkage heap leaching". The mining profession mines and transports different types of ores separately and stores them in their respective stockpiles. The ore dressing profession divides the upper heap solution of each stockpile into two types: raffinate and intermediate solution. The lower heap solution is divided into two types: intermediate solution and qualified solution. The stockpile is divided into old heap area and new heap area according to the ore leaching time. The raffinate solution produced by the extraction workshop is all piled up in the old heap area for acid reduction. The lower heap solution and intermediate solution can be piled up in the old heap area or the new heap area separately or simultaneously for acid reduction again. During the rainy season, the copper-containing rainwater in the stockpile is discharged to the bottom of the mining pit for storage. After being diluted by the rainwater in the pit, the pH rises, and Fe3+ precipitates and settles at the bottom of the pit, achieving the effect of reducing iron and acid, and reducing the occurrence of environmental accidents. During the dry season, the low-acid and low-iron solution on the surface of the bottom of the mining pit is returned to the intermediate solution of the stockpile to compensate for evaporation and reduce the acid and iron concentrations in the heap leaching solution system. The intermediate liquids of different stockpiles can circulate with each other to target and regulate the leaching environment and balance the liquid level of the stockpiles. When the average total iron concentration of the stockpiles exceeds 45g / L and the acidity exceeds 14g / L, ferrous oxide microbial activity inhibitors are added to regulate the activity of ferrous oxide microorganisms and reduce the oxidation rate of pyrite. For the stockpiles that have reached the designed height, benign waste rock is used to seal the stockpiles, isolate the leached slag from the external environment, and stop the continuous oxidation of pyrite from the source.

[0039] (3) "Mineral Processing-Smelting Linkage" The plan is to have at least two extraction-electrodeposition workshops and one independent electrodeposition workshop. The processes of the two extraction-electrodeposition workshops are both "two-stage series extraction-one-stage stripping-one-stage washing-electrodeposition copper" processes, and the independent electrodeposition workshop only has the electrodeposition copper process. Each extraction-electrodeposition workshop can receive qualified liquid from different stockpiles, and can transport its own residual liquid to the old stockpile area of ​​different stockpiles. The wastewater from the washing section in the extraction-electrodeposition workshop is directly discharged into the intermediate liquid for use as heap leaching water. The rich liquid produced by each extraction-electrodeposition workshop can flow to the independent electrodeposition workshop, and the lean liquid produced by the independent electrodeposition workshop can be mixed with the lean liquid produced by any extraction-electrodeposition workshop and flow to the stripping section.

[0040] Taking a copper mine with an annual output of 50,000 tons of cathode copper as an example, a biological heap leaching copper mine has an annual mining output of 20 million tons and an average grade of 0.38% of the raw ore. The raw ore mainly contains blue chalcocite, covellite, pyrite, quartz, alum, feldspar, talc, etc., among which the pyrite content is as high as 20%. As the acid and iron in the heap leaching system continue to accumulate, the average acid concentration of the stockpile solution rises to 10g / L, and the average iron concentration rises to 45g / L, which affects the extraction rate and cathode copper production to a certain extent. In order to efficiently utilize copper resources and maximize the output of cathode copper, the following "mining-selection-smelting" linkage scheme is adopted to achieve an annual output (330 days) of 55,836 tons of cathode copper, eliminating the environmental risks in the rainy season. First, the ore type of the raw ore is divided into high clay ore and low clay ore according to the different clay content. The high clay ore is directly transported to the 2# stockpile by truck and directly piled by truck. The low clay ore is crushed to P 80 =70mm, then it is transported by belt to No. 1 yard for pile building by placing machine. The leaching cycle in No. 1 and No. 2 yards is more than 300 days, which is called old pile, and the leaching cycle is less than or equal to 300 days, which is called new pile. No. 1 yard is equipped with No. 1 extraction electrowinning system, No. 2 yard is equipped with No. 2 extraction electrowinning system, and No. 3 electrowinning system is set up independently. Under production conditions, qualified liquid in No. 1 yard can be supplied to No. 1 and No. 2 extraction electrowinning systems, and qualified liquid in No. 2 yard can be supplied to No. 1 and No. 2 extraction electrowinning systems. Intermediate liquid in No. 1 and No. 2 yards can be exchanged with each other. The raffinate of No. 1 extraction electrowinning system can be supplied to the old pile area of ​​No. 1 and No. 2 yards, and the raffinate of No. 2 extraction electrowinning system can be supplied to the old pile area of ​​No. 1 and No. 2 yards. The rich liquid of No. 1 and No. 2 extraction electrowinning system can be supplied to No. 3 electrowinning system, and the lean liquid of No. 3 electrowinning system can be supplied to the stripping section of No. 1 and No. 2 extraction electrowinning system. When the rainy season comes, part of the intermediate liquid in the lower pile of the stockpile is directly discharged into the open pit, forming high-acid, high-iron copper-containing rainwater. Affected by rainfall, the acidity of the copper-containing rainwater in the pit dropped to 2.5g / L, and the total iron concentration dropped to 17g / L, forming low-acid, low-acid copper-containing rainwater. In the dry season, low-acid, low-iron rainwater on the surface of the pit is selected to replenish the stockpile. Every year, when the average total iron concentration in the stockpile exceeds 45g / L and the acidity exceeds 14g / L, ferrous oxide microbial activity inhibitors are added to the stockpile intermediate liquid to maintain the concentration of the agent not less than 100mg / L to regulate the activity of ferrous oxide microorganisms and reduce the oxidation rate of pyrite. Since the 3# stockpile has reached the designed height, the solution is stopped from piling up, and it is completely sealed with benign waste rock to isolate the leaching slag from the external environment and stop the continuous oxidation of pyrite from the source. The specific process operation parameters and process indicators of the extraction and electrowinning processes are shown in Table 1 below:

[0041] Table 1: Process operating parameters and process indicators

[0042]

[0043]

[0044] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A large-scale industrial development method for low-grade complex secondary copper sulfide ore, characterized in that: The following steps are involved: Step 1: After drilling the ore body, the drilled powder is tested to determine the type of ore and classify the ore body into low-clay ore and high-clay ore; Step 2: Mining different types of ores and transporting them to their respective stockpiles, dividing the upper stockpile solution of each stockpile into: raffinate and intermediate solution, and dividing the lower stockpile solution into: intermediate solution and qualified solution; The stockpile is divided into old stockpile area and new stockpile area according to the ore leaching time. The intermediate liquids in different stockpiles are circulated with each other to regulate the ore leaching environment and balance liquid level in the stockpile. Step 3: Equip at least two extraction electrowinning workshops and one independent electrowinning workshop. Each of the extraction electrowinning workshops receives qualified liquid from different stockpiles, and transports its own raffinate to the old stockpiles in different stockpiles. The rich liquid produced by each extraction electrowinning workshop flows to the independent electrowinning workshop, and the lean liquid produced by the independent electrowinning workshop is mixed with the lean liquid produced by any extraction electrowinning workshop and flows to the stripping section.

2. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: In step 1, the high-clay ore and the low-clay ore are classified into different ore types according to the different clay contents in the ore. The high-clay ore is transported to the 2# yard and directly piled, and the low-clay ore is crushed to P80=70mm and then transported to the 1# yard by a belt conveyor and piled by a placing machine.

3. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: In step 3, the raffinate produced in the extraction electrowinning workshop is piled up in the old pile area for acid reduction, and the intermediate liquid of the lower pile solution is piled up in the old pile area or the new pile area separately or simultaneously for acid reduction again, thereby reducing the acidity of the qualified liquid and increasing the copper ion concentration.

4. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: During the heap leaching process in step 2, during the rainy season, the copper-containing rainwater in each stockpile is discharged to the bottom of the mining pit for storage. During the dry season, the low-acid and low-iron solution on the surface of the bottom of the mining pit is returned to the intermediate solution of the stockpile to compensate for evaporation and reduce the acid and iron concentrations in the heap leaching solution system.

5. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: In step 2, when the average total iron concentration of each stockpile exceeds 45 g / L and the acidity exceeds 14 g / L, a ferrous oxide microbial activity inhibitor is added to regulate the ferrous oxide microbial activity and reduce the pyrite oxidation rate.

6. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: For the stockpile that has reached the designed height, benign waste rock is used to seal the stockpile to isolate the leached slag from the external environment.

7. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 1, characterized in that: In step 3, the configuration of each workshop is as follows: the 1# storage yard is equipped with a 1# extraction electrowinning system, the 2# storage yard is equipped with a 2# extraction electrowinning system, and an independent 3# electrowinning system is set up.

8. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 7, characterized in that: The 1# stockpile qualified liquid and the 2# stockpile qualified liquid are both supplied to the 1# extraction electrowinning system and the 2# extraction electrowinning system.

9. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 7, characterized in that: The raffinate of the 1# extraction electrowinning system is supplied to the old stockpile areas of the 1# and 2# stockpile yards, and the raffinate of the 2# extraction electrowinning system is supplied to the upper stockpile solution of the old stockpile areas of the 1# and 2# stockpile yards.

10. The large-scale industrial development method of low-grade complex secondary copper sulfide ore according to claim 7, characterized in that: The rich solution of the 1# and 2# extraction electrowinning systems is supplied to the 3# electrowinning system, and the lean solution of the 3# electrowinning system is supplied to the stripping section of the 1# and 2# extraction electrowinning systems.

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