CN111139357A

CN111139357A - Method for diluting copper-containing sludge

Info

Publication number: CN111139357A
Application number: CN202010015040.9A
Authority: CN
Inventors: 郭亚光; 陈学刚; 裴忠冶
Original assignee: China ENFI Engineering Corp
Current assignee: China ENFI Engineering Corp
Priority date: 2020-01-07
Filing date: 2020-01-07
Publication date: 2020-05-12

Abstract

The invention provides a depletion method of sludge containing copper. The device adopted by the dilution method comprises a dilution treatment device and a wire feeding device, wherein the dilution treatment device takes electric heat or plasma heat as a heat source, and is provided with a feed inlet, a wire feeding hole and a matte discharging hole; the depletion method comprises the following steps: drying the copper-containing sludge to obtain a dry material, wherein the water content of the dry material is less than or equal to 20%; adding dry materials and a slagging agent into a dilution treatment device through a feeding port, feeding a carbon powder wire into the dilution treatment device through a wire feeding hole by using a wire feeding device, and reducing and diluting the dry materials by using the carbon powder wire, wherein the iron-silicon ratio in the slagging agent is 0.4-0.8, and the calcium-silicon ratio in the slagging agent is 0.6-0.9. The method for diluting is not only beneficial to improving the reaction rate, the recovery rate of copper element and the environmental protection performance in the diluting process, but also beneficial to reducing the treatment cost.

Description

Method for diluting copper-containing sludge

Technical Field

The invention relates to the field of metal smelting, in particular to a depletion method of copper-containing sludge.

Background

In order to treat heavy metal wastewater generated in the industries of electroplating, manufacturing and the like, related enterprises generate a large amount of copper-containing sludge every year. The direct stockpiling of the copper-containing sludge may cause heavy metals in the sludge to be re-dissolved out, which causes secondary pollution to the environment, and the sludge contains valuable metals such as copper, nickel and the like, so that the sludge has high utilization value.

At present, the recovery method of valuable metals in the copper-containing sludge mainly comprises an acid leaching method, an ammonia leaching method and a high-temperature smelting method. The main process of the acid leaching method is to leach valuable metals in the copper-containing sludge by adopting sulfuric acid, hydrochloric acid or nitric acid and the like. The acid leaching method has high leaching efficiency, but has the defects that a plurality of metals are difficult to separate by leaching at the same time, the corrosion to equipment is serious, and the operating environment is poor. The ammonia leaching method generally adopts ammonia water solution as a leaching agent to perform complex reaction with copper and nickel in sludge to obtain a leaching solution, and then valuable metals are recovered. The ammonia leaching method has good selectivity on valuable metals such as copper, nickel and the like, but has high requirement on the sealing property of the device, and the leaching solution is easy to volatilize and has great harm to the environment. The high-temperature smelting method is mainly characterized by heating sludge to about 1300 ℃ in a blast furnace, adding a reducing agent and a slagging agent to melt and reduce valuable metals, slagging oxides and obtaining blister copper, and the method has high energy consumption. The prior document provides a method for comprehensively treating copper-containing sludge and waste circuit boards by using a side-blown converter, wherein the copper-containing sludge and the waste circuit boards are subjected to side-blown smelting together. The method has large smoke volume and violent molten pool stirring, and is not beneficial to the settlement of metals such as copper, nickel and the like.

Disclosure of Invention

The invention mainly aims to provide a method for diluting copper-containing sludge, which solves the problems of poor environmental protection, harsh reaction conditions or low recovery rate of copper metal and the like in the conventional treatment method for the copper-containing sludge.

In order to achieve the aim, the invention provides a dilution method of copper-containing sludge, wherein a device adopted in the dilution method comprises a dilution treatment device and a wire feeding device, the dilution treatment device takes electric heat or plasma heat as a heat source, and the dilution treatment device is provided with a charging hole, a wire feeding hole and a matte discharging hole; the depletion method comprises the following steps: drying the copper-containing sludge to obtain a dry material, wherein the water content of the dry material is less than or equal to 20%; adding dry materials and a slagging agent into a dilution treatment device through a feeding port, feeding a carbon powder wire into the dilution treatment device through a wire feeding hole by using a wire feeding device, and reducing and diluting the dry materials by using the carbon powder wire, wherein the iron-silicon ratio in the slagging agent is 0.4-0.8, and the calcium-silicon ratio in the slagging agent is 0.6-0.9.

Furthermore, the addition amount of the slag former is 15-40% in terms of the weight percentage of the slag former in the dry materials.

Further, the slag former is iron ore and quartz, preferably, the addition amount of the quartz sand is 5-20% and the addition amount of the iron ore is 5-20% in percentage by weight of the dry materials.

Further, the adding amount of the carbon powder in the carbon powder line is 0.1-5% by weight of the copper-containing sludge.

Furthermore, the temperature of the reduction and dilution treatment is 1200-1400 ℃.

Further, the temperature of the reduction and dilution treatment is 1300-1350 ℃.

Further, the content of copper element in the dry material is 5-15% and the content of nickel element in the dry material is 0.15-0.5% in percentage by weight of the dry material.

Further, the dilution treatment device is a mine thermal furnace or a plasma furnace.

Further, the products obtained in the reduction and dilution treatment step comprise copper matte, slag and tail gas, and the dilution method further comprises the step of using the copper matte for preparing an anode plate.

Further, the enleanment process comprises the step of post-treating the tail gas, the post-treating step comprising: carrying out waste heat recovery treatment on the tail gas to obtain cold flue gas; and carrying out dust collection treatment on the cold flue gas.

By applying the technical scheme of the invention, the copper-containing sludge contains certain moisture, so that the copper-containing sludge needs to be dried in order to improve the safety of the depletion method. The water content of the copper-containing sludge is limited to 20% or less, so that the safety of the reduction and dilution process is improved, and the reaction rate of the reduction and dilution process is improved. Feeding the carbon powder into a dilution treatment device by adopting a wire feeding process, and then carrying out reduction and dilution treatment on the copper slag by taking electric heat or plasma heat as a heat source. Meanwhile, in the reduction and dilution treatment process, a slagging agent with a specific composition is added through a feed inlet. Compared with other slagging agents, under the action of the slagging agent, the copper element in the copper-containing sludge can be separated at a higher speed, and the recovery rate of metal elements such as the copper element is higher. In addition, the process flow of the depletion method is short, the flue gas volume of the device occupied area is small, volatile and harmful gas can not be generated, and therefore the method has higher environmental protection performance. On the basis, the method for diluting is favorable for improving the reaction rate of the diluting process, the recovery rate of copper elements and the environmental protection performance, and is also favorable for reducing the treatment cost.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.

As described in the background art, the existing treatment method for the copper-containing sludge has the problems of poor environmental protection, harsh reaction conditions or low recovery rate of copper metal and the like. In order to solve the technical problem, the application provides a dilution method of copper-containing sludge, wherein a device adopted in the dilution method comprises a dilution treatment device and a wire feeding device, the dilution treatment device takes electric heat or plasma heat as a heat source, and the dilution treatment device is provided with a feeding hole, a wire feeding hole and a matte discharging hole; the above depletion process comprises: drying the copper-containing sludge to obtain a dry material, wherein the water content of the dry material is less than or equal to 20%; adding dry materials and a slagging agent into a dilution treatment device through a feeding port, feeding a carbon powder wire into the dilution treatment device through a wire feeding hole by using a wire feeding device, and reducing and diluting the dry materials by using the carbon powder wire, wherein the iron-silicon ratio in the slagging agent is 0.4-0.8, and the calcium-silicon ratio in the slagging agent is 0.6-0.9.

Since the copper-containing sludge contains a certain amount of water, the copper-containing sludge needs to be dried in order to improve the safety of the depletion method. The water content of the copper-containing sludge is limited to 20% or less, so that the safety of the reduction and dilution process is improved, and the reaction rate of the reduction and dilution process is improved. Feeding the carbon powder into a dilution treatment device by adopting a wire feeding process, and then carrying out reduction and dilution treatment on the copper slag by taking electric heat or plasma heat as a heat source. Meanwhile, in the reduction and dilution treatment process, a slagging agent with a specific composition is added through a feed inlet. Compared with other slagging agents, under the action of the slagging agent, the copper element in the copper-containing sludge can be separated at a higher speed, and the recovery rate of metal elements such as the copper element is higher. In addition, the process flow of the depletion method is short, the flue gas volume of the device occupied area is small, volatile and harmful gas can not be generated, and therefore the method has higher environmental protection performance. On the basis, the method for diluting is favorable for improving the reaction rate of the diluting process, the recovery rate of copper elements and the environmental protection performance, and is also favorable for reducing the treatment cost.

More preferably, the water content of the dry material is less than or equal to 10 percent. This is advantageous for further improving the safety and the enleaning efficiency of the reductive enleaning process.

In order to further shorten the recovery period of the copper-containing sludge and simultaneously improve the recovery rate of copper elements and the like, in a preferred embodiment, the addition amount of the slagging constituent is 15-40% in terms of the weight percentage of the dry materials.

Preferably, the above slag former includes, but is not limited to, one or more of the group consisting of iron ore, iron oxide, magnetite, vanadium titano-magnetite, sea sand, sand stone and quartz stone having the above-described specific composition. In order to further improve the dilution efficiency of the copper-containing sludge and the recovery rate of copper elements, the addition amount of quartz sand is more preferably 5 to 20% and the addition amount of iron ore is more preferably 5 to 20% in terms of the weight percentage of dry materials.

The carbon powder line used in the above-described depletion process of the present invention may be a carbon powder line currently commercially available. In a preferred embodiment, the diameter of the carbon powder wire is 10-30 mm, and the carbon content of the carbon powder in the carbon powder wire is 50-98%. More preferably, the carbon powder wire comprises a carbon powder core layer and a metal sheath coated on the surface of the carbon powder core layer, the metal sheath is made of iron sheet or aluminum sheet, and the thickness of the metal sheath is preferably 0.1-0.5 mm. The metal sheath can be melted at high temperature after entering the dilution treatment device, or can be dissolved in slag after being oxidized by reacting with other metal oxides. More preferably, the addition amount of the carbon powder in the carbon powder line is 0.1-5% by weight of the copper-containing sludge.

In a preferred embodiment, in the step of feeding the carbon powder line, the end of the carbon powder line is placed in a slag layer in a depletion treatment device, the height of the slag layer in the depletion treatment device is recorded as H, and the height of the end of the carbon powder line from the surface of the slag layer is recorded as H, wherein H/H is 1/5-4/5. On one hand, the carbon powder line can be more fully contacted with slag to be reacted, the depletion condition is better, on the other hand, the metal oxide in the middle of the molten pool can enter the bottom of the molten pool through the sedimentation after the reduction reaction is finished, a more stable copper matte layer is formed, and the copper matte can be conveniently discharged. The soot line did not react with the sediment in the lower layer of slag.

In a preferred embodiment, the temperature of the reductive depletion treatment is 1200 to 1400 ℃. The temperature of the reduction smelting includes, but is not limited to, the above range, and it is preferable to limit the temperature to the above range to further improve the efficiency of depletion of the copper-containing sludge and the recovery rate of copper element. More preferably, the temperature of the reduction and depletion treatment is 1300-1350 ℃.

The above depletion methods provided herein can be applied to copper-containing sludge produced in the electroplating and manufacturing industries. In a preferred embodiment, the content of copper element in the dry material is 5-15% and the content of nickel element in the dry material is 0.15-0.5% in percentage by weight of the dry material.

In a preferred embodiment, the depletion treatment device is a mine thermal furnace or a plasma furnace. The ore-smelting electric furnace or the plasma furnace can provide stable heat for the dilution process of the copper-containing sludge, and the added carbon powder line can basically and completely serve as a reducing agent, so that the dilution kinetic condition can be further improved, and the production efficiency is improved.

Preferably, the product obtained in the reduction and dilution treatment step comprises copper matte, slag and tail gas, and the dilution method further comprises the step of using the copper matte for preparing an anode plate. The content of copper element in the slag is less than or equal to 0.35 percent.

In a preferred embodiment, the enleanment process further comprises the step of post-treating the tail gas, the post-treatment step comprising: carrying out waste heat recovery treatment on the tail gas to obtain cold flue gas; and carrying out dust collection treatment on the cold flue gas.

The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.

Example 1

And (3) transferring the copper-containing sludge subjected to drying granulation after premixing to a dilution treatment device (an ore-smelting electric furnace) for drying treatment, wherein the copper content in the copper-containing sludge after drying is 13.5 percent, and the Ni content in the copper-containing sludge after drying is 0.38 percent.

The temperature in the dilution treatment apparatus (ore-smelting electric furnace) is maintained at 1350 ℃, and the metal oxides such as copper, nickel and the like are reduced to be metallic state and then aggregated and settled. The carbon powder amount in the carbon powder line accounts for 3 percent of the copper-containing sludge amount. The diameter of the carbon powder wire is 15mm, the carbon content in the carbon powder is 90%, and the carbon powder is wrapped by iron sheet (aluminum sheet or copper sheet) with the thickness of 0.15 mm. The carbon powder wire is fed into the copper-containing sludge by a wire feeding machine, the head part of the carbon powder wire is positioned at the height 1/2 of the slag layer, and the wire feeding machine controls the entering speed of the carbon powder wire.

The slagging agent is quartz Sand (SiO)₂The content reaches 96 percent) and iron ore (the content of Fe reaches 63 percent), the adding amount of quartz sand is 12 percent of the total weight of the copper-containing sludge, the adding amount of the iron ore is 8 percent of the total weight of the copper-containing sludge, the iron-silicon ratio in the slag former is 0.6, and the calcium-silicon ratio in the slag former is 0.8.

The iron sheet (aluminum sheet or copper sheet) wrapped with carbon powder is melted at high temperature or is dissolved in slag after being reacted and oxidized with other metal oxides, and the carbon powder enters the melt and then is reacted with Cu (Ni) oxide to generate CO and CO₂Gas, reducing metals such as Cu existing in an oxide state into a metal state, and discharging other metals such as Cu through a copper discharging port after the other metals are settled; and in the process that the gas escapes from the melt, the copper-containing sludge is reduced in the furnace, and the heat preservation and sedimentation time is 1-3 h.

The Cu content in the tailings obtained by dilution treatment is less than or equal to 0.35, and the Ni content is less than or equal to 0.05.

The copper content in the copper matte is 62%, and the copper is discharged from a copper discharging port at the bottom of the furnace for subsequent treatment to produce an anode plate; the CO gas is combusted at the upper portion of the slag to provide heat to the furnace. The tailings are discharged from the slag discharge port, and because the tailings are generated after melting and slagging, and heavy metals in the slag are recycled, the tailings do not belong to hazardous wastes, and the influence on the surrounding environment is extremely low.

Example 2

The differences from example 1 are: the iron-silicon ratio of the slagging constituent is 0.4, and the calcium-silicon ratio is 0.9.

The tailings obtained by the dilution treatment have a Cu content of 0.34 wt%, a Ni content of 0.08 wt%, and a copper content of 60 wt%.

Example 3

The differences from example 1 are: the iron-silicon ratio of the slagging constituent is 0.8, and the calcium-silicon ratio is 0.6.

The tailings obtained by the dilution treatment have a Cu content of 0.32 wt%, a Ni content of 0.07 wt%, and a copper content of 64 wt%.

Example 4

The differences from example 1 are: based on the weight percentage of dry materials in the copper-containing sludge, the adding amount of quartz sand is 5% of the total weight of the copper-containing sludge, and the adding amount of iron ore is 20% of the total weight of the copper-containing sludge.

The tailings obtained by the dilution treatment have a Cu content of 0.36 wt%, a Ni content of 0.08 wt%, and a copper content of 61 wt%.

Example 5

The differences from example 1 are: based on the weight percentage of dry materials in the copper-containing sludge, the adding amount of quartz sand is 5% of the total weight of the copper-containing sludge, and the adding amount of iron ore is 5% of the total weight of the copper-containing sludge.

The tailings obtained by the dilution treatment have a Cu content of 0.38 wt%, a Ni content of 0.10 wt%, and a copper content of 55 wt% in copper matte.

Example 6

The differences from example 1 are: the temperature of the reduction depletion treatment was 1300 ℃.

The tailings obtained by the dilution treatment have a Cu content of 0.35 wt%, a Ni content of 0.07 wt%, and a copper content of 61 wt%.

Example 7

The differences from example 1 are: the temperature of the reduction impoverishment treatment was 1250 ℃.

The tailings obtained by the dilution treatment have a Cu content of 0.41 wt%, a Ni content of 0.12 wt%, and a copper content of 57 wt%.

Example 8

The differences from example 1 are: the dilution treatment device is a plasma furnace, and the dilution temperature is 1400 ℃.

The tailings obtained by the dilution treatment have a Cu content of 0.25 wt%, a Ni content of 0.04 wt%, and a copper content of 63 wt%.

Comparative example 1

The differences from example 1 are: in the slag former, the content of silicon oxide in quartz sand is 92%, the content of iron in iron ore is 51%, the iron-silicon ratio is 0.5, and the calcium-silicon ratio is 0.3.

The tailings obtained by the dilution treatment had a Cu content of 0.42 wt%, a Ni content of 0.11 wt%, and a copper content of 51 wt% in copper matte.

Comparative example 2

The differences from example 1 are: the dilution treatment device is a blast furnace, and the dilution temperature is 1250 ℃.

The tailings obtained by the dilution treatment have a Cu content of 0.55 wt%, a Ni content of 0.13 wt%, and a copper content of 57 wt%.

From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: the method for diluting is beneficial to improving the reaction rate of the diluting process, the recovery rate of copper elements and the environmental protection performance.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The method for diluting the copper-containing sludge is characterized in that a device adopted in the method for diluting comprises a diluting treatment device and a wire feeding device, wherein the diluting treatment device takes electric heat or plasma heat as a heat source, and the diluting treatment device is provided with a feeding port, a wire feeding hole and a matte discharging port; the depletion process comprises:

drying the copper-containing sludge to obtain a dry material, wherein the water content of the dry material is less than or equal to 20%;

and adding the dry material and a slagging agent into the dilution treatment device through the feeding port, feeding a carbon powder line into the dilution treatment device through the line feeding hole by using the line feeding device, and performing reduction and dilution treatment on the dry material by using the carbon powder line, wherein the iron-silicon ratio in the slagging agent is 0.4-0.8, and the calcium-silicon ratio in the slagging agent is 0.6-0.9.

2. The depletion method according to claim 1, wherein the slag former is added in an amount of 15-40% by weight of the dry material.

3. The depletion method according to claim 2, wherein the slag former is iron ore and quartz stone, preferably, the quartz sand is added in an amount of 5-20% and the iron ore is added in an amount of 5-20% in percentage by weight of the dry materials.

4. The depletion method according to claim 1, wherein the amount of carbon powder added to the carbon powder line is 0.1-5% by weight of the copper-containing sludge.

5. The enleanment process according to claim 1, characterized in that the temperature of the reductive enleanment process is 1200-1400 ℃.

6. The depletion method according to claim 5, wherein the temperature of the reductive depletion process is 1300-1350 ℃.

7. The depletion method according to claim 1, wherein the dry material contains 5 to 15 wt% of copper element and 0.15 to 0.5 wt% of nickel element.

8. The depletion method according to any one of claims 1 to 7, characterized in that the depletion treatment device is a mine thermal furnace or a plasma furnace.

9. The enleanment process according to claim 8, wherein the product of the reductive enleanment process step comprises copper matte, slag and tail gas, and the enleanment process further comprises using the copper matte for the production of an anode plate.

10. The enleanment process according to claim 9, further comprising the step of post-treating the tail gas, the post-treatment step comprising:

carrying out waste heat recovery treatment on the tail gas to obtain cold flue gas; and

and carrying out dust collection treatment on the cold flue gas.