CN116397111A - A method for producing high-grade coarse bismuth from copper-removing slag - Google Patents

Abstract

The invention discloses a method for producing high-grade crude bismuth by decoppering slag, which comprises the steps of decoppering slag smelting, arsenic and antimony removal by oxidation, copper removal by liquation, copper removal by adding sulfur, silver removal by adding zinc and the like.

Description

A method for producing high-grade coarse bismuth from copper-removing slag

technical field

The application of the present invention relates to the technical field of metallurgy, in particular to a method for producing high-grade coarse bismuth from copper-removing slag.

Background technique

Domestic bismuth oxide production rough bismuth process technology: according to the composition of bismuth oxide, determine the proportioning ratio, add sulfur concentrate, soda ash, fluorite powder, coal powder, iron filings and other additives, and then carry out reduction smelting in the converter to enhance the reducing atmosphere. The bismuth and most of the lead are reduced to metal to form coarse bismuth. Because lead has a strong affinity for noble metals, and most of the noble metals exist in the form of metals, most of them dissolve in coarse bismuth, while copper with a high affinity for sulfur , iron, then form sulfide to form matte, a small part of lead and precious metals are also dissolved in matte, a part of sodium enters into matte, which reduces the melting point and density of matte, due to the strong reducing atmosphere, part of arsenic, Antimony is also reduced in coarse bismuth, and most of it is oxidized and volatilized or slags with soda ash.

There is also a patent name: a method for reclaiming refined bismuth and refined copper from high-copper bismuth slag, comprising the following steps: 1) high-copper bismuth slag is mixed with coke, soda ash, borax, pyrite, fluorite, and silica in proportion Mixing to obtain a mixed material, the mixed material is subjected to matte smelting, the temperature of the melt is controlled, and coarse bismuth, matte, alkali slag and smoke are produced. The above process technologies are all industrial technologies for producing coarse bismuth in one converter, and there is no technology for producing coarse bismuth from copper-removing slag.

When chlorine gas is used for production, the production cycle for lead removal is long, the cost of chlorine gas usage is high, the incomplete reaction of chlorine gas in the production process causes environmental pollution due to the overflow of the collection system, the direct recovery rate of bismuth in the production process is low, and the first pass rate of products is low. The cost of follow-up treatment of lead chloride is high, the danger of chlorine gas is high, the procurement procedures of chlorine gas are complicated, the conditions of production and storage are harsh, and it is easy to leak during storage and production and use, resulting in safety risks.

Contents of the invention

In order to solve or partially solve the problems existing in the related technologies, the present invention provides a method for producing high-grade coarse bismuth from copper-removing slag.

Include the following steps:

S1. Smelting of copper-removing slag: After adding additives such as copper-removing slag, pyrite, soda ash and coal powder into the converter, reduction smelting is carried out in the converter to produce primary bismuth;

S2. Oxidative removal of arsenic and antimony: Oxidation and refining to remove arsenic and antimony is to use the free enthalpy of arsenic, antimony oxides and bismuth oxides to differ greatly. Arsenic and antimony are preferentially oxidized to generate arsenic oxide and antimony oxide to volatilize bismuth liquid to remove arsenic and antimony. The operation time is 4-10 hours, and the end point is when the volatilized white smoke is thin, and the scum is removed;

S3. Copper removal by melting: In the smelting pot, using the characteristic that the solubility of copper in bismuth liquid varies with temperature, the temperature is controlled at 500°C to make copper form a refractory compound or eutectic solid solution to precipitate out as scum, which can be removed. 50% copper is removed by melting;

S4. Adding sulfur to remove copper: the copper content is still greater than 0.3%. It is necessary to add sulfur and then stir to remove copper. The temperature of the sulfur addition operation is controlled at 280-330°C, and sulfur and copper are used to generate cuprous sulfide with a low density and not meltable in bismuth liquid. And remove, finally, when the temperature rises to 650°C, blow in compressed air to oxidize the residual sulfur to generate _SO2 gas, and the copper removal operation ends;

S5. Adding zinc to remove silver: In the smelting pot, adopt low temperature operation, 420-500 ℃, add zinc to remove silver based on the formation of stable refractory compounds between zinc and silver, and remove them as scum with low density. The quality and recovery rate of the refined bismuth is greatly affected by the quality of the silver removal operation. The silver content of the bismuth liquid is less than 0.003%, and the operation is over.

Further, if the scum in S2 is thin, add an appropriate amount of caustic soda or sawdust to make the scum dry so as to remove the scum.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

Beneficial technical effect of the present invention:

1. The crude bismuth produced by this process has high grade and low gold and silver content, and can be sold directly as a product.

2. This process is beneficial to reduce production costs and safety risks in the production process.

Detailed ways

Alternative embodiments of the present application will be described in more detail below. While alternative embodiments of the present application have been described, it should be understood that the present application can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

The terms used in the present application are for the purpose of describing particular embodiments only, and are not intended to limit the present application. As used in this application and the appended claims, the singular forms "a", "the", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and/or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

For more clarity, detailed description is given below through the following examples.

Example 1

S1. Smelting of copper-removing slag: After adding additives such as copper-removing slag, pyrite, soda ash and coal powder into the converter, reduction smelting is carried out in the converter to produce primary bismuth;

S2. Oxidative removal of arsenic and antimony: Oxidation and refining to remove arsenic and antimony is to use the free enthalpy of arsenic, antimony oxides and bismuth oxides to differ greatly. Prioritize oxidation to generate arsenic oxide and antimony oxide and volatilize bismuth liquid to remove arsenic and antimony. The operation time is 4 hours, and the end point is when the volatilized white smoke is thin, and the scum is removed; if the scum is thin, add an appropriate amount of caustic soda or sawdust, Dry the scum so it can be scooped out.

S3. Copper removal by melting: In the smelting pot, using the characteristic that the solubility of copper in bismuth liquid varies with temperature, the temperature is controlled at 500°C to make copper form a refractory compound or eutectic solid solution to precipitate out as scum, which can be removed. 50% copper is removed by melting;

S4. Adding sulfur to remove copper: the copper content is still greater than 0.3%. It is necessary to add sulfur and then stir to remove copper. The temperature of the sulfur addition operation is controlled at 280 ° C. Sulfur and copper are used to form cuprous sulfide that has a low density and does not melt in bismuth liquid. , and finally, when the temperature rises to 650°C, blow in compressed air to oxidize the residual sulfur to generate SO ₂ gas, and the copper removal operation ends;

S5. Adding zinc to remove silver: In the smelting pot, adopt low temperature operation, add zinc to remove silver at 420°C, based on the formation of stable refractory compounds between zinc and silver, which are removed in the form of scum with low density. The quality and recovery rate of the refined bismuth is greatly affected by the quality of the silver removal operation. The silver content of the bismuth liquid is less than 0.003%, and the operation is over.

Secondary coarse bismuth is produced, and the bismuth content is greater than 70%, which can be directly sold outside.

Example 2

S1. Smelting of copper-removing slag: After adding additives such as copper-removing slag, pyrite, soda ash and coal powder into the converter, reduction smelting is carried out in the converter to produce primary bismuth;

S2. Oxidative removal of arsenic and antimony: Oxidation and refining to remove arsenic and antimony is to use the free enthalpy of arsenic, antimony oxides and bismuth oxides to differ greatly. Prioritize oxidation to generate arsenic oxide and antimony oxide to volatilize bismuth liquid to remove arsenic and antimony. The operation time is 4-10 hours, and the end point is when the volatilized white smoke is thin, and the scum is removed; if the scum is thin, add an appropriate amount of caustic soda or Sawdust, to dry out the scum so it can be scooped out.

S3. Copper removal by melting: In the smelting pot, using the characteristic that the solubility of copper in bismuth liquid varies with temperature, the temperature is controlled at 500°C to make copper form a refractory compound or eutectic solid solution to precipitate out as scum, which can be removed. 50% copper is removed by melting;

S4. Adding sulfur to remove copper: the copper content is still greater than 0.3%. It is necessary to add sulfur and then stir to remove copper. The temperature of the sulfur addition operation is controlled at 330 ° C. Sulfur and copper are used to form cuprous sulfide with a small density and not meltable in bismuth liquid. , and finally, when the temperature rises to 650°C, blow in compressed air to oxidize the residual sulfur to generate SO ₂ gas, and the copper removal operation ends;

S5. Adding zinc to remove silver: In the smelting pot, adopt low temperature operation, add zinc to remove silver at 500°C, based on the formation of stable refractory compounds between zinc and silver, and remove them as scum with low density. The quality and recovery rate of the refined bismuth is greatly affected by the quality of the silver removal operation. The silver content of the bismuth liquid is less than 0.003%, and the operation is over.

Secondary coarse bismuth is produced, and the bismuth content is greater than 70%, which can be directly sold outside.

Example 3

S1. Smelting of copper-removing slag: After adding additives such as copper-removing slag, pyrite, soda ash and coal powder into the converter, reduction smelting is carried out in the converter to produce primary bismuth;

S2. Oxidative removal of arsenic and antimony: Oxidative refining for arsenic and antimony removal is to use the free enthalpy of arsenic, antimony oxides and bismuth oxides. Preferentially oxidize arsenic oxide and antimony oxide to volatilize bismuth liquid to remove arsenic and antimony. The operation time is 7 hours until the volatilized white smoke is thin, which is the end point, and the scum is removed; if the scum is thin, add an appropriate amount of caustic soda or sawdust, Dry the scum so it can be scooped out.

S3. Copper removal by melting: In the smelting pot, using the characteristic that the solubility of copper in bismuth liquid varies with temperature, the temperature is controlled at 500°C to make copper form a refractory compound or eutectic solid solution to precipitate out as scum, which can be removed. 50% copper is removed by melting;

S4. Adding sulfur to remove copper: the copper content is still greater than 0.3%. It is necessary to add sulfur and then stir to remove copper. The temperature of the sulfur addition operation is controlled at 300 ° C. Sulfur and copper are used to form cuprous sulfide that has a low density and does not melt in bismuth liquid. , and finally, when the temperature rises to 650°C, blow in compressed air to oxidize the residual sulfur to generate SO ₂ gas, and the copper removal operation ends;

S5. Adding zinc to remove silver: In the smelting pot, adopt low temperature operation, add zinc to remove silver at 450 ° C, based on the formation of stable refractory compounds between zinc and silver, and remove them as scum with low density. The quality and recovery rate of the refined bismuth is greatly affected by the quality of the silver removal operation. The silver content of the bismuth liquid is less than 0.003%, and the operation is over.

Secondary coarse bismuth is produced, and the bismuth content is greater than 70%, which can be directly sold outside.

Claims (2)

1. The method for producing high-grade crude bismuth by decoppering slag is characterized by comprising the following steps:

s1, smelting decoppered slag: adding decoppered slag, pyrite (3-5% of the weight of the decoppered slag), soda (10-13% of the weight of the decoppered slag) and coal dust (2-4% of the weight of the decoppered slag) into a converter, and then carrying out reduction smelting in the converter to produce primary crude bismuth;

s2, oxidizing and removing arsenic and antimony: the arsenic and antimony are removed by oxidation refining, the free enthalpy of arsenic, antimony oxide and bismuth oxide are greatly different, compressed air is blown in when the temperature is increased to 680-750 ℃ in a smelting pot, arsenic and antimony are preferentially oxidized to generate arsenic oxide and antimony oxide to volatilize bismuth liquid, so that the arsenic and antimony are removed, the operation time is 4-10h, the endpoint is reached when the volatilized white smoke is thin, and scum is fished out;

s3, copper removal by liquation: in a smelting pot, 50% of copper can be removed by smelting by controlling the temperature to 500 ℃ to enable copper to generate refractory compounds or eutectic solid solution to be separated out in a scum way by utilizing the characteristic that the solubility of copper in bismuth liquid varies with the temperature;

s4, adding sulfur and removing copper: copper is still more than 0.3%, sulfur is added, stirring is carried out to remove copper, the temperature of the vulcanizing operation is controlled to 280-330 ℃, the copper and sulfur are utilized to generate cuprous sulfide with small density and not melted in bismuth liquid for removal, and finally compressed air is blown when the temperature is raised to 650 ℃, SO that residual sulfur is oxidized to generate SO ₂ Gas, and ending the copper removal operation;

s5, adding zinc and removing silver: in a smelting pot, low-temperature operation is adopted, zinc addition and silver removal are based on stable refractory compounds generated by zinc and silver, the density is small, scum removal is performed, the silver removal operation is good or bad, the influence on the quality and recovery rate of refined bismuth is large, the silver content of bismuth liquid is lower than 0.003%, and the operation is finished.

2. The method for producing high-grade crude bismuth from decoppered slag as claimed in claim 1, wherein if the dross is thin in S2, a proper amount of caustic soda or wood chips is added to dry the dross so as to scoop the dross.