CN103966449B - A kind of method for preparing lead-tin alloy from copper anode slime silver slag - Google Patents

Abstract

The invention relates to a recycling technology for separating silver slag from copper anode slime, in particular to a method for preparing lead-tin alloy from copper anode slime separating silver slag. First, carry out hot acid leaching of the silver separation slag, leaching barium and silver into the hot acid leaching solution, leaving tin and lead in the hot acid leaching slag; keeping the hot acid leaching slag at a temperature of 800-1000°C for 2-4 hours to make Lead sulfate is converted into lead oxide, and then a reducing agent is added, and the temperature is raised to 1100-1500°C for reduction smelting to obtain a lead-tin alloy; lead or tin is added to the reduced lead-tin alloy, which can be melted and cast into various grades of lead-tin alloy. The invention effectively releases the lead and tin wrapped by barium by removing the harmful barium with high content, and at the same time eliminates the harm of barium to reduction smelting. The lead-tin alloy is directly prepared by the fire method, which greatly shortens the production process of the traditional lead-tin alloy The process reduces the production cost; it has the advantages of short process flow, simple equipment, high metal recovery rate, etc., and is suitable for large-scale industrial production.

Description

A kind of method for preparing lead-tin alloy from copper anode slime silver slag

technical field

The invention relates to a recycling technology for separating silver slag from copper anode slime, in particular to a method for preparing lead-tin alloy from copper anode slime separating silver slag.

Background technique

Lead-tin alloy has stable performance, low melting point, good fluidity, fine grain, good polishing and electroplating effects, and is widely used in aerospace, electronic and electrical industries. The traditional production method of lead-tin alloy is to smelt pure lead and pure tin in a certain proportion, while pure lead is generally obtained from lead concentrate through oxygen-enriched low blowing, flash smelting and other methods, and pure tin is obtained from tin concentrate through enriched Oxygen top-blown smelting or reverberatory furnace smelting, the process is long and the cost is high.

Silver separation slag is the residual slag after extracting precious metals such as gold, silver, platinum, palladium and copper, selenium, tellurium and other valuable metals from copper anode slime, which contains more tin, lead and barium. Especially in recent years, with the increase of miscellaneous copper processing, the tin content in the silver slag of copper anode slime has been increasing, which has a high recycling value.

At present, there are not many domestic studies on the recycling of lead and tin in silver slag, and most of the smelters return the silver slag to the pyromelting furnace (application number: 200810049459.5), which increases the processing of furnace materials, and tin and lead cannot be recovered in an open way , continue to accumulate, may affect the operation of copper electrolysis. Patent application 200910084613.7 discloses a method for recovering lead and tin from copper anode sludge by separating silver slag on circuit boards. Patent application 201110292654.2 discloses a method for preparing Babbitt alloy from copper anode sludge by separating silver slag. The recovery of lead and tin, but mainly for the separation of silver slag from copper anode slime on circuit boards. Different from the silver slag of copper anode slime for circuit boards, the silver slag of anode slime obtained from copper sulfide ore or miscellaneous copper smelting process contains about 30% barium besides more lead and tin. The presence of barium in the form of silver brings great difficulties to the recovery of lead and tin from the silver slag. On the one hand, the barium wraps a large amount of tin and lead, which reduces the recovery rate of lead and tin; on the other hand, if the fire method is used to recover lead and tin, a large amount of barium will greatly increase the melting point of the smelting slag, making the smelting operation difficult .

Contents of the invention

The purpose of the present invention is to provide a method for preparing lead-tin alloy from silver slag in copper anode slime, and solve the problem of recovering lead-tin from silver slag in copper anode slime with high barium content.

In order to achieve the above object, the technical scheme that the present invention takes: a kind of method for preparing lead-tin alloy from copper anode slime silver slag, comprises the following steps:

A. Put the silver slag from copper anode slime into the stirring tank, add concentrated sulfuric acid for hot acid leaching, so that barium is dissolved in hot concentrated sulfuric acid, and is leached into the leach solution together with other metals. Lead is in the form of PbSO ₄ , tin is in the form of SnO ₂ The form is left in the leaching residue, and the leaching residue and leaching liquid are obtained by filtration. The leaching process parameters are: the liquid-solid mass ratio is 2:1-10:1, the temperature is 200-500°C, and the time is 5-60 minutes;

B. Put the leach slag into the reaction vessel, heat up to carry out high-temperature transformation, and convert lead sulfate to lead oxide. The transformation temperature is 800-1000°C, and the transformation time is 2-4 hours;

C. After the high temperature transition, add a reducing agent into the reaction vessel, mix evenly, heat up for reduction smelting to obtain a lead-tin alloy, the melting temperature is 1100-1500°C, and the smelting time is 1-5 hours. The reducing agent is pulverized coal or coke Powder, added in an amount of 5 to 50% of the weight of the leaching slag;

D. Add pure tin or pure lead to the lead-tin alloy obtained by reduction smelting, melt it at 200-600°C for 2-5 hours, and cast the lead-tin alloy of standard grade; the amount of pure tin or pure lead added is calculated by the following formula :

In the formula: m is the mass of the lead-tin alloy obtained by reduction smelting, in g; w ₁ is the mass percentage of tin in the lead-tin alloy obtained by reduction smelting, %; w ₂ is the tin in the standard grade of lead-tin alloy to be prepared The mass percentage content, %.

The various reagents are all industrial grade reagents.

Compared with the traditional preparation method of lead-tin alloy, the present invention uses the silver slag of copper anode slime as raw material, effectively releases the wrapped lead and tin by removing the harmful barium with high content, improves the recovery rate, and the yield of lead and tin The recovery rates are above 97.5% and 96.1% respectively; at the same time, the harm of barium to the reduction smelting process is avoided, and the lead-tin alloy is directly prepared by the fire method, which greatly shortens the process flow of traditional lead-tin alloy production and reduces the production cost; The advantages of short process, simple equipment and high metal recovery rate are suitable for large-scale industrial production.

Description of drawings

Accompanying drawing is process flow chart of the present invention.

detailed description

As shown in the accompanying drawings, the present invention can be widely used in the recovery of lead and tin from various types of copper anode slime silver slag, and is especially suitable for the treatment of anode slime silver slag obtained from copper sulfide ore or miscellaneous copper smelting processes. Its main components range Calculated in weight percent (%): Pb5.0-20.0, Sn2.0-20.0, Ag1.0-10.0, Ba10.0-40.0.

Example 1:

The main components of the silver separating slag are (%) by weight percentage: Pb15.0, Sn7.5, Ag1.76, Ba30.97.

Add 1050ml of concentrated sulfuric acid to 500g of silver slag, leaching at 250°C for 50 minutes, filter to obtain leaching solution and leaching residue, the dry weight of leaching residue is 161.5g; put the leaching residue into the reaction vessel, heat up to 900°C, and keep the temperature for 3 hours , add pulverized coal 65g in the reaction vessel, after mixing evenly, be heated up to 1300 ℃ and carry out reduction smelting 4 hours, obtain lead-tin alloy 109g, the weight percent of lead and tin in the alloy is respectively 66.7% and 32.9%, the percentage of lead and tin The recoveries were 97.5% and 96.1%, respectively. Add 6.65g of pure tin to the lead-tin alloy, melt it at 400°C for 3 hours, and cast it to obtain the lead-tin alloy with the brand name 91XS40PR1.

Example 2:

The main components of the silver separation slag are (%) by weight percentage: Pb12.55, Sn10.5, Ag3.85, Ba28.95.

Add 900ml of concentrated sulfuric acid to 500g of silver slag, leaching at 350°C for 30 minutes, filter to obtain leaching solution and leaching slag, the dry weight of leaching slag is 160.3g; put the leaching slag into the reaction vessel, heat up to 800°C, and keep the temperature for 4 hours , add coke 50g in reaction vessel, after mixing evenly, be heated up to 1200 ℃ and carry out reduction smelting 4 hours, obtain lead-tin alloy 112g, the weight percentage of lead and tin in the alloy is respectively 54.2% and 45.3%, the recovery of lead and tin The rates reached 98.1% and 97.2% respectively. Add 9.38g of pure lead to the lead-tin alloy, melt it at 300°C for 4 hours, and cast it to obtain the lead-tin alloy with the brand name 91XS40PR3.

Example 3:

The main components of the silver separation slag are (%) by weight percentage: Pb19.58, Sn7.3, Ag4.18, Ba24.95.

Add 700ml of concentrated sulfuric acid to 500g of silver slag, leaching at 450°C for 10 minutes, filter to obtain leaching solution and leaching slag, the dry weight of leaching slag is 189.5g; put the leaching slag into the reaction vessel, heat up to 1000°C, and keep the temperature for 2 hours , add coke 70g in reaction vessel, after mixing, be heated up to 1500 ℃ and carry out reduction smelting 2 hours, obtain lead-tin alloy 132g, the weight percent of lead and tin in the alloy is respectively 72.4% and 27.3%, the recovery of lead and tin The rates reached 98.5% and 97.4% respectively. Add 3.12g of pure tin to the lead-tin alloy, melt it at 500°C for 2 hours, and cast it to obtain the lead-tin alloy with the brand name 91XS30PR1.

Claims (2)

1. a method for preparing lead-tin alloy from copper anode slime silver slag, is characterized in that: comprise the following steps: A. Put the silver slag from the copper anode slime into the stirring tank, add concentrated sulfuric acid for hot acid leaching, and obtain the leaching residue and leaching liquid after filtration; the leaching process parameters are: the liquid-solid mass ratio is 2:1-10:1, the temperature 200～500℃, the time is 5～60 minutes; B. Put the leach slag into the reaction vessel, heat up to carry out high-temperature transformation, and convert lead sulfate to lead oxide. The transformation temperature is 800-1000°C, and the transformation time is 2-4 hours; C. After the high-temperature transition, add pulverized coal or coke powder reducing agent into the reaction vessel, mix evenly, heat up for reduction smelting to obtain lead-tin alloy, the melting temperature is 1100-1500°C, and the melting time is 1-5 hours. The addition amount is 5-50% of the weight of the leaching slag; D. Add pure tin or pure lead to the lead-tin alloy obtained by reduction smelting, melt it at 200-600°C for 2-5 hours, and cast the lead-tin alloy of standard grade; the amount of pure tin or pure lead added is calculated by the following formula : In the formula: m is the mass of the lead-tin alloy obtained by reduction smelting, in g; w ₁ is the mass percentage of tin in the lead-tin alloy obtained by reduction smelting, %; w ₂ is the tin in the standard grade of lead-tin alloy to be prepared The mass percentage content, %. 2. A kind of method for preparing lead-tin alloy from copper anode slime silver slag according to claim 1, is characterized in that: optimal implementation condition: divide silver slag by 500g and add concentrated sulfuric acid 700ml, leaching 10 at 450 ℃ Minutes, filter to obtain leaching solution and leaching residue, the dry weight of leaching residue is 189.5g; put the leaching residue into the reaction vessel, heat up to 1000°C, keep the temperature for 2 hours, add 70g of coke to the reaction vessel, mix well, and heat up to 1500°C ℃ of reduction smelting 2 hours, obtains lead-tin alloy 132g, and the percentage by weight of lead and tin is respectively 72.4% and 27.3% in the alloy, and the recovery rate of lead and tin reaches respectively 98.5% and 97.4%; Add in this lead-tin alloy 3. 12g of pure tin was melted at 500°C for 2 hours and cast to obtain a lead-tin alloy with the brand name 91XS30PR1.