CN120843838A - A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilization - Google Patents
A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilizationInfo
- Publication number
- CN120843838A CN120843838A CN202511357394.0A CN202511357394A CN120843838A CN 120843838 A CN120843838 A CN 120843838A CN 202511357394 A CN202511357394 A CN 202511357394A CN 120843838 A CN120843838 A CN 120843838A
- Authority
- CN
- China
- Prior art keywords
- arsenic
- lead
- containing waste
- grade
- iron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Processing Of Solid Wastes (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
本发明公开了一种一步法实现高砷含铅废渣无害化资源化的综合利用方法，以含铅废渣、自产烟灰、活性铁粉、添加剂作为原料，经过配料、混匀、制块、还原熔炼得到粗铅、水淬渣、低品位冰铜、砷铁合金。通过本技术方案，能够在回收含铅废渣中有价元素的同时，同步实现砷的选择性分离和产品化，将有毒元素砷转变成砷铁合金，合金中砷铁含量之和大于85%、铁含量大于60%、砷含量小于30%，满足现行砷铁合金的产品标准，实现砷铁产品开路；同时将价值较低的低品位冰铜转化熔炼所需的活性铁粉，大幅降低高砷含铅废渣的处置成本，工艺流程短，物料得到充分的利用，降低高砷含铅废渣的吨处理成本，实际应用价值和经济效果显著。
The present invention discloses a one-step method for the harmless resource utilization of high-arsenic lead-containing waste slag. The method uses lead-containing waste slag, self-produced soot, activated iron powder, and additives as raw materials. Through batching, mixing, agglomeration, and reduction smelting, crude lead, water-quenched slag, low-grade matte, and arsenic-iron alloy are obtained. This technical solution simultaneously recovers valuable elements from the lead-containing waste slag while selectively separating and commercializing arsenic. The toxic element arsenic is converted into an arsenic-iron alloy with a combined arsenic and iron content greater than 85%, an iron content greater than 60%, and an arsenic content less than 30%, meeting current arsenic-iron alloy product standards and achieving the production of arsenic-iron products. Simultaneously, the less valuable low-grade matte is converted into the activated iron powder required for smelting, significantly reducing the disposal cost of high-arsenic lead-containing waste slag. The process is short, materials are fully utilized, and the per-ton processing cost of high-arsenic lead-containing waste slag is reduced, resulting in significant practical application value and economic benefits.
Description
Technical Field
The invention relates to the technical field of solid waste reclamation and nonferrous metallurgy, in particular to a comprehensive utilization method for realizing harmless reclamation of high-arsenic lead-containing waste residues by a one-step method.
Background
The lead-containing waste residues generated by copper-lead-zinc smelting enterprises comprise smoke dust and smelting residues generated by pyrometallurgy enterprises, leaching residues, replacement residues, lead-silver residues, lead sludge and the like generated by wet smelting enterprises, and the waste residues have the characteristics of multiple generation sources, large quantity, complexity and non-uniformity and have the dual attributes of resources and environment. The resource attribute of the method is the associated recyclable valuable metal resource, particularly valuable and scattered metals such AS Bi, in, au, ag, and the environment attribute of the method is the toxicity and nondegradability of the heavy metal elements such AS Pb, AS, hg and the like which are rich in the valuable metal resource, so that the valuable metal resource can be long-term and form potential threat to the environment, and the waste residues are mostly dangerous wastes.
The existing lead-containing waste residue treatment process mainly comprises collocation treatment, for example, copper-lead smelting ash can be returned to a blast furnace for sintering and proportioning, lead mud and lead sulfate slag can be proportioned to enter a bottom blowing furnace or a side blowing furnace for treatment, but because the lead-containing waste residue contains toxic element arsenic, the lead mud and the lead sulfate slag directly return to pyrometallurgy, the lead-containing waste residue can circularly reciprocate in a system, the balance of the system is destroyed, the quality of a rear-end product can be influenced, the existing arsenic removal method has the problems of high cost, long flow and unstable effect, and meanwhile, the economy cannot be ensured because the lead grade of most of lead-containing waste residues is lower than 15 percent by adopting an overlong treatment process.
The traditional arsenic treatment method has high cost and can not realize productization, thereby causing a large amount of hazardous waste containing arsenic and accumulation of the arsenic-containing products.
Therefore, an economic and efficient low-cost arsenic removal technology for lead-containing waste residues is developed, the selective separation of arsenic is realized, and the problems of arsenic removal and open circuit in the recycling process of the lead-containing waste residues are solved.
Disclosure of Invention
In order to solve the problems, the invention provides the comprehensive utilization method for realizing harmless recycling of the high-arsenic lead-containing waste residues by the one-step method, and by adopting the technical scheme, the selective separation and productization of arsenic can be synchronously realized while valuable elements in the lead-containing waste residues are recovered, the arsenic is converted into an arsenic-iron product, the process flow is short, the disposal cost of the high-arsenic lead-containing waste residues is greatly reduced, and the dual purposes of economic benefit and environmental protection are realized.
The invention provides a comprehensive utilization method for realizing harmless recycling of high-arsenic lead-containing waste residues by a one-step method, which takes the lead-containing waste residues, self-produced ash, active iron powder and additives as raw materials, and obtains crude lead, water quenched slag, low-grade matte and arsenic-iron alloy through proportioning, mixing, briquetting and reduction smelting, and specifically comprises the following steps:
Step 1, crushing the waste materials before uniformly mixing, grinding the materials to enough particle size, preferably crushing the materials to below 5mm, and re-crushing and grinding the materials after sieving the materials to obtain oversized particles;
And 2, mixing the lead-containing waste residues, the self-produced ash, the active iron powder, the additive and the water into various materials according to a certain proportion by adopting a mass mixing method to form a mixture.
And 3, sending the mixed materials into a full-automatic hydraulic molding brick making machine to prepare mixed brick materials for later use, wherein the materials are sprayed in advance in the brick making process, and the materials are directly pressed and molded under the condition of keeping proper humidity without adding other binders.
And 4, conveying the brick materials, the reducing agent and the returned slag into roasting equipment, uniformly distributing, roasting in a reducing atmosphere, wherein the roasting temperature is 1200-1400 ℃, respectively obtaining crude lead, water quenching slag, low-grade matte and arsenic-iron alloy after smelting, and discharging the flue gas reaching the standard after dust collection and desulfurization.
As a further improvement of the invention, the grade of iron in the active iron powder is not lower than 55%, and the FeO content of the iron-containing phase is not lower than 50%.
As a further improvement of the present invention, the additive is waste glass, limestone, silica, or the like.
As a further improvement of the invention, the quality of the mixture is controlled to be 10-20% of Pb grade, less than 5% of copper grade and 10-15% of water.
As a further improvement of the invention, the low-grade matte is crushed, oxidized and reduced and roasted to produce roasting iron powder.
As a further improvement of the invention, the roasting system in the oxidation stage is that the temperature is 800-950 ℃, the retention time is 3-4 hours, the excess air coefficient is 1.2-1.4 or the oxygen enrichment concentration is 25-30%, and the oxygen stopping time is that the sulfur dioxide content is lower than 400mg/Nm 3.
As a further improvement of the invention, the roasting system in the reduction stage is that the temperature is 600-800 ℃ and the retention time is 1-2 h.
As a further improvement of the invention, the roasted iron powder can replace active iron powder, and is used as an auxiliary material for smelting reduction matte, and the replacement proportion is 70% -100% of outsourcing iron powder.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention adopts a one-step pyrogenic process to treat the high-arsenic lead-containing waste slag, and synchronously realizes the selective separation and the productization of toxic element arsenic while recovering valuable elements in the lead-containing waste slag.
2. The invention can convert harmful element arsenic into the arsenic-iron alloy, the sum of the arsenic-iron content in the alloy is more than 85 percent, the iron content is more than 60 percent, and the arsenic content is less than 30 percent, thereby meeting the product standard of the existing arsenic-iron alloy, meeting the hazardous waste identification standard in leaching toxicity and realizing the open circuit of the arsenic-iron product.
3. The invention can convert low-grade matte with lower value into active iron powder composed of specific phases, thereby not only reducing the environmental hazard caused by stacking of the low-grade matte and reducing the occupied cost of stock, but also realizing the internal circulation process of converting self-produced waste into raw materials.
4. The invention has simple process, the produced crude lead, low-grade matte, water quenching slag and arsenic-iron alloy can be used as products, the materials are fully utilized, the ton treatment cost of high-arsenic lead-containing waste slag is reduced, and the practical application value and the economic effect are remarkable.
Drawings
FIG. 1 is a flow chart of a comprehensive utilization method for realizing harmless recycling of high-arsenic lead-containing waste residues by a one-step method disclosed by the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
The invention is further described in detail below with reference to the accompanying drawings, as shown in fig. 1, the invention provides a comprehensive utilization method for realizing harmless recycling of high-arsenic lead-containing waste residues by a one-step method, which comprises the following steps:
s1, uniformly mixing high-arsenic lead-containing waste residues with auxiliary materials containing iron powder, and blocking the uniformly mixed materials to obtain mixed brick materials, wherein the mixed brick materials and a reducing agent are sent to roasting equipment, are uniformly distributed, are roasted in a reducing atmosphere, and are respectively obtained into crude lead, water quenching residues, low-grade matte and arsenic-iron alloy after smelting is completed;
S2, sampling and analyzing low-grade copper matte produced by smelting reduction matte production of lead-containing waste, wherein the iron grade is 45% -50%, the sulfur grade is about 15%, the copper grade is about 1% -3%, the low-grade copper matte produced by smelting reduction matte production of lead-containing waste residues is crushed to 10% -50 mm, the low-grade copper matte is uniformly mixed with an initial reducing agent (coke or anthracite) according to a certain proportion, the addition amount of the initial reducing agent accounts for 5% -10% of the mass ratio of the input low-grade copper matte, and a mixed material is prepared;
S3, throwing the mixed material into a rotary kiln, and treating the mixed material in two stages in roasting equipment by adopting gradient heating and dynamic oxygen potential control:
① The oxidation stage comprises the steps of roasting at 800-950 ℃ for 3-4 hours, introducing excessive air or oxygen-enriched air, wherein the excess air coefficient is 1.2-1.4 or the oxygen-enriched concentration is 25-30%, the blast volume is 100-180 Nm 3/min, and the kiln mouth static pressure is 20-25 KPa. Self-heating reaction and oxidation desulfurization reaction occur in the roasting equipment;
② And in the reduction stage, monitoring the sulfur dioxide content in the flue gas in real time, stopping introducing air or enriching oxygen when the sulfur dioxide content is reduced to a certain degree, adding a secondary reducing agent (coke or anthracite) into roasting equipment for reduction roasting, wherein the addition amount of the secondary reducing agent accounts for 10% -15% of the mass ratio of the low-grade copper matte, the roasting system is at 600-800 ℃, the retention time is 1-2 h, and the atmosphere is controlled to be weak reducing atmosphere.
S4, cooling the roasted hot slag in a cooling kiln to produce active iron powder, wherein the FeO content is not lower than 50%, and the active iron powder is used as an auxiliary material for reducing and matte smelting instead of outsourcing iron powder, and on the premise that the crude vertical yield is 85% and the water quenching slag copper grade is lower than 0.6%, the substitution ratio can reach 70% -100% of the outsourcing iron powder, the sum of the generated arsenic and iron contents is more than 85%, the iron content is more than 60% and the arsenic content is less than 30%, so that the product standard of the existing arsenic and iron alloy is met, and the product of toxic arsenic is realized;
S5, returning the collected dust generated in the roasting process to a smelting system for proportioning, recovering rare noble metals such as lead, zinc, gold, silver, bismuth and the like in the collected dust, and discharging the treated flue gas reaching the standard.
Example 1:
the smelting white smoke dust generated by smelting a certain copper is used as a raw material, and the main chemical components are as follows:
Copper 5.50%, lead 32.13%, zinc 4.50%, arsenic 6.82%, sulfur 6.35%, and main phases of the smelting white dust are lead sulfate, zinc sulfate, copper sulfate and the like.
The method comprises the steps of taking outsourcing active iron powder as an auxiliary material, cooperatively disposing lead-containing waste residues, mixing smelted white smoke dust, waste glass and iron powder into various materials according to a certain proportion to form a mixture, adding the mixture into a roasting furnace according to the proportion of 65%, 5% and 30%, wherein the lead grade of the mixed brick material is 18%, the copper grade is 6% and the sulfur grade is 8%, returning the mixed brick material to the roasting furnace, roasting at 1200-1400 ℃ in a tuyere zone, optimizing and adjusting the coke ratio by the oxygen-enriched concentration to ensure that the furnace condition and the product index meet the requirements, and under the condition, the coke ratio is 20%, the lead yield is 18%, the lead grade of water quenching slag is less than 1%, and the copper grade of water quenching slag is less than 0.5%.
Example 2:
(1) Single oxidation roasting test group
Fully mixing the crushed low-grade copper matte and coke powder to form a mixed material, wherein the addition amount of the coke powder is 10.0%, the total weight of the mixed material is 300 tons, adding the mixed material into a rotary kiln in 3 batches, the feeding speed is 10t/h, the frequency of a kiln body dragging motor is controlled to be 5.5-6.5 Hz, the rotating speed of the kiln body is controlled to be 3min/r, the blast volume is 120Nm 3/min, the static pressure at a kiln mouth is 25KPa, and the temperature of a reaction zone is controlled to be about 800 ℃. The kiln is ignited to the temperature of a sedimentation chamber at the outlet of the kiln tail to 280 ℃, then the feeding is started, after the high-temperature roasting and desulfurization are carried out by the rotary kiln, the iron grade is improved to 54%, the sulfur grade is reduced to 3% from 15%, the yield of the finished product is 75.23% (accounting for the proportion of low-grade copper matte), the smoke dust rate is 8.55% (accounting for the proportion of low-grade copper matte), the kiln condition and the discharging are relatively stable, and the desulfurization index achieves the expected effect.
(2) Oxidative roasting-reductive roasting test group
Fully mixing the crushed low-grade copper matte and bituminous coal to form a mixed material, wherein the addition amount of the bituminous coal is 10.0%, the total weight of the mixed material is 300 tons, adding the mixed material into a rotary kiln in 3 batches, the feeding speed is 10t/h, the frequency of a kiln body dragging motor is controlled to be 5.5-6.5 Hz, the rotation speed of the kiln body is controlled to be 3min/r, the blast volume is 120Nm 3/min, the static pressure at a kiln mouth is 25KPa, and the temperature of a reaction zone is controlled to be about 800 ℃. Starting feeding after the temperature of a kiln furnace is ignited to reach 280 ℃ until the temperature of a kiln tail outlet settling chamber, roasting and desulfurizing by a rotary kiln at a high temperature, wherein the iron grade is increased to 55%, the sulfur grade is reduced to 1.5% from 15%, the yield of finished products is 81.41% (accounting for the proportion of low-grade copper matte) and the smoke dust rate is 9.05% (accounting for the proportion of low-grade copper matte), stopping feeding oxygen enrichment when the sulfur dioxide content in smoke gas is reduced to be lower than 400mg/Nm < 3 >, adding anthracite accounting for 10% -15% of the mass ratio of low-grade copper matte into roasting equipment, and carrying out reduction roasting at 700-950 ℃ for 1-2 h, wherein the iron grade is increased to 58% from 55%.
(3) Auxiliary material replacement test
And replacing outsourcing iron powder with the 2 groups of cooled roasting products, returning to the smelting process of reducing the lead-containing waste slag to produce the matte, and carrying out replacement ratio experimental study. As a result, the method has the advantages that under the premise that the crude vertical yield is 85%, the copper grade of water quenching slag is lower than 0.6%, roasting slag of oxidizing roasting is singly adopted, the arsenic-iron yield is lower, arsenic cannot be effectively enriched and produced, the coke ratio is greatly increased to 19% from about 16%, the roasting slag of oxygen-enriched roasting-reduction roasting treatment is adopted to replace outsourcing iron powder, the crude vertical yield and the tail-escaping condition meet the requirements, the coke rate is increased to 14% from about 16%, the sum of the generated arsenic-iron contents is more than 85%, the iron content is more than 60%, and the arsenic content is less than 30%, and the product standard of the existing arsenic-iron alloy is met.
(4) Under this condition, the annual growth benefit is estimated as follows:
① Taking lead smelting with a annual disposal scale of 10 ten thousand tons/year as an example, the iron powder adding proportion is 40%, the annual iron powder consumption is about 4 ten thousand tons/year, the purchasing average price is 1000 yuan/ton, and the iron powder purchasing cost is 4000 ten thousand yuan/year;
② According to the statistical result in the factory, the treatment cost of roasting in the rotary kiln is 550 yuan/ton, the crushing processing cost of the iron powder is 100 yuan/ton, and the comprehensive cost is 650 yuan/ton;
③ The self-produced iron powder is adopted to replace outsourcing iron powder, the stable replacement amount of the iron powder can reach 70% on the premise of ensuring that the product index is basically unchanged, the replacement amount of the iron powder is 2.8 ten thousand tons, the cost per ton of the iron powder can be saved to (1000-650) =350 yuan/ton, and the direct purchasing cost 980 ten thousand yuan (without containing other valuable metal values recovered for the second time) can be saved each year after replacement.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511357394.0A CN120843838A (en) | 2025-09-23 | 2025-09-23 | A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202511357394.0A CN120843838A (en) | 2025-09-23 | 2025-09-23 | A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN120843838A true CN120843838A (en) | 2025-10-28 |
Family
ID=97423675
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202511357394.0A Pending CN120843838A (en) | 2025-09-23 | 2025-09-23 | A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN120843838A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5282881A (en) * | 1989-08-24 | 1994-02-01 | Ausmelt Pty. Ltd. | Smelting of metallurgical waste materials containing iron compounds and toxic elements |
| CN107354299A (en) * | 2017-05-23 | 2017-11-17 | 西北矿冶研究院 | Method for recycling Cu, Pb, Zn and Fe in slag in metal smelting process |
| CN116574907A (en) * | 2023-03-30 | 2023-08-11 | 中国恩菲工程技术有限公司 | Method for cooperatively treating arsenic-containing hazardous waste and application |
| CN117535520A (en) * | 2024-01-09 | 2024-02-09 | 北京高能时代环境技术股份有限公司 | A method for internal circulation of iron powder to strengthen the reduction and matte smelting of lead-containing waste slag |
| CN118813893A (en) * | 2024-06-25 | 2024-10-22 | 昆明理工大学 | A method for producing arsenic-iron alloy from arsenic-containing waste |
| CN118813967A (en) * | 2024-06-25 | 2024-10-22 | 云南铜业股份有限公司西南铜业分公司 | A method for recovering valuable metals and arsenic in arsenic-containing copper ash |
| CN119776666A (en) * | 2024-12-10 | 2025-04-08 | 北京科技大学 | Method for recovering tin and copper resources from copper slag by two-step gas phase oxidation-reduction roasting |
-
2025
- 2025-09-23 CN CN202511357394.0A patent/CN120843838A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5282881A (en) * | 1989-08-24 | 1994-02-01 | Ausmelt Pty. Ltd. | Smelting of metallurgical waste materials containing iron compounds and toxic elements |
| CN107354299A (en) * | 2017-05-23 | 2017-11-17 | 西北矿冶研究院 | Method for recycling Cu, Pb, Zn and Fe in slag in metal smelting process |
| CN116574907A (en) * | 2023-03-30 | 2023-08-11 | 中国恩菲工程技术有限公司 | Method for cooperatively treating arsenic-containing hazardous waste and application |
| CN117535520A (en) * | 2024-01-09 | 2024-02-09 | 北京高能时代环境技术股份有限公司 | A method for internal circulation of iron powder to strengthen the reduction and matte smelting of lead-containing waste slag |
| CN118813893A (en) * | 2024-06-25 | 2024-10-22 | 昆明理工大学 | A method for producing arsenic-iron alloy from arsenic-containing waste |
| CN118813967A (en) * | 2024-06-25 | 2024-10-22 | 云南铜业股份有限公司西南铜业分公司 | A method for recovering valuable metals and arsenic in arsenic-containing copper ash |
| CN119776666A (en) * | 2024-12-10 | 2025-04-08 | 北京科技大学 | Method for recovering tin and copper resources from copper slag by two-step gas phase oxidation-reduction roasting |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104263965B (en) | The method that gold and lead are reclaimed in difficult-treating gold mine collocation lead containing sludge raw material oxygen enriched molten bath melting | |
| CN106756027B (en) | A method for synergistic smelting of antimony-gold ore and gold-bearing pyrite slag to enrich valuable metals | |
| CN108456789B (en) | Extraction method of antimony metal | |
| CN102586636B (en) | Method for preparing molybdenum nickel alloy by directly reducing and smelting molybdenum nickel ore | |
| CN102634653A (en) | Side-blowing material-smelting production method | |
| CN112522521A (en) | Method for treating lead slag by rotary hearth furnace | |
| CN102220479A (en) | Beneficiation method for comprehensive recovery of valuable metals from sulfuric acid residues through chlorination and segregation | |
| CN118813893A (en) | A method for producing arsenic-iron alloy from arsenic-containing waste | |
| CN114381606A (en) | Recycling harmless treatment method for copper smelting lead-and zinc-containing intermediate product | |
| CN111979424A (en) | Metallurgy method of high-sulfur lead slag containing zinc and tin | |
| CN111088434B (en) | A method for comprehensive utilization of lead and zinc smelting slag resources | |
| CN110724821A (en) | Method for comprehensively recovering valuable metals from low-grade multi-metal hazardous wastes | |
| CN105714120A (en) | Comprehensive utilization method of low-quality ferromanganese ore slag and steel iron industrial waste | |
| CN113846234A (en) | Rotary kiln volatilization treatment method for high-silicon zinc leaching residues | |
| CN120843838A (en) | A one-step method for the comprehensive utilization of high-arsenic and lead-containing waste residues to achieve harmless resource utilization | |
| CN113215394A (en) | Treatment method of stone coal | |
| CN117535520A (en) | A method for internal circulation of iron powder to strengthen the reduction and matte smelting of lead-containing waste slag | |
| CN108239707B (en) | Method for distributing high-arsenic gold ore calcine into side-blown reduction furnace of lead smelting system | |
| CN117418108A (en) | Reduction smelting production process of low-sulfur lead-containing secondary materials and low-sulfur copper-containing materials | |
| CN114540631B (en) | Method for smelting copper dross and recovering valuable metal | |
| CN118406874B (en) | Recycling method for cooperatively disposing lead-containing waste residues through steel dust and mud | |
| CN1037915C (en) | Technology for recovery gold from waste carbon | |
| CN115786694B (en) | Pretreatment method of zinc-lead-copper mineral aggregate and application thereof | |
| CN212560387U (en) | Device that hot pressing steel scrap recarburization used | |
| JPH022932B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |