CN101812597B - Secondary refining process for silver - Google Patents
Secondary refining process for silver Download PDFInfo
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- CN101812597B CN101812597B CN2009102270767A CN200910227076A CN101812597B CN 101812597 B CN101812597 B CN 101812597B CN 2009102270767 A CN2009102270767 A CN 2009102270767A CN 200910227076 A CN200910227076 A CN 200910227076A CN 101812597 B CN101812597 B CN 101812597B
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Abstract
The invention relates to a secondary refining process for silver, which belongs to the technical field of precious metal melting. A process of blasting air and adding lead for oxidizing refining is added after the process of oxidizing refining in a small converter for precious lead, wherein the process is implemented in a cupellation silver refining furnace of which the production capacity is 150 kg dore silver per pool at one time. The secondary refining process for the silver can enhance the process of oxidizing refining, so that the final dore silver grade reaches over 98.5 percent and the first-grade product ratio of silver ingots is up to 100 percent.
Description
Technical field
The present invention relates to a kind of secondary oxidation refinery practice of silver, belong to the precious metal smelting technical field.
Background technology
The silver-colored smelting technology method of prior art is: precious metals containing lead → primary converter oxidation refining → thick silver → electrorefining → separate out silver powder → casting mold → silver ingot.Primary converter oxidation refining step wherein is in the oxidation refining converter, to carry out, and is referred to as oxidation refining again because a large amount of air blast forms oxidizing atmosphere.Avidity according to each metal and oxygen varies in size, and utilizes self lead in the precious metals containing lead raw material oxidized, earlier plumbous oxidation as oxygenant in oxidising process; Antimony, lead, bismuth, copper etc. get in flue dust and the slag with oxide form, and tellurium is oxidized to tellurous oxide, and part generates sodium tellurite with the soda ash that adds and forms the tellurium slag; Gold and silver is because little with the avidity of oxygen; Improve constantly purity in the process, purify thereby reach preliminary refining, its process product is electrum copper, lead, bismuth oxidation sludge and tellurium slag.The process reaction formula is following:
2Pb+O
2＝2PbO
4Sb+3O
2＝2Sb
2O
3↑
4Bi+3O
2＝3Bi
2O
3
4Cu+O
2＝2Cu
2O
Te+O
2＝TeO
2
TeO
2+Na
2CO
3＝Na
2TeO
3+CO
2↑
The defective of this technology is: the thick silver-colored argentiferous that oxidation refining obtains through primary converter is not high; Only containing Au+Ag is more than 97.5%; And impure copper, bismuth, tellurium are higher, and the silver ingot ratio of first-grade products is about 60%, therefore are necessary to improve primary converter oxidation refining technology; Improve thick silver-colored silver content, so that guarantee the silver ingot quality.
Summary of the invention
Technical problem to be solved by this invention is not high to the thick silver-colored silver content of existing silver-colored smelting technology technology; The defective that the silver ingot ratio of first-grade products is low; A kind of secondary oxidation refinery practice of silver is proposed; It can strengthen the oxidation refining process, and final thick silver-colored grade has been reached more than 98.5%, and the silver ingot ratio of first-grade products reaches 100%.
The technical scheme that the present invention deals with problems is:
A kind of secondary oxidation refinery practice of silver is that the primary converter oxidation refining operation at precious metals containing lead increases by one air blast at the back, leading oxidation refining operation; Concrete technology is following:
1. the thick silver-colored removal of impurities operation of once oxidation refining
1a steps on the pond: evenly apply one deck dry cement in bottom, cambered surface refining pond;
1b adds slightly silver of once oxidation refining: in ash blows the refining pond of silver-colored refining furnace, evenly add the thick silver bullion of once oxidation refining, grade Ag >=80% of the thick silver of once oxidation refining;
1c does pond arch: convert water with yellow mud and cement and mix and stir into mud and do the pond and encircle; Cover iron covering again, open the flue gas exhaust valve, be communicated with the airduct of going up gas blower and following gas blower respectively;
1d igniting: add the charcoal of igniting in the combustion chamber, after the igniting, add smokeless lumped coal, close blast inlet air intake lock; Open gas blower down, the flue dust retrieving arrangement; Open down blast inlet air intake lock and flue dust vent valve; Observe the firepower situation then, burn down and just replenish smokeless lumped coal;
1e removing impurities by oxidation: treat once slightly silver fusing, when temperature reaches more than 1000 ℃, blow adding electricity lead in the silver-colored refining furnace refining pond at ash; Close down gas blower and following blast inlet air intake lock, gas blower in the unlatching is opened blast inlet air intake lock, makes lead and foreign metal successively be oxidized into flue gas or scum silica frost and removes; According to thick silver-colored purity, it is plumbous suitably to replenish above-mentioned electricity; When the refining of this operation reached 4～5h, flame-out, one step of this moment, thick silver-colored purity reached more than 98%;
2. once clear pond operation
Treat that refining pond that ash blows silver-colored refining furnace after the 8h cooling, begins to tear open Lu Qingchi; Its working order is: and opening iron covering → dismounting pond encircles → and slightly silver → with cement → removing combustion chamber cinder at the bottom of the drill rod removing pond, each link all need be removed totally to take out a step of having become monoblock with drill rod;
3. purification process
3a repeats stepping on the pond, do the pond arch in 1a → 1d operation, top iron and screw lid, lighting up procedure; 1b wherein adds the thick silver of once oxidation refining and changes into and add purity to reach the step of one 98% or more thick silver-colored;
3b removing impurities by oxidation: after treating that a step, thick silver melted, add saltpetre and soda ash and remove tellurium, fully stir, and the adding electricity is plumbous smokeless lumped coal;
3c extracts final thick silver: when the refining of this operation reached 4～5h, thick silver-colored purity reached the final thick silver that was regarded as coming out of the stove greater than 99% o'clock; The experience of judging directly perceived is: not having above the final thick silver of coming out of the stove has yellowish green copper, bismuth fault; Glue thick silver with stainless steel bar at the refining pond internal rotation that ash blows silver-colored refining furnace this moment; Every rotation 2～3 circles propose in water, to cool off, and constantly repeat this operation, and when thick silver was accumulated to the 20kg left and right sides on rod, rod iron was retreated out in cooling, and it is good that final thick silver is put into the neat sign indicating number of iron case.Finish when the thick silver of residue is less than 1kg at the bottom of the refining pond, flame-out;
4. the clear pond of secondary operation
This operation is identical with the once clear pond of 2. step operation, waits until down stove from a small amount of thick silver that goes out clearly at the bottom of ash blows silver-colored refining furnace hearth and melts down.
Ash of the present invention blows silver-colored refining furnace; Be commonly called as and fry in shallow oil silver stove; Mainly be made up of body of heater and an iron covering of building block with refractory materials, oxidation space, combustion chamber and cambered surface refining pond are arranged in the body of heater, encircle in the interim pond that the useful yellow mud in oxidation space of top, refining pond and cement mixing are done; There is the air outlet upper end, oxidation space of body of heater, and the air outlet connects the flue dust retrieving arrangement through vent valve; Upper and lower two blast inlets are arranged on the furnace body wall; Last blast inlet leads to the oxidation space; Following blast inlet leads to the combustion chamber, and each blast inlet connects a gas blower respectively through the airduct of bringing air lock into.
The technological principle of technological principle of the present invention and prior art initial refining is basic identical, is to metal melt air blast oxidative slagging equally.Avidity according to each metal pair oxygen varies in size, and in oxidising process, arsenic, antimony, lead, bismuth, copper etc. get in flue dust and the slag with oxide form in regular turn.What the present invention was different with the prior art initial refining is: the leading technology of increase, be earlier plumbous oxidation as oxygenant, oxidation is sorted at further oxidative slaggings of impurity such as the arsenic of plumbous front, antimony, thus more thorough to the removal of impurity; Make tellurium slag operation and be with saltpetre as oxygenant, further the most dysoxidizable tellurium and copper oxidative slagging, the soda ash of part tellurium and adding generates sodium tellurite and forms the tellurium slag.Gold and silver improves constantly purity owing to little with the avidity of oxygen in the process, purify thereby reach further refining.Its reaction formula is following:
Leading, air blast operation:
2Pb+O
2＝2PbO
3PbO+2As＝3Pb+As
2O
3
3PbO+2Sb＝3Pb+Sb
2O
3
4As(Sb)+3O
2＝2As
2O
3(Sb
2O
3)↑
4Bi+3O
2＝3Bi
2O
3
4Cu+O
2＝2Cu
2O
Add soda ash, saltpetre is made tellurium slag operation:
At high temperature, saltpetre decomposes precipitated oxygen 2KNO
3=K
2O+N
2↑+2.5O
2↑
4Cu+O
2＝2Cu
2O
Te+O
2＝TeO
2
TeO
2+Na
2CO
3＝Na
2TeO
3+CO
2↑。
The present invention is because secondary refining can some oxidation sludges plumbous and copper of accumulation in the cement powder at the bottom of frying in shallow oil the silver stove pond, and saturated very soon, so need clear up at the bottom of the pond, does twice impurity and purification.The initial refining primary converter feeds intake about the 6t/ stove relatively; Fry in shallow oil the every pond of silver stove and only drop into the once thick silver in 150kg/ pond; Because the melt amount is few; Air blast oxidation and make tellurium slag effect and be much higher than initial refining, this has also guaranteed the refining impurity-eliminating effect and has improved thick silver-colored grade that therefore final thick silver-colored main grade >=98.5%th accomplished easily.Because fuel is changed into the anthracite block coal of secondary refining by the diesel oil of initial refining, change low-pricedly by expensive, practice thrift cost and also be inevitable.
Compared with prior art, ash of the present invention blows refining furnace, can strengthen the oxidation refining process, and final thick silver-colored grade has been reached more than 98.5%, has guaranteed that the silver ingot ratio of first-grade products reaches 100%.Specifically obtained following positively effect:
(1) having improved the handicraft product quality is thick silver-colored grade
The applicant adopts initial refining, like annual thick silver-colored argentiferous average out to 97.71% in 2008, implements the thick silver-colored argentiferous of secondary refining now and has improved 1.40%.
(2) reduced the foreign matter content of thick silver
Annual thick silver-colored major impurity copper average out to 1.2% in 2008 is implemented the thick silver-colored average out to 0.30% of secondary refining now, and adopting new technology has on average descended 0.90%.
(3) shortened next procedure---silver-colored electrolytic electrolysing period
Because thick silver-colored grade improves, foreign matter content reduces, and can strengthen electric current and accelerate speed of separating out, so electrolysing period has dropped to 1 day by 1.5 days, has reduced unit power consumption.
(3) reduce silver electrolyte and purified the frequency
Because thick silver-colored major impurity copper declines to a great extent; The electrolytic solution cupric is increased to limit 30g/l speed and slows down; Originally need about 10 days to purify once, can extend to 2 months once now, reduced sodium hydroxide consumption that purifies and the silver-colored mud output that needs Returning smelting.When having shortened the once oxidation refining furnace; Fuel economy diesel oil effect is obvious: because the grade of the thick silver of once oxidation refining drops to Ag >=80% by Ag >=97.5%; Reduced initial refining master grade requirement, the primary converter oxidation refining is reduced to the 40h/ stove by original 72～96h/ stove, and the applicant's diesel oil unit consumption drops to the present 358kg/t anode sludge by the 544kg/t anode sludge in 2008; Practicing thrift the diesel oil unit consumption is the 186kg/t anode sludge, and the saving ratio is 34.2%.And ash blows silver-colored refining furnace and only increases the coal consumption 960kg/12 stove of smokeless lumped coal (annotate: ash blows silver-colored refining furnace 6 stove processing power=primary converters 1 stove processing power, and primary converter is opened 2 at every turn); Promptly increase i.e. 14 * 1.1 yuan/kg=15.4 unit/t anode sludge of the coal consumption 14kg/t anode sludge, still practice thrift 635.6 yuan/t of the oil consumption anode sludge.
Description of drawings
Fig. 1 is technological process of production figure of the present invention;
Embodiment
The present invention is elaborated with specific embodiment below in conjunction with accompanying drawing.
The secondary oxidation refinery practice figure of a kind of silver of accompanying drawing 1 expression is that the primary converter oxidation refining operation at precious metals containing lead increases by one air blast at the back, leading oxidation refining operation; This operation is to blow in the silver-colored refining furnace at an ash to realize, its throughput is the once thick silver of every pond 150kg; Concrete technology is following:
1. the thick silver-colored removal of impurities operation of once oxidation refining
1a steps on the pond: evenly apply one deck dry cement in bottom, cambered surface refining pond, cement consumption is every pond one bag;
1b adds slightly silver of once oxidation refining: in ash blows the refining pond of silver-colored refining furnace, evenly add the thick silver bullion of once oxidation refining, grade Ag >=80% of the thick silver of once oxidation refining; The thick silver-colored addition of once oxidation refining is every pond 150kg;
1c does pond arch: convert water with yellow mud and cement and mix and stir into mud and do the pond arch, pond arch thickness 30～40mm requires good sealing effect, stifled quirk and flue gas, blast channel, maintenance air smoothness; Cover iron covering again, open the flue gas exhaust valve, be communicated with the airduct of going up gas blower and following gas blower respectively;
1d igniting: add charcoal 2～3kg/ pond of igniting in the combustion chamber, after the igniting, add smokeless lumped coal 8～10kg, close blast inlet air intake lock; Open gas blower down, the flue dust retrieving arrangement; Open down blast inlet air intake lock and flue dust vent valve; Observe the firepower situation then, burn down and just replenish smokeless lumped coal, this operation need drop into smokeless lumped coal and amount to 38～40kg/ pond;
1e removing impurities by oxidation: treat once thick silver fusing, when temperature reaches more than 1000 ℃, blow electric plumbous one that adds 10～11kg in the silver-colored refining furnace refining pond at ash; Close down gas blower and following blast inlet air intake lock, gas blower in the unlatching is opened blast inlet air intake lock, makes lead and foreign metal successively be oxidized into flue gas or scum silica frost and removes; According to thick silver-colored purity, suitably electric plumbous 1～2 of additional above-mentioned specification, this operation amounts to and drops into 2～3/pond of electric lead; When the refining of this operation reached 4～5h, flame-out, one step of this moment, thick silver-colored purity reached more than 98%;
2. once clear pond operation
Treat that refining pond that ash blows silver-colored refining furnace after the 8h cooling, begins to tear open Lu Qingchi; Its working order is: and opening iron covering → dismounting pond encircles → and slightly silver → with cement → removing combustion chamber cinder at the bottom of the drill rod removing pond, each link all need be removed totally to take out a step of having become monoblock with drill rod;
3. purification process
3a repeats stepping on the pond, do the pond arch in 1a → 1d operation, top iron and screw lid, lighting up procedure; 1b wherein adds the thick silver of once oxidation refining and changes into and add purity to reach the step of one 98% or more thick silver-colored;
3b removing impurities by oxidation: after treating thick silver fusing of a step, add each 1.5～3kg/ pond of saltpetre and soda ash and remove tellurium, fully stir, and add electric lead totally 2/pond, the smokeless about altogether 40kg/ of lumped coal pond;
3c extracts final thick silver: when the refining of this operation reached 4～5h, thick silver-colored purity reached the final thick silver that was regarded as coming out of the stove greater than 99% o'clock; The experience of judging directly perceived is: not having above the final thick silver of coming out of the stove has yellowish green copper, bismuth fault; Glue thick silver with stainless steel bar at the refining pond internal rotation that ash blows silver-colored refining furnace this moment; Every rotation 2～3 circles propose in water, to cool off, and constantly repeat this operation, and when thick silver was accumulated to the 20kg left and right sides on rod, rod iron was retreated out in cooling, and it is good that final thick silver is put into the neat sign indicating number of iron case.Finish when the thick silver of residue is less than 1kg at the bottom of the refining pond, flame-out;
4. the clear pond of secondary operation
This operation is identical with the once clear pond of 2. step operation, waits until down stove from a small amount of thick silver that goes out clearly at the bottom of ash blows silver-colored refining furnace hearth and melts down.
The raw materials consumption of present embodiment:
Table 1 is fried in shallow oil the whole technology raw materials consumption quotas of silver stove (normal circumstances)
| Once thick silver-colored kg/ pond | Electricity lead/pond | Cement bag/pond | Anthracite block coal kg/ pond | Charcoal Kg/ pond | Soda ash Kg/ pond | Saltpetre Kg/ pond | Blow-on quantity stove (pond)/inferior |
| About 150 | 4.5～5 (about 11kg/ pieces) | 2 | About 80 | 4～6 | 1.5～3 | 1.5～3 | 5～7 (looking once thick silver-colored quantity and dust collection effect confirms) |
The quality product of present embodiment requires:
(1) final thick patina composition requires: Ag>=98.5%, Cu≤0.50%, Bi≤0.10%, Te≤0.06%, Pb≤0.50%.
(2) final thick silver-colored physical specification requires: size evenly, external foreign material such as adhesive tape cement not.
The comprehensive grade of present embodiment product:
Table 2 uses the comprehensive grade of thick silver of this technology
Claims (1)
1. the secondary oxidation refinery practice of a silver is characterized in that increasing by one air blast at the back in the primary converter oxidation refining operation of precious metals containing lead, leading oxidation refining operation; Concrete technology is following:
1. the thick silver-colored removal of impurities operation of once oxidation refining
1a steps on the pond: evenly apply one deck dry cement in bottom, cambered surface refining pond;
1b adds slightly silver of once oxidation refining: in ash blows the refining pond of silver-colored refining furnace, evenly add the thick silver bullion of once oxidation refining, grade Ag >=80% of the thick silver of once oxidation refining;
1c does pond arch: convert water with yellow mud and cement and mix and stir into mud and do the pond and encircle; Cover iron covering again, open the flue gas exhaust valve, be communicated with the airduct of going up gas blower and following gas blower respectively;
1d igniting: add the charcoal of igniting in the combustion chamber, after the igniting, add smokeless lumped coal, close blast inlet air intake lock; Open gas blower down, the flue dust retrieving arrangement; Open down blast inlet air intake lock and flue dust vent valve; Observe the firepower situation then, burn down and just replenish smokeless lumped coal;
1e removing impurities by oxidation: treat once slightly silver fusing, when temperature reaches more than 1000 ℃, blow adding electricity lead in the silver-colored refining furnace refining pond at ash; Close down gas blower and following blast inlet air intake lock, gas blower in the unlatching is opened blast inlet air intake lock, makes lead and foreign metal successively be oxidized into flue gas or scum silica frost and removes; According to thick silver-colored purity, it is plumbous suitably to replenish above-mentioned electricity; When the refining of this operation reached 4～5h, flame-out, one step of this moment, thick silver-colored purity reached more than 98%;
2. once clear pond operation
Treat that refining pond that ash blows silver-colored refining furnace after the 8h cooling, begins to tear open Lu Qingchi; Its working order is: and opening iron covering → dismounting pond encircles → and slightly silver → with cement → removing combustion chamber cinder at the bottom of the drill rod removing pond, each link all need be removed totally to take out a step of having become monoblock with drill rod;
3. purification process
3a repeats stepping on the pond, do the pond arch in 1a → 1d operation, top iron and screw lid, lighting up procedure; 1b wherein adds the thick silver of once oxidation refining and changes into and add purity to reach the step of one 98% or more thick silver-colored;
3b removing impurities by oxidation: after treating that a step, thick silver melted, add saltpetre and soda ash and remove tellurium, fully stir, and the adding electricity is plumbous smokeless lumped coal;
3c extracts final thick silver: when the refining of this operation reached 4～5h, thick silver-colored purity reached the final thick silver that was regarded as coming out of the stove greater than 99% o'clock; The experience of judging directly perceived is: no yellowish green copper and bismuth fault above the final thick silver of coming out of the stove; Glue thick silver with stainless steel bar at the refining pond internal rotation that ash blows silver-colored refining furnace this moment; Every rotation 2～3 circles propose in water, to cool off, and constantly repeat this operation, and when thick silver was accumulated to 20kg on rod, rod iron was retreated out in cooling, and it is good that final thick silver is put into the neat sign indicating number of iron case; Finish when the thick silver of residue is less than 1kg at the bottom of the refining pond, flame-out;
4. the clear pond of secondary operation
This operation is identical with the once clear pond of 2. step operation, waits until down stove from a small amount of thick silver that goes out clearly at the bottom of ash blows silver-colored refining furnace hearth and melts down.
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|---|---|---|---|
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|---|---|---|---|
| CN2009102270767A CN101812597B (en) | 2009-11-25 | 2009-11-25 | Secondary refining process for silver |
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| CN103266225A (en) * | 2013-05-26 | 2013-08-28 | 湖南宇腾有色金属股份有限公司 | Side-blown furnace reduction smelting technology for lead anode mud |
| CN109825709A (en) * | 2019-01-29 | 2019-05-31 | 郴州雄风环保科技有限公司 | A kind of precious metal alloys purification Concentration of Gold silver process |
| CN113201650B (en) * | 2021-03-26 | 2023-03-17 | 青海昆仑黄金有限公司 | Treatment process of high-silver tellurium-containing gold mud |
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