CN115141935B - Copper refining slag depletion method - Google Patents

Abstract

A copper refining slag depletion method belongs to the field of environment, slag metallurgy and comprehensive resource utilization. After the copper pyrometallurgical refining oxidation period is over, the method directly adds a new depletion agent to the copper refining slag in the copper pyrometallurgical refining furnace, or adds the depletion agent and the copper refining slag to a high-temperature furnace, and introduces an oxidizing gas to achieve the reduction of the copper component in the copper refining slag and the deep depletion of the slag. The deep depletion slag is used as a raw material for reducing ironmaking or cement raw material or a raw material for flotation separation of copper. The new depletion agent has the advantages of high specific gravity, controllable reaction, small addition amount, no need for heating, no need for additional equipment, clean, low cost, good depletion effect, etc., and is a composite depletion agent.

Description

A copper refining slag depletion method

Technical Field

The invention belongs to the fields of environment, slag metallurgy and comprehensive utilization of resources, and in particular relates to a copper refining slag depletion method.

Background Art

During the pyrometallurgical smelting of copper sulfide ore and recycled copper, a large amount of copper refining slag is produced, and the copper content in the slag is as high as 45wt%. In the smelting process of copper sulfide ore, the copper refining slag is returned to the blowing process for treatment. This method reduces the processing volume of cold materials in the blowing process, reduces the efficiency of the enterprise, and causes waste of physical heat of the refining slag. The slag contains high copper, serious smoke leakage, and pollutes the environment. After the copper refining slag produced in the pyrometallurgical smelting process is treated by a high-temperature furnace, the copper content of the depleted slag is greater than 1wt%, which is much higher than the optional grade of copper ore 0.1wt%, resulting in a waste of copper resources.

In order to solve the above problems, it is necessary to develop new copper refining slag depletion methods and depletion reagents, which must meet the following requirements: (1) Utilize the physical heat of copper refining slag without heating or with a small amount of heating; (2) Develop a reasonable process route to reduce the copper content in the slag; (3) Develop new depletion reagents to reduce the copper content in the slag; (4) Realize the utilization of the physical heat and iron components of the slag; (5) It should be clean, short in process, low in cost, not affect subsequent production and tailings utilization, and have no solid waste emissions.

Summary of the invention

In view of the problems existing in the prior art, a method for utilizing copper refining slag is provided. After the oxidation period of copper pyrometallurgical refining is completed, the method directly adds a new type of depletion agent to the copper refining slag in the copper pyrometallurgical refining furnace, or adds the depletion agent and the copper refining slag to a high-temperature furnace, and introduces an oxidizing gas to achieve the reduction of the copper component in the copper refining slag and the deep depletion of the slag, and the deep depletion of the slag is used as a raw material for reducing ironmaking or cement raw material or a raw material for flotation separation of copper. The new type of depletion agent has the advantages of high specific gravity, controllable reaction, small addition amount, no need for heating, no need for additional equipment, clean, low cost, good depletion effect, etc., and is a composite depletion agent.

This method has short reaction time, low copper content in slag, low production cost, short process, large processing volume, environmental friendliness, high economic benefits, and can effectively solve problems such as environmental pollution, efficient utilization of heat energy and resources, and realize the utilization of copper refining slag.

A method for utilizing copper refining slag of the present invention specifically comprises the following steps:

A copper refining slag depletion method specifically comprises the following steps:

Step (1) Reduction and depletion of reagents

After the oxidation period of copper pyro-refining is over, the depleting agent and the reducing agent are directly added to the copper refining slag in the copper pyro-refining furnace; or the depleting agent, the reducing agent and the copper refining slag are added to a high-temperature furnace for heating; then an oxidizing gas is introduced to perform high-temperature melting reduction depletion, so that the copper oxide in the copper refining slag is reduced to metallic copper, and after sedimentation and depletion, a copper-rich phase and depleted slag are obtained;

The reduction depletion temperature is 1150-1450°C;

Step (2) Depletion of slag matte

Adding matte to the depleted slag in step (1) for deep depletion, so that the residual copper oxide in the slag is converted into metallic copper, which is then precipitated and depleted to obtain a copper-rich phase and deeply depleted slag;

The specific gravity of the depleted agent is greater than 2.6 g/cm ³ .

Furthermore, the depletion agent is one or a combination of two or more selected from ferroalloy, coal-fired slag, coal gangue, fly ash, carbide, coal gasification slag, oil shale, and oil shale slag, or one or a combination of two or more selected from ferroalloy, coal-fired slag, coal gangue, fly ash, carbide, coal gasification slag, oil shale, and oil shale slag is added to a combination of one or more selected from ferroalloy, coal _- fired slag, coal gangue, _{fly ash} , carbide, coal gasification slag, oil shale, and oil shale slag.

Furthermore, the carbide is one or a combination of two or more of iron carbide, manganese carbide, chromium carbide, titanium carbide, silicon carbide, and vanadium carbide; the ferroalloy is one or a combination of two or more of ferrosilicon, silicon manganese, silicon calcium iron, silicon aluminum iron, silicon calcium aluminum iron, silicon carbon iron, and silicon carbon alloy.

Furthermore, based on the total amount of copper refined slag being 100wt%, the added amount of the depleted agent is ≤2wt%; and the particle size of the depleted agent is 30μm to 4mm.

Furthermore, the reducing agent is one or a combination of two or more of diesel, heavy oil, firewood, coal powder, natural gas, and coal gas; based on the total amount of copper refining slag as 100wt%, the amount of reducing agent added is 100wt% of the stoichiometric ratio of copper oxide in the slag to reduce the copper oxide to metallic copper.

Furthermore, the oxidizing gas is one or a combination of two or more of air, oxygen-enriched air, oxygen, and carbon dioxide.

Furthermore, the amount of copper matte added is 100wt% of the stoichiometric ratio of the residual copper oxides in the slag converted into metallic copper.

Furthermore, the sedimentation time in step (1) and step (2) is ≥30 min.

Furthermore, the copper-rich phase in step (1) is sent to a converting furnace; and the copper-rich phase in step (2) is sent to a copper refining process or a converting process.

Furthermore, after the high-temperature molten reduction depletion in step (1), the copper content of the slag is ≤2.0wt%; after the deep depletion in step (2), the copper content of the slag is ≤0.3wt%; the slag after the deep depletion is used as molten reduction ironmaking or as cement raw material after water quenching or as raw material for flotation separation of copper after being poured into a slag bag and slowly cooled, and the copper content of the tailings after flotation is ≤0.18wt%.

Furthermore, the high temperature furnace is an electric furnace, an ore-fired furnace, a reverberatory furnace or a rotary furnace; the matte is in a cold state, a hot state or a molten state, and the molten state comes directly from a copper smelting furnace.

Principles and advantages of the present invention:

(1) Principles and advantages of reduction depletion

Principles and advantages: ① The new depletion agent is a composite agent with a high specific gravity, which is similar to or greater than the specific gravity of the slag. It has a large contact area with the slag, does not float, has a long reaction time, reacts completely, and reduces the copper content in the slag; ② The new depletion agent can provide a composite reducing agent to accelerate the reduction of Cu ₂ O; ③ The new depletion agent can release Cu ₂ O from the silicate phase to a free state, accelerate the reduction, and reduce the copper content in the slag; ④ The reducing agent and the new depletion agent work together to reduce the use of the new depletion agent and reduce costs.

For example, adding iron carbide to react with Cu ₂ O, FeC+Cu ₂ O＝Cu+FeO+CO, Cu ₂ O+CO＝Cu+CO ₂ , 2FeO+2Cu ₂ O·SiO ₂ ＝2Cu ₂ O+2FeO·SiO ₂

(2) Principle and advantages of deep depletion of slag by adding copper matte

Principle: ① The melting point of matte is low, so it melts quickly and reacts quickly; ② The Cu ₂ S in matte reacts with the residual Cu ₂ O in the slag, Cu ₂ S+Cu ₂ O＝Cu+SO ₂ , generating metallic copper with high specific gravity and low melting point, which accelerates the sedimentation of metallic copper; ③ The FeS in matte makes the sulfur component in the slag excessive, causing the Cu ₂ O and magnetite phase to disappear, thus promoting the sedimentation and flotation separation of the copper component;

Advantages: ① The product is metallic copper, which has great economic benefits; ② The metallic copper is easy to settle and the slag contains low copper; ③ The melting point of matte is low, no or little heating is required, and the energy consumption is low; ④ The matte can be processed at the same time, which has great benefits; ⑤ The molten matte is directly used without heating.

DETAILED DESCRIPTION

The present invention will be further described below based on a specific embodiment of the present invention. Of course, this embodiment is only a part of the embodiments of the present invention and does not represent all the embodiments of the present invention.

Example 1

A copper refining slag impoverishment method and a novel impoverishment agent, specifically comprising the following steps:

Step (1) Reduction and depletion of reagents

After the oxidation period of the copper reverberatory refining furnace is over, ferrosilicon powder (specific gravity is 3.0 g/cm ³ ) with a particle size of 140-180 μm and an addition amount of 1.3 wt % of the total slag and firewood are added to the copper refining slag (the slag contains 27.95 wt % copper) in the copper reverberatory refining furnace, and air is introduced to carry out high-temperature melting reduction and depletion. The reduction and depletion temperature is 1230-1300° C., so that the copper oxide in the slag is reduced to metallic copper, and the slag is depleted for 30 minutes to obtain a copper-rich phase and a depleted slag. The depleted slag contains 1.6 wt % copper. The molten copper-rich phase is sent to the converter for blowing. The amount of firewood added is 100 wt % of the stoichiometric ratio of the copper oxide in the slag to reduce to metallic copper.

Step (2) Depletion of slag matte

Adding molten copper matte to the slag after depletion in step (1) for deep depletion, so that the residual copper oxide in the slag is converted into metallic copper, and the slag is depleted by sedimentation for 30 minutes, and a copper-rich phase and deeply depleted slag are obtained, and the copper content of the deeply depleted slag is 0.28wt%; the molten copper matte comes directly from a copper flash smelting furnace, and the amount of copper matte added is 100wt% of the stoichiometric ratio of the residual copper oxide in the slag converted into metallic copper;

Example 2

A copper refining slag impoverishment method and a novel impoverishment agent, specifically comprising the following steps:

Step (1) Reduction and depletion of reagents

Iron carbide (specific gravity 7.7 g/cm ³ ) with a particle size of 120-160 μm and an addition amount of 0.8 wt % of the total slag, CaO (specific gravity 3.35 g/cm ³ ) with an addition amount of 1.0 wt %, heavy oil and recycled copper refining slag (slag containing 38.23 wt % copper) are added into a submerged arc furnace, and air is introduced to carry out high-temperature melting reduction and depletion. The reduction and depletion temperature is 1200-1280° C., and the copper oxide in the slag is reduced to metallic copper, and the slag is depleted by sedimentation for 40 minutes to obtain a copper-rich phase and depleted slag. The depleted slag contains 1.5 wt % copper. The molten copper-rich phase is sent to a converter for blowing. The amount of heavy oil added is such that the copper oxide in the slag is reduced to 100 wt % of the stoichiometric ratio of metallic copper.

Step (2) Depletion of slag matte

Adding cold copper matte to the slag after depletion in step (1) for deep depletion, so that the residual copper oxide in the slag is converted into metallic copper, and the slag is depleted by sedimentation for 80 minutes, and a copper-rich phase and deeply depleted slag are obtained, and the copper content of the deeply depleted slag is 0.24wt%; the molten copper matte comes directly from the copper side-blown smelting furnace, and the amount of copper matte added is 100wt% of the stoichiometric ratio of the residual copper oxide in the slag converted into metallic copper;

Example 3

A copper refining slag impoverishment method and a novel impoverishment agent, specifically comprising the following steps:

Step (1) Reduction and depletion of reagents

Coal gangue (specific gravity: 3.0 g/cm ³ ) with a particle size of 100-140 μm and an addition amount of 1.6 wt % of the total slag, heavy oil and recycled copper refining slag (slag containing 37.19 wt % copper) are added into an electric furnace, and air is introduced to carry out high-temperature melting reduction and depletion. The reduction and depletion temperature is 1220-1290° C., and the copper oxide in the slag is reduced to metallic copper, and the slag is depleted by sedimentation for 60 minutes to obtain a copper-rich phase and depleted slag. The depleted slag contains 1.7 wt % copper. The molten copper-rich phase is sent to a converter for blowing. The amount of heavy oil added is such that the copper oxide in the slag is reduced to 100 wt % of the stoichiometric ratio of metallic copper.

Step (2) Depletion of slag matte

Adding cold copper matte to the slag after depletion in step (1) for deep depletion, so that the residual copper oxide in the slag is converted into metallic copper, and the slag is depleted by sedimentation for 80 minutes, and a copper-rich phase and deeply depleted slag are obtained. The deeply depleted slag contains 0.22wt% copper, and the tailings are used as raw materials for ironmaking; the molten copper matte comes directly from a copper low-blowing smelting furnace, and the amount of copper matte added is 100wt% of the stoichiometric ratio of the residual copper oxide in the slag converted into metallic copper;

Comparative Example 1

A copper refining slag depletion method and a novel depletion agent are provided, which are the same as those in Example 1, except that: no ferrosilicon powder is added, the reduction is incomplete, the copper content in the slag after depletion in step (1) is 24.19wt%, and after deep depletion in step (2), the copper content in the slag is 1.98wt%, which is much higher than the optional grade of copper ore 0.1wt%, resulting in a waste of copper resources and the tailings cannot be used.

Comparative Example 2

A copper refining slag dilution method and a novel dilution agent are provided, which are the same as those in Example 1, except that: the deep dilution of the matte in step (2) is not performed, and after reduction dilution in step (1), the dilution slag contains 1.6wt% copper, which is much higher than the optional grade of copper ore of 0.1wt%, resulting in a waste of copper resources and the tailings cannot be used.

Comparative Example 3

A copper refining slag depletion method and a novel depletion agent are the same as those in Example 2, except that: no iron carbide powder is added, the reduction is incomplete, the copper content in the slag after depletion in step (1) is 25.28wt%, and after deep depletion in step (2), the copper content in the slag is 2.89wt%, which is much higher than the optional grade of copper ore 0.1wt%, resulting in a waste of copper resources and the tailings cannot be used.

Claims (6)

1. The copper refining slag depletion method is characterized by comprising the following steps of:

step (1) reduction and depletion of the depletion agent

After the copper fire refining oxidation period is finished, directly adding a depletion agent and a reducing agent into copper refining slag in a copper fire refining furnace; then introducing oxidizing gas, and carrying out high-temperature melting reduction and depletion to reduce copper oxide in the copper refining slag into metallic copper, and obtaining copper-rich phase and depleted slag after sedimentation and depletion;

The reduction and dilution temperature is 1150-1450 ℃;

depth depletion of slag matte after depletion in step (2)

Adding matte into the slag after the depletion in the step (1) for deep depletion, so that residual copper oxide in the slag is converted into metallic copper, and settling and depletion to obtain a copper-rich phase and slag after the deep depletion;

The specific gravity of the depleted medicament is greater than 2.6g/cm ³;

The said depletion agent is one or more than two kinds of iron alloy, coal-fired slag, gangue, fly ash, carbide, coal gasification slag, oil shale slag, or one or more than two kinds of composition of iron alloy, coal-fired slag, gangue, fly ash, carbide, coal gasification slag, oil shale slag, then one or more than two kinds of composition of TiO ₂、FeO、SiO₂、CaCO₃, caO, blast furnace slag, steel slag are added;

the addition amount of the matte is 100wt% of the stoichiometric ratio of the residual copper oxide in the slag to the metallic copper;

The addition amount of the depletion agent is less than or equal to 2wt percent based on 100wt percent of the total amount of the copper refining slag; the granularity of the depletion agent is 30 mu m-4 mm;

After the high-temperature melting reduction depletion in the step (1), the copper content of the slag is less than or equal to 2.0wt%; after the deep depletion in the step (2), the copper content of the slag is less than or equal to 0.3wt%; the slag after deep depletion is used as a cement raw material after smelting reduction iron making or water quenching or is used as a raw material for separating copper by floatation after being poured into a slag ladle for slow cooling, and the copper content of tailings after floatation is less than or equal to 0.18wt%.

2. The method for refining copper slag depletion according to claim 1, wherein the carbide is one or a combination of more than two of iron carbide, manganese carbide, chromium carbide, titanium carbide, silicon carbide and vanadium carbide; the ferroalloy is one or the combination of more than two of ferrosilicon, ferrosilicon-aluminum, ferrosilicon-calcium-aluminum and ferrosilicon.

3. The copper refining slag depletion method according to claim 1, wherein the reducing agent is one or a combination of more than two of diesel oil, heavy oil, firewood, coal dust, natural gas and coal gas; the amount of reducing agent added was 100wt% based on 100wt% total copper refining slag to reduce copper oxide in the slag to metallic copper stoichiometry.

4. The copper refining slag depletion method as claimed in claim 1, wherein said oxidizing gas is one or a combination of two or more of air, oxygen-enriched air, oxygen and carbon dioxide.

5. The copper refining slag depletion method as claimed in claim 1, wherein the sedimentation time in the steps (1) and (2) is not less than 30min.

6. The copper refining slag depletion method as claimed in claim 1, wherein the matte is in a cold state, a hot state or a molten state, and the molten state is directly from a copper smelting furnace; the copper-rich phase in the step (1) is sent to a converting furnace; the copper-rich phase in the step (2) is sent to a copper refining process or a converting process.