Method for extracting precious metal from aluminum-silicon refractory material

Abstract

The invention relates to a method for extracting precious metals from an aluminum-silicon refractory material, which is characterized by comprising the following steps: (1) crushing a waste refractory material to-3.2 mm to obtain powder, adding sodium hydroxide or sodium carbonate which is 0.8-1.6 times of the mass of the powder into the powder, uniformly mixing, and carrying out high-temperature alkali fusion; (2) dissolving with clear water after high-temperature alkali fusion, filtering, leaching the filtered flocculate with clear water again, dissolving the filter residue with a hydrochloric acid solution, performing secondary filtering, and sorting the filter residue after secondary filtering with a shaking table; (3) the obtained heavy mineral fine sand is a precious metal product A, the middlings and the tailings continue to be graded, graded coarse particles serve as waste to be discarded, graded fine particles are subjected to ball milling, and the content of the particles with the particle size being-0.074 mm after ball milling is controlled to exceed 97%; and (4) the ball-milled product is treated again through the methods in the step (1) and the step (2), and filter residues obtained after secondary filtering are the precious metal product B. The method has the advantages that the recovery rate of platinum metal reaches 95% or above, the recovery rate of rhodium metal reaches 90% or above, and the enrichment ratio of precious metal exceeds 20.

Description

Technical Field

[0001] The invention belongs to the field of precious metal beneficiation and resource recovery, and relates to a method for extracting precious metals from aluminum-silicon refractory materials. Background Art

[0002] At present, there are many TFT-LCD glass substrate production lines in China, as well as glass fiber production lines, high-aluminum cover glass, special glass production lines, etc. A large number of production lines use platinum channels. Due to long-term use in high-temperature environments, platinum and rhodium are physically adhered to the surface of refractory materials, forming a concentrated distribution; on the other hand, high-temperature diffusion causes them to be deposited into the refractory materials of the platinum channels. When the channels are repaired, it can be clearly found that the surface or shallow part of the refractory materials contains impregnation or adhesion, and an effective process is needed to purify precious metals such as platinum and rhodium in refractory materials.

[0003] At present, the main methods for processing such secondary resources are ore dressing, iron enrichment, and aqua regia dissolution. The ore dressing method uses the "gravity separation-magnetic separation-flotation" process to continuously discard tailings to remove refractory materials and enrich platinum-rhodium alloys, but the platinum-rhodium grade in the tailings is about 80g / t or more, and still needs subsequent recovery and treatment; the amount of slag in the iron enrichment method is large, and the residual platinum-rhodium grade in the slag is about 7 g / t, which is difficult to effectively recover, and the carbon content in the iron is high, making subsequent treatment difficult; the platinum-rhodium content in the leaching slag of the aqua regia dissolution method is high (about 30∼68 g / t), and there is silica colloid in the leachate, and the colloid gelation brings difficulties to solid-liquid separation and refining treatment; the main problems of the above three methods are low recovery rate, low enrichment ratio, and many difficulties in practical application. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of low recovery rate and low enrichment ratio of precious metals such as platinum and rhodium in refractory materials after long-term use of platinum channels and many difficulties in practical application, and to provide a method for extracting precious metals from aluminum-silicon refractory materials.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for extracting precious metals from aluminum-silicon refractory materials, characterized by comprising the following steps: (1) The waste refractory material is crushed to -3.2 mm to obtain a powder, and then 0.8 to 1.6 times the mass of sodium hydroxide or sodium carbonate is added to the powder to mix evenly, and then the mixture is subjected to high-temperature alkali melting (treated at 600°C to 900°C for 1h to 3h). The molten sodium hydroxide or sodium carbonate reacts with the main components of the refractory material to generate soluble substances; (2) The solid powder after high-temperature alkali fusion is dissolved in clean water, filtered after the dissolution is completed, and the flocculants generated by hydrolysis are produced after filtration. Clean water is added for elution, and then the filter residue is stirred with hydrochloric acid solution for 5-30 minutes. After the flocculants are dissolved, secondary filtration is performed. The filter residue after the secondary filtration (mainly precious metals and unreacted impurities) is sorted using a shaking table; (3) The shaking table has a good enrichment effect on coarse-grained heavy minerals. The obtained heavy mineral concentrate is the precious metal product A (coarse-grained platinum-rhodium alloy). Fine-grained precious metals exist in the middlings and tailings. The middlings and tailings are further classified. The particle size is controlled to be 0.1~0.2mm. The classified coarse particles basically do not contain precious metals and are discarded as waste. The classified fine particles are ball-milled. The particle size after ball milling is controlled to be -0.074mm and the content exceeds 97%; (4) The product after ball milling is processed again by the method of step (1) and step (2). The particle size of the reaction raw materials after the secondary processing is finer, and the impurities are dissolved more fully. The filter residue after the secondary filtration is the precious metal product B (fine particle precious metal).

[0006] Furthermore, the temperature of the hydrochloric acid solution is 25°C to 50°C.

[0007] The present invention crushes the raw materials to -3.2 mm, and then adopts the process of "ingredient mixing - high temperature alkali melting - water dissolution - primary filtration - acid dissolution - secondary filtration - shaking table selection" for primary enrichment. The shaking table concentrated sand is the precious metal product A, and the shaking table tailings are secondary enriched by the process of "screening and tailings casting - ball milling - ingredient mixing - high temperature alkali melting - water dissolution - primary filtration - acid dissolution - secondary filtration" to obtain the precious metal product B.

[0008] The beneficial effects of the present invention are: 1. The present invention can separate precious metal minerals from refractory materials, using strong alkali and dilute hydrochloric acid as chemical reagents, the treatment process is highly safe, the process is mature, the equipment is relatively simple, and it is very convenient to organize production; 2. A large amount of aluminum-silicon refractory materials are produced in China every year. This process greatly simplifies the efficient utilization of such resources. The platinum metal recovery rate reaches more than 95%, the rhodium metal recovery rate reaches more than 90%, and the precious metal enrichment ratio exceeds 20. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The present invention is a simplified process flow diagram for extracting precious metals from aluminum-silicon refractory materials. DETAILED DESCRIPTION

[0010] Combination Figure 1 , the present invention is further described: A method for extracting precious metals from aluminum-silicon refractory materials, the specific implementation steps are as follows: Example

[0011] (1) The refractory bricks produced by the overhaul of the glass substrate production line have enriched precious metals on their surface. The precious metals that are obviously attached to the surface bricks are directly polished and peeled off. Some fragments with high precious metal content are combined and crushed to -3.2 mm to obtain powder. The precious metals are subjected to ICP quantitative analysis and XRF analysis. The results are shown in Tables 1 and 2. The raw materials are rich in platinum-rhodium alloy and have complex impurity components, mainly corundum, silica, mullite and calcium aluminate. Take 2000 g of powder, add 2000 g of sodium hydroxide to the powder and mix evenly, then perform high-temperature alkali melting on the mixture, react at 900 ° C for 1 hour, and the molten sodium hydroxide reacts with the main components in the refractory material to generate soluble substances. (2) The solid powder melted by high temperature alkali was dissolved in clean water and stirred for 10 minutes to fully dissolve. After standing for 0.5 hours, the upper solution was filtered after clarification. The flocculants generated by hydrolysis were washed with clean water. The residue was stirred with a 3% mass concentration hydrochloric acid solution (25°C) for 20 minutes. After the flocculants were dissolved, secondary filtration was performed. The residue after secondary filtration (mainly precious metals and unreacted impurities) 368.12g was sorted using a shaking table; (3) The shaking table has a good enrichment effect on coarse-grained heavy minerals. The obtained heavy mineral concentrate of 45.10g is the precious metal product A (coarse-grained platinum-rhodium alloy). Fine-grained precious metals exist in the middlings and tailings. The middlings and tailings are further classified, and the particle size is controlled to be 0.1~0.2mm. The classified coarse particles basically do not contain precious metals and are discarded as waste. The classified fine particles are ball-milled, and the particle size after ball milling is controlled to be -0.074mm with a content of more than 97%; (4) 175 g of the product after ball milling was processed again using the method of step (1) and step (2). The particle size of the reaction raw materials after the secondary processing was finer, and the impurities were dissolved more fully. The filter residue after the secondary filtration was 34.2 g of the precious metal product B (fine particle precious metal).

[0012] The chemical index analysis of precious metal products A and B is shown in Table 3, and both platinum and rhodium elements are effectively recovered. Example

[0013] (1) The refractory bricks produced by the overhaul of the glass substrate production line have enriched precious metals on their surface. The precious metals that are obviously attached to the surface bricks are directly polished and peeled off. Some fragments with high precious metal content are combined and crushed to -3.2 mm to obtain powder. The precious metals are subjected to ICP quantitative analysis and XRF analysis. The results are shown in Tables 1 and 2. The raw materials are rich in platinum-rhodium alloy and have complex impurity components, mainly corundum, silica, mullite and calcium aluminate. Take 1000g of powder, add 1200g of sodium carbonate to the powder and mix them evenly, then perform high-temperature alkali melting (react at 900℃ for 1.5h), and the molten sodium carbonate reacts with the main components in the refractory material to generate soluble substances. (2) The solid powder melted by high temperature alkali was dissolved in clean water, stirred for 12 minutes, and then filtered after being fully dissolved. After filtration, the flocs generated by hydrolysis were added to rinse with clean water. The filter residue was stirred for 10 minutes with a hydrochloric acid solution (30°C) with a mass concentration of 3%. After the flocs were dissolved, secondary filtration was performed. After the secondary filtration, the filter residue (mainly precious metals and unreacted impurities) of 216.23 g was sorted using a shaking table; (3) The shaking table has a good enrichment effect on coarse-grained heavy minerals. The obtained heavy mineral concentrate of 18.72g is the precious metal product A (coarse-grained platinum-rhodium alloy). Fine-grained precious metals exist in the middlings and tailings. The middlings and tailings are further classified, and the particle size is controlled to be 0.1~0.2mm. The classified coarse particles basically do not contain precious metals and are discarded as waste. The classified fine particles are ball milled, and the particle size after ball milling is controlled to be -0.074mm with a content of more than 97%; (4) 108.21 g of the product after ball milling was processed again using the method of step (1) and step (2). The particle size of the reaction raw materials after the secondary processing was finer, and the impurities were dissolved more fully. The filter residue after the secondary filtration was 13.43 g of the precious metal product B (fine particle precious metal). Example

[0014] (1) The refractory bricks produced by the overhaul of the glass substrate production line have enriched precious metals on their surface. The precious metals that are obviously attached to the surface bricks are directly polished and peeled off. Some fragments with high precious metal content are combined and crushed to -3.2 mm to obtain powder. The precious metal quantitative analysis and XRF analysis are performed on the powder. The results are shown in Tables 1 and 2. The raw material contains rich platinum-rhodium alloy and has complex impurity components, mainly corundum, silica, mullite and calcium aluminate. 4000 g of powder is taken, 3600 g of sodium hydroxide is added to the powder to mix evenly, and then the mixture is subjected to high-temperature alkali melting (reacted at 900°C for 1 hour). The molten sodium hydroxide reacts with the main components in the refractory material to generate soluble substances. (2) The high-temperature alkali-fused solid powder was dissolved in clean water, stirred for 8 minutes, and then filtered. After filtration, the flocs generated by hydrolysis were added to the filtered residues for elution. The residues were stirred for 30 minutes with a hydrochloric acid solution (35°C) with a mass concentration of 3%. After the flocs were dissolved, they were filtered for the second time. After the second filtration, the residue (mainly precious metals and unreacted impurities) of 624.51 g was sorted using a shaking table. (3) The shaking table has a good enrichment effect on coarse-grained heavy minerals. The obtained heavy mineral concentrate of 38.31g is the precious metal product A (coarse-grained platinum-rhodium alloy). Fine-grained precious metals exist in the middlings and tailings. The middlings and tailings are further classified. The particle size is controlled to be 0.1~0.2mm. The classified coarse particles basically do not contain precious metals and are discarded as waste. The classified fine particles are ball-milled. The particle size after ball milling is controlled to be -0.074mm and the content exceeds 97%; (4) 326.45 g of the product after ball milling was processed again using the method of step (1) and step (2). The particle size of the reaction raw materials after the secondary processing was finer, and the impurities were dissolved more fully. The filter residue after the secondary filtration was 33.80 g of the precious metal product B (fine particle precious metal).

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Claims

1. A method for extracting precious metals from aluminum-silicon refractory materials, Features The steps include: (1) crushing the waste refractory material to -3.2 mm to obtain powder, then mixing sodium hydroxide or sodium carbonate into the powder, and then subjecting the mixture to high-temperature alkali melting; (2) After high-temperature alkali fusion, the solid powder is dissolved and filtered by stirring with clean water. After filtering, the flocculants generated by hydrolysis are rinsed with clean water, and the filter residue is dissolved with hydrochloric acid solution and filtered for a second time. The filter residue after the second filtration is sorted with a shaking table; (3) The shaking table has a good enrichment effect on coarse-grained heavy minerals. The obtained heavy mineral concentrate is the precious metal product A. The middlings and tailings are further classified. The particle size is controlled to be 0.1~0.2mm. The classified coarse particles are discarded as waste, and the classified fine particles are ball-milled. The particle size after ball milling is controlled to be -0.074mm and the content exceeds 97%; (4) The product after ball milling is processed again using the method of step (1) and step (2). The particle size of the reaction raw materials after the secondary processing is finer, and the impurities are dissolved more fully. The filter residue after the secondary filtration is the precious metal product B.

2. A method for extracting precious metals from aluminum-silicon refractory materials according to claim 1, Features: The added amount of the sodium hydroxide or sodium carbonate is 0.8 to 1.6 times the mass of the powder.

3. A method for extracting precious metals from aluminum-silicon refractory materials according to claim 1, Features: The temperature of high temperature alkali dissolution is 600℃~900℃, and the time is 1h~3h.

4. A method for extracting precious metals from aluminum-silicon refractory materials according to any one of claims 1 to 3, Features: The temperature of the hydrochloric acid solution is 25°C to 50°C.

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