Method for integrally strengthening, reducing and separating multiple metals such as lead, zinc and iron in slag

Abstract

The invention discloses a method for integrally strengthening, reducing and separating multiple metals such as lead, zinc and iron in molten slag, which comprises the following steps: the molten slag enters a reducing atmosphere electrode furnace chamber and flows towards a set direction; sequentially flowing through an echelon-rising temperature area; the temperature of the first temperature area is set to be 1000-1200 DEG C; the temperature of the second temperature area is set to be 1200-1350 DEG C; the temperature of the third temperature area is set to be 1350-1550 DEG C; adding a reducing agent and an auxiliary agent; lead metal is reduced in a first temperature zone, zinc metal is reduced in a second temperature zone, and iron metal is reduced in a third temperature zone; respectively collecting lead, iron and zinc; and the reduced waste slag is independently collected. According to the invention, through different temperatures, by utilizing the reduction reaction temperatures and reduction difficulty of different metal oxides and the characteristics of different melting points and boiling points of lead, iron and zinc, by combining the control on the addition amount of a reducing agent and an auxiliary agent and by utilizing a zinc reduction section, a physical partition is arranged; and separating the iron metal melt reduced and deposited at the inner bottom of the electrode furnace chamber at the tail section from the lead metal melt reduced and deposited at the front section, discharging zinc formed by reduction in the second temperature zone out of the furnace in the form of zinc steam, and condensing to obtain zinc liquid. The lead, the iron and the iron are respectively collected through control of the reducing atmosphere and different directions of the lead, the zinc and the iron, so that the lead, the iron and the zinc in the slag are respectively recycled at one time.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-ferrous metal metallurgy, and particularly relates to a method for integrally strengthening the reduction and separation of lead, zinc and iron in molten slag. Background Art

[0002] In the non-ferrous metal smelting in China, the smelting of lead and zinc is mainly single smelting or multi-process hierarchical smelting. Iron enters the slag and is stored as a large amount of solid waste and hazardous waste. The smelting of lead is mainly by pyrometallurgical process. The direct reduction of liquid slag and zinc extraction by fuming in a three-stage furnace device are mainly used in pyrometallurgical lead smelting. The by-product zinc is mainly recovered and enriched by a fuming furnace to obtain low-value zinc oxide. The enriched zinc oxide is then processed by a hydrometallurgical zinc smelting process to obtain metallic zinc. The smelting of zinc is mainly by hydrometallurgical process, mainly using a series of devices for sulfuric acid leaching, purification and electrowinning. For the integrated smelting of lead and zinc, there is currently only the ISP integrated lead-zinc smelting process.

[0003] In short, the current separate or integrated smelting of lead and zinc has problems such as long process flow, high energy consumption, low operation efficiency, low metal recovery rate, and failure to recover iron with high value. Summary of the Invention

[0004] The present invention provides a method for integrally strengthening the reduction and separation of lead, zinc and iron in molten slag to solve the deficiencies described in the above prior art.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A method for integrally strengthening the reduction and separation of lead, zinc and iron in molten slag includes the following steps:

[0007] The molten slag enters the reduction atmosphere furnace cavity and flows in a set direction;

[0008] It sequentially flows through temperature zones with gradually increasing temperatures;

[0009] The temperature of the first temperature zone is set at 1000 - 1200 °C;

[0010] The temperature of the second temperature zone is set at 1200 - 1350 °C;

[0011] The temperature of the third temperature zone is set at 1350 - 1550 °C;

[0012] A reducing agent and an auxiliary agent are added;

[0013] Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron and zinc are collected separately;

[0014] The reduced waste molten slag is collected separately.

[0015] As a preferred embodiment of the present invention, the first temperature zone and the third temperature zone are physically isolated by the second temperature zone to prevent the mixing of lead and iron reduced from the first temperature zone and the third temperature zone.

[0016] As a preferred embodiment of the present invention, the reducing agent includes, but is not limited to, one or more of coal, carbon, graphite.

[0017] As a preferred embodiment of the present invention, the additives include one or more of additive A and additive B; the additive A includes, but is not limited to, one or more of quicklime and calcium carbonate;

[0018] The additive B includes, but is not limited to, one or more of silicon dioxide, sodium silicate, and zinc silicate.

[0019] As a preferred embodiment of the present invention, the particle diameter of the reducing agent is 5 mm - 30 mm; the water content is less than 1%; the addition amount of the reducing agent in the front section of the first temperature zone is 60 - 100 kg per ton of lead; the addition amount in the tail section of the first temperature zone is 230 - 300 kg per ton of zinc; the addition amount in the tail section of the second temperature zone is 240 - 310 kg per ton of iron.

[0020] As a preferred embodiment of the present invention, the particle diameter of the additive is 5 mm - 30 mm; the addition amount of the additive in the tail section of the first temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.6 - 0.8; the addition amount in the tail section of the second temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.8 - 1.2.

[0021] As a preferred embodiment of the present invention, during the reduction process, multiple plasma injections into the slag are set.

[0022] As a preferred embodiment of the present invention, the plasma is a reducing substance plasma.

[0023] As a preferred embodiment of the present invention, the plasma injection port simultaneously injects one or more reducing substances including, but not limited to, carbon powder and CO gas.

[0024] The beneficial effects of the present invention are as follows: By using different temperatures, taking advantage of the reduction reaction temperatures of different metal oxides, and the characteristics that the melting points and boiling points of lead, iron, and zinc are all different, combined with the control of the addition amounts of the reducing agent and the additives, the present invention mainly reduces lead metal in the front section, mainly reduces zinc metal in the middle section. At the same time, the reduced zinc metal becomes zinc vapor and is collected, and a physical partition is set using the physical space in the zinc reduction section to separate the iron metal reduced in the tail section from the lead metal reduced in the front section, and they are collected separately, realizing the primary separate recovery of lead, iron, and zinc metals in the slag.

[0025] Meanwhile, through the creative introduction of plasma, the high-activity characteristics of plasma are utilized to improve the reduction efficiency and reduce energy consumption. Further, when plasma is injected, reducing substances are introduced into the slag to deeply participate in the reaction. Compared with the traditional technology where the reducing agent only floats on the surface of the slag to participate in the reaction, the reduction speed is further increased.

[0026] The technical solution has further evolved. In the case where there is no plasma injection device, directly feeding the reducing substance into the slag can also greatly increase the reaction rate. Specific implementation manner

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0028] Embodiment 1:

[0029] A method for integrally strengthening the reduction and separation of lead, zinc, and iron multi-metals in slag, comprising the following steps:

[0030] The slag enters the reduction atmosphere furnace cavity and flows in a set direction;

[0031] Sequentially flow through temperature zones with gradually increasing temperatures;

[0032] The temperature of the first temperature zone is set to 1000 °C;

[0033] The temperature of the second temperature zone is set to 1200 °C;

[0034] The temperature of the third temperature zone is set to 1350 °C;

[0035] Add a reducing agent and an additive; the reducing agent is coke granules, and the additive is quicklime and silica;

[0036] Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron, and zinc are collected separately; the first temperature zone and the third temperature zone are physically separated by the second temperature zone to prevent the lead and iron reduced in the first temperature zone and the third temperature zone from mixing; the reduced waste slag is collected separately.

[0037] The coke granules have a particle diameter of 5 mm - 30 mm; the water content is less than 1%; the addition amount of the coke granules in the front section of the first temperature zone is 60 kg per ton of lead; the addition amount in the tail section of the first temperature zone is 230 kg per ton of zinc; the addition amount in the tail section of the second temperature zone is 240 kg per ton of iron;

[0038] The diameter of the quicklime particles is 5 mm - 30 mm; the additive is added at the end of the first temperature zone, and the addition amount makes the calcium-silicon ratio (by weight) in the slag 0.6; the additive is added at the end of the second temperature zone, and the addition amount makes the calcium-silicon ratio (by weight) in the slag 0.8.

[0039] Example 2:

[0040] A method for integrally strengthening the reduction and separation of lead, zinc and iron multi-metals in slag, comprising the following steps:

[0041] The slag enters the reduction atmosphere furnace cavity and flows in a set direction;

[0042] It sequentially flows through temperature zones with gradually increasing temperatures;

[0043] The temperature of the first temperature zone is set at 1200 °C;

[0044] The temperature of the second temperature zone is set at 1350 °C;

[0045] The temperature of the third temperature zone is set at 1550 °C;

[0046] A reducing agent and an additive are added; the reducing agent is coke, and the additive is calcium carbonate and sodium silicate;

[0047] Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron and zinc are collected separately; the first temperature zone and the third temperature zone are physically separated by the second temperature zone to prevent the lead and iron reduced in the first temperature zone and the third temperature zone from mixing; the reduced waste slag is collected separately.

[0048] The diameter of the coke particles is 5 mm - 30 mm; the water content is less than 1%; the addition amount of the coke in the front section of the first temperature zone is 100 kg per ton of lead; the addition amount of the coke in the end section of the first temperature zone is 300 kg per ton of zinc; the addition amount of the coke in the end section of the second temperature zone is 310 kg per ton of iron;

[0049] The diameter of the silicon dioxide particles is 5 mm - 30 mm; the additive is added at the end of the first temperature zone, and the addition amount makes the calcium-silicon ratio (by weight) in the slag 0.8; the additive is added at the end of the second temperature zone, and the addition amount makes the calcium-silicon ratio (by weight) in the slag 1.2.

[0050] Example 3

[0051] A method for integrally strengthening the reduction and separation of lead, zinc and iron multi-metals in slag, comprising the following steps:

[0052] The slag enters the reduction atmosphere furnace cavity and flows in a set direction;

[0053] It sequentially flows through temperature zones with gradually increasing temperatures;

[0054] The temperature of the first temperature zone is set to 1100 °C;

[0055] The temperature of the second temperature zone is set to 1300 °C;

[0056] The temperature of the third temperature zone is set to 1400 °C;

[0057] A reducing agent and an auxiliary agent are added; the reducing agent is coke pellets, and the auxiliary agent is quicklime and zinc silicate;

[0058] Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron, and zinc are collected separately; the first temperature zone and the third temperature zone are physically isolated by the second temperature zone to prevent the lead and iron reduced in the first temperature zone and the third temperature zone from mixing; the reduced waste slag is collected separately.

[0059] The coke pellets have a particle diameter of 5 mm - 30 mm; the water content is less than 1%; the addition amount of the coke pellets in the front section of the first temperature zone is 65 kg per ton of lead; the addition amount in the tail section of the first temperature zone is 250 kg per ton of zinc; the addition amount in the tail section of the second temperature zone is 260 kg per ton of iron;

[0060] The calcium carbonate has a particle diameter of 5 mm - 30 mm; the addition amount of the auxiliary agent in the tail section of the first temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.7; the addition amount in the tail section of the second temperature zone makes the calcium-silicon ratio (by weight) in the slag 1.0.

[0061] Example 4

[0062] A method for integrally strengthening the reduction and separation of lead, zinc, and iron in slag, comprising the following steps:

[0063] The slag enters the reduction atmosphere furnace cavity and flows in a set direction;

[0064] It sequentially flows through temperature zones with gradually increasing temperatures;

[0065] The temperature of the first temperature zone is set to 1000 °C;

[0066] The temperature of the second temperature zone is set to 1200 °C;

[0067] The temperature of the third temperature zone is set to 1350 °C;

[0068] A reducing agent and an auxiliary agent are added; the reducing agent is coke pellets, and the auxiliary agent is quicklime and silica;

[0069] Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron, and zinc are collected separately; the first temperature zone and the third temperature zone are physically isolated by the second temperature zone to prevent the lead and iron reduced in the first temperature zone and the third temperature zone from mixing; the reduced waste slag is collected separately; during the reduction process, plasma injection ports are provided at multiple locations in the furnace cavity to inject plasma into the slag, and at the same time, a reducing substance is additionally injected into the slag to participate in the reduction reaction and improve the reaction rate.

[0070] The coke particles have a particle diameter of 5 mm - 30 mm; the water content is less than 1%; the addition amount of the coke in the front section of the first temperature zone is 80 kg per ton of lead; the addition amount of the coke in the tail section of the first temperature zone is 280 kg per ton of zinc; the addition amount of the coke in the tail section of the second temperature zone is 290 kg per ton of iron;

[0071] The quicklime particles have a particle diameter of 5 mm - 30 mm; the addition amount of the additive in the tail section of the first temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.66; the addition amount of the additive in the tail section of the second temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.98.

[0072] In the description of this specification, the descriptions with reference to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0073] As described above, the above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes an equivalent replacement or change, and should be covered by the protection scope of the present invention.

Claims

1. An integrated method for strengthening the reduction and separating lead, zinc and iron in slag, characterized in that: The slag enters the reduction atmosphere furnace cavity and flows in a set direction; Sequentially flow through temperature zones with gradually increasing temperatures; The temperature of the first temperature zone is set at 1000 - 1200 °C; The temperature of the second temperature zone is set at 1200 - 1350 °C; The temperature of the third temperature zone is set at 1350 - 1550 °C; Add a reducing agent and an additive; Lead metal is reduced in the first temperature zone, zinc metal is reduced in the second temperature zone, and iron metal is reduced in the third temperature zone; lead, iron and zinc are collected separately; The reduced waste slag is collected separately.

2. The method for integrally strengthening, reducing and separating lead, zinc and iron polymetals in slag according to claim 1, characterized in that: The first temperature zone and the third temperature zone are physically separated by the second temperature zone to prevent the mixing of lead and iron reduced in the first temperature zone and the third temperature zone.

3. The method for integrally strengthening and reducing and separating lead, zinc and iron polymetals in slag according to claim 1, characterized in that: The reducing agent includes, but is not limited to, one or more of coal, carbon, graphite.

4. A method for integrally strengthening the reduction and separation of lead, zinc and iron polymetals in slag, according to claim 1, characterized in that: The additive includes one or more of additive A and additive B; The additive A includes, but is not limited to, one or more of quicklime and calcium carbonate; The additive B includes, but is not limited to, one or more of silicon dioxide, sodium silicate and zinc silicate.

5. A method for integrally strengthening the reduction and separation of lead, zinc and iron polymetals in slag, according to claim 1, characterized in that: The particle diameter of the reducing agent is 5 mm - 30 mm; the water content is less than 1%; the addition amount of the reducing agent in the front section of the first temperature zone is 60 - 100 kg per ton of lead; the addition amount in the tail section of the first temperature zone is 230 - 300 kg per ton of zinc; the addition amount in the tail section of the second temperature zone is 240 - 310 kg per ton of iron.

6. The method for integrally strengthening, reducing and separating lead, zinc and iron polymetals in slag according to claim 1, characterized in that: The particle diameter of the additive is 5 mm - 30 mm; the addition amount of the additive in the tail section of the first temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.6 - 0.8; the addition amount in the tail section of the second temperature zone makes the calcium-silicon ratio (by weight) in the slag 0.8 - 1.

2.

7. A method for integrally strengthening and reducing and separating lead, zinc and iron polymetals in slag, according to claim 1, characterized in that: During the reduction process, plasma is injected into the slag at multiple locations.

8. A method for integrally strengthening the reduction and separation of lead, zinc and iron polymetals in slag according to claim 7, characterized in that: The plasma is a plasma of reducing substances.

9. The method for integrally strengthening and reducing and separating lead, zinc and iron multi-metals in slag according to claim 7, characterized in that: The plasma injection port simultaneously injects one or more reducing substances including, but not limited to, carbon powder and CO gas.