Indium-tin smelting method with improved smelting efficiency

Abstract

Disclosed in the present invention is an indium-tin smelting method with an improved smelting efficiency. The method comprises the following steps: 1) smelting: feeding a polymetallic zinc ore into an oxidation furnace for smelting to produce oxidized flue gas and smelting slag, wherein the oxidized flue gas is used to prepare sulfuric acid, and the smelting slag, granular material and reduced coal are mixed and smelted in an agitated molten bath equipped with a lead rain condenser; 2) subjecting the crude zinc alloy to multi-stage distillation; and 3) subjecting the indium-tin-zinc alloy to crushing, primary leaching, extraction and stripping, tin precipitation by soda ash, zinc replacement, and crude indium electrolysis, so as to obtain tin and indium. According to the present invention, heat and mass transfer are enhanced during the reaction process in smelting, the smelting efficiency is improved, the enrichment of elements such as copper in raw materials in a sulfide or metal state is facilitated, and the metal recovery rate is improved. Moreover, harmful organic impurities in the waste can be decomposed and converted into non-toxic substances at a high temperature, and fluorine is solidified in the smelting slag as calcium fluoride, which is beneficial for ensuring that the smelting slag is harmless.

Description

A method for improving smelting efficiency indium-tin smelting Technical Field

[0001] This invention relates to the field of ore smelting technology, and in particular to an indium-tin smelting method for improving smelting efficiency. Background Technology

[0002] my country has abundant mineral resources, and polymetallic zinc resources are a part of these resources. However, due to extensive development and utilization, a large amount of resources have been wasted.

[0003] During the smelting of lead and zinc ores and downstream development, a large amount of indium-tin mixtures are generated. Waste powder is generated during the production of ITO powder. In addition, waste indium-tin solder is also generated during the coating sputtering production. These waste targets, waste powder, and waste indium-tin solder are all indium-tin mixtures and have high economic value for recycling.

[0004] Furthermore, existing zinc ore smelting technologies suffer from low recovery rates for other valuable metals, which severely impacts economic returns and work efficiency, causing certain economic losses to enterprises.

[0005] Therefore, there is an urgent need for an indium-tin smelting method that improves smelting efficiency to solve the above problems.

[0006] Summary of the Invention

[0007] The purpose of this invention is to provide an indium-tin smelting method that improves smelting efficiency.

[0008] The solution of the present invention is:

[0009] An indium-tin smelting method for improving smelting efficiency includes the following steps:

[0010] 1) Smelting: Polymetallic zinc ore is fed into an oxidation furnace for smelting, producing oxidizing flue gas and smelting slag. The oxidizing flue gas is used to produce sulfuric acid. The smelting slag, granular material, and reducing coal are mixed and smelted in a stirred molten pool with a lead rain condenser at a smelting temperature of 1250-1350℃. The oxygen-enriched air is introduced into the furnace at a temperature of 800-1000℃, producing crude zinc alloy, coarse mixed metal, and slag. The granular material includes recycled material, flux, sodium silicate, and water, which are mixed and dried to form 0.1-2cm granules.

[0011] 2) The crude zinc alloy undergoes multi-stage distillation, including primary, secondary, tertiary, and quaternary vacuum distillation. The crude zinc alloy undergoes primary vacuum distillation at a temperature of 650–750°C, producing a zinc-cadmium alloy and a zinc-indium-tin bottom solution. The zinc-cadmium alloy undergoes secondary vacuum distillation at a temperature of 600–650°C, producing pyrometallurgically distilled zinc and a high-cadmium zinc alloy. The pyrometallurgically distilled zinc is cast and cooled to obtain zinc ingots. The high-cadmium zinc alloy undergoes tertiary vacuum distillation at a temperature of 500–600°C, producing a crude cadmium product and a low-cadmium zinc alloy. The low-cadmium zinc alloy is returned to the secondary vacuum distillation stage. The zinc-indium-tin bottom solution undergoes quaternary vacuum distillation at a temperature of 950–1000°C, producing a high-indium-tin zinc alloy and high-temperature crude zinc. The high-temperature crude zinc is returned to the primary vacuum distillation stage.

[0012] 3) The indium-tin-zinc alloy is subjected to crushing, primary leaching, extraction and back-extraction, soda ash tin precipitation, zinc replacement, and crude indium electrolysis to obtain tin and indium.

[0013] As a preferred technical solution, the polymetallic zinc ore is fed into an oxidation furnace for smelting, and the oxidation smelting temperature is 1200-1300℃.

[0014] As a preferred technical solution, smelting is carried out in a stirred molten pool with a lead rain condenser using oxygen-enriched blowing.

[0015] As a preferred technical solution, the recycled material is one or more of the following: tin-indium containing flue dust, ITO waste, and polymetallic zinc-tin industrial waste; and the flux is one or more of the following: calcium oxide, silicon dioxide, and iron disulfide.

[0016] As a preferred technical solution, the mass ratio of the recycled material, flux, and sodium silicate is 1:0.1 to 0.3:0.06; and the material is dried until the moisture content of the particles is less than 1%.

[0017] As a preferred technical solution, the mass ratio of the sum of the smelting slag and granular material to the mass of reducing coal is 1:0.3 to 0.5.

[0018] As a preferred technical solution, the oxygen-enriched air includes oxygen and air; the oxygen content in the oxygen-enriched air is 40-60 vol%.

[0019] As a preferred technical solution, the crushing in step 3) is mechanical crushing.

[0020] As a preferred technical solution, the oxygen concentration injected into the oxidizing furnace is 30%; the stirring pool with lead rain condenser is smelted for 30 to 50 minutes, and its sulfur partial pressure logarithm is -7 to -5.

[0021] Advantages of this invention:

[0022] This invention enhances the heat and mass transfer during the smelting process of smelting slag, tin-indium-containing dust, ITO waste, and polymetallic zinc-tin industrial waste, thereby improving smelting efficiency. It also facilitates the enrichment of elements such as copper in the raw materials in sulfide or metallic form, which is beneficial for improving metal recovery rate. Furthermore, it can decompose and convert harmful organic impurities in the waste into non-toxic substances at high temperatures, and solidify fluorine in the slag with calcium fluoride, which helps to ensure that the slag is harmless.

[0023] It is beneficial to improve the treatment efficiency of tin-indium-containing fumes, ITO waste and polymetallic zinc-tin industrial waste, and reduce the energy consumption of smelting. Attached Figure Description

[0024] Figure 1 is a flowchart of the present invention. Detailed Implementation

[0025] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0026] The following embodiments are only for further detailed description of the present invention, but do not constitute any limitation on the present invention; the materials used in the following embodiments, unless otherwise specified, were purchased from conventional chemical reagent companies and raw material suppliers.

[0027] Example 1:

[0028] A polymetallic zinc ore containing 12% Fe, 0.04% In, 0.1% Cu, 0.2% Cd, 0.01% Ag, 0.1% Sn, 42% Zn, and 26% S;

[0029] 1) Smelting: Polymetallic zinc ore is fed into an oxidation furnace at a rate of 10 t / h for smelting at a temperature of 1200℃, producing oxidizing flue gas and smelting slag. The oxidizing flue gas is used to produce sulfuric acid. The smelting slag, granular material, and reducing coal are mixed and smelted in a stirred molten pool equipped with two lead rain condensers at a smelting temperature of 1250℃. The oxygen-enriched air entering the furnace is at a temperature of 800℃, producing crude zinc alloy, coarse mixed metal, and slag. The granular material includes recycled material, flux, sodium silicate, and water, which are then dried to form 0.1 cm granules. The daily output of crude zinc alloy contains 98.2% Zn, 0.012% In, 0.02% Cu, 0.54% Cd, and 0.06% Sn. The daily output of coarse mixed metal contains 87.3% Cu, 2.1% Fe, 0.018% In, 4.3% Ag, and 6.7% Sn.

[0030] 2) The crude zinc alloy is subjected to multi-stage distillation, which is multi-stage vacuum distillation. In the multi-stage vacuum distillation, the distillation stage above 950°C produces indium tin zinc alloy and crude zinc. The crude zinc is returned to the distillation stage at 650-750°C in the multi-stage distillation.

[0031] 3) The indium-tin-zinc alloy is processed using the following process: mechanical crushing, dilute sulfuric acid dissolution, P2O4 organic matter extraction, hydrochloric acid back-extraction, soda ash tin precipitation, zinc ingot replacement, and crude indium electrolysis. Each batch is 1.0t, producing a refined indium product containing 99.995% In and recovering tin raw materials containing 53.8% Sn.

[0032] The smelting process employs a stirred molten pool with a lead rain condenser and utilizes oxygen-enriched blowing.

[0033] The recycled material is flue dust containing 53.25% Sn, 2.62% Pb, 1.12% Fe, 0.01% Cu, 3.412% Zn, and 0.598% S, and the flux is calcium oxide.

[0034] The mass ratio of the recycled material, flux, and sodium silicate is 1:0.1:0.06; the material is dried until the moisture content of the particles is less than 1%.

[0035] The sum of the masses of the smelting slag and granular material is in a mass ratio of 1:0.3 to the mass of the reducing coal.

[0036] The oxygen-enriched air comprises oxygen and air; the oxygen content in the oxygen-enriched air is 40 vol%.

[0037] The crushing described in 3) is mechanical crushing.

[0038] The oxygen concentration injected into the oxidizing furnace is 30%; the stirring pool with lead rain condenser is smelted for 30 to 50 minutes, and its sulfur partial pressure logarithm is -7 to -5.

[0039] Example 2:

[0040] Zinc concentrate containing 18% Fe, 0.09% In, 0.2% Cu, 0.3% Cd, 0.018% Ag, 0.16% Sn, 48% Zn, and 27% S,

[0041] 1) Smelting: Polymetallic zinc ore is fed into an oxidation furnace at a rate of 10 t / h for smelting at a temperature of 1250℃, producing oxidizing flue gas and smelting slag. The oxidizing flue gas is used to produce sulfuric acid. The smelting slag, granular material, and reducing coal are mixed and smelted in a stirred molten pool equipped with two lead rain condensers at a smelting temperature of 1300℃. The oxygen-enriched air is introduced into the furnace at a temperature of 900℃, producing crude zinc alloy, coarse mixed metal, and slag. The granular material includes recycled material, flux, sodium silicate, and water, which are then dried to form 1 cm granules.

[0042] The daily output of crude zinc alloy contains 98.9% Zn, 0.042% In, 0.02% Cu, 0.83% Cd, and 0.16% Sn, while the daily output of crude mixed metal contains 85.2% Cu, 2.6% Fe, 0.015% In, 3.8% Ag, and 5.2% Sn.

[0043] 2) The crude zinc alloy is subjected to multi-stage distillation, which is multi-stage vacuum distillation. In the multi-stage vacuum distillation, the distillation stage above 950°C produces indium tin zinc alloy and crude zinc. The crude zinc is returned to the distillation stage at 650-750°C in the multi-stage distillation.

[0044] 3) The indium-tin-zinc alloy is processed using the following process: mechanical crushing, dilute sulfuric acid dissolution, P2O4 organic matter extraction, hydrochloric acid back-extraction, soda ash tin precipitation, zinc ingot replacement, and crude indium electrolysis. Each batch is 1.0t, producing a refined indium product containing 99.995% In and recovering tin raw materials containing 54.1% Sn.

[0045] The smelting process employs a stirred molten pool with a lead rain condenser and utilizes oxygen-enriched blowing.

[0046] The recycled material is SnO2-containing 10% ITO waste, and the flux is iron disulfide.

[0047] The mass ratio of the recycled material, flux, and sodium silicate is 1:0.2:0.06; the material is dried until the moisture content of the particles is less than 1%.

[0048] The sum of the masses of the smelting slag and granular material is in a mass ratio of 1:0.4 to the mass of the reducing coal.

[0049] The oxygen-enriched air comprises oxygen and air; the oxygen content in the oxygen-enriched air is 50 vol%.

[0050] The oxidation furnace is injected with an oxygen concentration of 30% for smelting; the stirring pool with lead rain condenser is smelted for 40 minutes, and its sulfur partial pressure logarithm is -7 to -5.

[0051] Example 3:

[0052] Zinc concentrate containing 21% Fe, 0.12% In, 0.4% Cu, 0.3% Cd, 0.03% Ag, 0.4% Sn, 48% Zn, and 15% S.

[0053] 1) Smelting: Polymetallic zinc ore is fed into an oxidation furnace at a rate of 10 t / h for smelting at a temperature of 1300℃, producing oxidizing flue gas and smelting slag. The oxidizing flue gas is used to produce sulfuric acid. The smelting slag, granular material, and reducing coal are mixed and smelted in a stirred molten pool with a lead rain condenser at a temperature of 1350℃. The oxygen-enriched air is fed into the furnace at a temperature of 1000℃, producing crude zinc alloy, coarse mixed metal, and slag. The granular material includes recycled material, flux, sodium silicate, and water, which are then dried to form 2cm granules.

[0054] The daily output of crude zinc alloy contains 98.3% Zn, 0.03% Cu, 0.035% In, 0.75% Cd, and 0.18% Sn; the daily output of crude mixed metal contains 85.4% Cu, 2.6% Fe, 0.012% In, 2.6% Ag, and 3.6% Sn.

[0055] 2) The crude zinc alloy is subjected to multi-stage distillation, which is multi-stage vacuum distillation. In the multi-stage vacuum distillation, the distillation stage above 950°C produces indium tin zinc alloy and crude zinc. The crude zinc is returned to the distillation stage at 650-750°C in the multi-stage distillation.

[0056] 3) The indium-tin-zinc alloy is processed using the following process: mechanical crushing, dilute sulfuric acid dissolution, P2O4 organic matter extraction, hydrochloric acid back-extraction, soda ash tin precipitation, zinc ingot replacement, and crude indium electrolysis. Each batch is 1.0t, producing a refined indium product containing 99.995% In and recovering tin raw materials containing 52.6% Sn.

[0057] The smelting process employs a stirred molten pool with a lead rain condenser and utilizes oxygen-enriched blowing.

[0058] The recycled material is a polymetallic zinc-tin industrial waste containing 0.42% Zn and 1.8% Sn, and the flux is calcium oxide.

[0059] The mass ratio of the recycled material, flux, and sodium silicate is 1:0.3:0.06; the material is dried until the moisture content of the particles is less than 1%.

[0060] The sum of the masses of the smelting slag and granular material is in a mass ratio of 1:0.5 to the mass of the reducing coal.

[0061] The oxygen-enriched air comprises oxygen and air; the oxygen content in the oxygen-enriched air is 60 vol%.

[0062] The oxidation furnace is injected with an oxygen concentration of 30% for smelting; the stirring pool with lead rain condenser is smelted for 50 minutes, and its sulfur partial pressure logarithm is -7 to -5.

[0063] The multi-stage vacuum distillation includes a first-stage vacuum distillation at 750°C, producing a zinc-cadmium alloy and a zinc-indium-tin bottom solution; the zinc-cadmium alloy enters a second-stage vacuum distillation at 650°C, producing vacuum-distilled zinc and a high-cadmium zinc alloy, which is then cast and cooled to obtain zinc ingots; the high-cadmium zinc alloy enters a third-stage vacuum distillation at 600°C, producing a low-cadmium zinc alloy, which is returned to the cadmium tower for a second-stage vacuum distillation; the zinc-indium-tin bottom solution enters a fourth-stage vacuum distillation at 1000°C, producing 0.06 t / h of high-indium-tin zinc alloy and high-temperature crude zinc, which is returned to the lead tower for a first-stage vacuum distillation.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for improving the smelting efficiency of indium-tin smelting, characterized in that, Includes the following steps: 1) Smelting: Polymetallic zinc ore is fed into an oxidation furnace for smelting, producing oxidizing flue gas and smelting slag. The oxidizing flue gas is used to produce sulfuric acid. The smelting slag, granular material, and reducing coal are mixed and smelted in a stirred molten pool with a lead rain condenser at a smelting temperature of 1250-1350℃. The oxygen-enriched air is introduced into the furnace at a temperature of 800-1000℃, producing crude zinc alloy, coarse mixed metal, and slag. The granular material includes recycled material, flux, sodium silicate, and water, which are mixed and dried to form 0.1-2cm granules. 2) The crude zinc alloy is subjected to multi-stage distillation to produce high indium tin zinc alloy and high-temperature crude zinc. The high-temperature crude zinc is returned to the first stage of vacuum distillation in the multi-stage distillation. 3) The indium-tin-zinc alloy is subjected to crushing, primary leaching, extraction and back-extraction, soda ash tin precipitation, zinc replacement, and crude indium electrolysis to obtain tin and indium.

2. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The recycled material is one or more of the following: tin-indium containing flue dust, ITO waste, and polymetallic zinc-tin industrial waste; the flux is one or more of the following: calcium oxide, silicon dioxide, and iron disulfide.

3. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The mass ratio of the recycled material, flux, and sodium silicate is 1:0.1 to 0.3:0.06; the material is dried until the moisture content of the particles is less than 1%.

4. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The ratio of the total mass of the smelting slag and granular material to the mass of the reducing coal is 1:0.3 to 0.

5.

5. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The oxygen-enriched air comprises oxygen and air; the oxygen content in the oxygen-enriched air is 40-60 vol%.

6. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The crushing described in 3) is mechanical crushing.

7. The indium-tin smelting method for improving smelting efficiency as described in claim 1, characterized in that: The oxygen concentration injected into the oxidizing furnace is 30%; the stirring pool with lead rain condenser is smelted for 30 to 50 minutes, and its sulfur partial pressure logarithm is -7 to -5.

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