Method for stabilizing beryllium-containing waste residues by using pH buffer mechanism

Abstract

The invention relates to the technical field of safe disposal of dangerous solid wastes, in particular to a method for stabilizing beryllium-containing waste residues by using a pH buffer mechanism, which comprises the following steps: using minerals with a pH alkaline buffer effect or a mixture of minerals and solid wastes as a blocky pH alkaline buffer agent raw material; crushing and grinding the blocky pH alkaline buffering agent raw material, then carrying out screening and grading treatment, and selecting particles with the particle size of less than or equal to 1mm as the pH alkaline buffering agent; the method comprises the following steps: uniformly mixing a pH alkaline buffer agent with beryllium-containing waste residues according to a weight ratio of 1: 5-50: 1 to obtain a mixture capable of fixing soluble beryllium ions in the beryllium-containing waste residues into Be (OH) 2 beryllium indissolvable substances after meeting water; and the mixture is subjected to landfill. The method solves the problems of high energy consumption, high secondary pollution risk and insufficient long-term stability in the existing beryllium-containing waste residue harmless treatment technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of safe disposal of hazardous solid waste, in particular to a method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism. BACKGROUND

[0002] Beryllium is a kind of rare light metal, which has irreplaceable strategic value in military industry, aerospace and other fields. However, soluble compounds of beryllium have high toxicity and are listed in the National Hazardous Waste List (HW20), and the concentration of its leachate must be strictly controlled below 0.02 mg / L. In the process of beryllium resource development in China, especially in the preparation of low-grade beryllium ore by hydrometallurgy and beryllium oxide, tens of thousands of tons of beryllium-containing waste residue are generated every year. If a large amount of beryllium-containing waste residue is only stored or simply landfilled, beryllium ions will migrate with rainwater, seriously threatening the ecological environment and human health, so further treatment of beryllium-containing waste residue is needed.

[0003] The existing beryllium-containing waste residue treatment methods are high-temperature smelting method, chemical stabilizer method and cement solidification method. The high-temperature smelting method mixes beryllium-containing waste residue with a fluxing agent (calcite) and smelts at high temperature. At high temperature, the metallic beryllium component in the beryllium-containing waste residue melts and separates from the impurities, forming a liquid alloy and slag. After cooling, the metal alloy is separated from the slag. However, the smelting temperature of this method is as high as 1250-1300 DEG C, the energy consumption accounts for more than 60% of the total cost, and the supporting waste gas treatment system is complex. The chemical stabilizer method is a technology that adds chemical reagents to fix beryllium in the waste residue through precipitation, adsorption or chemical bonding to reduce its migration and toxicity. However, chemical reagents can easily cause secondary pollution and have poor adaptability to high-acidity or complex-ligand-containing waste residue. The cement solidification method is a technology that realizes harmlessness treatment by fixing harmful components in beryllium-containing waste residue in the solidified body through the hydration reaction of cement. However, the long-term stability of this cement solidification method is limited by the strength of the cement solidification, and the strength decreases sharply when the waste residue content exceeds 20%, resulting in beryllium ion leaching.

[0004] In view of the above technical bottlenecks, it is necessary to develop an efficient, low-cost and non-secondary pollution harmless disposal technology to solve the core problems of leaching toxicity standard difficulty, poor process economy and meet the needs of environmental protection compliance and industry sustainable development. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism, which solves the problems of high energy consumption and complex treatment process existing in the prior art of harmless treatment of beryllium-containing waste residue.

[0006] To solve the above technical problems, the implementation scheme provided by the present application is to provide a method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism, which includes the following steps: The mineral or the mixture of the mineral and the solid waste is used as the block pH alkaline buffer raw material, wherein the solid waste does not include the beryllium-containing waste residue of the present application, and the solid waste is any one or more of the aluminosilicate minerals, carbide slag or fly ash; The block pH alkaline buffer raw material is crushed and ground, and then is classified by screening, and the particles with a particle size of less than or equal to 1 mm are selected as the pH alkaline buffer; The pH alkaline buffer and the beryllium-containing waste residue are mixed uniformly at a weight ratio of 1:5 to 50:1, so that the mixture can fix the soluble beryllium ions in the beryllium-containing waste residue into Be(OH)2 beryllium insoluble substance after being contacted with water. The mixture is landfilled.

[0007] Preferably, the pH alkaline buffer contains carbonate ions, and the pH value of the leaching solution after mixing the pH alkaline buffer with the beryllium-containing waste residue is 7 to 12.

[0008] Preferably, the pH value is 8 to 10.

[0009] Preferably, the mass fraction of the particles with a particle size of less than or equal to 200 μm in the pH alkaline buffer is greater than or equal to 20%.

[0010] Preferably, the weight ratio of the pH alkaline buffer to the beryllium-containing waste residue is 1:1 to 20:1.

[0011] Preferably, the mixing time of the pH alkaline buffer and the beryllium-containing waste residue is 5 minutes to 6 hours.

[0012] Preferably, the mineral is any one or more of calcite, dolomite or magnesite; and the solid waste is any one or more of carbide slag, fly ash, montmorillonite, kaolinite or bentonite.

[0013] Preferably, the block pH alkaline buffer raw material is mixed by any proportion of one or more of calcite, dolomite or magnesite, or the block pH alkaline buffer raw material is mixed by two parts of A and B at a mass ratio of A:B>1:5, wherein raw material A is composed of any one or more of calcite, dolomite or magnesite, and raw material B is composed of any one or both of carbide slag and fly ash, wherein the carbide slag or fly ash is mixed to achieve the purpose of solid waste consumption. or, the block pH alkaline buffer raw material is mixed by two parts of C and D at a mass ratio of C:D>1:5, wherein raw material C is composed of any one or more of calcite, dolomite or magnesite, and raw material D is composed of any one or more of montmorillonite, kaolinite or bentonite, wherein the montmorillonite, kaolinite or bentonite is an aluminosilicate mineral with adsorption performance, and is used to enhance the buffering performance of the stabilizer.

[0014] Preferably, the beryllium leaching concentration is ≤0.02 mg / L after landfill.

[0015] Compared with the prior art, the present application has the following beneficial effects: The present application uses alkaline minerals or their mixture with solid waste as raw materials, which can be used as block-shaped pH alkaline buffer after being simply crushed to ≤1 mm; without heating or adding any chemical reagents, it can be directly mixed with beryllium-containing waste residues in a certain weight ratio. After being exposed to water, the buffer continuously consumes hydrogen ions and maintains an alkaline environment for a long time, so that different forms of beryllium in beryllium-containing waste residues, such as Be 2+ , [Be3(OH)3] 3+ , [Be5(OH)6] 4+ , [Be2(OH)] 3+ , BeCl2, Be(NO3) 2、 BeSO4, etc., are all converted into insoluble Be(OH)2 and fixed for a long time, significantly reducing the leaching risk. The whole process has extremely low energy consumption and extremely simple operation, breaking through the industry dilemma of low efficiency and poor stability of traditional beryllium fixation process. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a process flow chart of the method for stabilizing beryllium-containing waste residues by using pH buffering mechanism.

[0017] Figure 2 It is the ion state of beryllium under different pH conditions.

[0018] Figure 3 It is the leaching rule of beryllium-containing solid waste under long leaching time. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0020] It should be noted that the professional terms used in the present application are only for the purpose of describing the specific embodiments and are not intended to limit the protection scope of the present application. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in the following embodiments of the present application can be purchased from the market or prepared by the existing method.

[0021] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in Embodiments 1 to 13, preferred embodiments are described in this invention to avoid redundancy. However, this invention is not limited to these, but can be specifically implemented in other ways within the scope of the technical solutions defined in the appended claims.

[0022] The raw materials for the blocky pH alkaline buffer are composed of two parts, A and B, mixed in a mass ratio of A:B > 1:5. Raw material A is composed of any one or more of calcite, dolomite, and magnesite, and raw material B is composed of any one or two of carbide slag and fly ash. In the following examples, calcite is mixed with carbide slag and fly ash in a mass ratio of 1:5. Alternatively, the raw materials for the blocky pH alkaline buffer are composed of two parts, C and D, mixed in a mass ratio of C:D > 1:5. Raw material C is composed of any one or more of calcite, dolomite, and magnesite, and raw material D is composed of any one or more of montmorillonite, kaolinite, and bentonite. In the following examples, calcite and montmorillonite are mixed with kaolinite in a mass ratio of 1:5.

[0023] The technical solution of the present invention will be further illustrated below with specific examples.

[0024] Example 1 like Figure 1 As shown, a method for stabilizing beryllium-containing waste using a pH buffering mechanism includes the following steps: Calcite, which has a pH alkaline buffering effect, is used as the raw material for the blocky pH alkaline buffer.

[0025] The raw material for the lumpy pH alkaline buffer, calcite, is crushed and ground using a jaw crusher, double roll crusher, impact crusher, hammer crusher, shear crusher, pebble mill, ball mill, vertical mill, disc mill, or rod mill to reduce the particle size of the calcite to less than 1 mm. The ground calcite is then screened through a 200-mesh sieve to obtain finely crushed calcite with a -200-mesh content of 50%, which is used as the pH alkaline buffer.

[0026] A pH alkaline buffer containing 50% fine calcite (200 mesh) and beryllium-containing waste residue were mixed in a mixing tank at a mass ratio of 1:1 for 5 minutes to obtain a mixture. The mixture was then directly landfilled, with a beryllium leaching rate below 0.02 mg / L and a leaching pH value of 9.

[0027] Example 2 like Figure 1 As shown, a method for stabilizing beryllium-containing waste using a pH buffering mechanism includes the following steps: Dolomite with pH alkaline buffering effect is used as the bulk pH alkaline buffer raw material.

[0028] The bulk pH alkaline buffer raw material: dolomite is crushed and ground by a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shear crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the dolomite is less than 1 mm. Then, the ground dolomite is sieved to 200 meshes, and fine crushed dolomite with a -200 mesh proportion of 50% is obtained as the pH alkaline buffer.

[0029] The fine crushed dolomite with a -200 mesh proportion of 50% as the pH alkaline buffer is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, the mixing time is 5 min, and a mixture is obtained. The mixed material is directly landfilled, the leaching rate of beryllium is below 0.02 mg / L, and the leaching pH value is 9.

[0030] Example 3 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: Dolomite with pH alkaline buffering effect is used as the bulk pH alkaline buffer raw material.

[0031] The bulk pH alkaline buffer raw material: dolomite is crushed and ground by a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shear crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the dolomite is less than 1 mm. Then, the ground dolomite is sieved to 200 meshes, and fine crushed dolomite with a -200 mesh proportion of 50% is obtained as the pH alkaline buffer.

[0032] The fine crushed dolomite with a -200 mesh proportion of 50% as the pH alkaline buffer is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, the mixing time is 5 min, and a mixture is obtained. The mixed material is directly landfilled, the leaching rate of beryllium is below 0.02 mg / L, and the leaching pH value is 9.

[0033] Example 4 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: Dolomite with pH alkaline buffering effect is used as the bulk pH alkaline buffer raw material.

[0034] The blocky pH alkaline buffer raw material: calcite and magnesite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the calcite and magnesite is less than 1 mm. Then, the ground calcite and magnesite is screened to have a -200 mesh content of 50%, and the fine crushed calcite and magnesite with a -200 mesh content of 50% is used as the pH alkaline buffer.

[0035] The fine crushed calcite and magnesite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, and the mixing time is 5 min. The mixture is directly landfilled, the leaching rate of beryllium is less than 0.02 mg / L, and the leaching pH value is 9.

[0036] Example 5 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: Dolomite and magnesite with a pH alkaline buffering effect are used as the blocky pH alkaline buffer raw material.

[0037] The blocky pH alkaline buffer raw material: dolomite and magnesite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the calcite and magnesite is less than 1 mm. Then, the ground calcite and magnesite is screened to have a -200 mesh content of 50%, and the fine crushed calcite and magnesite with a -200 mesh content of 50% is used as the pH alkaline buffer.

[0038] The fine crushed dolomite and magnesite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, and the mixing time is 5 min. The mixture is directly landfilled, the leaching rate of beryllium is less than 0.02 mg / L, and the leaching pH value is 9.

[0039] Example 6 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: Dolomite and magnesite with a pH alkaline buffering effect are used as the blocky pH alkaline buffer raw material.

[0040] The blocky pH alkaline buffer raw material: dolomite and calcite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, a rod mill, so that the particle size of the dolomite and calcite is less than 1 mm. Then, the ground dolomite and calcite is screened to have a -200 mesh content of 50%, and the fine crushed dolomite and calcite with a -200 mesh content of 50% is used as the pH alkaline buffer.

[0041] The pH alkaline buffer with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1 for 5 minutes to obtain a mixture. The mixture is directly landfilled, the leaching rate of beryllium is below 0.02 mg / L, and the leaching pH value is 9.

[0042] Example 7 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffer mechanism includes the following steps: The blocky pH alkaline buffer raw material is obtained by mixing dolomite, magnesite and calcite at a weight ratio of 1:2:1.

[0043] The blocky pH alkaline buffer raw material: dolomite, magnesite and calcite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, a rod mill, so that the particle size of the dolomite and calcite is less than 1 mm. Then, the ground dolomite and calcite is screened to have a -200 mesh content of 50%, and the fine crushed dolomite and calcite with a -200 mesh content of 50% is used as the pH alkaline buffer.

[0044] Example 8 The difference between Example 8 and Example 1 is that the fine crushed calcite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 5:1 for 10 minutes to obtain a mixture. The mixture is directly landfilled, the leaching rate of beryllium is below 0.02 mg / L, and the leaching pH value is 7.

[0045] Example 9 The difference between Example 9 and Example 1 is that the fine crushed calcite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 10:1 for 50 minutes to obtain a mixture. The mixture is directly landfilled, the leaching rate of beryllium is below 0.02 mg / L, and the leaching pH value is 12.

[0046] Example 10 The difference between Example 10 and Example 1 is only that the fine calcite -200 mesh accounting for 50% of the pH alkaline buffer and containing beryllium waste residue in the stirring tank according to the mass ratio of 20:1 is mixed, the mixing time is 2h, the mixture is obtained, the mixed material is directly filled, the beryllium leaching rate is below 0.02mg / L, and the leaching pH value is 10.

[0047] Example 11 The difference between Example 11 and Example 1 is only that the fine calcite -200 mesh accounting for 50% of the pH alkaline buffer and containing beryllium waste residue in the stirring tank according to the mass ratio of 50:1 is mixed, the mixing time is 6h, the mixture is obtained, the mixed material is directly filled, the beryllium leaching rate is below 0.02mg / L, and the leaching pH value is 10.

[0048] Example 12 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using pH buffering mechanism, comprising the following steps: The calcite and fly ash with pH alkaline buffering effect are used as blocky pH alkaline buffer raw materials, and the mass ratio of calcite to fly ash is >1:5.

[0049] The blocky pH alkaline buffer raw materials: calcite and fly ash are crushed and ground by using jaw crusher, roller crusher, impact crusher, hammer crusher, shear crusher, gravel mill, ball mill, vertical mill, disc mill and rod mill, so that the particle size of calcite and fly ash is less than 1mm, and then the ground calcite and fly ash are screened by 200 mesh to obtain fine calcite and fly ash with -200 mesh accounting for 50% as pH alkaline buffer.

[0050] The fine calcite and fly ash -200 mesh accounting for 50% of the pH alkaline buffer and containing beryllium waste residue in the stirring tank according to the mass ratio of 1:1 is mixed, the mixing time is 5min, the mixture is obtained, the mixed material is directly filled, the beryllium leaching rate is below 0.02mg / L, and the leaching pH value is 9.

[0051] Example 13 As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using pH buffering mechanism, comprising the following steps: The calcite and (montmorillonite + kaolin) with pH alkaline buffering effect are used as blocky pH alkaline buffer raw materials, and the mass ratio of calcite to (montmorillonite + kaolin) is >1:5.

[0052] The blocky pH alkaline buffer raw material: calcite and (montmorillonite + kaolin) is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the calcite and (montmorillonite + kaolin) is less than 1 mm. Then, the ground calcite and (montmorillonite + kaolin) is screened to have a -200 mesh content of 50%, and the fine crushed calcite and (montmorillonite + kaolin) with a -200 mesh content of 50% is used as the pH alkaline buffer.

[0053] The pH alkaline buffer with a -200 mesh content of 50% of the fine crushed calcite and (montmorillonite + kaolin) is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:5 for 5 minutes to obtain a mixture. The mixture is directly landfilled, the beryllium leaching rate is below 0.02 mg / L, and the leaching pH value is 8.

[0054] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the particle size of the pH alkaline buffer is different.

[0055] A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism, comprising the following steps: The calcite with a pH alkaline buffering effect is used as the pH alkaline buffer.

[0056] The calcite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill to obtain the pH alkaline buffer with a particle size of 3 mm.

[0057] The pH alkaline buffer with a particle size of 3 mm is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1 for 5 minutes to obtain a mixture. The mixture is directly landfilled.

[0058] The beryllium leaching concentration is above 0.02 mg / L. Since the particle size of the pH stabilizer is too large, the pH buffering performance is not obvious, and the beryllium leaching concentration exceeds the national standard.

[0059] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the mass ratio of the pH alkaline buffer with a -200 mesh content of 50% of the fine crushed calcite to the beryllium-containing waste residue is different.

[0060] As shown in FIG. Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism, comprising the following steps: The calcite with a pH alkaline buffering effect is used as the blocky pH alkaline buffer raw material.

[0061] The blocky pH alkaline buffer raw material: calcite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the calcite is less than 1 mm. Then, the ground calcite is sieved to 200 mesh, and fine crushed calcite with a -200 mesh content of 50% is obtained as the pH alkaline buffer.

[0062] The fine crushed calcite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 0.1:1, and the mixing time is 5 min. The mixture is directly landfilled, the pH alkaline buffer does not have a buffering effect, and the beryllium leaching concentration is above 0.02 mg / L.

[0063] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the mass ratio of the fine crushed calcite with a -200 mesh content of 50% to the beryllium-containing waste residue is different.

[0064] As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: The calcite with a pH alkaline buffering effect is used as the blocky pH alkaline buffer raw material.

[0065] The blocky pH alkaline buffer raw material: calcite is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill, and a rod mill, so that the particle size of the calcite is less than 1 mm. Then, the ground calcite is sieved to 200 mesh, and fine crushed calcite with a -200 mesh content of 50% is obtained as the pH alkaline buffer.

[0066] The fine crushed calcite with a -200 mesh content of 50% is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 100:1, and the mixing time is 5 min. The mixture is directly landfilled, the pH alkaline buffer does not have a buffering effect, and the beryllium leaching concentration is above 0.02 mg / L.

[0067] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the mixing time of the fine crushed calcite with a -200 mesh content of 50% and the beryllium-containing waste residue is different.

[0068] As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: The calcite with pH alkaline buffering effect is used as the blocky pH alkaline buffer raw material.

[0069] The blocky pH alkaline buffer raw material, calcite, is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill and a rod mill, so that the particle size of the calcite is less than 1 mm. Then, the ground calcite is screened by using a 200-mesh screen, so that the fine crushed calcite with a -200 mesh content of 50% is obtained as the pH alkaline buffer.

[0070] The fine crushed calcite with a -200 mesh content of 50% as the pH alkaline buffer is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, and the mixing time is 1 min. The mixture is directly landfilled. The pH alkaline buffer does not have a buffering effect, and the beryllium leaching concentration is above 0.02 mg / L.

[0071] Comparative Example 5 The difference between Comparative Example 4 and Example 1 is that the mixing time of the fine crushed calcite with a -200 mesh content of 50% as the pH alkaline buffer and the beryllium-containing waste residue is different.

[0072] As shown in Figure 1 A method for stabilizing beryllium-containing waste residue by using a pH buffering mechanism includes the following steps: The calcite with pH alkaline buffering effect is used as the blocky pH alkaline buffer raw material.

[0073] The blocky pH alkaline buffer raw material, calcite, is crushed and ground by using a jaw crusher, a roller crusher, an impact crusher, a hammer crusher, a shearing crusher, a gravel mill, a ball mill, a vertical mill, a disc mill and a rod mill, so that the particle size of the calcite is less than 1 mm. Then, the ground calcite is screened by using a 200-mesh screen, so that the fine crushed calcite with a -200 mesh content of 50% is obtained as the pH alkaline buffer.

[0074] The fine crushed calcite with a -200 mesh content of 50% as the pH alkaline buffer is mixed with the beryllium-containing waste residue in a stirring tank at a mass ratio of 1:1, and the mixing time is 10 h. The mixture is directly landfilled. The pH alkaline buffer does not have a buffering effect, and the beryllium leaching concentration is above 0.02 mg / L.

[0075] Experimental verification Figure 2 The existence form of beryllium in different pH value solutions is that in a strong acid condition (pH < 3), beryllium will exist in the form of beryllium ions (Be 2+) form; in weakly acidic, neutral to weakly alkaline conditions, beryllium element exists in the form of Be(OH)2, and the precipitation increases with the increase of PH; in strong alkaline (pH>13) conditions, the generated precipitate is dissolved in the form of beryllate ([Be(OH)4] 2- ).

[0076] Figure 3 The leaching concentration of beryllium ions at different pH values is shown in the table. The leaching test is carried out on beryllium-containing waste residues with a concentration of 5g / L and a particle size of 0.035mm~1mm under the conditions of pH=3, pH=6, pH=9, using dilute hydrochloric acid or dilute sodium hydroxide solution as leaching agent. The results show that the leaching concentration of beryllium ions at pH=9 is much less than 0.02mg / L and can be stably maintained under long leaching time.

[0077] The blocky pH buffer raw material used in the method of the present application is an alkaline mineral or a mixture of alkaline mineral and solid waste. After crushing, the particles with a particle size of ≤1mm are taken as the pH alkaline buffer, and are fully mixed and uniformly mixed with the beryllium-containing waste residues according to the weight ratio, and can continuously consume hydrogen ions in water after meeting water, and can long-term maintain the alkaline environment in the environment, so that the beryllium in different occurrence forms in the beryllium-containing waste residues, such as Be 2+ , [Be3(OH)3] 3+ , [Be5(OH)6] 4+ , [Be2(OH)] 3+ , BeCl2, Be(NO3) 2、 BeSO4, can be converted into the difficultly soluble component Be(OH)2 and long-term maintained. Through the above-mentioned alkaline buffer-precipitation conversion mechanism, the stabilization effect on the beryllium-containing waste residues is significantly enhanced, and the key problem of long-term stability deficiency of the existing beryllium-containing waste residue harmless treatment technology is effectively solved. The present application realizes the harmless treatment of the beryllium-containing waste residues, does not need heating and does not add chemical reagents, greatly reduces the possibility of beryllium leaching in solution, and breaks the industry dilemma of low efficiency and poor stability in the traditional beryllium fixation process.

[0078] In addition, the blocky pH alkaline buffer raw material used in the method of the present application is a mineral or a mixture of mineral and solid waste, and because the mineral and ordinary solid waste do not exist environmental harmful substances, there is no risk of secondary pollution, and the present application realizes the harmless treatment of the beryllium-containing waste residues, does not need heating and does not add chemical reagents, greatly reduces the possibility of beryllium leaching in solution, and breaks the industry dilemma of low efficiency and poor stability in the traditional beryllium fixation process.

[0079] Obviously, a person skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A method for stabilizing beryllium-containing waste residue using a pH buffering mechanism, characterized by, It comprises the following steps: The mineral or the mixture of the mineral and the solid waste with pH alkaline buffering effect is used as the blocky pH alkaline buffer raw material; The blocky pH alkaline buffer raw material is crushed and ground, and then is subjected to screening and grading treatment, and the particles with a particle size of ≤1 mm are selected as the pH alkaline buffer; The pH alkaline buffer is uniformly mixed with the beryllium-containing waste residue at a weight ratio of 1:5-50:1 to obtain a mixture which can fix the soluble beryllium ions in the beryllium-containing waste residue into Be(OH)2 beryllium insoluble matter after water is encountered; The mixture is landfilled.

2. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized by, The pH alkaline buffer contains carbonate ions, and the pH value of the pH alkaline buffer leached after being mixed with the beryllium-containing waste residue is 7-12.

3. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 2, characterized by, The pH value is 8-10.

4. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized in that, The mixing time of the pH alkaline buffer and the beryllium-containing waste residue is 5 min-6 h.

5. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized in that, The weight ratio of the pH alkaline buffer and the beryllium-containing waste residue is 1:1-20:

1.

6. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized in that, The mineral is any one or more of calcite, dolomite or magnesite; and the solid waste is any one or more of carbide slag, fly ash, montmorillonite, kaolinite or bentonite.

7. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized by, The blocky pH alkaline buffer raw material is mixed by any proportion of one or more of calcite, dolomite or magnesite, or the blocky pH alkaline buffer raw material is mixed by two parts A and B at a mass ratio A:B>1:5, wherein raw material A is composed of any one or more of calcite, dolomite or magnesite, and raw material B is composed of any one or both of carbide slag and fly ash. Or, the blocky pH alkaline buffer raw material is mixed by two parts C and D at a mass ratio C:D>1:5, wherein raw material C is composed of any one or more of calcite, dolomite or magnesite, and raw material D is composed of any one or more of montmorillonite, kaolinite or bentonite.

8. The method for stabilizing beryllium-containing waste residue using a pH buffering mechanism according to claim 1, characterized by, After landfill, the beryllium leaching concentration is ≤0.02 mg / L.

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