阅读说明：本技术 一种复杂铅铋合金中深度除杂和富集贵金属的方法 (Method for deeply removing impurities and enriching precious metals in complex lead-bismuth alloy ) 是由 钟清慎 贺秀珍 张燕 朱纪念 于 2019-10-23 设计创作，主要内容包括：本发明公开了一种复杂铅铋合金中深度除杂和富集贵金属的方法,包括：投料、反复除杂、终次除杂和分离得到贵金属合金。本发明所解决的技术问题是创新性的采用复杂铅铋合金深度除杂工艺技术,将复杂铅铋合金中铜镍及其他杂质去除,实现从除杂后的铅铋合金中应用连续真空蒸馏富集贵金属核心关键技术提取贵金属,得到的贵金属合金,贵金属品位极高,各种杂质元素含量尤其是Ni含量很低,并入卡尔多炉工序很容易进行氧化吹炼处理,得到合格银阳极板。(The invention discloses a method for deeply removing impurities and enriching precious metals in a complex lead-bismuth alloy, which comprises the following steps: and feeding, repeatedly removing impurities, finally removing impurities and separating to obtain the noble metal alloy. The technical problem solved by the invention is that a complex lead bismuth alloy deep impurity removal process technology is innovatively adopted to remove copper, nickel and other impurities in the complex lead bismuth alloy, so that precious metals are extracted from the lead bismuth alloy after impurity removal by applying a key technology of continuously vacuum distilling precious metal enrichment core, the obtained precious metal alloy has extremely high precious metal grade and low content of various impurity elements, particularly Ni, and is easy to perform oxidation converting treatment when being merged into a Kaldo furnace process, and a qualified silver anode plate is obtained.)

1. A method for deeply removing impurities and enriching precious metals in a complex lead-bismuth alloy is characterized by comprising the following steps:

A. feeding:

adding complex lead bismuth alloy into a graphite crucible of an intermediate frequency furnace, wherein the feeding amount of the complex lead bismuth alloy is W_Pb+BiAdding crushed complex lead-bismuth alloy according to 60-80% of the crucible capacity of the intermediate frequency furnace for 10-150 kg/heat;

B. repeatedly removing impurities:

melting the complex lead-bismuth alloy obtained in the step A at the temperature of 750-;

C. final impurity removal:

when no impurity particles are separated out, heating the obtained impurity-removed alloy to 560-;

D. separating to obtain a noble metal alloy:

and D, vacuumizing the impurity-removed lead-bismuth alloy obtained in the step C, heating, preserving heat and distilling for 2 hours in a vacuum state, naturally cooling to normal temperature, taking out solidified steaming residues and volatile lead-bismuth binary alloy, accurately weighing the mass of the solidified steaming residues and the volatile lead-bismuth binary alloy on an electronic scale respectively, and analyzing the content of base metals or oxides and the content of precious metals after sampling treatment.

2. The method for deeply removing impurities and enriching noble metals in the complex lead-bismuth alloy as claimed in claim 1, characterized in that: the additives in the steps B and C are flour and sodium carbonate.

3. The method for deeply removing impurities and enriching noble metals in the complex lead-bismuth alloy as claimed in claim 2, characterized in that: the total adding amount of the flour is 0.3 percent of the weight of the complex lead-bismuth alloy, and the total adding amount of the sodium carbonate is 1.0 percent of the weight of the complex lead-bismuth alloy.

4. The method for deeply removing impurities and enriching noble metals in the complex lead-bismuth alloy as claimed in claim 3, characterized in that: and the time for removing impurities and fishing slag in the steps B and C is 10 min.

5. The method for deeply removing impurities and enriching noble metals in the complex lead-bismuth alloy as claimed in claim 4, wherein the method comprises the following steps: in the step D, the vacuum degree of the vacuum pumping is 30Pa, and the temperature of the heat preservation distillation is 1150 ℃.

6. The method for deeply removing impurities and enriching noble metals in the complex lead-bismuth alloy as claimed in claim 5, wherein the method comprises the following steps: the number of repetition in the step B is not less than 6.

Technical Field

The invention belongs to the technical field of rare and precious metal pyrometallurgy, and particularly relates to a method for deeply removing impurities and enriching precious metals in a complex lead bismuth alloy.

Background

The pressurized leaching slag for treating the copper anode slime adopts a Kaldo furnace smelting converting process, the nickel and copper content of the pressurized slag of the copper anode slime is higher, the nickel and copper content of produced smelting slag, converted lead slag and the like is also high, and the complex lead bismuth alloy produced by smelting the smelting slag and the converted lead slag through reduction enrichment contains nearly twenty elements, wherein the nickel and copper content is higher, the material composition is complex, and great difficulty is brought to the reprocessing of the complex lead bismuth alloy. For the complex lead bismuth alloy with 60-70% of Pb + Bi and 30-40% of impurities and rare and precious metal elements, the impurity removal process and method are not reported in relevant documents, so that a circulating impurity removal method is not available.

Disclosure of Invention

The invention aims to provide a method for deeply removing impurities and enriching precious metals in a complex lead-bismuth alloy so as to solve the problems.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for deeply removing impurities and enriching precious metals in a complex lead-bismuth alloy comprises the following steps:

A. feeding:

adding complex lead bismuth alloy into a graphite crucible of an intermediate frequency furnace, wherein the feeding amount of the complex lead bismuth alloy is W_Pb+BiAdding crushed complex lead-bismuth alloy according to 60-80% of the crucible capacity of the intermediate frequency furnace for 10-150 kg/heat;

B. repeatedly removing impurities:

melting the complex lead-bismuth alloy obtained in the step A at the temperature of 750-;

C. final impurity removal:

when no impurity particles are separated out, heating the obtained impurity-removed alloy to 560-;

D. separating to obtain a noble metal alloy:

and D, vacuumizing the impurity-removed lead-bismuth alloy obtained in the step C, heating, preserving heat and distilling for 2 hours in a vacuum state, naturally cooling to normal temperature, taking out solidified steaming residues and volatile lead-bismuth binary alloy, accurately weighing the mass of the solidified steaming residues and the volatile lead-bismuth binary alloy on an electronic scale respectively, and analyzing the content of base metals or oxides and the content of precious metals after sampling treatment.

To further carry out the invention, the additives mentioned in steps B and C are flour and sodium carbonate.

In order to further realize the invention, the total adding amount of the flour is 0.3 percent of the weight of the complex lead-bismuth alloy, and the total adding amount of the sodium carbonate is 1.0 percent of the weight of the complex lead-bismuth alloy.

In order to further realize the method, the time for removing impurities and fishing slag in the steps B and C is 10 min.

In order to further realize the invention, the vacuum degree of the vacuumizing in the step D is 30Pa, and the temperature of the heat preservation distillation is 1150 ℃.

In order to further realize the invention, the number of times of the repetition in the step B is not less than 6 times.

Compared with the prior art, the invention has the beneficial effects that:

the technical problem solved by the invention is that a complex lead bismuth alloy deep impurity removal process technology is innovatively adopted to remove copper, nickel and other impurities in the complex lead bismuth alloy, so that precious metals are extracted from the lead bismuth alloy after impurity removal by applying a key technology of continuously vacuum distilling precious metal enrichment core, the obtained precious metal alloy has extremely high precious metal grade and low content of various impurity elements, particularly Ni, and is easy to perform oxidation converting treatment when being merged into a Kaldo furnace process, and a qualified silver anode plate is obtained.

The deep impurity removal is based on the physical property that the solubility of copper in lead is increased and decreased along with the rise and fall of temperature, a differential theory method is adopted, the complex lead bismuth alloy is heated to a certain temperature and then added with an additive, then the temperature is slowly reduced to remove impurities such as copper, nickel and the like in a scum form, namely, the impurities are melted by heating for many times, the additive is added, and slag is fished out after reaction, so that the aim of completely removing high-content impurity elements in the complex lead bismuth alloy can be achieved.

Under the non-equilibrium condition, a large amount of Ag-Ni-Cu-Pb-Bi multi-element alloy solid solution crystals and lead matte nickel crystals appear in the temperature range of 326 ℃ and 271 ℃ which is far higher than the melting point temperature of Pb and Bi, and the temperature range is 400-650 ℃, and the crystals are easily mistaken for impurity elements and compound particles thereof to be mixed with impurity removal tailings in the hot slag removing process, so that the amount of impurity removal mixed slag is increased sharply. The impurity removal times must be greatly increased, and meanwhile, the temperature and the slow cooling time are controlled, so that the purpose of deep impurity removal can be realized by performing fine operation under the approximate balance condition to prevent the lead-copper-nickel matte and the multi-element alloy solid solution from being fished out.

The lead bismuth alloy after impurity removal is continuously distilled at high temperature in vacuum, the metal vacuum distillation technology mainly utilizes the metal with different metal boiling points and low boiling point and high volatility to be distilled and volatilized in the form of volatile matters under high temperature vacuum, the metal is collected into volatile alloy after being condensed, the metal with high boiling point is basically non-volatile and still remains in the crucible melt alloy as evaporation residue, namely precious metal alloy, so that the separation between the metals is realized.

(1) The invention innovatively develops a process technical route of complex lead-bismuth alloy → deep impurity removal → impurity removal of lead-bismuth precious metal alloy → high-temperature vacuum distillation separation of lead-bismuth enriched precious metal;

(2) innovatively providing that in the deep impurity removal process, in order to efficiently separate impurity elements and compound particles thereof and simultaneously prevent alloy oxidation, a proper amount of composite additive needs to be added;

(3) innovatively providing that in the deep impurity removal process, compared with the traditional resistance heating, the electromagnetic induction stirring of an intermediate frequency furnace can better meet the requirements of complete rapid melting of complex lead-bismuth alloy, good melt flowability, uniform stirring and the like;

(4) after deep impurity removal and copper-nickel and other impurities removal, the nickel and copper content in the lead-bismuth alloy reaches a very low level, both the copper and the nickel can be reduced to below 0.05 percent, relatively pure lead-bismuth rare noble metal alloy can be almost obtained, and the copper-nickel separation effect is ideal;

(5) in the process of deep impurity removal, more than 85% of noble metals such as gold, silver, platinum, palladium and the like enter the lead-bismuth rare noble metal alloy;

(6) after the impurities are removed, the noble metal alloy obtained by continuously carrying out high-temperature vacuum distillation on the lead-bismuth alloy is high in grade and contains more than 70% of Ag and more than 1% of Au;

(6) convenient operation, low labor intensity, high efficiency and easy control of the production process.

Detailed Description

The present invention will be further described with reference to the following embodiments.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for deeply removing impurities and enriching precious metals in a complex lead-bismuth alloy comprises the following steps:

A. feeding:

adding complex lead bismuth alloy into a graphite crucible of an intermediate frequency furnace, wherein the feeding amount of the complex lead bismuth alloy is W_Pb+BiAdding crushed complex lead-bismuth alloy according to 60-80% of the crucible capacity of the intermediate frequency furnace for 10-150 kg/heat;

B. repeatedly removing impurities:

melting the complex lead-bismuth alloy obtained in the step A at the temperature of 750-;

C. final impurity removal:

when no impurity particles are separated out, heating the obtained impurity-removed alloy to 560-;

D. separating to obtain a noble metal alloy:

and D, vacuumizing the impurity-removed lead-bismuth alloy obtained in the step C, heating, preserving heat and distilling for 2 hours in a vacuum state, naturally cooling to normal temperature, taking out solidified steaming residues and volatile lead-bismuth binary alloy, accurately weighing the mass of the solidified steaming residues and the volatile lead-bismuth binary alloy on an electronic scale respectively, and analyzing the content of base metals or oxides and the content of precious metals after sampling treatment.

The additives in the steps B and C are flour and sodium carbonate.

The total adding amount of the flour is 0.3 percent of the weight of the complex lead-bismuth alloy, and the total adding amount of the sodium carbonate is 1.0 percent of the weight of the complex lead-bismuth alloy.

And the time for removing impurities and fishing slag in the steps B and C is 10 min.

In the step D, the vacuum degree of the vacuum pumping is 30Pa, and the temperature of the heat preservation distillation is 1150 ℃.

The number of repetition in the step B is not less than 6.